III . Времена группы Perfect действительного залога. — Студопедия.Нет

(совершенное длительное время в действительном залоге)

Времена группы Perfect Continuous употребляются для выражения длительного действия, начавшегося до определенного момента в настоящем, прошедшем или будущем и длившегося известный период времени,включая этот момент.

Present Perfect Past Perfect Future Perfect

Continuous Continuous Continuous

Ihave been writingIhad been writingIshall have been writing

the letter for an hour the letter for an hour the letter for an hour

when he came when he comes

Я пишу письмо (уже) Я писал письмо (уже) Я буду писать письмо

час час, когда он пришел (уже) час, когда он придет

Perfect Continuous употребляются с такими обозначениями времени, как

for (an hour, a month, a long time) – в течение (часа, месяца, долгого времени

lately – последнее время

since (yesterday, five o’clock) – с (вчерашнего дня, пяти часов)

Since then

Since the time when

for…by the time

Present Perfect Continuous переводится на русский язык глаголом в настоящем времени, часто с наречием «уже»

I have been waitingfor a long time for my brother

Я жду своего брата уже давно

Past Perfect Continuous переводится на русский язык прошедшим временем глагола несовершенного вида, часто с наречием «уже»

Ihad been workingfor a long time when my brother came.

Я уже долго работал, когда пришел мой брат.

Future Perfect Continuous переводится на русский язык будущим временемнесовершенного вида (эта форма употребляется очень редко)

I shall begin to work at ten o’clock in the morning. When you return home at five o’clock, I shall have been workingfor seven hours.

Я начну работать в 10 часов утра. Когда вы вернетесь домой в 5 часов, я буду уже работать семь часов.

Exercise . Выберите правильное предложение, используя данные варианты

1. Она рисовала плакат уже 2 часа, когда преподаватель пришел в кабинет.

a) She was painting the poster when the teacher came in the classroom.

b) She has already painted this poster.

c) She had been painting the poster for two hours already when the teacher came in the classroom.

2. Студент чертит график уже в течение долгого времени.

a) The student draws diagram for a long time.

b) The student was drawing diagram for a long time.

c) The student has been drawing diagram for a long time.

3. Я буду писать уже три часа, когда он придет.

a) I will have written for 3 hours when he comes.

b) I will have been writing for 3 hours when he comes.

c) I will write for 3 hours when he comes.

Radar Types

Найдите в словаре и запишите в тетрадь транскрипцию данных слов. Прочитайте их вслух несколько раз.

Continuous, surveillance, saturation, simultaneous, weight, dimension, guide, sequence, precision, gauge, echo, acquire.

Words to be learnt

to divide into- делить на…

hardware- оборудование, аппаратное обеспечение

software- программное обеспечение

to develop- развивать, разрабатывать

damage assessment- оценка (анализ) неисправности

mainly- в основном, главным образом

array- многовибраторная антенна

saturation attack- массированная атака

jamming- помехи, глушение

sumiltaneous- одновременный

data rate- скорость передачи данных

resolution- разрешение

to meet- отвечать(напр.требованиям)

to intercept- перехватить (самолёт, информацию…)

precision- точный

to observe- наблюдать

speed gauge- прибор для измерения скорости

altimeter- высотометр

scatterometer- измеритель рассеяния

to emit- излучать

transponder- приёмоответчик

Text

Radar systems may be divided into types based on the designed use. Radars configurations include Monopulse radar, Bistatic radar, Doppler radar, Continuous-wave radar, etc. depending on the types of hardware and software used. It is used in aviation (Primary and secondary radar), sea vessels, law enforcement, weather surveillance, ground mapping, geophysical surveys, and biological research. Radar originally was developed to meet the needs of the military services, and it continues to have critical applications for national defense purposes. For instance, radars are used to detect aircraft, missiles, artillery and mortar projectiles, ships, land vehicles, and satellites. In addition, radar controls and guides weapons; allows one class of target to be distinguished from another; aids in the navigation of aircraft and ships; and assists in reconnaissance and damage assessment. Military radar systems can be divided into three main classes based on platform: land-based, shipborne, and airborne. Within these broad classes, there are several other categories based mainly on the operational use of the radar system.

Multi Function Radars

Active array MultiFunction Radars (MFRs) enable modern weapon systems to cope with saturation attacks of very small radar cross-section missiles in a concentrated jamming environment. Such MFRs have to provide a large number of fire-control channels, simultaneous tracking of both hostile and defending missiles and mid-course guidance commands.

Multi Target Tracking Radar

Operational functions of a MultiTarget Tracking Radar (MTTR) include:

• long-range search;

• search information with high data rate for low-flying aircraft;

• search information with high resolution of close in air targets;

• automatic position and height information;

• simultaneous tracking of a lot of aircraft targets;

• target designation facilities for other systems.

Air Traffic Control Radar Sets

Air traffic control radars are used both at civilian and military airports. Airborne radar is designed especially to meet the strict space and weight limitations that are necessary for all airborne equipment. Even so, airborne radar sets develop the same peak power as shipboard and shore-based sets. In fighter aircraft, the primary mission of radar is to aid in the search, interception, and destruction of enemy aircraft.

Air-Defense Radar

Air-Defense Radars can detect air targets and determine their position, course, and speed in a relatively large area. The maximum range of Air-Defense Radar can exceed 300 miles, and the bearing coverage is a complete 360-degree circle. Air-Defense Radars are usually divided into two categories, based on the amount of position information supplied. Radar sets that provide only range and bearing information are referred to as two-dimensional, or 2D, radars. Radar sets that supply range, bearing, and height are called three-dimensional, or 3D, radars. Air-Defense Radars are used as early-warning devices because they can detect approaching enemy aircraft or missiles at great distances. Another function of the Air-Defense Radar is guiding combat air patrol (CAP) aircraft to a position suitable to intercept an enemy aircraft.

Air Surveillance Radar Sets

This radar equipment is used for the identification of aircrafts, determination of aircrafts approach sequence and for individual aircraft approach controls by Air Traffic Security operators. This radar network could be used under all weather conditions.

Precision Approach Radar Sets

The precision approach radar guide aircraft to safe landing under conditions approaching zero visibility. By means of radar, aircraft are detected and observed

during the final approach and landing sequence. Guidance information is supplied to the pilot in the form of verbal radio instructions, or to the automatic pilot (autopilot) in the form of pulsed control signals.

Weather Radar Sets

The weather data it finds could be used both for approach support and for feeding into the wider weather data concentration systems.Radar in recent years has become an important tool for the measurement of precipitation and the detection of hazardous weather conditions.

Missile Guidance Radar

A radar system that provides information used to guide a missile to a hostile target is called Guidance Radar.

Navigation Radar

Navigation radars are designed for ship navigation and surface surveillance. When weather conditions render visual piloting impossible on a vessel, radar navigation provides a method of fixing a vessel’s position with sufficient accuracy to allow safe passage.

Imaging Radar / Non-Imaging Radar

An Imaging Radar forms a picture of the observed object or area. Imaging radars have been used to map the Earth, other planets, asteroids, other celestial objects and to categorize targets for military systems. Typically implementations of a Non-Imaging Radar system are speed gauges and radar altimeters. These are also called scatterometers since they measure the scattering properties of the object or region being observed.

Primary Radar

A Primary Radar transmits high-frequency signals which are reflected at targets. The arisen echoes are received and evaluated. This means, unlike secondary radar sets a primary radar unit receive its own emitted signals as an echo again.

Secondary Radar

At these radar sets the airplane must have a transponder (transmitting responder) on board and this transponder responds to interrogation by transmitting a coded reply signal. This response can contain much more information, than a primary

radar unit is able to acquire (E.g. an altitude, an identification code or also any technical problems on board such as a radio contact loss …).

Pulse Radars

Pulse radar sets transmit a high-frequency impulse signal of high power. After this impulse signal, a longer break follows in which the echoes can be received, before a new transmitted signal is sent out. Direction, distance and sometimes if necessary the height or altitude of the target can be determined from the measured antenna position and propagation time of the pulse-signal.

Continuous- Wave Radar

CW radar sets transmit a high-frequency signal continuously. The echo signal is received and processed. The receiver needs not to be mounted at the same place as the transmitter.

Unmodulated CW- Radar

The transmitted signal of these equipments is constant in amplitude and frequency. This equipment is specialized in speed measurings. Distances cannot be measured.

Modulated CW-Radar

The transmitted signal is constant in amplitude but modulated in frequency. It is an advantage of this equipment that an evaluation is carried out without reception break and the measurement result is therefore continuously available. These radar sets are used when the measuring distance isn’t too large and it’s necessary a continuous measuring.

Задание. Используя дополнительные источники информации (напр. Интернет), подготовьте презентацию одного из типов радара, о котором вы прочитали в тексте.

Unit 10.

Grammar Revision

Если подлежащее обозначает лицо или предмет, который совершает действие не сам, а подвергается действию со стороны другого лица или предмета, то глагол — сказуемое используется в форме страдательного залога.

“Poltava” was written by Pushkin in 1828.

Времена страдательного залога образуются при помощи вспомогательного глагола to be в соответствующем времени и формы причастия прошедшего времени (Participle II ), т.е III формы смыслового глагола.

Таким образом, при спряжении глагола в страдательном залоге изменяется только глагол to be, смысловой же глагол имеет во всех временах одну и ту же форму- Participle II.

Indefinite Passive

PresentI am (am not) asked. Am I asked?

He, She, It is (isn’t) asked. Is he asked?

You, We, They are (aren’t) asked. Are you asked?

PastI, He, She, It was (wasn’t) asked. Was he asked?

You, We, They were (weren’t) asked. Were you asked?

FutureI, We shall (shan’t) be asked. Shall we be asked?

You, He, She, It will (won’t) be asked. Will you be asked?

Exercise. Измените предложения, заменив форму действительного залога глагола-сказуемого на форму страдательного залога. Полученные предложения запишите в отрицательной и вопросительной форме.

1. His friend often invites him to international conferences.

2. We shall build a new house next year.

3. Bell invented the telephone in 1876.

Communication Satellite

Пользуясь словарем, найдите и запишите транскрипцию следующих слов. Правильно прочитайте эти слова вслух и постарайтесь запомнить их произношение

Artificial, via, serve, tower, launch, fuel, adjust, cause, power, frequency, mutual, division, assign

Words to be leant

artificial satellite – искусственный спутник

to facilitate – облегчать

via – посредством

relay tower – ретранслятор

low-noise – низкошумный

launch – запуск, запускать

capacity – ёмкость

rotation rate – скорость вращения

solar cell – солнечная батарея

to supply – снабжать, обеспечивать

adjust – настраивать

to offset – возмещать, противостоять

to cause – вызывать, быть причиной, заставлять

reference point – опорная точка

to complete – составлять, включать в себя

to reduce – уменьшать

power output – выходная мощность

range – диапазон

mutual interference – взаимные помехи

multiplexed – многоканальный

frequency band – полоса пропускания частоты, диапазон частоты

Text

A communication satellite is an artificial satellite placed into orbit around Earth to facilitate communication on Earth. Most long-distance radio communication across land is sent via microwave relay towers. The towers, 30 to 60 m (100 to 200 ft) high, are typically spaced 30 to 50 km (20 to 30 mi) apart, and 100 of them are needed to cross the United States. In effect, a satellite serves as a tall microwave link or a cable, it can interconnect any number of stations that are included within the antenna beams of the satellite rather than simply the two ends of the microwave link. The concept of using a satellite repeater was first proposed by Arthur C. Clarke in the October 1945 issue of Wireless World. The development of powerful rockets in the mid-1950s and the simultaneous development of sensitive low-noise receiving equipment made communication satellites a realistic consideration.

The period from 1958 to 1963 was one of experimentation with both active satellites, those electronic instrumentation, and passive satellites, those which simply reflected signals. On Dec. 18, the U.S. Army places Score in a low altitude orbit. It had only one voice cannel and could retransmit messages directly or store them for later playback. On Aug. 1960, NASA launched ECHO, a passive aluminized plastic balloon, 30 m (100 ft) in diameter, into an orbit 1 600 km (1000 mi) above the Earth. In 1962 experiments were conducted on TELSTAR and RELAY, medium-altitude active satellites with the capacity of the television channel or several hundred voice channels. In 1963, SYNCOM 2 became the first

synchronous satellite with a period matching the Earth’s rotation rate. These satellites proved the concepts and were the later commercial satellite design.

Communication satellites are platform that house radio receivers and their antennas receive signals from the Earth stations, and amplify and pass the signals to a transmitter and antenna, with sufficient power to the amplifiers (about 500 watts in Intelsat IV); fuel to periodically adjust the satellite’s position to offset forces caused by the Sun and Moon; and altitude control equipment to keep the satellites antenna pointed properly at the Earth, using either the Sun, the edge of the Earth, or radio beacon on Earth as a reference point. Telemetry encoders and transmitters measure voltages, currents, temperatures, and other parameters describing the condition of the satellite and transmit this information to Earth. Finally, a structure must house all this equipment. For example, an Intelsat V weighs more than 1 950 kg (4 300 lb).

The major Earth stations that communicate with these satellites typically comprise an antenna about 30 m (100 ft) in diameter, a receiver that is cooled to 14 K in order to reduce its noise, and a radio transmitter with a power output in the range of several hundred to several thousand watts to send signals to the satellite. Smaller Earth stations are also used, but on a more restrictive basis because of their greater demands on satellite capacity.

International and domestic satellites use frequency bands that already heavily used by terrestrial radio relay stations: 5 925 to 6 425 megahertz or MHz (1 hertz = 1 cycle per second) from Earth station to satellite; and 3 700 to 4 200 MHz from satellite to Earth station. Mutual interference is avoided by appropriate location of the Earth stations; for example, they are not located within major telecommunications centers. Some satellite systems operate on the basis of frequency division – each Earth stations is assigned, a different radio frequency on which are multiplexed, or packaged, all of the voice channels carried by that station. Alternatively, speech signals can be converted to digital pulses, and such pulses from the various stations are interleaved in time and amplified in the satellite through a common receiver/transmitter. In order to meet the needs of increased communications traffic, projected at more than 1000 000 circuits in the 1990s, speech will be converted to digital bits, a method already used to a great extent in communications networks.

Additional capacity is obtained by using the same frequency band several times over multiple narrow beams from the satellite, and by extending the

frequency band to the 11 and 14 GHz region and eventually to other bands. Private business satellites for a wide variety of services are becoming common, and the availability of higher-powered satellites permits smaller antennas for Earth stations, with modest traffic demands. (The range of 12.2 to 12.7 GHz, for example, is already reserved for direct broadcasting to individual users). Satellites are coming into routine use for communications to ships and planes. The trend will be toward higher capacity at lower cost for each circuit. In some areas of the world, satellites can broadcast directly to individual homes.

Задание I. Задайте вопросы и ответьте на них, закончив предложения в соответствии с содержанием текста.

1. A communication satellite is…(where, how, what)

2. Most long- distance radio communication is sent…(when, why, how)

3. A satellite serves as…(whose, who, what, how)

4. Arthur C. Clarke proposed…(why, which, when, what)

5. The U.S. Army places Score in…(what, when, where)

6. NASA launched ECHO on…(why, how, when, where)

7. Communication satellites amplify and pass signals to…(what, where, why, how)

8. Telemetry encoders and transmitters measure…(who, how, what)

9. Mutual interference is avoided…(why, who, how, where)

10. Additional capacity is obtained…(why, when, where, how)

Задание II. Выделите главную мысль каждого абзаца в виде кратких, логичных, своих собственных предложений на английском языке

Задание III.Напишите собственное краткое содержание текста на русском, а затем на английском языке, используя свои предложения по абзацам

Unit 11.

Grammar Revision

Страдательный залог группы Continuous образуется при помощи вспомогательного глагола to beвPresentилиPast Continuous Participle IIсмыслового глагола

Лицо Present Past

I am being asked was being asked

He, She, it is being asked was being asked

We, You, They are being asked were being asked

(меня, его, её, нас, (меня…спрашивали)

тебя/вас, их спрашивают)

Страдательный залог времен группы Continuous переводится глаголом несовершенного вида

During the experiment the air in the Во время эксперимента воздух

laboratory was being purifiedby two в лаборатории очищался двумя

ventilators вентиляторами

Страдательный залог времен группы Perfectобразуется при помощи вспомогательного глагола to be в соответствующем времени Perfect Participle IIсмыслового глагола

Лицо Present Past Future

I (we, you, they) have been asked had been asked This work will

He (she, it) has been asked had been asked have been

Меня (нас, тебя, Меня…спросили done by 7

их, его, её) спросили (до того, как…) o’clock

Эта работа

будет сделана

к 7 часам

Страдательный залог времен группы Perfect переводится по общим правилам перевода глагола в страдательном глаголе

Great deposits of coal have beenКрупные залежи угля (были)

discoveredin our region открытыв нашем районе

The construction of this plant Строительство этого завода

had been finished by the end было завершено к концу

of last year прошлого года

Exercise . Переведите данные предложения

1. An interesting research in the field of electronics is being done at our Institute.

2. The information about these conditions was being studied by our group for a week.

3. New methods of obtaining polymers have been applied at our plant.

4. The flexible line that has been recently developed at our laboratory has greatly improved the production process.

5. One machine tool is being worked at in our laboratory.

6. New solar energy and its usage are being studied by a lot of research groups.

7. A great number of experiments at the designing institute had been made before the flood defense system was worked out.

8. Our workshop will have been equipped with new multipurpose machine tools by the time when the reconstruction of the plant is over.

9. Almost all chemical elements which have been found on Earth have been discovered in the Sun and the planets of solar system.

10. Much attention is being paid to the development of three-dimensional television.

Military Satellites

Найдите в словаре и запишите в тетрадь транскрипцию данных слов. Прочитайте их вслух несколько раз.

Manufacture, Earth, forecast, ocean, scientific, ensure, enough, deny, acknowledge, identify.

Words to be learnt

continuous- непрерывный, длительный

to forecast- прогнозировать, предсказывать

to transfer- передавать, перемещать

according to…- в соответствии с чем-то, согласно чему-то

vulnerable- уязвимый

environment- окружающая среда

similar- подобный, похожий

valuable- ценный, значимый

spy satellite- спутник- разведчик

eavesdropping- подслушивание, «прослушка»

covert communication- секретная связь

to ensure- обеспечивать, гарантировать

to take picture- фотографировать

to keep watch on…- вести наблюдение за…

safe (secure) link- безопасная линия (для связи)

retaliatory strike- ответный удар

to replace with…- заменить на…

to improve- улучшить, усовершенствовать

to reach the orbit- достигать орбиты

to afford- позволить себе

Text

An artificial satellite is a manufactured object that continuously orbits Earth or some other body in space. Most artificial satellites orbit Earth. People use them to study the universe, help forecast the weather, transfer telephone calls over the oceans, assist in the navigation of ships and aircraft, monitor crops and other

resources, and support military activities. There are six main types of artificial satellites: scientific research, weather, communications, navigation, Earth observing, and military ones. Artificial satellites are classified according to their mission. Military communication satellites differ from commercial satellites only in that they contain specialized components, certain capabilities, and multiple redundant systems designed to make them less vulnerable and more effective in a hostile environment. Military satellites include weather, communications, navigation, and Earth observing satellites used for military purposes. From orbit, it is possible to obtain a wide-field-of-view image of the Earth, its cloud formations, and their movements. This meteorological information is valuable for military planning and operations. Some military satellites, often called spy satellites, officially referred to as reconnaissance satellites, can detect the launch of missiles, the course of ships at sea, and the movement of military equipment on the ground. Here are some of reconnaissance satellite missions: high resolution photography, measurement and Signature Intelligence, communications eavesdropping, covert communications, monitoring of nuclear test ban compliance and detection of missile launches.

The earliest satellites were made for the armed forces of the United States and Soviet Union military forces, which are still in use today. The armed forces use these orbiting satellites to research battlefield information, locate known or missing troops, ensure communication, and take pictures. There are certain satellites that keep watch on signs of a possible potential nuclear missile and a nuclear explosion. One of the most important functions of military satellites is to provide reliable and secure communication links. The Armed forces need safe links to communicate with ships, aircraft, and mobile receivers on the land surface. The majority of the time these links are quiet, but during training exercises and battles the traffic will be heavy. Military satellites differ from commercial satellites in one respect: military communication satellites have periods of less activity than the commercial satellites that need to carry a continuous string of high volume traffic.

The DSP, which stands for Defense Support Program, satellites have been in GEO orbits since the 1970’s. These satellites monitor the Earth’s surface using sensors for detection of ballistic missiles. Any ballistic missile will be detected within seconds, which has greatly reduced the chances of a surprise attack by an enemy. The ability to detect the missiles so quickly provides enough time for a retaliatory strike.

Spy satellites are owned by several nations. The French Helios satellite can see an object as small as a bike on Earth’s surface. For the most part, military satellite functions are not well-known, since they would not be spy satellites if everyone knew their capabilities. A 10 year program was started by the United States Government in the latter years of 1990 to replace DSP satellites with the SBIRS, Space-Based Infrared System. This fleet of satellites has sensors capable of detecting missile launches and will provide. The first recon information SBIRS is scheduled to be launched into geostationary and elliptical orbits by the United States Defense Department. The low-Earth orbit satellites will work with satellites in the higher orbit to improve missile warnings. The band frequencies used fall within the infrared and visible radiation areas of the spectrum.

A vast majority of the satellites the Soviet Union had launched between 1960 and 1990 carried military duties. Publicly, however, the USSR would deny the very existence of the military space program in the country. Not surprisingly, numerous military space projects have never been officially acknowledged until the last decade of the 20th century. Most Russian military payloads reaching the orbit would be identified only as Cosmos satellites with particular numbers. Any civilian satellites, whose purpose the government would not want to explain, would also receive Cosmos names. It was up to independent observers and historians around the world to struggle with a puzzle of secret space programs. They based their analysis on a combination of available official data and satellite tracking information. The post-Soviet Russia adopted somewhat «westernized» approach to information policy on military space: the military launches are identified as such and receive traditional Cosmos names. During the 1990s, Russian military assets in orbit continuously degraded, as the Ministry of Defense could not afford to launch new spacecraft to replace aging and failing satellites. The situation started changing to the better in the first decade of the 21th century. Russia also maintains global navigation satellite systems. Its Tsikada/Nadezhda low-Earth-orbit system functions similar to the United States’ decommissioned Transit system. In addition, Russia operates the GLONASS navigation system. Similar to GPS, the system is less complex, but its satellites have proven less reliable than the United States’ version. Receivers are available that will accept navigational data from either GPS or GLONASS.

Задание I.Скажите, верны или нет данные утверждения. Неверные утверждения исправьте, а верные дополните 1-2 предложениями. Для того, чтобы начать свое высказывание, используйте следующие фразы

It’s true (false), I agree (disagree) with…, That’s right (wrong).

1. An artificial satellite continuously orbits the Earth to provide people with valuable information.

2. There are only two types of artificial satellites.

3. Military communication satellites differ from commercial satellites in the way they are launched into orbit.

4. Spy satellites have very important missions.

5. Military satellites don’t include weather satellites.

6. To provide reliable and secure communication links is one of the most important functions of military satellites.

7. A ballistic missile can be detected within an hour by means of a military satellite.

8. Some earliest US and Soviet Union military satellites are still in use today.

9. Spy satellites are owned only by the USA and Russia.

10. In 1990s the Defense Ministry of Russia could not afford to launch new satellites.

Задание II. Приготовьтесь побеседовать по изученной теме в группе и с преподавателем.

Unit 12.

Grammar Revision

Модальные глаголы

Глаголы can (could), may (might), must, ought, need относятся к группе модальных глаголов. Модальные глаголы не употребляются самостоятельно, а только в сочетании с инфинитивом смыслового глагола. Они обозначают возможность, способность, вероятность, необходимость совершения действия, выраженного смысловым глаголом

Модальные глаголы употребляются:

1. Безчастицыto(кроме ought)

I can do it.——Я могу сделать это

You maytake it.——Вы можете взять это

I mustgo there.——Я должен пойти туда

You needn’t do it.——Вам не нужно делать этого

НО! You ought tohelp him.——Вам следовало бы помочь ему

2. Безокончания –sв 3-ем лице единственного числа

He cando it.

He mustgo.

3. Безвспомогательного глагола to doв вопросительной и отрицательной формах

Can you do it?—-You cannot do it.

MayI take it?——You may nottake it.

Musthe go there?——He must notgo there.

Oughthe to help him?——He ought notto help him.

Needhe do it?——He need notdo it.

Present Past Future Эквиваленты

Must-должен —— —— to have to…

Can– мочь could —— to be able to…

могу, умею

May – в значении might —— to be allowed to…

«разрешено»,

«возможно»

Exercise 1. Поставьте следующие предложения в вопросительной и отрицательной форме. Переведите предложения

1. We must use the tools to cut and form this metal part.

2. This equipment can produce parts with very high accuracy.

3. They could easily define the properties of this material.

4. He may complete all necessary measurements himself.

5. With the help of a new device the scientist could see some strange rays.

Exercise 2. Прочитайте и переведите предложения с модальными глаголами

1. We must use new methods in our research work.

2. Due to the energy of the atom man can produce electric energy at atomic power stations.

3. You may use this instrument for measuring gas pressure.

4. The planet Pluto is so far away that we cannot study it easily.

5. They ought to help their friends to solve this important problem.

6. He couldn’t complete his research in time as he worked very slowly.

7. You should turn off the light before you leave the room.

Laser

Пользуясь словарем, найдите и запишите транскрипцию следующих слов. Правильно прочитайте эти слова вслух и постарайтесь запомнить их произношение

Divergence, define, wavelength, incandescent, opaque, property, bounce, coupler, ensure, require, due to, junction, storage, ubiquitous

Words to be learnt

low-divergence beam – луч с низкой дивергенцией (рассеиванием)

well-defined wavelength – точно определенная длина волн

incandescent light bulb – электрическая лампа накаливания

large solid angle – большой пространственный угол

out of step with each other – не соответствующие друг другу

intermittent – прерывающийся, пульсирующий

opaque – светонепроницаемый, непрозрачный

gain medium – среда усиления

optical cavity – оптический резонатор

transparent – прозрачный

to ensure – гарантировать, обеспечивать

pumping – накачка

flash lamp – импульсная лампа

solid state – твердотельный

due to – благодаря, из-за

visible emission – оптическое излучение

junction – переход

storage device – запоминающее устройство

ubiquitous – повсеместный, встречающийся повсюду

Text

A laser is an optical device that produces coherent radiation. Because the microwave equivalent of the laser, the maser, was developed first, devices that emit microwave and radio frequencies are usually called masers. In early literature, the laser was often called the optical maser. The term “laser” is an acronym: Light Amplification by Stimulated Emission of Radiation. A typical laser emits light in a narrow, low-divergence beam and with a well-defined wavelength (corresponding to a particular color if the laser is operating in the visible spectrum). This is in contrast to a light source such as the incandescent light bulb, which emits into a large solid angle and over a wide spectrum of wavelength.

We know that light consists of waves. An ordinary light consists of waves all out of phase, out of step with each other. All the waves in a laser beam have the same wavelength. A laser beam has a very definite color. The red color of the ruby is one of the most widely seen colors in it. But the difference between an ordinary beam of ruby red light and a laser beam of ruby red light is that in the laser beam the waves are all in step with each other. This orderly behavior of the laser beam makes a big difference, and there is one to be mentioned. Most beams of light are continuous. But the laser beam is intermittent, and it is off much longer than it is on. Because these switches on and off are very fast an eye doesn’t see them. While the laser beam is off the energy for the next flash is building up, and when this flash comes, it comes very intensively. An ordinary beam of light diverges, but laser beam doesn’t diverge at all. So it carries its energy in a compact form, until it is absorbed when it strikes something opaque.

A laser consists of a gain medium inside an optical cavity, with a means to supply energy to the gain medium. The gain medium is a material (gas, liquid, solid or free electrons) with appropriate optical properties. In its simplest form, a cavity consists of two mirrors arranged such that light bounces back and forth, each time passing through the gain medium. Typically, one of the two mirrors, the output coupler, is partially transparent. The output laser beam is emitted through this mirror.

Light of a specific wavelength that passes through the gain medium is amplified (increases in power); the surrounding mirrors ensure that most of the light makes many passes through the gain medium. Part of the light that is between the mirrors (i.e., is in the cavity) passes through the partially transparent mirror and appears as a beam of light. The process of supplying the energy required for the amplification is called pumping and the energy is typically supplied as an electrical current or as light at a different wavelength. In the latter case, the liquid source can

be a flash lamp or another laser. Most practical lasers contain additional elements that affect properties such as the wavelength of the emitted light and the shape of the beam.

The first working laser was demonstrated in May 1960 by Theodore Maiman. He used a solid-state flash lamp-pumped synthetic ruby crystal to produce red laser light at 694 nanometers wavelength. Maiman’s laser, however, was only capable of pulsed operation due to its three energy level pumping scheme. Later in 1960 the Iranian physicist Ali Javan made the first gas laser using helium and neon. Javan later received the Albert Einstein Award in 1993.The concept of the semiconductor laser diode was proposed by Basov and Javan. The first laser diode was demonstrated by Robert N. Hall in 1962. Hall’s device was made of gallium arsenide and emitted at 850 nm in the near-infrared region of the spectrum. The first semiconductor laser with visible emission was demonstrated later the same year by Nick Holonyak. As with the first gas lasers, these early semiconductor lasers could be used only in pulsed operation, and indeed only when cooled to liquid nitrogen temperatures (77 K). In 1970 Zhores Alferov in the Soviet Union developed laser diodes continuously operating at room temperature, using the heterojunction structure.

Recently, lasers have become a multi-billion dollar industry. The most widespread use of lasers is in optical storage devices such as compact disc and DVD players, in which the laser (a few millimeters in size) scans the surface of the disc. In industry, lasers are used for cutting steel and other metals and for inscribing patterns (such as the letters on computer keyboards). Lasers are also commonly used in various fields in science, especially spectroscopy, typically because of their well-defined wavelength or short pulse duration in the case of pulsed lasers. They have become ubiquitous, finding utility in thousands of highly varied applications in every section of modern society, including consumer electrons, information technology, science, medicine, industry, law enforcement, entertainment and the military.

Задание I.Выберите правильный ответ на вопрос по тексту:

1. What kind of device is called maser?

a) device that emits radiation

b) device that produces electrical energy

c) device that emits microwave and radio frequency

2. What does a typical laser emit?

a) visible spectrum

b) high-divergence beam

c) light in a narrow, low-divergence beam

3. What do all the waves in a laser beam have?

a) different wavelength

b) the same color

c) the same wavelength

4. What kind of beam is the laser beam?

a) continuous

b) intermittent

c) long

5. What does a laser consist of?

a) semiconductor and isolator

b) high-divergence beams

c) a gain medium inside an optical cavity

6. The material of the gain medium is…, isn’t it?

a) a silicon with chemical properties

b) a glass with physical properties

c) a material with optical properties

7. Where is light of a specific wavelength amplified?

a) in voltage

b) in current

c) in power

8. What is the process of supplying the energy required for the amplification called?

a) multiplication

b) enhancing

c) pumping

9. When did the first working laser demonstrated?

a) In 1962

b) In 1961

c) In 1960

10. Who developed the first laser diodes with heterojunction structure?

a) Nick Holonyak

b) Robert Hall

c) Zhores Alferov

Задание II.Найдите все цепочки слов в тексте и разберите их с преподавателем (последнее слово – определяемое). Выпишите их в свою тетрадь и составьте с ними свои предложения по теме “ Laser”

Задание III. Выполнив все упражнения, будьте готовы побеседовать на английском языке по теме «Laser» с группой и с преподавателем

Unit 13.

Grammar Revision

Модальные глаголы являются недостаточными, т.к. они не имеют всех форм, присущих другим глаголам. Для того, чтобы восполнить недостающие временные формы некоторых модальных глаголов, используются их эквиваленты. Эквиваленты модальных глаголов часто несут дополнительную эмоциональную окраску.

To be able to

Сочетание to be able to является эквивалентом модального глагола can, в т. ч. для выражения возможности или способности совершения действия.

He is able to help you. Он может помочь вам.

He was able to help you. Он смог помочь вам.

He will be able to help you. Он сможет помочь вам.

To be allowed to

To be permitted to

Словосочетания to be allowed to и to be permitted to являются эквивалентами модального глагола may.

I am allowed to use this device. Мне разрешено (я могу) использовать этот прибор.

He will be allowed to use this device. Ему разрешат пользоваться этим прибором.

To have to

Глагол to have to служит эквивалентом модального глагола must, в т.ч. для выражения необходимости совершить действие в силу определённых обстоятельств. Часто соответствует русскому «придётся, пришлось».

It was very dark and we had to stay at home. Было очень темно, и нам пришлось остаться дома.

I don’t have to stay here. Мне не нужно здесь оставаться.

To be to

Глагол to be to служит эквивалентом глагола must, в т. ч. для выражения необходимости совершения действия в соответствии с предыдущей договорённостью или заранее намеченным планом.

I was to meet her at 3 o’clock. Я должен был встретить её в 3 часа.

They are to begin this work at once. Они должны начать работу немедленно.

Should

Глагол should в основном используется для выражения совета, рекомендации как заменитель глагола must.

You should see a doctor. Вам следует показаться врачу.

Ought to

Глaголought to в качестве эквивалента глагола must используется для выражения морального долга или настоятельного совета.

You ought to help your parents. Вы должны помогать своим родителям.

Exercise. Замените данный в скобках модальный глагол подходящим к ситуации эквивалентом. Поставьте его в правильной грамматической форме.

1. Jack and Mike are playing tennis tomorrow. Mike is a very good player but I think Jack (can) win.

2. You (must) read this book. It is very interesting.

3. Nobody (may) take photos in this secret laboratory.

4. Yesterday I (must) leave the meeting because I (must) go to the airport to meet my mother.

5. You (must) send all the documents now. We need them very much.

6. My friends (must) arrive next week.

7. The fire was great but fortunately everybody (can) escape.

8. I’m not working tomorrow so I (must not) get up early.

9. Tomorrow’s conference is very important for your future work. You (must) come.

10. You (must not) believe everything you read in newspapers.

Antenna

Найдите в словаре и запишите транскрипцию следующих слов. Правильно прочитайте данные слова несколько раз вслух и постарайтесь запомнить их произношение

Oscillation, diligent, viable, subsequent, concisely, either, essential, aperture, grind, accept, view, rewrite, surface

Words to be learnt

to conduct — проводить

viable source – жизнеспособный источник

resonant antenna – резонансная антенна

fully yet concisely – полно, но в сжатой форме

essential part – значимая часть

to emerge – возникать, появляться

a new breed – новое поколение

the origin – происхождение, начало

plane subreflector – плоский подрефлектор

grinding -шлифование

surface — поверхность

equation — уравнение

to predict — предвидеть

to cause – заставлять, быть причиной

to accept – принимать, согласовывать

to trace back to – проследить, начиная от

society — общество

to recognize – признавать

to simplify — упрощать

to rewrite – переписать

Text

Antennas have been used for 100 years since Hertz conducted his experiments in the 1880s. First, he had to develop a source of very rapid electrical oscillations. After very careful and diligent development, he had a viable source and detector which formed the basis of the apparatus used in subsequent experiments. Hertz discovered the principles of a resonant antenna. Hertz was not only a brilliant experimentalist but also an extremely good writer. He wrote all his work up into papers which describe fully yet concisely the details of all his experiments. The main papers were collected together and published as a book in 1893.

An antenna is a wire or metal conductor used either to radiate energy from a transmitter or to pick up energy at a receiver. It is insulated from the ground and may be situated vertically or horizontally. Antennas are an essential part of every radio system and the steady growth of radio communications has increased the demand for antennas. The 100year period can be broadly divided into two halves. From the start to the 1930s, the story of antenna development follows in a single chronological path, from Hertz work to the early microwave period to long wave communications and then to short wave communications. Most antenna development in this period was empirical. The 1930s represents a clear break point in the history of radio communications and hence antennas. The uses of radio expanded rapidly and separate subject areas emerged. Radar started, microwaves returned, broadcasting expanded and radio astronomy started. A new breed of antenna engineers used rigorous theory to analyze and design antennas. Each of the areas has its own story to tell and the antennas for each area developed to some extent separately with a common theory linking all types.

Hertz was the first person to develop and use antennas in order to verify the existence of radio waves. But microwave engineers now often design antennas using optical principles. Thus the origin of the large aperture antenna can be traced back to the optical telescope of Newton and others. The first reflecting telescope was proposed by the Scottish mathematician James Gregory in 1663, but it was Isaac Newton who built the first instrument in 1672. This used a spherical main reflector and a plane subreflector to produce a focal point on one side of the telescope. In the same year that Isaac Newton proposed his telescope to the Royal society, George Gassegram proposed a reflecting mirror and a subreflector to refocus the light to a point behind the main reflector. However neither the Gassegram nor the Gregorian telescope was practical until James Short developed a method of grinding nonspherical surfaces in 1740.

The formulation of Maxwell`s Equations and hence the start of antennas theory also came before the classical experiments of Hertz. The research of James Clerk Maxwell was founded on the experimental work of Michael Faraday who discovered electromagnetic induction. Maxwell was a brilliant theoretician who predicted that all changes in electrical and magnetic fields cause waves to be propagated in space and that light was just another form of electromagnetic wave. This was a revolutionary suggestion at that time because the generally accepted view was that the ether behaved as a fluid and Newtonian physics of action-at-a-distance applied. Maxwell first published his ideas in 1862 and subsequently expanded them into a book in 1873. The book is recognized as a classical but it was and still is extremely difficult to follow. It was Hertz and Heaviside who simplified and rewrote the Equations in the form we know today.

Задание I. Поставьте вопросы и ответьте на них, закончив предложения по тексту:

1. An antenna is … (what, where, when)

2. Essential part of every radio system is … (what, where, why)

3. The 100year period can be divided into … (what, how, where)

4. Hertz conducted his experiments … (what, who, when)

5. Hertz discovered … (what, who, where, when)

6. The story of antenna development started … (when, where, what, why)

7. James Gregory proposed … (what, when, where, who)

8. Isaac Newton built … (what, who, when)

9. George Gassegram proposed…(what, who, why, where)

10. A method of grinding nonspherical surfaces was developed by…(what, who)

11. Electromagnetic induction was discovered by…(who, what, why)

12. Maxwell first published his ideas…(when, who, what, where)

13. Hertz and Heaviside simplified and rewrote…(what, who, why, when, where)

Задание II. Выделите главную мысль каждого абзаца в виде 3-4 кратких, логичных, своих собственных предложений

Задание III. Тщательно выполнив все упражнения, будьте готовы на английском языке побеседовать по теме «Антенна» с преподавателем и с группой

Unit 14.

Grammar Revision

Имя числительное

Числительное— часть речи, которая обозначает количество предметов (количественные) или их порядок при счете (порядковые).

Количественные числительные обозначают количество предметов и отвечают на вопрос Сколько? -How many?

Количественные числительные от 1 до 12 — простые. Они не имеют специальных окончаний.

1- one 7- seven

2- two 8- eight

3- three 9- nine

4- four 10- ten

5- five 11- eleven

6- six 12- twelve

Количественные числительные от 13 до 19образуются от простых при помощи суффикса — teen.

13- thirteen

14- fourteen

……………

19- nineteen

Количественные числительные, обозначающие десятки, оканчиваются на суффикс – ty

20- twenty

30- thirty

……………

90- ninety

Количественные числительные используются для обозначения:

1. Дат

She was born on March 4, 1982.

Дата читается: оn March fourth nineteen eighty two или on the fourth of March nineteen eighty two.

2. Номеров

o домов, квартир:

I live in flat 14. / Читается как flat fourteen /.

o автобусов, троллейбусов:

Take bus 5 to get to the park. / Читается как bus five /.

o глав, страниц книги:

Open the book at page 20. / Читается как page twenty /.

Числительные в этом случае стоят после определяемого слова.

Порядковые числительные обозначают порядок предметов при счете. Порядковые числительные часто используются в ответе на вопрос Какой? (по порядку) — Which? Существительные в этом случае используются с определенным артиклем (the), который ставится перед порядковым числительным.

Форму некоторых порядковых числительных следует запомнить:

первый — the first третий – the third

второй — the second пятый – the fifth

Порядковые числительные от 4 до 20 образуются от количественных при помощи суффикса — th.

4ый — the fourth

6ой — the sixth

7ой — the seventh

. . . . . . . . . . . .

19ый — the nineteenth

20ый — the twentieth

При образовании числительных, обозначающих десятки, буква y меняется на букву i:

30ый- thirtieth

40ой- fortieth

50ый- fiftieth

………………

90ый- ninetieth

Сложные числительные при образовании порядкового числительного изменяют форму только второго слова.

21ый — the twenty-first

22ой — the twenty-second

23ий — the twenty-third

. . . . . . . . . . . . . . .

55ый — the fifty-fifth

Exercise1. Напишите словами по-английски и произнесите вслух.

1. 5.08.1900

2. page 74

3. 8 25 = 33

4. I live in Kirensky Street 25, flat 69

5. 1 216 square miles

6. 8.07

7. 09.03.1879

8. 649 books

Exercise2.Вставьте порядковое или количественное числительные.

1. There are ________ months in a year.

2. January is ________ month of the year.

3. May is ________ month of the year.

4. There are ________ months in winter.

5. December is ________ month of the year and ________ month of winter.

6. There are ________ days in a week: ________ one is Monday, ________ one is Tuesday, ________one is Wednesday, ________ one is Thursday, ________ one is Friday, ________ one is Saturday and ________ one is Sunday.

7. Sunday is ________ day of the week in England and ________ one in Russia.

8. Monday is ________ day in Russia and ________ in Great Britain.

9. There are ________ hours in a day, ________ minutes in an hour and ________ seconds in a minute.

10. September, April, June and November have ________ days. All the rest have ________ except February.

11. There are ________ days in February except the leap year. It’s the time when February has ________ days.

Radar Antenna

Найдите в словаре и запишите в тетрадь транскрипцию данных слов. Прочитайте их вслух несколько раз.

Azimuth, accuracy, equate, weigh, ratio, rectangular, desired, aperture, key, major, vary.

Words to be learnt

to perform- выполнять, исполнять

essential- важнейший, основной, неотъемлемый

distribution- распределение, распространение

to apply- применять, прикладывать

accurate- точный

in the case of…- в случае…

revolution rate- скорость вращения

in terms of…- с точки зрения…, в пересчете на…

to take into account- брать в расчет, принимать во внимание

gain- коэффициент усиления

to compare- сравнивать

field- поле, область

radiation pattern- диаграмма излучения

axis- ось

intersection- перекрещивание, пересечение

beam- луч, пучок света

lobe- лепесток диаграммы направленности антенны

to eliminate- устранять, аннулировать

appropriate- подходящий, соответствующий

(un) desirable- (не) желательный

Text

The antenna is one of the most critical parts of a radar system. It performs the following essential functions:

• It transfers the transmitter energy to signals in space with the required distribution and efficiency. This process is applied in an identical way on reception.

• It ensures that the signal has the required pattern in space. Generally this has to be sufficiently narrow in azimuth to provide the required azimuth resolution and accuracy.

• It has to provide the required frequency of target position updates. In the case of a mechanically scanned antenna this equates to the revolution rate. A high revolution rate can be a significant mechanical problem given that a radar antenna in certain frequency bands can have a reflector with immense dimensions and can weigh several tons.

• It must measure the pointing direction with a high degree of accuracy.

The antenna structure must maintain the operating characteristics under all environmental conditions. The basic performance of radar can be shown to be proportional to the product of the antenna area or aperture and the mean transmitted power. Investment in the antenna therefore brings direct results in terms of system performance. Taking into account these functions and the required efficiency of a radar antenna, two arrangements are generally applied:

• the parabolic dish antenna

• the array antenna.

Independently of the use of a given antenna for transmitting or receiving, an important characteristic of this antenna is the gain. Some antennas are highly directional; that is, more energy is propagated in certain directions than in others. The ratio between the amount of energy propagated in these directions compared to the energy that would be propagated if the antenna were not directional (Isotropic Radiation) is known as its gain. When a transmitting antenna with a certain gain is used as a receiving antenna, it will also have the same gain for receiving.

Most radiators emit (radiate) stronger radiation in one direction than in another. A radiator such as this is referred to as anisotropic. However, a standard method allows the positions around a source to be marked so that one radiation

pattern can easily be compared with another. The energy radiated from an antenna forms a field having a definite radiation pattern. A radiation pattern is a way of plotting the radiated energy from an antenna. This energy is measured at various angles at a constant distance from the antenna. The shape of this pattern depends on the type of antenna used. To plot this pattern, two different types of graphs, rectangular-and polar-coordinate graphs are used. The polar-coordinated graph has proved to be of great use in studying radiation patterns. In the polar-coordinate graph, points are located by projection along a rotating axis (radius) to an intersection with one of several concentric, equally-spaced circles.

The main beam (or main lobe) is the region around the direction of maximum radiation (usually the region that is within 3 dB of the peak of the main beam). The sidelobes are smaller beams that are away from the main beam. These sidelobes are usually radiation in undesired directions which can never be completely eliminated. The sidelobe level (or sidelobe ratio) is an important parameter used to characterize radiation patterns. It is the maximum value of the sidelobes away from the main beam and is expressed in Decibels. One sidelobe is called backlobe. This is the portion of radiation pattern that is directed opposing the main beam direction.

For the analysis of an antenna pattern the following simplifications are used:

Beam Width

The angular range of the antenna pattern in which at least half of the maximum power is still emitted is described as a „Beam With”. Bordering points of this major lobe are therefore the points at which the field strength has fallen in the room around 3 dB regarding the maximum field strength. This angle is then described as beam width or aperture angle or half power (- 3 dB) angle.

Aperture

The effective aperture of an antenna Ae is the area presented to the radiated or received signal. It is a key parameter, which governs the performance of the antenna.The aperture efficiency depends on the distribution of the illumination across the aperture.

Major and Side Lobes (Minor Lobes)

The radiation intensity in one lobe is considerably stronger than in the other. The strongest lobe is called major lobe; the others are (minor) side lobes. Since the complex radiation patterns associated with arrays frequently contain several lobes of

varying intensity, you should learn to use appropriate terminology. In general, major lobes are those in which the greatest amount of radiation occurs. Side or minor lobes are those in which the radiation intensity is least.

Front-to-Back Ratio

The front-to-back ratio of an antenna is the proportion of energy radiated in the principal direction of radiation to the energy radiated in the opposite direction. A high front-to-back ratio is desirable because this means that a minimum amount of energy is radiated in the undesired direction.

Задание I.Найдите в тексте ответы на вопросы. Отработайте вопросы и ответы в парах. Старайтесь проговаривать их, не глядя в текст.

1. What are the essential functions of a radar antenna?

2. What are the main types of a radar antenna?

3. Why is the antenna structure very important?

4. What are the main characteristics of an antenna?

5. What is antenna gain?

6. What is an anisotropic radiator?

7. What is the main beam of the antenna?

8. What is beam width?

9. What is aperture?

10. What is front-to-back ratio of the antenna?

Задание II. Приготовьтесь побеседовать по изученной теме в группе и с преподавателем.

Unit 15.

Grammar Revision

Повелительное наклонение

Глагол в повелительном наклонении выражает побуждение к действию, т.е. приказание, просьбу, совет и т. п.

Утвердительная форма повелительного наклонения совпадает с основой глагола (инфинитив без частицы to):

to read- читать Read! — Читайте! (Читай!)

Отрицательная форма образуется при помощи вспомогательного глагола do и отрицательной частицы not. Таким же способом образуется отрицательная форма повелительного наклонения глаголов to be и to have:

Do not (don’t) wait. — Не ждите.

Don’t be late! — Не опаздывайте!

Don’t have а meal at night. — Не ешьте ночью.

Вспомогательный глагол do ставится перед утвердительной формой повелительного наклонения для усиления просьбы:

Do help him! — Непременно помоги ему!

Для выражения побуждения к действию, обращенного к первому и третьему лицу, используется глагол let, соответствующее местоимение в объектном падеже (или существительное в общем падеже) и основа глагола:

Let me do it myself. — Давайте я сделаю это сам.

Let us (Let’s) ask John. — Давайте cпросим Джона.

Let him (Jim) work. — Пусть он (Джим) работает.

Let her (Mary) speak! — Пусть она (Мэри) говорит!

Let them (students) use dictionaries. — Пусть они (студенты) пользуются словарями.

Don’t let him go there! — Пусть он туда не ходит!

Exercise 1. Вставьте глаголы, данные в скобках, в форме повелительного наклонения. Устно переведите предложения на русский язык.

1. ………….out late. (not to go)

2. Please, …………ready in 15 minutes. (to be)

3…………. about that. (not to worry)

4. ………..me! (they, to ask)

5. ………….careful not to fall. (to be)

6. …………..everything you hear! (not to believe)

7. Always ………… both ways before crossing the street. (to look)

8. ………..here. (he, to wait)

9. ………..your own business! (to mind)

10……….. a letter if you have no time (not to send)

Radar Receiver (part I)

Найдите в словаре и запишите в тетрадь транскрипцию данных слов. Прочитайте их вслух несколько раз.

Temperature, automatic, purpose, synthesize, pseudo, nearby, attenuator, bias, proportional, simultaneous.

Words to be learnt

to tune- настраивать

external signal- сигнал от внешних устройств

oscillator- излучатель

to retain — сохранять, удерживать

reference frequency — основная, эталонная частота, частота обращений

wiring — эл. проводка

instead of…- вместо…

pulse repetition period — период повторения импульсов

bias — смещение

to decrease — снижать, понижать, уменьшать

to prevent — предотвратить

leakage — утечка, рассеяние

to saturate — насыщать, переполнять

instantaneous — мгновенный, немедленный

average — средний (напр. о значении)

weak signal — слабый сигнал

strong signal — cильный, устойчивый сигнал

the number of — ряд (некоторое количество)

Text

The radar receiver requires a limited tuning range to compensate for transmitter and local oscillator frequency changes because of variations in temperature and

loading. Microwave radar receivers usually use automatic frequency control (AFC) for this purpose. AFC circuits are used in situations where you must accurately control the frequency of an oscillator by some external signal. The AFC circuit senses the difference between the actual oscillator frequency and the frequency that is desired and produces a control voltage proportional to the difference. This variant of AFC circuits is used in radio receivers, fm transmitters, and frequency synthesizers to maintain frequency stability. It requires relatively constant amplitude of the (received) input-signal. For pulse-radar sets this form isn’t practicable therefore.

Automatic frequency control circuits in a non-coherent or pseudo-coherent radar set use two similar systems: the transmitter’s frequency readjusts the receiver; the receiver’s frequency readjusts the transmitter. Both systems retain a sample of the transmitted signal using a Directional Coupler fitted between the transmitter and the Duplexer. This RF-signal will be mixed with the local oscillator frequency to form an AFC-IF-signal. This signal is applied to a frequency-sensitive discriminator that produces an output voltage proportional in amplitude and polarity to any change in AFC-IF frequency. If the IF signal is at the discriminator center frequency, no discriminator output occurs. The center frequency of the discriminator is essentially a reference frequency for the IF signal. The output of the discriminator provides a control voltage to maintain the local oscillator at the correct frequency.

The Local Oscillator is adapted to the actual line frequency in this wiring. As a second variant the control circuit can control the transmitters frequency instead of the LO frequency! In this case the transmitter-frequency would regulate to the more stable LO-frequency. In radar receivers the wide variation in return signal amplitudes make adjustment of the gain difficult. The adjustment of receiver gain for best visibility of nearby target return signals is not the best adjustment for distant target return signals. Circuits used to adjust amplifier gain with time, during a single pulse repetition period, are called STC circuits, or „swept gain attenuator”.

Sensitivity time-control circuits apply a bias voltage that varies with time to the IF amplifiers to control receiver gain. When the transmitter fires, the STC circuit decreases the receiver gain to zero to prevent the amplification of any leakage energy from the transmitted pulse. At the end of the transmitted pulse, the STC voltage begins to rise, gradually increasing the receiver gain to maximum. In the ideal case the the receiver gain is proportionally to R4. The STC voltage effect on receiver gain is usually limited to approximately 50 miles. This is because close-in

targets are most likely to saturate the receiver; beyond 50 miles, STC has no affect and the receiver operates normally.

Gain control is necessary to adjust the receiver sensitivity for the best reception of signals of widely varying amplitudes. A complex form of automatic gain control (AGC) or instantaneous automatic gain control (IAGC) is used during normal operation. The simplest type of AGC adjusts the IF amplifier bias (and gain) according to the average level of the received signal. With AGC, gain is controlled by the largest received signals. When several radar signals are being received simultaneously, the weakest signal may be of greatest interest. IAGC is used more frequently because it adjusts receiver gain for each signal.

The AGC circuit is essentially a wide-band, dc amplifier. It instantaneously controls the gain of the IF amplifier as the radar return signal changes in amplitude. The effect of IAGC is to allow full amplification of weak signals and to decrease the amplification of strong signals. The range of IAGC is limited, however, by the number of IF stages in which gain is controlled. When only one IF stage is controlled, the range of IAGC is limited to approximately 20 dB. When more than one IF stage is controlled, IAGC range can be increased to approximately 40 dB.

The logarithmic amplifier is a nonsaturating amplifier that does not ordinarily use any special gain-control circuits. The output voltage of the logarithmic amplifier is a linear function of the input voltage for low-amplitude signals. It is a logarithmic function for high-amplitude signals. In other words, the range of linear amplification does not end at a definite saturation point, as is the case in normal IF amplifiers. Therefore, a large signal does not saturate the logarithmic amplifier; rather, it merely reduces the amplification of a simultaneously applied small signal.

Задание I. Задайте вопросы к данным предложениям, начиная их словами, предложенными в скобках.

1. The radar receiver requires a limited tuning range. (Why?)

2. AFC circuits are used in microwave radar receivers. (In what situations?)

3. AFC circuits are used to maintain frequency stability. (Where?)

4. RF signal is mixed with the local oscillator frequency. (What…for?)

5. The output discriminator produces an output voltage. (What…for?)

6. It is difficult to make the adjustment of the radar receiver gain. (Why?)

7. The STC voltage begins to rise, increasing the receiver gain. (When?)

8. Gain control is necessary. (Why?)

9. The weakest signal may be of the greatest interest. (When?)

10. The range of IAGC is limited. (What…by?)

11. A large signal doesn’t saturate the logarithmic amplifier. (Does…?)

Задание II. Пользуясь текстом, ответьте на составленные вами вопросы.

Unit 16.

Grammar Revision

Инфинитив

Инфинитив – неличная форма глагола, называющая действие в процессе его совершения, не указывая ни лица, ни числа, ни наклонения. Инфинитив соответствует в русском языке неопределенной форме глагола (инфинитиву), которая отвечает на вопрос что делать? что сделать? :

To read – читать, прочитать

To write – писать, написать

To buy – покупать, купить

To sell –продавать, продать

Существуют 4 формы инфинитива в действительном залоге (Active) и 2 формы в страдательном залоге (Passive)

Active Passive

Indefinite to ask to be asked

спрашивать быть спрошенным

Continuous to be asking ———-

Perfect to have asked to have been asked

Perfect Continuous to have been asking —————

Инфинитив переводится на русский язык:

1. Неопределенной формой глагола

2. Существительным

To operate the complex device is rather difficult.

Управлять (управление) этим сложным механизмом довольно трудно

3. Придаточным предложением

The metal to be used in our experiment is to be hard.

Металл, который будет использован (нужно, можно использовать) в нашем опыте, должен быть твердым.

Все формы инфинитива, кроме Indefinite Active и Passive, переводятся только в контексте.

Indefinite Infinitive Active и Passive являются наиболее распространенными формами инфинитива.

Отрицательная частица not ставится перед инфинитивом:

notto ask

not to be asked

Exercise. Переведите следующие предложения

1.To train highly qualified scientific workers is extremely important for the development of science.

2. To study this phenomenon requires much knowledge.

3. Our task is to obtain a new mixture with new properties.

4. The engineer must know the condition under the new material is to be utilized.

5. They hope to be sent to the conference.

6. The engineer was asked to design a transistor device which will regulate the temperature in the laboratory.

7. To increase the productivity of the machine tool one should know the characteristics of the material which is being machined.

8. In order to break this glass and great amount of force must be applied.

9. This method is accurate enough to give reliable results.

10. This problem is too complex to be solved.

11. The process to be analyzed in this article is known as ionization.

12. The famous Russian scientist Lebedev was the first to solve the problem of synthetic rubber.

13. The laboratory assistant will be the last to leave the classroom.

14. The problem to find a more economical way of production is to be solved soon.

Radar receiver (part II)

Найдите в словаре и запишите в тетрадь транскрипцию данных слов. Прочитайте их вслух несколько раз.

Echo, sufficient, accept, dynamically, measure, furthermore, ahead, enough, dial, easily

Words to be learnt

sufficiently- достаточно, в достаточной мере

pulse envelope- огибающая импульса

to feed- поставлять, снабжать, обеспечивать

to accept- принимать

intermediate frequency- промежуточная частота

clutter level- уровень шума (помех)

magnitude- величина

cell- элемент, секция

abrupt- внезапный, неожиданный

to destroy- разрушать

to affect- оказывать влияние на…, воздействовать

to process- обрабатывать

frequency-band- частотный диапазон

unwanted signal- посторонний сигнал

bandwidth- полоса частот, полоса пропускания, пропускная способность

to pick up a signal- поймать, уловить сигнал

image frequency- частота зеркального канала

swept gain- рабочий коэффициент усиления

Text

The function of the receiver is to take the weak echoes from the antenna system, amplify them sufficiently, detect the pulse envelope, amplify the pulses, and feed them to the indicator. The receivers used in radars are capable of accepting weak echoes and increasing their amplitudes by a factor of 20 or 30 million. Since radar frequencies are not easily amplified, a superheterodyne receiver changes the radio frequency to an intermediate frequency for amplification.

Local clutter levels dictate the magnitude of swept gain and different requirements for swept gain are presented as the antenna rotates. Modern systems dynamically measure clutter levels for a large number of cells within the coverage area of the radar. These measurements are slowly adjusted to take account of changing clutter levels and used to set the swept gain attenuator to an appropriate level for the range azimuth cell currently being processed. In most cases, the values used are a variation on the normal static law. This approach, while simple in principle, can risk reduction of MTI performance at the edges of clutter. This is due to abrupt changes in swept gain law destroying the integrity of the clutter amplitudes. Furthermore if long or compressed pulses are used, amplitude changes can affect the performance. Swept gain is generally applied to pin diodes, which are biased to provide a reasonably linear characteristic.

The superheterodyne receiver changes the RF frequency into an easier to process lower IF- frequency. This IF- frequency will be amplified and demodulated to get a video signal. The RF-carrier comes in from the antenna and is applied to a filter. The output of the filter is only the frequencies of the desired frequency-band. These frequencies are applied to the mixer stage. The mixer also receives an input from the local oscillator. These two signals are beat together to obtain the IF through the process of heterodyning. There is a fixed difference in frequency between the local oscillator and the RF signal at all times by tuning the local oscillator. This difference in frequency is the IF. This fixed difference ensures a constant IF over the frequency range of the receiver. The IF-carrier is applied to the IF-amplifier. The amplified IF is then sent to the detector. The output of the detector is the video component of the input signal.

A low-noise RF amplifier stage ahead of the converter stage provides enough selectivity to reduce the image-frequency response by rejecting these unwanted signals and adds to the sensitivity of the receiver. The borders of the bandwidth of this amplifier are chosen to eliminate the image frequencies. Many older radar receivers do not use a low-noise pre-amplifier (RF stage), they simply send the echo signal directly to a crystal mixer stage. It is possible for these receivers to receive two different stations at the same point of the dial.

The mixer stage is used to increase the received frequency to an intermediate frequency. The result is a second reception frequency as a „mirror image” around the intermediate frequency. Assuming an intermediate frequency of 60 MHz, the local oscillator will track at a frequency of 60 MHz higher than the incoming signal. For example, suppose the receiver is tuned to pick up a signal on a frequency of 1030 MHz. The local oscillator will be operating at a frequency of 1090 MHz. The received and local oscillator signals are mixed, or heterodyned, in the converter stage and one of the frequencies resulting from this mixing action is the difference between the two signals, or 60 MHz, the IF frequency. This IF frequency is then amplified in the IF stages and sent on to the detector and audio stages. Any signal at a frequency of 60 MHz that appears on the plate of the converter circuit will be accepted by the IF amplifier and passed on.

Задание I. Внимательно прочитайте текст еще раз. Подобрав части предложений, друг к другу, составьте из них целые предложения.

1. The receiver… …to eliminate the image frequencies.

2. A superheterodyne receiver… …the radio frequency to an intermediate frequency.

3. Local clutter levels… …the received and local oscillator signals are mixed.

4. Modern radar systems are capable of.. …from the local oscillator.

5. IF is amplified and demodulated… …to get a video signal.

6. The mixer receives the input signal… …the received frequency increases to an intermediate frequency.

7. The output of the detector is… …takes the weak echoes from the antenna, amplifies them, detects the pulse envelope, amplifies the pulses and feeds them to the indicator.

8. The borders of the amplifier bandwidth are chosen… …dictate the magnitude of swept gain.

9. During the mixer stage… …the video component of the input signal.

10. During the converter stage… …measuring clutter levels for a large number of cells within the coverage area of the radar.

Задание |II. Задайте вопросы к составленным предложениям.

Unit 17.

Grammar Revision

Герундий

Герундий – неличная форма глагола, выражающая название действия и обладающая как свойствами глагола, так и свойствами существительного. В русском языке нет формы соответствующей герундию. Функции герундия сходны с функциями инфинитива.

Существуют 2 формы герундия в действительном залоге (Active) и

2 формы в страдательном залоге (Passive)

Active Passive

Indefinite reading being read

Perfect having read having been read

Герундий переводится на русский язык различными способами:

Существительным

Reading is his favorite occupation.—-Чтение –его любимое занятие.

Инфинитивом

He finished reading the book.—-Он закончил читать книгу.

Деепричастием

On coming home he began to read.—-Придя домой, он начал читать.

Глаголом в личной форме

I remember seeingher there.—-Я помню, что видел её там.

Besides being clever he is very industrious.—-Помимо того, что он умен, он очень трудолюбив.

She reproached herself for having said it.—-Она упрекала себя за то, что

сказала это.

Exercise. Переведите данные предложения

1. Maintaining constant temperature and pressure during the test was absolutely necessary.

2. The student’s taking part in the research was of great help to the whole laboratory.

3. His offering new temperature conditions for the system will give greater efficiency.

4. The task of the factory was producing corrosion-resistant polymers in far larger quantities.

5. Their aim is finding new ways of utilizing this first-class polymer in light industry.

6. The experimentalist suggested purifying the solution by a new method.

7. The researcher took great interest in our improving the properties of the rubber.

8. We know of silver and cooper being very good conductors of electricity.

9. The new heating and lighting installations supply the shops of our plant with heat and light.

10. At present scientists take great interest in the methods of turning the light and heat of the sun directly into electricity.

11. By subjecting air to very great pressure and cooling it is possible to transform it to the liquid state.

12. One cannot transform water into steam without heating it.

13. In converting water into ice we do not change its composition.

14. Physical changes are those which influence the condition or state of matter without changing its composition.

Radar Receiver (part III)

Найдите в словаре и запишите в тетрадь транскрипцию данных слов. Прочитайте их вслух несколько раз.

Rather, through, circuit, interference, high, excite, value, either, neither, actual.

Words to be learnt

to get through- проходить, проводить

jack- разъем, гнездо

bandpass- полоса пропускания

to reject- отклонять, отвергать

actual signal- фактический, текущий сигнал

to match- подбирать, выравнивать, согласовывать

variable- переменный, непостоянный

indicating device- сигнальное устройство

frequency response- частотная характеристика

emitter follower- эмиттерный повторитель

low- impedance- низкоомный

to couple- соединять, сцеплять

to excite- возбуждать, вызывать (напр. ток)

both…and…- и…и…

frequency shift- уход, сдвиг частоты

either…or…- или…или…, либо…либо…

ahead of…- перед…

Text

There are receivers with no RF amplifier. In them the input to the converter is rather broadly tuned and some signals, other than the desired signal, will get through to the input jack of the converter stage. Normally these other signals will mix with the local oscillator signal and produce frequencies that are outside the bandpass of the 60 MHz IF amplifiers and will be rejected. However, if there is a station operating on a frequency of 1150 MHz, and this signal passes through the rather broad tuned input circuit and appears on the input jack of the converter stage, it also will mix with the local oscillator and produce a frequency of 60 MHz.

This signal will also be accepted by the IF amplifier stage and passed on, thus both signals will be indicated on the screen. This is known as image-frequency interference.

IF-Filter must filter the desired intermediate frequency out from the mixture frequencies arisen in the mixer stage. It is designed as one or more bandpasses. Normally, the bandpass is as narrow as possible without affecting the actual signal energy. When a selection of pulse widths is available, such as short and long pulses, the bandpass must be able to match the bandwidth of the two different signals.

The IF amplifier has the capability to vary both the bandpass and the gain of a receiver. After conversion to the intermediate frequency, the signal is amplified in several IF- amplifier stages. Most of the gain of the receiver is developed in the IF amplifier stages. The overall bandwidth of the receiver is often determined by the bandwidth of the IF stages. Gain must be variable to provide a constant voltage output for input signals of different amplitudes.

The detector in a microwave receiver serves to convert the IF pulses into video pulses. The simplest form of detector is the diode detector. The video amplifier receives pulses from the detector and amplifies these pulses for application to the indicating device. A video amplifier is fundamentally an RC coupled amplifier that uses high-gain transistors. However, a video amplifier must be capable of a relatively wide frequency response. The output stage of the receiver is normally an emitter follower. The low-impedance output of the emitter follower matches the impedance of the cable. The video pulses are coupled through the cable to the indicator for video display on the CRT.

The local oscillator excites a frequency for mixing with the incoming signal to get the intermediate frequency. Most radar receivers use megahertz intermediate frequency (IF) with a value between 30 and 75 megahertz. The IF is produced by mixing a local oscillator signal with the incoming signal. The local oscillator is, therefore, essential to efficient operation and must be both tunable and very stable. For example, if the local oscillator frequency is 3,000 megahertz, a frequency change of 0.1 percent will produce a frequency shift of 3 megahertz. This is equal to the bandwidth of most receivers and would greatly decrease receiver gain. The power output requirement for most local oscillators is small (20 to 50 milliwatts) because most receivers use crystal mixers that require very little power. The local oscillator output frequency must be tunable over a range of several megahertz in

The 4,000-megahertz region. The local oscillator must compensate for any changes in the transmitted frequency and maintain a constant 30 or 75 megahertz difference between the oscillator and the transmitter frequency. A local oscillator that can be tuned by varying the applied voltage is most desirable. The exiting frequency is either higher or lower than the incoming frequency. An RF amplifier stage ahead of the converter stage provides enough selectivity to reduce the image-frequency response by rejecting these unwanted signals and adds to the sensitivity of the receiver.

Задание I. Найдите в тексте ответы на данные вопросы. Поработайте в парах: постарайтесь проговорить вопросы и ответы, не глядя в текст.

1. What occurs with frequencies that are outside the bandpass of the 60 MHz IF amplifiers?

2. What is known as image- frequency interference?

3. What is the function of the IF-Filter?

4. What capability does the IF amplifier have?

5. What is the overall bandwidth of the receiver determined by?

6. Must the gain be variable? Why?

7. What is the function of the detector in a microwave receiver?

8. What capability must a video amplifier have?

9. What frequency do most radar receivers have?

10. What capability must the local oscillator have?

Задание II. Приготовьтесь побеседовать по изученной теме в группе и с преподавателем.

Unit 18.

Grammar Revision

Причастие

Причастие — неличная форма глагола, которая соответствует в русском языке причастию и деепричастию, обладает свойствами прилагательного.

Существуют 2 формы причастия действительного залога (Active) и

3 формы причастия страдательного залога (Passive)

Active Passive

Present asking being asked

Past —- asked

Perfect having asked having been asked

1. Present Participle Active образуется путем прибавления –ingк глаголу в форме инфинитива ( без частицы to)

to read – читать reading – читающий, читая

to build – строить building – строящий, строя

2. Past Participle Active и Passive от правильных глаголов образуется путем прибавления окончания – edк глаголу в инфинитиве

to ask – спросить, спрашивать asked – спрошенный, спрашиваемый

to order – заказать, заказывать ordered – заказанный, заказываемый

Past Participle от неправильных глаголов образуется различными способами – это III форма глагола

To give – дать, давать given – данный, даваемый

To send – послать, посылать sent – посланный, посылаемый

To buy – купить, покупать bought – купленный, покупаемый

Active Voice

Present Participle

Throwing — бросающий, бросавший, бросая, бросив

The boy throwingstones into the pond is my brother.

Мальчик, бросающий камни в пруд, мой брат.

The boy throwing stones into the pond laughed loudly.

Мальчик, бросавший камни в пруд, громко смеялся.

The boy stood on the bank throwing stones into the pond.

Мальчик стоял на берегу, бросая камни в пруд.

Throwingthe letter into the fire he left the room.

Бросив письмо в огонь, он вышел из комнаты.

Perfect Participle

Having thrown – бросив

Having thrown the ball into the water, the boy could not get it back.

Бросив мяч в воду, мальчик не мог достать его.

Passive Voice

Present Participle

Being thrown – бросаемый, будучи брошен, так как (когда) был брошен

The stones being thrown by the boys are galling into the water.

Камни, бросаемые мальчиками, падают в воду.

Being thrown with great force, the stone reached the opposite bank. Так как камень был брошен (будучи брошен) с большой силой, он долетел до противоположного берега.

Past Participle

Thrown – бросаемый, брошенный

Stones thrown into the water go to the bottom.

Камни, бросаемые в воду, идут ко дну.

The stone thrown by the boy reached the bank/

Камень, брошенный мальчиком, долетел до противоположного берега.

Perfect Participle

Having been thrown – так как (после того как) был брошен

Having once been thrown into the water by the children, the dog always ran away when it saw them.

Так как собака была однажды брошена детьми в воду, она всегда убегала при виде их.

Exercise. Переведите данные предложения

a) Participle I

1. A molecule is a compound consisting of two or more atoms.

2. Combining hydrogen with oxygen in the proportion of two atoms of hydrogen and one atom of oxygen we produce water.

3. While burning different substances combine with oxygen.

4. The assistant was preparing the solution very carefully.

5. The solution is boiling.

6. The boiling solution has neither color nor odour.

b) Participle II

1. The solution of the problem required concentrated efforts of many scientists.

2. The data required were analyzed in our laboratory.

3. When required, the data will be applied in our practical work.

4. The investigations analyzed resulted in an interesting discovery.

5. Heated glass is plastic.

6. When heated, glass can be easily worked.

7. Some new properties of the polymer found during the experiments were quite unexpected.

Optical technology

Найдите в словаре и запишите транскрипцию следующих слов. Правильно прочитайте данные слова несколько раз вслух и постарайтесь запомнить их произношение

Fiber, improve, reliability, noteworthy, ultra-thin, technique, transparency, waveguide, storage, indestructible, versatile

Words to be learnt

optical fiber – оптоволокно

to replace – замещать, заменять

to promise – обещать

capacity – емкость, объём

reliability – надежность

set in motion – приводить в действие

a train of events – череда событий

long-lived source – долговременный источник

low loss – низкие потери

technique – метод

incredible – безграничный

transparency – прозрачность

coherent form – последовательная форма

waveguide – волновод

to accommodate – согласовывать, размещать

storage – накопление, сохранение, запоминание

underway – на пути прогресса, в развитии, в движении

indestructible – неразрушимый

thin film – тонкая плёнка

versatile – разносторонний

noteworthy – заслуживающий внимания, ценный

Text

One of the most interesting developments in telecommunication is the rapid progress of optical communication where optical fibers are replacing conventional telephone wires and cables. Just as digital technologies greatly improved the telephone system, optical communication promises a considerable increase in capacity, quality, performance and reliability of the global telecommunication network. New technologies such as optical fibers will increase the speed of telecommunication and provide new, specialized information service. Voice, computer data, even video images, will be increasingly integrated into a single

digital communication network capable to process and transmit virtually any kind of information.

The advent of the laser in the early 1960 set in motion a train of events that is steadily changing the outlook for optical communication. The past few years have been made three important advances. One was the invention of the semiconductor-diode laser, which satisfied the need for a cheap, efficient and long-lived source of coherent light waves to serve as the carrier waves for encoded signals. Another noteworthy advance was the development of ultra-thin, low-loss optical fibers, which are well suited for the long-range transmission of light waves, and, finally, an entire new generation of compact optical devices based on the precise guiding of laser light is being devised. Two technologies were combined: the laser, first demonstrated in 1960, and the fabrication 10 years later of ultra-thin silicon fibers which can serve as light wave conductors. With the further development of very efficient lasers plus continually improved techniques to produce thin silica fibers of incredible transparency, optical systems can transmit pulses of light as far as 135 kilometers without the need for amplification or regeneration.

At present high-capacity optical transmission systems are being installed between many major cities at a rapid rate. This system has a number of basic constituents. First, there must be an oscillator of some kind to generate the “carrier waves “in a highly coherent form (that is, with the all in step at the same frequency). Next, the waves must be modulated to carry information by varying either their frequency or their amplitude. The modulated microwave beam is then transmitted either by channeling it through a metallic waveguide or by propagating it through the atmosphere. The system most widely used now operates at 147 megabits (thousand bits) per second and accommodates 6 000 circuits over a single pair of glass fibers (one for each direction of transmission). This system will soon be improved to operate at 1.7 gigabits (thousand million bits) per second and handle 24 000 telephone channels simultaneously.

A revolution in information storage is underway with optical disk technology. The first optical disks appeared in the early 1970-s. They were and are used to record video films, but in a continuous spiral rather than digitally. The first digital optical disks were produced in 1982 as compact disks for music. They were further developed as a storage medium for computers. The disks are made of plastics coated with aluminium. The information is recorded by using a powerful laser to imprint bubbles on the surface of the disk. A less powerful laser reads back

the pictures, sound or information. An optical disk is almost indestructible and can store about 1 000 times more information than a plastic disk of the same sizе.

The latest optical disk development is a system which enables computer users to record their own information on a glass or plastic disk coated with a thin film of tellurium. Such a disk can store 200 megabytes (200 million characters).Besides, it is reported that an optical equivalent of a transistor has been produced and intensive research on optical electronic computers is under way at a number of US companies as well as in countries around the world. It is found that optical technology is cost-effective and versatile. It finds new application every day – from connecting communication equipment or computers within the same building or room to long distance transcontinental, transoceanic and space communications.

Задание I. Выберите правильное утверждение в соответствии с содержанием текста. Объясните его смысл своими собственными словами.

1. a) Optical communication provides a new generation of communication satellites

b) Optical communication promises a considerable increase in networks

c) Optical communication promises a considerable increase in capacity, quality, performance and reliability of the global telecommunication networks

2. a) One advance was the invention of the coherent light waves

b) One advance was the development of a new type of diodes

c) One advance was the invention of the semiconductor-diode laser

3. a) Optical systems can transmit ultra-high frequencies

b) Optical systems can transmit pulses of light without the need for amplification or regeneration

c) Optical systems can’t transmit pulses of light without the need for regeneration

4. a) There must be an semiconductor of some kind to generate the “carrier waves” in a highly coherent form

b) There must be modulated waves to carry information by varying either their frequency or their amplitude

c) There must be oscillator to transmit microwave beam

5. a) The modulated microwave beam is transmitted by the optical disks

b) The modulated microwave beam is transmitted by propagating it through the atmosphere

c) The modulated microwave beam is transmitted either by channeling it through metallic waveguide or by propagating it through the atmosphere

6. a) The first optical disks appeared in the early 1970-s

b) The first optical waveguide appeared in the early 1970-s

c) The first optical system appeared in the early 1970-s

7. a) The lasers were developed as a storage medium for computers

b) The first digital optical disks were developed as a storage medium for waveguide

c) The first digital optical disks were developed as a storage medium for computers

8. a) The optical technology is inefficient

b) The optical technology is one-sided

c) The optical technology is cost-effective and versatile

Задание II. Дайте название каждому абзацу текста. К абзацу составьте различные типы вопросов. Задайте вопросы в группе.

Задание III. Тщательно выполнив все задания, будьте готовы побеседовать по теме « Optical technology ».

Unit 19.

Grammar Revision

-er to convert – преобразовывать converter – преобразователь

-or to insulate – изолировать insulator – изолятор

-ing to bеgin – начинать beginning – начало

-ment to develop – развивать development – развитие

-th strong – сильный strength –сила

-ion to express –выражать expression –выражение

-ation to inform –сообщать information – сообщение

-sion to decide – решать decision – решение

-ssion to permit –разрешать permission – разрешение

-ance to assist – помогать assistance – помощь

-ity equal –равный equality – равенство

-ness happy – счастливый happiness – счастье

-ancy constant – постоянный constancy – постоянство

-ence to differ – отличаться difference – отличие

-ency to depend – зависеть dependency – зависимость

-age to break – ломать breakage – поломка

Exercise 1. Образуйте существительные с помощью данных суффиксов. Переведите исходные и производные слова

-ist physic (s), telegraph, special, social

-ity equal, human, activ(e), relativ(e), productiv(e)

-er to read, to lectur(e), to report, to convert

-ness thick, black, great, rough

-ance import(ant), dist(ant)

-ment to measure, to develop

-ency effici(ent), to depend

Exercise 2. В выделенных словах укажите суффиксы существительных и переведите данные сочетания

The usage of a word; the simplicityof the equation; the expression of relativity; the roughness of the surface; temperature readings; atom structure; the solution of the problem; the productivityof a worker; the efficiency of the method; the equality of positions

Internet

Найдите в словаре и запишите транскрипцию следующих слов. Правильно прочитайте данные слова несколько раз вслух и постарайтесь запомнить их произношение

Defense, agency, initiate, survive, available, request, early, service, via, dial, accept, huge, expectation

Words to be learnt

The U.S. Defense Advanced Research Project Agency – американское агентство (управление) перспективных технологий (перспективного планирования научно-исследовательских работ) при Министерстве Обороны США

to initiate – выдвигать, начинать

objective – цель

internetting project – проект межсетевого взаимодействия

to embrace – охватывать

to survive – пережить

to device – придумывать, изобретать

request – просьба, запрос

to resemble – напоминать, быть похожим

it wasn’t until… that…- только в …

to share information – делиться информацией

early taker – первый потребитель

huge – гигантский

to hire – брать в аренду

superhighway – магистраль

to be phased out – быть замененным, вытесненным

to accept – принимать

to fall outside – выпасть из … (хода событий, истории, процесса)

to keep up to the minute with – быть в курсе … (событий, новостей и т.д.)

commodity – предмет потребления

Text

In 1973, the U.S. Defense Advanced Research Project Agency (DARPA) initiated a research program to investigate techniques and technologies for interlinking packet networks of various kinds. The objective was to develop communication protocols, which would allow networked computers to communicate transparently across multiple, linked packet networks. This was called the Internetting project and the system of networks which emerged from the research was known as the “Internet”. The system of protocols, which was

developed over the course of this research effort, became known as the TCP/IP Protocol Suite: Transmission Control Protocol (TCP) and Internet Protocol (IP).

The Internet, a global computer network which embraces millions of users all over the world, began in the United States as a military experiment. It was started by the US Department of Defense for research into networking sometime in 1969. It was designed to survive a nuclear war. Information sent over the Internet takes the shortest path available from one computer to another.

Many people wanted to put their ideas into the standards for communication between the computers that made up this network, so a system was devised for putting forward ideas. Basically they wrote your ideas in a paper called a “Request for Comments” (RFC for short), and let everyone use it. People commented on and improved their ideas in new RFCs. The first RFC was written on April 7^th, 1969 – this is probably the closest thing to a “start date” for the Internet. There are now over 2000 RFCs, describing every aspect of how the Internet functions.

ARPANET was opened to non-military users later in the 1970s, and early takers were the big universities – although at this stage it resembled nothing like the Internet we know today. International connections (i.e. outside America) started in 1972, but the Internet was still just a way for computers to talk to each other and for research into networking there was no World-Wide-Web and e-mail as we know it. It wasn’t until the early to mid 1980s that the services we use most now started appearing on the Internet. The concept of «domain names», things like ‘www.microsoft.com.’ (Microsoft’s web server), wasn’t even introduced until 1984 – before that all the computers were just addressed by their IP addresses (numbers). Most protocols for e-mail and other services appeared after this.

The part of the Internet most people are probably most familiar with is the World-Wide-Web. This is a collection of hyperlinked pages of information distributed over the Internet via a network protocol called HTTP (hyper-text-transfer-protocol). This was invented by Tim Berners Lee in 1989. He was a physicist working at CERN, the European Particle Physics Laboratory, and wanted a way for physicists to share information about their research – the World-Wide-Web was his solution. So the web started, although at this time it was text only. Graphics came later with a browser called NCSA Mosaic. Both Microsoft’s Internet Explorer and Netscape were originally based on NCSA Mosaic.

The graphical interface opened up the Internet to novice users and in 1993 its use exploded as people were allowed to dial-in to the Internet using their computer

at home and a modem to ring up an “Internet Service Provider” (ISP) to get their connection of this (now huge) network. Before this the only computers connected were at Universities and other large organizations that could afford to hire cables between each other to transfer the data over – but now anyone could use the Internet and evolved into Information Superhighway that we know and (possibly) love today.

Electronic mail was introduced in 1972 by Ray Tomlinson. NCP was phased out by a new communications protocol technology—Transmission Control Protocol/Internet Protocol (TCP/IP) which was created by Bob Kahn and Vint Cerf in1973. It was accepted by the U.S. government in 1978, and became de facto networking standard in 1983. More networks began to pop up in the 1980s. Educational and commercial organizations that fell outside the original charter wanted to use the same packet-switching technologies. And the system came to be known as the Internet during this period. It had far exceeded its original purpose, and was providing the impetus for a vast technological revolution that was just ahead.

Today people can search thousands of databases and libraries worldwide in several languages, browser through hundreds of millions of documents, journals, books, and computer programs, and keep up to the minute with wire-service news, sports, and weather reports. An increasing number of people shop, bank, and pay bills on the Internet. Many people invest in stocks and commodities online. It’s a powerful symbol of society’s expectations about the future—fast-moving technology that adds convenience and efficiency to their lives.

Задание I. Выберите правильный ответ на вопрос по тексту:

1. What did DARPA initiate?

a) internetting project

b) TCP/IP protocol Suite

c) a research program for internetting packet networks

2. What was a reason of creation the Internet?

a) to talk with each other

b) to survive a nuclear war

c) to send an important information

3. What could people do in the RFCs?

a) comment and improve their ideas of communication

b) get acquaintance

c) write letters

4. Who were the early takers of Internet?

a) the Russian Department of Defense

b) civil users

c) big universities and large organizations

5. Why did Tim Bernes Lee invent the WWW?

a) to become famous

b) to earn his living

c) to share information about physicists’ research

6. What was introduced by Ray Tomlinson?

a) graphical interface

b) electronic mail

c) browser

Задание II. Используя слова и комбинации слов из текста, выделите главную мысль каждого абзаца своими собственными 2-3 предложениями на английском языке. Предложения должны быть краткими, логичными, связанными друг с другом.

Задание III. Выполнив все упражнения, будьте готовы побеседовать по теме «Интернет» на английском языке в группе.

Unit 20.

Grammar Revision

Вы можете значительно облегчить процесс чтения, если поймете, как образуются многие английские слова.

Основа слова — его корень, основной элемент, который сохраняется для всех производных.

Префикс — элемент слова, который ставится перед корнем.

Суффикс — элемент слова, который ставится после корня слова. Префикс обычно изменяет значение слова, а суффикс — часть речи.

В таблице приведены наиболее употребительные префиксы и суффиксы глаголов.

Exercise. Переведите следующие глаголы на русский язык, обращая внимание на суффикс или префикс. Проверьте себя по словарю.

Unpack, dislike, reconstruct, misunderstand, enlarge, decontrol, overpay, undervalue, trans-ship, dictate, widen, simplify, crystallize, distrust, strengthen, populate, disarm, misinform, enrich, unload.

Cellular Communication

History

Найдите в словаре и запишите в тетрадь транскрипцию данных слов. Прочитайте их вслух несколько раз.

Duplex, paging, coverage, accessories, wire, enhance, version, vehicle, assign, sequence.

Words to be learnt

сellphone (сellular phone) — сотовый телефон

cell site — узел сотовой связи

subscriber — aбонент

as opposed to…- в отличие от…, в противоположность чему-то

to handoff (to handover) — передать, переадресовать

coverage area — зона действия, зона покрытия

wireless — беспроводной (радио)

to page — перелистывать, передавать сообщение

rotary dial — дисковый номеронабиратель

to require — требовать

switchboard — панель управления, коммутатор

to enhance — увеличить, повысить, улучшить

operational reliability — надежность в эксплуатации

rival — конкурент, противник

to introduce — вводить, внедрять

simultaneous — одновременный

spread-spectrum — с широким диапазоном

to assign — назначать, устанавливать

jamming — помехи при приеме, глушение радиопередач

to foil — мешать, расстраивать (планы)

broadband network — широкополосная сеть

Text

A mobile phone or mobile (also called cell phone and hand phone) is an electronic device used for mobile telecommunications (mobile telephony, text messaging or data transmission) over a cellular network of specialized base stations known as cell sites. Mobile phones differ from cordless telephones, which only offer telephony service within a limited range, e.g. within a home or an office, through a fixed line and a base station owned by the subscriber and also from satellite phones and radio telephones. As opposed to a radio telephone, a cell phone offers full duplex communication, automatised calling to and paging from a public land mobile network (PLMN), and handoff (handover) during a phone call when the user moves from one cell (base station coverage area) to another. In addition to the standard voice function, current mobile phones may support many additional services, and accessories, such as SMS for text messaging, email, packet switching for access to the Internet, gaming, Bluetooth, camera with video recorder and MMS for sending and receiving photos and video, MP3 player, radio and GPS.

In 1908, U.S. Patent 887,357 for a wireless telephone was issued to Nathan B. Stubblefield of Murray, Kentucky. He applied this patent to «cave» radio telephones and not directly to cellular telephony as the term is currently

understood. Cells for mobile phone base stations were invented in 1947 by Bell Labs engineers at AT&T and further developed by Bell Labs during the 1960s. Radiophones have a long and varied history going back to Reginald Fessenden’s invention and shore-to-ship demonstration of radio telephony, through the Second World War with military use of radio telephony links and civil services in the 1950s, while hand-held mobile radio devices have been available since 1973. A patent for the first wireless phone as we know today was issued in US Patent Number 3,449,750 to George Sweigert of Euclid, Ohio on June 10, 1969.

In 1960, the world’s first partly automatic car phone system Mobile System A (MTA) |MTA was launched in Sweden. With MTA, calls could be made and received in the car to/from the public telephone network, and the car phone could be paged. The phone number was dialed using a rotary dial. Calling from the car was fully automatic, while calling to it required an operator. The system was developed by Sture Laurén and other engineers at Televerket network operator. Ericsson provided the switchboard while Svenska Radioaktiebolaget (SRA) owned by Ericsson and Marconi provided the telephones and base station equipment. MTA phones consisted of vacuum tubes and relays, and had a weight of 40 kg. In 1962, a more modern version called Mobile System B (MTB) was launched which used transistors in order to enhance the telephone’s calling capacity and improve its operational reliability.

In 1971 the MTD version was launched, opening for several different brands of equipment and gaining commercial success. Martin Cooper, a Motorola researcher and executive is considered to be the inventor of the first practical mobile phone for hand-held use in a non-vehicle setting. Cooper is the first inventor named on «Radio telephone system» filed on October 17, 1973 with the US Patent Office. Using a modern, if somewhat heavy portable handset, Cooper made the first call on a hand-held mobile phone on April 3, 1973 to a rival, Dr. Joel S. Engel of Bell Labs.

In 1945, the zero generation (0G) of mobile telephones was introduced. Like other technologies of the time, it involved a single, powerful base station covering a wide area, and each telephone would effectively monopolize a channel over that whole area while in use. The first «modern» network technology on digital 2G (second generation) cellular technology was launched by Radiolinja (now part of Elisa Group) in 1991 in Finland on the GSM standard. GSM, short for Global System for Mobile Communications, is one of the leading digital cellular systems. GSM uses narrowband TDMA, which allows eight simultaneous calls on the same

radio frequency. GSM was first introduced in 1991. As of the end of 1997, GSM service was available in more than 100 countries and has become the de facto standard in Europe and Asia. The first SMS text message was sent from a computer to a mobile phone in 1992 in the UK, while the first person-to-person SMS from phone to phone was sent in Finland in 1993.

The first mobile news service, delivered via SMS, was launched in Finland in 2000. In 2001 the first commercial launch of 3G (Third Generation) was again in Japan by NTT DoCoMo on the WCDMA standard. CDMA, short for Code-Division Multiple Access, a digital cellular technology that uses spread-spectrum techniques. Unlike competing systems, such as GSM, that use TDMA, CDMA does not assign a specific frequency to each user. Instead, every channel uses the full available spectrum. Individual conversations are encoded with a pseudo-random digital sequence. CDMA consistently provides better capacity for voice and data communications than other commercial mobile technologies, allowing more subscribers to connect at any given time, and it is the common platform on which 3G technologies are built. CDMA is a military technology first used during World War II by English allies to foil German attempts at jamming transmissions. The allies decided to transmit over several frequencies, instead of one, making it difficult for the Germans to pick up the complete signal. Because Qualcomm created communications chips for CDMA technology, it was privy to the classified information. Once the information became public, Qualcomm claimed patents on the technology and became the first to commercialize it.

The next evolution that recently was released is the 4th generation, also known as Beyond 3G , with the aim to offer broadband wireless access with nominal data rates of 100 Mbit/s to fast moving devices, and 1 Gbit/s to stationary devices defined by the ITU-R 4G systems may be based on the 3GPP LTE (Long Term Evolution) cellular standard, offering peak bit rates of 326.4 Mbit/s. It may perhaps also be based on WiMax or Flash-OFDM wireless metropolitan area network technologies that promise broadband wireless access with speeds that reaches 233 Mbit/s for mobile users. By 2022 it is expected that wireless companies will launch 4G Broadband networks.

Задание I. Ответьте на следующие вопросы:

1. What is a cellphone?

2. What is a cell site?

3. What is the difference between a cellphone and any other types of telephones?

4. What are additional services of a cellphone?

Задание IIa) Найдите в тексте информацию о том, каким событием отмечен тот или иной год в истории развития сотовой связи. Особое внимание обратите на следующие годы:

1945, 1947, 1960, 1962, 1969, 1971, 1973, 1991, 1992, 1993, 2000, 2001 и 2022.

б) Расскажите историю развития сотовой связи, предварительно составив план, состоящий из указания года и нескольких ключевых слов.

Например: In 1908- the first patent

was issued

“cave” radio telephone

In 1908 the first patent for a wireless telephone was issued. It was applied to ‘cave’ radio telephone.

Unit 21.

Grammar Revision

Наиболее употребительные префиксы и суффиксы прилагательных и наречий:

Exercise 1. Образуйте наречия от следующих прилагательных.

Easy (просто), usual (обычно), special (особо), north (к северу), regular (регулярно), functional (функционально), home (к дому), main (главным образом), sea (к морю).

Exercise 2. При помощи таблицы подберите подходящий суффикс или префикс к данным словам и образуйте прилагательные. Проверьте себя по словарю.

Form, to insist, value, element, to compare, wax, violet, fruit, Atlantic, important, Scott, hope, to act, complete, fame, brown, possible, economy, essential, human, historic, town, revolutionary, imperialist, sun.

Cellular Communication

Найдите в словаре и запишите в тетрадь транскрипцию данных слов. Прочитайте их вслух несколько раз.

Occupy, entire, height, audio, cause, portion, feature, routing, certain.

Words to be learnt

single- один, одиночный

to hold (held, held) — поддерживать, удерживать

entire- полный, целый, весь

pitch- модуль, высота (звука)

to cause- вызывать, быть причиной

sample- образец, пример

recovered signal- восстановленный сигнал

to distort- искажать

to deliver- доставлять, снабжать

landline- линия проводной связи

to store- накапливать, запасать

feature- особенность, характеристика

call forwarding- динамическая переадресация вызова

debit card- платежная карта

routing element- трассировочный элемент

predominant- преобладающий, доминирующий

interim- промежуточный, временный

Text

Many different types of systems have provided city-wide two-way communications, such as radio systems for taxis or the police. In these systems, a single antenna is located near the center of the city. Each two-way conversation occupied one channel so if there were 100 channels in the city, only 100

simultaneous conversations could be held. To cover the entire city, the antenna is placed on a tall building and emits a very strong signal. In the cellular phone system, the city is divided into smaller sections, or cells. Each cell contains its own antenna and uses only a subset of all the channels. Each antenna is lower in height and emits a much weaker signal so that the same subset of channels can be used in a cell somewhere else within the city.

Cellular telephone systems can be «analog» or «digital». Older systems (AMPS, TACS, NMT) are «analog» and newer systems (GSM, PCS) are «digital». The major difference is in how the audio signal, e.g. your voice, is transmitted between the phone and base station. «Analog» and «digital» refer to this transmission mechanism. In either system, the audio at the microphone always starts out as a voltage level that varies continuously over time. High frequencies (high pitch) cause rapid changes and low freqs cause slow changes. With analog systems, the audio is modulated directly onto a carrier. This is very much like (if not identical) to FM radio where the audio signal (in that case music) is translated to the RF signal. With digital systems, the audio is converted to digitized samples at about 8000 samples per second or so. The digital samples are numbers that represent the time-varying voltage level at specific points in time. With analog transmissions, interference (RF noise or some other anomaly that affects the transmitted signal) gets translated directly into the recovered signal. The neat thing about digital is that the 1s and 0s can not be easily confused or distorted during transmission, plus extra data is typically included in the transmission to help detect and correct any errors.

The cellular network operates on a combination of network hardware and software to operate. They are:

Mobile Base Stations — otherwise known as the cell site. The radio signal of each cell site covers a portion of a service area. A service area can have hundreds of cell sites.

Mobile Switching Centers (MSC) — The MSC connects the voice path for a call. The MSC and cell site work together to determine which radios the mobile phone will use when delivering calls. It interprets the digits entered by the mobile phone user and delivers the call accordingly. As the mobile subscriber moves to new cell site areas, the MSC reconnects the call to a new radio in that cell. It provides the path to the public switched telephony network (PSTN), for delivering calls to land-

line phones or to long-distance numbers. There can be many MSCs in a single service area.

Home Location Register (HLR) — The HLR is a database where the subscriber’s feature profile is stored. It will keep information on the subscribers phone number, the electronic serial number of the mobile phone, and the features the customer has (call forwarding, call waiting, 3-way calling, voice mail, etc.). The HLR is a software element. It can be an integral part of the MSC, or stored on a separate platform.

Service Control Point (SCP) — The SCP holds databases that control customer features and services. The HLR is a primary example of a database on the SCP. Some other examples include 800-number lookup services, calling card services, calling number identification, short message service, message waiting indicator, and debit card services.

Signal Transfer Point (STP) — The STP is a network routing element. It takes a message in, checks the routing information, and sends the message toward its destination. STPs use the signaling system seven (SS7) protocol to transport messages.

Protocols — Data messages are formatted in a way that allows switches and network elements to understand them. The formatting follows certain rules and these rules are called a protocol. The predominant protocols used in roaming networks are signaling system seven (SS7), and interim standard-41 (IS-41). We also use X.25 packet switched data, global system for mobile communications (GSM), Ethernet, and the transmission control protocol/internet protocol (TCP/IP) for messaging.

Задание. Выпишите из соответствующих абзацев текста ключевые слова, которые помогут вам:

— объяснить принцип действия системы сотовой связи;

— рассказать о различиях между аналоговыми и цифровыми системами связи;

-перечислить и дать краткую характеристику элементов, составляющих сеть сотовой связи.

Unit 22.

Grammar Revision

Исходная форма Сравнительная Превосходная

степень степень

односложные short shorter the shortest

и некоторые короткий короче самый короткий

двусложные easy easier the easiest

прилагательные лёгкий легче самый лёгкий

и наречия late later latest

поздно позднее позднее всего

двусложные и important more important the most important

многосложные важный более важный, самый важный

прилагательные важнее

и наречия easily more easily most easily

легко легче легче всего

Прилагательные и наречия, образующие степени сравнения не по правилу

Исходная форма Сравнительная степень Превосходная степень

Good-хороший better-лучше the best-наилучший

Well-хорошо better-лучше best-лучше всего

Bad-плохой worse-хуже the worst-наихудший

Badly-плохо worse-хуже worst-хуже всего

Many-много more-больше, более the most-наибольший

Much-много more-больше most-больше всего

Little-маленький less-меньше, менее the least-наименьший

Little-мало less-меньше least-меньше всего

Far- далекий farther-более отдаленный the farthest-самый отдаленный

Far-далеко further-дальше further-дальше всего

Exercise 1. Переведите предложения

1. This classroom is larger and lighter than other classroom. It is the largest and the lightest room here.

2. The red line of this drawing is shorter than other lines. It is the shortest line.

3. Mathematics is more important for technical students than many other subjects. It is one of the most important subjects at any technical institute.

4. The results of his last experiment were worse than before. He got the worst results this time.

Exercise 2. Поставьте данное в скобках слово в нужной степени сравнения

1. The (good) time to see Venus is spring.

2. Mercury is the (little) planet in our solar system.

3. We gave the (many) possible pressure.

4. The pressure in the boiler is (little) than it is necessary.

5. Silver is the (good) conductor of electricity. Gold conducts the electricity (bad) than silver.

GPS

Найдите в словаре и запишите транскрипцию следующих слов. Правильно прочитайте данные слова несколько раз вслух и постарайтесь запомнить их произношение

Precisely, identify, circling, maintenance, weapon, engage, surveyor, missile, munitions, guidance, reconnaissance

Words to be learnt

precisely identify – точно определить

by measuring – путем измерения

ongoing maintenance – постоянно ведущиеся эксплуатационные работы

military application – военное применение

troop deployment – расположение войск

recreational – прогулочный, развлекательный, для отдыха

surveyor – наблюдатель

weapon – оружие

commonplace – привычная вещь

emergency roadside assistant – помощь при аварии на дорогах

to span – охватывать, включать

saving – сбережения, спасение

to flag – сигнализировать

hostile – вражеский, неприятельский

howitzer – гаубица

reconnaissance – разведка, рекогносцировка

detonation – взрыв, детонация

to keep track – проследить

turning – хронирование

unmanned monitoring station – автоматическая станция

master control station – ведущая станция контроля

uplinks – спутниковый канал связи

Text

Global Positioning System is a network of satellites that continuously transmit coded information, which makes it possible to precisely identify locations on earth by measuring distance from the satellites. GPS stands for Global Positioning System, and refers to a group of U.S. Department of Defense satellites constantly circling the earth. The satellites transmit very low power radio signals allowing anyone with a GPS receiver to determine their location on Earth.

This remarkable system was not cheap to build, costing the U.S. billions of dollars. Ongoing maintenance, including the launch of replacement satellites, adds to the cost of the system. GPS actually predates the introduction of the personal computer. The designers originally had a military application in mind. The first satellite navigation system, Transit, used by the United States Navy, was first successfully tested in 1960. It used a constellation of five satellites and could provide a navigational fix approximately once per hour. In 1967, the U.S. Navy developed the Timation satellite which proved the ability to place accurate clocks in space, a technology that GPS relies upon. In the 1970s, the ground-based Omega Navigation System, based on phase comparison of signal transmission from pairs of stations, became the first worldwide radio navigation system. The design of

GPS is based partly on similar ground-based radio navigation systems, such as LORAN and the Decca Navigator developed in the early 1940s, and used during World War II. The military applications of GPS span many purposes:

• Navigation: GPS allows soldiers to find objectives in the dark or in unfamiliar territory, and to coordinate the movement of troops and supplies. The GPS-receivers that commanders and soldiers use are respectively called the Commanders Digital Assistant and the Soldier Digital Assistant.

• Target tracking: Various military weapons systems use GPS to track potential ground and air targets before they are flagged as hostile. These weapon systems pass GPS co-ordinates of targets to precision-guided munitions to allow them to engage the targets accurately. Military aircraft, particularly those used in air-to-ground roles use GPS to find targets.

• Missile and projectile guidance: GPS allows accurate targeting of various military weapons including ICBMs, cruise missiles and precision-guided munitions. Artillery projectiles with embedded GPS receivers able to withstand accelerations of 12,000g’s or about

117,600 meters/second2 have been developed for use in 155 mm howitzers.

• Search and Rescue: Downed pilots can be located faster if they have a GPS receiver.

• Reconnaissance and Map Creation: The military use GPS extensively to aid mapping and reconnaissance.

• The GPS satellites also carry a set of nuclear detonation detectors consisting of an optical sensor (Y-sensor), an X-ray sensor, a dosimeter, and an electromagnetic pulse (EMP) sensor (W-sensor) which form a major portion of the United States Nuclear Detonation Detection System.

Fortunately, an executive decree in the 1980s made GPS available for civilian use also. Land-based applications are more diverse. The scientific community uses GPS for its precision timing capability and a myriad of other applications. Surveyors use GPS for an increasing portion of their work. GPS offers an incredible cost savings by drastically reducing setup time at the survey site. It also provides amazing accuracy. Basic survey units can offer accuracies down to one meter. More expensive systems can provide accuracies to within a centimeter! Recreational uses of GPS are almost as varied as the number of recreational sports

available. GPS is becoming increasingly popular among hikers, hunters, snowmobilers, mountain bikers, and crosscountry skiers, just to name a few. GPS is rapidly becoming commonplace in automobiles as well. Some basic systems are already in place, providing emergency roadside assistance at the push of a button (by transmitting your current position to a dispatch center).

The NAVSTAR system (the acronym for Navigation Satellite Timing and Ranging, the official U.S. Department of Defense name for GPS) consists of a space segment (the satellites), a control segment (the ground stations), and a user segment (you and your GPS receiver).The space segment, which consists of at least 24 satellites (21 active plus 3 operating spares) is the heart of the system. The satellites are in what’s called a «high orbit» about 12,000 miles above the Earth’s surface. Operating at such a high altitude allows the signals to cover a greater area. The satellites are arranged in their orbits so a GPS receiver on earth can always receive from at least four of them at any given time. The «control» segment does what its name implies — it «controls» the GPS satellites by tracking them and then providing them with corrected orbital and clock (time) information. There are five control stations located around the world — four unmanned monitoring stations and one «master control station». The four unmanned receiving stations constantly receive data from the satellites and then send that information to the master control station. The master control station «corrects» the satellite data and, together with two other antenna sites, sends («uplinks») the information to the GPS satellites. The user segment simply consists of you and your GPS receiver. As mentioned previously, the user segment consists of boaters, pilots, hikers, hunters, the military and anyone else who wants to know where they are, where they have been or where they are going.

Задание I. Выберите правильное утверждение и выучите его наизусть:

1. a) GPS is a network of satellites transmitting coded information to identify locations on Earth

b) GPS is a system of stations for measuring distance from the satellites

c) GPS is a network for monitoring satellite data

2. a) GPS actually predates the introduction of Internet

b) GPS actually predates the introduction of radar technology

c) GPS actually predates the introduction of the personal computer

3. a) The designers of GPS originally had commercial purposes in mind

b) The designers of GPS originally had educational application in mind

c) The designers of GPS originally had a military application in mind

4. a) Military aircraft can’t use GPS to find targets

b) GPS allows soldiers to find commanders

c) Various military weapons systems use GPS to track potential ground and air targets before they are flagged as hostile

5. a) GPS is popular among hikers, hunters, snowmobilers, mountain bikers and cross-country skiers.

b) GPS is not used for recreational uses

c) GPS is commonplace in automobiles in Russia

6. a) The NAVSTAR consists of the satellites

b) The NAVSTAR consists of the ground stations

c) The NAVSTAR consists of a space segment (the satellites), a control segment (the ground stations), and a user segment (you and your receiver)

Задание II. Задайте в группе все возможные виды вопросов, используя предложения, данные в задании I .

Задание III. Выполнив все задания, будьте готовы побеседовать по теме «GPS» на английском языке с группой и с преподавателем

Unit 23.

Grammar Revision

Сравнительные конструкции

При сравнении двух действий, которым присущ один и тот же признак, и с прилагательными и с наречиями, употребляется парный союз as … as

This plane moves asquickly Этот самолет движется так же быстро,

asthe sound does как и звук (т.е. со скоростью звука)

Сочетание as well asможет, наряду со сравнительной конструкцией, быть составным союзом так же, как (и). Сравните:

He knows mathematics as well as Он знает математику так же хорошо,

his friend does как и его друг

The English system of weights Английская система весов

was used in England as well as применялась в Англии так же,

in a number of other countries как и в ряде других стран

В сравнительной конструкции the (more) … the (better)артикли, стоящие перед прилагательными или наречиями в сравнительной степени, переводятся чем … тем:

The higherthe temperature, Чем выше температура,

the more rapidis the motion тем быстрее движение

of the molecules молекул

Exercise. Переведите предложения, обращая внимание на сравнительные конструкции

1. No planet is as hot as the Sun.

2. The speed at which the Earth revolves round the Sun is nearly as high as that of Venus.

3. The nearer the Earth, the denser the atmosphere.

4. The more experiments scientists make, the greater is their knowledge of the structure of matter.

5. Gold is not so light as aluminium.

6. A solid has length as well as width.

7. The bigger the mass, the bigger the weight of the body.

8. The stronger the magnet, the greater the distance through which it acts

9. Metals as well as minerals are of great importance in industry.

10. The nearer the centre of the Sun, the higher the temperature.

Galileo – European Satellite Navigation System

Найдите в словаре и запишите транскрипцию следующих слов. Правильно прочитайте данные слова несколько раз вслух и постарайтесь запомнить их произношение

Compliant, redundancy, negotiations, efficient, revenue, capturing, coverage, reliability, unfettered, envisage, genuine

Words to be learnt

to improve – улучшать

compliant – согласованный

requirement – требование

redundancy – достаточность, избыточность

integrity – целостность

high precision navigation – высокоточная навигация

public obligations – обязательства перед обществом

intense negotiations – активные переговоры

validation – соглашение, утверждение

to justify – оправдывать

capturing – овладение, захват

impediment – препятствие, задержка

reliability – надежность

implementation – осуществление, выполнение

to comply with – уступать, подчиняться, соглашаться

unfettered – неограниченный, нестесненный

to concern with – заниматься чем-либо, иметь дело с чем-либо

to gather pace – ускорять темп

constellation – набор (созвездие)

to envisage – предназначать, предусматривать

launcher – пусковая установка

Text

Europe is moving closer to the launch of its satellite navigation system Galileo. This will lead to a fully civilian controlled global satellite navigation system, with much improved navigation services and a certified positioning service. It is fully compliant with ICAO’s requirements for satellite navigation systems. The overall benefits include redundancy and integrity to meet the safety requirements of civil aviation and help the foil introduction of satellite navigation for all phases of flight. Whilst the battle with GPS is likely to be bitter, in the end

these two systems will benefit each other and massively extend the role of satellite navigation.

Galileo is an initiative of the European Union, in collaboration with the European Space Agency and European Industry, to launch a European financed global satellite navigation system under civilian control. Current work aims to develop the architecture and design required to provide high precision navigation, position, timing and integrity information to meet both user needs and public obligations, such as safety for all transport modes.

Galileo is proposed as a Public Private Partnership formed between the European Union, ESA and a consortium of private companies. The PPP partners include Astrium, Alcatel Space, Alenia Spazio and Thales. Galileo is, naturally enough, still a subject of intense negotiation and debate between the EU and its commercial partners, with the EU Council of Ministers pressing for a single and efficient management structure. Galileo is also a part of the EU’s wider strategic plan for space exploitation, which includes its program for Global Monitoring, Environment and Security (GMES). Although largely a European program, Galileo will also involve much international cooperation e.g. with the Russian Federation (on frequency sharing and validation).The calculated benefits and the direct and indirect revenues from Galileo are expected to be substantial, fully justifying Europe’s commitment. Galileo is very much a commercial initiative aimed at capturing a significant share of the satellite navigation market.

Galileo is a system that will benefit all modes of transport including road, rail, sea and air travel. Galileo will, in particular, result in real and direct benefits to civil aviation. The clearest of these is the fact that satellite navigation will become a fully redundant service for civil aviation users in the event of a satellite failure. The number of satellites in view will grow dramatically and become fully independent in the case of failure to either GPS or Galileo. Galileo will work with GPS to provide greatly improved satellite coverage and availability, ensuring that sufficient satellites are always in view to obtain an optimal navigation solution. This has been one of the major impediments of a GPS only system and one stumbling block to the potential wider benefits that satellite navigation could offer civil aviation, but which it has not so far been able to deliver.

Certified services will also be offered, with guaranteed service levels (in terms of accuracy, redundancy, integrity, reliability and availability) and a more robust signal in space. This will enable the global implementation of ICAO’s CNS/ATM

concept. These benefits will bring satellite navigation forward as a realistic replacement for conventional navigation aids in civil aviation. Despite the fact that satellite navigation has been with us for some time and that airlines have made significant investments, there has been, so far, relatively little return in terms of improved navigation services to airlines. Galileo looks set to change this and accelerate the introduction and benefits of satellite navigation for civil aviation Users. Galileo also complies with the need for civil aviation services to be free and unfettered, a fundamental requirement enshrined in the ICAO convention.

The definition phase of Galileo is already complete. The current phase is concerned with the detailed design and development of the full Galileo system. The schedule for Galileo will gather pace with a Galileo Test-Bed to be launched as piggyback payload on a next generation GLONASS satellite. Following this, the ‘In-Orbit Validation’ phase will begin, deploying a small constellation of satellites. An initial operational capability consists of twelve satellites. There is a definite «window of opportunity» for Galileo and it is believed that any delay in fully operational launching Galileo will lead to significant damage to Europe’s entry into the mass navigation market. Hence there are strong incentives for the launch of Galileo to be brought forward.

Galileo consists of a constellation of 30 satellites in Medium Earth Orbit (MEO) only. The 30 Galileo satellites are 3 orbital planes inclined at 54° and at an altitude of around 23,000 km. This is the simplest system to launch, operate and maintain and one that provides the greatest reliability for an operational service. Galileo satellites weigh around 650 kg when in orbit and generate approximately 1,500 watts of electrical power. The satellite geometry has been designed for the launch of multiple satellites with an Ariane launcher. Smaller launchers are envisaged for the replacement of individual satellites. A lot of sophisticated technology will go into Galileo, including highly advanced atomic clocks -giving greater accuracy and stability and being light weight with low power requirements. Sophisticated (next generation) electronics and the latest high performance antennas will be incorporated into the satellite, to generate the signal-in-space.

The implementation of Galileo is a welcome improvement to navigation services. Galileo vastly improves the accuracy, redundancy, integrity, reliability and availability of satellite navigation. It provides certified services and a level of integrity not achievable with GPS. More than anything else, it enables the full exploitation of satellite navigation for the benefit of civil aviation and hastens the

implementation of ICAO’s CNS/ATM concept. This leads to genuine improvements for all phases of flight and a significant safety benefits.

Задание I. Выберите правильный ответ в соответствии с содержанием текста.

1. What is Europe moving to?

a) redundancy and integrity of European Union

b) a fully civilian control of ICAO

c) the launch of its satellite navigation system Galileo

2. What does current work aim to provide?

a) safety for all phases of flights

b) comfort and design

c) high precision navigation, position, timing and integrity information

3. What does Galileo plan include?

a) intense negotiation and debate

b) ESA and a consortium of private companies

c) program for Global Monitoring, Environment and Security

1. What is Galileo?

a) a military strategy

b) a commercial initiative

c) a state plan

2. Where is Galileo used in?

a) in all modes of transport

b) in all types of satellite stations

c) in all kinds of ground stations

3. In what cases will satellite navigation become a fully redundant service for civil aviation users?

a) in the case of a spacecraft absence

b) in the event of global war

c) in the event of a satellite failure

4. Why will Galileo work with GPS?

a) to get some benefits

b) to ensure integrity

c) to provide improved satellite coverage and availability

5. What certified services are offered by Galileo?

a) the help in the case of failure

b) a significant share of the satellite navigation market

c) accuracy, redundancy, integrity, reliability and availability

6. What does Galileo consists of?

a) 30 ground stations

b) 54 electrical power stations

c) satellites

7. What are envisaged (offered) for the replacement of individual satellites?

a) spacecrafts

b) rockets

c) small launchers

Задание II. Сформулируйте основную мысль каждого абзаца в виде кратких, логичных (от 1 до 3) своих собственных высказываний на английском языке

Задание Ш. Выполнив все задания, будьте готовы побеседовать по теме на английском языке в группе и с преподавателем

Unit 24.

Grammar Revision

Форма глагола — сказуемого в страдательном залоге (см. Units 10, 11) образуется следующим образом:

to be Participle II

В английском языке существуют так же конструкции в страдательном залоге:

Present Infinitive: eg. My car needs to be serviced soon.

Мою машину скоро нужно ремонтировать.

Perfect Infinitive: eg. Му сar should have been serviced last month.

Мою машину нужно было отремонтировать в

прошлом месяце.

-ing form: eg. I insist on my car being serviced today.

Я настаиваю, чтобы мою машину отремонтировали

сегодня.

Modals: eg. My car must be serviced before the weekend.

Моя машина должна быть отремонтирована до

выходных.

Exercise. Переделайте предложения из действительного залога в страдательный, используя конструкции в страдательном залоге.

1. She must write all the letters till tomorrow morning.

2. They were to send the documents yesterday but they didn’t.

3. I dream to paint my car red.

4. They can pass the exams without bad marks.

5. It is necessary to install this equipment as soon as possible.

GLONASS

Найдите в словаре и запишите в тетрадь транскрипцию данных слов. Прочитайте их вслух несколько раз.

Government, alternative, Chinese, European, ascending, roughly, equator, sidereal, weight, cesium.

Words to be learnt

to complete- завершать, выполнять

to fall into disrepair- прийти в негодность

spares- запчасти

ascending node- восходящий узел

approximately- примерно, приблизительно

displacement- перемещение, смещение

altitude- высота над уровнем моря

latitude- широта (геогр.)

substantially- существенно, в значительной мере; главным образом

span- объем, размах, диапазон

aft- хвостовая часть

payload- полезная нагрузка

array- многовибраторная сложная антенна

booster- ракета- носитель; стартовый двигатель

to make use of- использовать

to undertake- предпринимать

Text

GLONASS (GLObal’naya NAvigatsionnaya Sputnikovaya Sistema; «GLObal NAvigation Satellite System» in English) is a radio-based satellite navigation system, developed by the former Soviet Union and now operated for the Russian government by the Russian Space Forces. It is an alternative and complementary to the United States’ Global Positioning System (GPS), the Chinese Compass navigation system, and the planned Galileo positioning system of the European Union (EU).

Development on the GLONASS began in 1976, with a goal of global coverage by 1991. Beginning from 12 October 1982, numerous rocket launches added satellites to the system until the constellation was completed in 1995. Following completion, the system rapidly fell into disrepair with the collapse of the Russian economy. Beginning from 2001, Russia committed to restoring the system, and in recent years has diversified, introducing the Indian government as a partner, and accelerated the program with a goal of restoring global coverage by 2009.

GLONASS was developed to provide real-time position and velocity determination, initially for use by the Soviet military for navigation and ballistic missile targeting. It was the Soviet Union’s second generation satellite navigation system, improving on the Tsiklon system which required one to two hours of signal processing to calculate a location with high accuracy. By contrast, once a GLONASS receiver is tracking the satellite signals, a position fix is available instantly. It is stated that at peak efficiency the system’s standard positioning and timing service provide horizontal positioning accuracy within 57–70 meters, vertical positioning within 70 meters, velocity vector measuring within 15 cm/s, and time transfer within 1 µs (all within 99.7% probability).

A fully operational GLONASS constellation consists of 24 satellites, with 21 used for transmitting signals and three for on-orbit spares, deployed in three orbital planes. The three orbital planes’ ascending nodes are separated by 120° with each

plane containing eight equally spaced satellites. The orbits are roughly circular, with an inclination of about 64.8°, and orbit the Earth at an altitude of 19,100 km (11,868 mi), which yields an orbital period of approximately 11 hours, 15 minutes. The planes themselves have a latitude displacement of 15°, which results in the satellites crossing the equator one at a time, instead of three at once. The overall arrangement is such that, if the constellation is fully populated, a minimum of five satellites are in view from any given point at any given time.

Over the three decades of development, the satellites themselves have gone through numerous revisions, separated here as generations. The name of each satellite was Uragan (English: hurricane), followed either by a number for operational satellites or by an acronym GVM (Russian: габаритно-весовой макет; English: size weight dummy) for test satellites.

The true first generation of Uragan (also called Glonass) satellites were all 3-axis stabilized vehicles, generally weighing 1,250 kg and were equipped with a modest propulsion system to permit relocation within the constellation. Over time they were divided into Block IIa, IIb, and IIv vehicles, with each block containing evolutionary improvements.Six Block IIa satellites were launched in 1985–1986 with improved time and frequency standards over the prototypes, and increased frequency stability. These spacecraft also demonstrated a 16-month average operational lifetime. Block IIb spacecraft, with a 2-year design lifetimes, appeared in 1987, of which a total of 12 were launched, but half were lost in launch vehicle accidents.

The second generation of satellites, known as Uragan-M (also called Glonass-M), were developed beginning in 1990 and first launched in 2001.These satellites possess a substantially increased lifetime of seven years and weigh slightly more at 1,480 kg. They are approximately 2.4 m (7 ft 10 in) in diameter and 3.7 m (12 ft) high, with a solar array span of 7.2 m (24 ft) for an electrical power generation capability of 1600 watts at launch. The aft payload structure houses 12 primary antennas for L-band transmissions. Laser corner-cube reflectors are also carried to aid in precise orbit determination and geodetic research. On-board cesium clocks provide the local clock source.A total of fourteen second generation satellites were launched through the end of 2007.

The third generation satellites are known as Uragan-K (also called Glonass-K) spacecraft. These satellites are designed with a lifetime of 10 to 12 years, a reduced weight of only 750 kg, and offer an additional L-Band navigational signal. As with

the previous satellites, these are 3-axis stabilized, nadir pointing with dual solar arrays. They will enter service in 2009.Due to their weight reduction, Uragan-K spacecraft can be launched in pairs from the Plesetsk Cosmodrome launch site using the substantially lower cost Soyuz-2 boosters or in six-at-once from the Baikonur Cosmodrome using Proton-K Briz-M launch vehicles.

The ground control segment of GLONASS is entirely located within former Soviet Union territory. The Ground Control Center and Time Standards are located in Moscow and the telemetry and tracking stations are in Saint Petersburg, Ternopol, Eniseisk, Komsomolsk-na-Amure.Septentrio, Topcon, JAVAD, Magellan Navigation, Novatel, Leica Geosystems and Trimble Inc produce GNSS receivers making use of GLONASS. NPO Progress describes a receiver called «GALS-A1» which combines GPS and GLONASS reception. SkyWave Mobile Communications manufactures an Inmarsat-based satellite communications terminal that uses both GLONASS and GPS.

With GLONASS falling rapidly into disrepair, a special-purpose federal program named «Global Navigation System» was undertaken by the Russian government on August 20, 2001. According to it, the GLONASS system was to be restored to fully deployed status (i.e. 24 satellites in orbit and continuous global coverage) by 2022.

Задание I. Задайте вопросы к предложениям, начиная их словами, предложенными в скобках.

1. GLONASS stands for GLObal NAvigation Satellite System. (What…for?)

2. GLONASS is a radio-based satellite navigation system. (What kind of…?)

3. The development of GLONASS began in 1976 in the Soviet Union. (When…?, Where…?)

4. Satellites constellation was completed in 1995. (When…?)

5. GLONASS was initially developed for the Soviet military navigation and ballistic missile targeting. (What …for?)

6. A fully operational GLONASS constellation consists of 24 satellites. (How many…?)

7. The name of each satellite of the system is Uragan. (What…?)

8. There are three generations of GLONASS satellites: Uragan, Uragan-M and Uragan-K. (How many…?)

9. The ground control segment of GLONASS is located within former Soviet Union territory. (Where…?)

10. According to the special- purpose federal program the GLONASS system is to be restored to fully deployed status by 2022. (When…?)

Задание II. a) Задайте составленные вами вопросы в группе.

b) Используя эти вопросы в качестве плана, расскажите о

GLONASS

Unit 25.

Grammar Revision

Условные предложения

Тип условного Условие Следствие

предложения (придаточное) (главное)

I тип – реальное условие, If he comes, I shall be glad

относится к будущему If he should come, I shall be glad

(без if) Should he come, I shall be glad

Если он придет, я буду рад

II тип – маловероятное If he came, I should be glad

условие, относится к настоя- If he should come, I should be glad

щему или будущему (форма Should he come, I should be glad

прошедшего времени с части- If he were to come, I should be glad

цей бы)Were he to come, I should beglad

Если бы он пришел, я был бы рад

(сегодня, завтра)

III тип – нереальное условие, If he had come, I should have been glad

относится к прошедшему Had he come, I should have been glad

(форма прошедшего времени Если бы он пришел, я был бы рад (вчера)

с частицей бы)

Союзы, вводящие условные предложения

If — если

In case – в случае

Provided (providing), on condition – при условии, в случае

Unless –если не …

But for –если бы не …

Exercise . Переведите следующие условные предложения

I. 1. If a solid body or a liquid is heated, it will usually expand.

2. The measurements were always correct provided the necessary instruments were used.

II. 1. Providing mercury did not expand when heated, it would not be used for taking temperatures.

2. But for electricity little could be done in a modern research laboratory.

III. 1. Provided the operator’s cabin had been equipped with electronic control, he would have been able to work faster and with greater precision.

3. The manned spaceships might not have been launched into the cosmos unless scientists had studied the information received from the space satellites.

Nanotechnology

Найдите в словаре и запишите транскрипцию следующих слов. Правильно прочитайте данные слова несколько раз вслух и постарайтесь запомнить их произношение

Successful, either, precision, approach, dimension, time-consuming, thread, issue, occur, average, flexibility, influence

Words to be learnt

to fulfill – выполнять

attempt – попытка, усилие

ultimate goal – окончательная цель

precision – точность

proof – доказательство

approach – подход, направление, способ

to strive – стараться,

simple logic gates – логичная манера поведения, образ действия

assembly – сборка, сбор

time-consuming – долговременный

three-dimensional – трёхмерный

to thread – проходить сквозь

to shrink – сжимать(ся)

feedback – обратная связь

relevant – относящийся к делу, подходящий

double-helical structure – двух-спиральная структура

strand – скрученная полоска, нить

backbone – основа, сущность; позвоночник

to occur – получаться, случаться, происходить

adjacent bases – смежные, близлежащие основы

Text

There is already one highly successful nanotechnological system: we call it life. All the goals of nanotechnology are already fulfilled in living systems, and most of our attempts at nanotechnological applications can be called biomimetic, either applying the structural principles of living systems to different compounds or using the compounds of living systems for different purposes.

Nanotechnology can be defined as the development and use of devices that have a characteristic size of only a few nanometers. The ultimate goal is to fabricate devices that have every atom in the right place. Such technology would give the opportunity to minimize the size of a device and to reduce the material, energy and time necessary to perform its task. Potential applications include electrical circuits, mechanical devices and medical instruments. Molecular biology is a source of inspiration in this field of research: Living cells can synthesize a wide variety of macromolecules with atomic precision, that all have a specific function in the cell. This can be considered as the proof that there are no physical laws that forbid the construction of structures with atomic precision.

Essentially, there are two approaches towards the fabrication of structures at or near the atomic level: The first is the ‘top down’ approach where the precision of existing macroscopic techniques is improved. This concept has been demonstrated in semiconductor industry, where lithographic processes are nowadays used to make integrated circuits with critical dimensions smaller than 100 nm. This precision will be improved further, but true atomic precision cannot be obtained with this approach. The second ‘bottom up’ approach strives to build structures using atoms or molecules as building blocks. Most striking are experiments where individual atoms are positioned on an atomically flat substrate using scanning-probe techniques. Patterns of atoms have even been demonstrated to act as simple logic gates. Such scanning-probe techniques however are not very practical: Assembly by placing a single atom at a time is a very time-consuming process.

A particularly interesting ‘bottom up’ approach is to assemble structures from molecular building blocks. Using synthetic chemistry, large amounts of identical building blocks can be obtained at low cost. One of the most promising ideas is to use building blocks from living systems: The advantages are that these molecules are intensively studied and that they can be synthesized with atomic precision. Moreover, DNA building blocks have been used to assemble three-dimensional structures from small synthetic building blocks.

This thesis describes experiments where we use silicon nanotechnology to address the physical properties of individual molecules. A first set of experiments probes the polymer dynamics of DNA threading through small pores. In order to fabricate holes with a diameter on the order of the diameter of DNA we have developed a new technique to controllably shrink larger silicon oxide pores with direct visual feedback. We have also addressed the question whether a single DNA molecule can carry an electrical current. This is an important issue for potential DNA-based electronics. The last topic is electrochemistry using nanometer-scale electrodes, fabricated using silicon processing. A standing goal is to develop the technology to perform electrochemical experiments on a single molecule.

Most experiments in this thesis are performed on DeoxyriboNucleic Acid (DNA). This section contains a brief review of the relevant properties of this unique molecule. The structure and function have been intensively studied and the basics can be found in many biological textbooks. It consists of two polymer chains. Each monomer consists of a sugar ring, a phosphate group, and one of the four bases Adenine (A), Guanine (G), Thymine (T) or Cytosine (C). Watson and Crick were the first to determine the double-helical structure of DNA. They found that DNA consists of two strands, running anti-parallel. On the outside are the sugar-phosphate chains, also known as the ‘backbone’ of the molecule. On the inside of the helix are the bases, occurring in specific pairs: Adenine (A) specifically binds to Thymine (T) and Guanine (G) to Cytosine (C). From X-ray diffraction experiments on fibers of DNA, Watson and Crick were able to deduce the double helical structure.

The structure as reported by Watson and Crick became known as the ‘B-DNA’ helix. The diameter is about 2 nm and the distance between two bases is 0.34 nm. Each 10.4 bases or 3.6 nm, DNA makes a full helical turn. The structure is stabilized by the base-specific hydrogen bonds between the strands and the hydrophobic interactions between adjacent bases. This B-DNA helix is the structure for DNA with a mixed sequence at physiological conditions. It should be

noted that these properties are averaged over many subunits, and that the structure can vary with temperature, buffer conditions and the local sequence of bases. An intriguing property of double-strand DNA is its moderate flexibility: It can be smoothly bent or twisted with very little influence on the helical properties. An important property for our work is the fact that DNA in solution is highly charged at neutral pH. Each phosphate group on the backbone has a negative charge, resulting in a linear charge density of 5.9 e per nanometer. The effective charge density however is considerably lower due to countering condensation.

Задание I. Расставьте вопросы в соответствии с содержанием текста

1. What are two approaches towards the fabrication of structures at or near the atomic level?

2. What is the reason of development a new technique of fabrication holes with the diameter of DNA?

3. What is important issue for potential DNA-based electronics?

4. What is the most successful nanotechnological system?

5. What is the structure of Watson and Crick stabilized by?

6. When can the structure vary?

7. What is intriguing property of double-strand DNA?

8. How can nanotechnology be defined?

9. What does DNA molecule consists of?

10. Who determined DNA as the double-helical structure?

Задание II. Задайте данные в предыдущем упражнении вопросы «по цепочке» в группе

Задание III. Будьте готовы побеседовать по теме «Nanotechnology» с преподавателем и с группой

Indefinite Past Indefinite Participle II Перевод

1. to be was, were been быть, находиться

2.to bear bore born рождать

3.to beat beat beaten бить

4.to become became become становиться

5.to begin began begun начинаться

6.to break broke broken ломать, разбивать

7.to bring brought brought приносить

8,to broadcast broadcast; -ed broadcast; -ed передавать, вещать

9.to build built built строить

10.to burn burnt burnt гореть, жечь

11.to buy bought bought покупать

12.to catch caught caught ловить, хватать

13.to choose chose chosen выбирать

14. to come came come приходить

15..to cost cost cost стоить

16.to cut cut cut резать

17.to deal (with) dealt (with) dealt (with) иметь дело с

18.to do did done делать

19.to draw drew drawn рисовать, чертить

20.to dream dreamt; -ed dreamt; -ed мечтать

21.to drink drank drunk пить

22.to drive drove driven управлять

23.to eat ate eaten есть

24.to fall fell fallen падать

25.to feed fed fed кормить, питать

26.to feel felt felt чувствовать

27.to fight fought fought сражаться

28.to find found found искать, находить

29.to fly flew flown летать

30.to foresee foresaw foreseen предвидеть

31.to forget forgot forgotten забывать

32.to freeze froze frozen замораживать

33.to get got got получать

34.to give gave given давать

35.to go went gone идти, ехать

36.to grow grew grown расти

37.to hang hung hung висеть, вешать

38.to have had had иметь

39.to hear heard heard слышать

40.to hold held held владеть

41.to keep kept kept хранить

42.to know knew known знать

43.to lay laid laid класть

44.to lead led led приводить к

45.to learn learnt; -ed learnt; -ed изучать

46.to leave left left покидать

47.to let let let позволять

48.to lie lay lain лежать

49.to light lit (lighted) lit (lighted) освещать

50.to lose lost lost терять

51.to make made made выполнять

52,to mean meant meant значить

53.to meet met met встречать

54.to overcome overcame overcome преодолевать

55.to pay paid paid платить

56.to put put put класть

57.to read read read читать

58.to ring rang rung звонить

59.to rise rose risen вставать

60.to run ran run бежать

61.to say said said сказать

62.to see saw seen видеть

63.to sell sold sold продавать

64.to send sent sent отправлять

65.to set set set устанавливать

66.to shine shone shone блестеть

67.to show showed shown; -ed показывать

68.to sit sat sat сидеть

69.to sleep slept slept спать

70.to speak spoke spoken говорить

71.to spend spent spent проводить

72.to split split split расщеплять

73.to spread spread spread распространять

74.to stand stood stood стоять

75.to strike struck struck ударять

76.to swim swam swum плавать

77.to take took taken брать

78.to teach taught taught учить, обучать

79.to tell told told рассказывать

80.to think thought thought думать

81.to throw threw thrown бросать

82.to undergo underwent undergone подвергаться

83.to understand understood understood понимать

84.to wake woke; -ed woken;-ed просыпаться

85.to wear wore worn носить

86.to win won won выигрывать

87.to withstand withstood withstood противостоять

88.to write wrote written писать

Оглавление (Contents)

Введение 3

Unit 1. Личные местоимения. Глагол to be 5

My University and my profession. 8

Unit 2. Оборот there be 12

The Russian Army 14

Unit 3. Глагол to have 19

The British Army 21

Unit 4. Глагол to do 25

The United States Army 27

Unit 5. Форма английского глагола 31

Radio 33

Unit 6. Времена группы Indefinite (Simple) действительного залога (Active Voice) 37

History of Radar 39

Unit 7. Времена группы Continuous (Progressive) действительного залога 43

Radar as a Weapon 46

Unit8. Времена группы Perfect (Active Voice) 48

Radar Components 53

Unit 9. Времена группы Perfect Continuous (Active Voice) 54

Radar Types 56

Unit 10. Времена группы Indefinite страдательного залога (Passive Voice) 61

Communication Satellite 63

Unit 11. Времена группы Continuous и Perfect (Passive Voice) 66

Military Satellite 68

Unit 12. Модальные глаголы 72

Laser 75

Unit 13. Эквиваленты модальных глаголов 79

Antenna 82

Unit 14. Имя числительное 85

Radar Antenna 90

Unit 15. Повелительное наклонение 93

Radar Receiver (part I) 97

Unit 16. Инфинитив 99

Radar Receiver (part II) 102

Unit 17. Герундий 105

Radar Receiver (part III) 107

Unit 18. Причастие 110

Optical technology 115

Unit 19. Словообразовательные суффиксы существительных 118

Internet 122

Unit 20. Cловообразовательные суффиксы глаголов 124

Cellular Communication. History 126

Unit 21. Cловообразовательные суффиксы прилагательных 130

Cellular Communication 133

Unit 22. Степени сравнения прилагательных и наречий 135

GPS 138

Unit 23. Сравнительные конструкции 142

Galileo 144

Unit 24. Конструкции в страдательном залоге 150

GLONASS 152

Unit 25. Условные предложения 156

Nanotechnology 159

Список неправильных глаголов 162