Английский язык. Практикум по чтению научно-популярных текстов

CHAPTER 3. SUPPLEMENTARY READING

Text 1. ENERGY

Read the text paying attention to the way energy is produced. Give the definitions to different forms of energy.

The structure of matter cannot be explained completely in terms of material particles alone. It is necessary to make use of another concept which takes into account the relations of the particles to one another and the extent to which they are in motion. This concept is known to be energy. A system is said to possess energy if it is able to do work. Work is done when the point of application of a force moves. If a force of 1 dyne (дина) moves 1 cm along its line of action 1 unit of work is done. This unit is known as the erg (эрг). Work is done in many processes and may be calculated as the product of two factors if this product is expressible in ergs.

Energy is a physical quantity that describes the amount of work that can be performed by a force. Energy which can be released from a system in the performance of work must previously have been stored in some manner within the system. The energy of a system may depend either on the relative positions of parts of it or on the motions of parts of the system. Energy due to position is potential energy; energy due to motion is kinetic energy. There are some other forms of energy: thermal, gravitational, sound, light, elastic, and electromagnetic. The forms of energy are often named after a related force. Any form of energy can be transformed into another form, but the total energy always remains the same.

Text 2. OUR ELECTRONIC WORLD

Read the text and find out the information about the main electronic devices. Use a dictionary if necessary.

Electronics is the tool of today. It has given us radar, automation, space vehicles, radio telescopes and a host of other inventions that have transformed our lives.

Electronics means putting electrons to work. An electron is one of the particles in an atom and travels at incredible speed round the nucleus. Also of the first importance are the facts that the electron has a negative charge, the nucleus has a positive one.

Many devices are used in our life. For example, transformers, transform or change one voltage to another, or perform other useful functions.

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A transistor is a device made from a semiconductor material, e.g. a tiny slice of germanium or silicon. It allows a small current (between base and emitter) to control a large current (between emitter and collector). It is used in TV, in computers and in many other devices.

In cathode ray tubes, an electron beam is deflected by an electric or a magnetic field and passes over the face of the tube. These tubes are employed in TV receivers, oscilloscopes and other equipment.

Electronic devices can send us information from satellites and space vehicles. Radio telescopes scan the heavens, gathering information from distances far beyond the range of visual observation.

Radar bounces radio signals off distant objects and uses the echo to give information on their distance and direction. Sonar in ships uses sound-wave echoes for depth sounding.

Solar cells produce a current when they are illuminated, giving power for space instruments. Light-sensitive diodes and transistors respond to light-pulses and control electric circuits by light. Other diodes produce light under the influence of an electric current. In fact, the skill of the electronics engineer makes electrons in motion an almost magical tool.

The science of electronics has revolutionized science and industry. It is bringing ever wider and faster changes. Computers can digest masses of statistics almost on the instant or perform mathematical calculations with breathtaking speed. Electronic devices can soar with space vehicles through unimaginable distances, can probe and examine and send back pictures and reports from outer space. Everywhere electronics is at work – for example, in medicine, building, accountancy, metallurgy, telecommunications, manufacturing, industry, etc.

Electronics is a fascinating world which electronics engineers are eager to explore as they carry out their researches.

Ex. 1. Complete the following statements by choosing the answer which you think fits best. Explain your choice.

1.An electron is one of the particles in an atom

a)which travels at high speed within the nucleus;

b)which has no charge;

c)which moves very fast around the nucleus;

d)the mass of which is about one tenthousandth the size of an atom.

2.A transistor is a device that

a)can send us information from space vehicles;

b)makes a small current control a large one;

c)transforms one voltage to another;

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d)produces a current when it is illuminated.

3.Electronics has revolutionized science and industry because

a)it means putting electrons to work;

b)it is a fascinating world which engineers are eager to explore;

c)it has given people a host of inventions and devices that have changed their lives;

d)it can gather information from distances far beyond the range of visual observation.

Ex. 2. Here are some answers to some questions about the text. Work out the questions.

1. An electron travels at incredible speed round the nucleus. 2. A transistor is made from semiconductor materials. 3. No, the cathode ray tubes are employed in TV receivers and other equipment. 4. Radar bounces radio signals off distant objects. 5. Solar cells produce a current when they are illuminated. 6. Computers can perform mathematical calculations with extreme speed. 7. Electronics has revolutionized science and industry.

Ex. 3. Answer the following questions, then render the text.

1. Why is electronics the tool of today? 2. What electronic devices are described in the text? 3. Where are transistors employed? 4. How are radars and sonars used? 5. When do solar cells produce a current? 6. How can electronic devices be used for exploring space? 7. Where is electronics at work now?

Text 3. DEVELOPMENT OF SEMICONDUCTOR DEVICES

Read the text concentrating on

1)the semiconductor devices widely used in modern technology;

2)the scientists working in the field of semiconductors.

It is mainly since the Second World War that semiconductors have been studied and developed on a large scale. But they are not new. Some of the properties which are now associated with semiconductors have been known for a century or more.

In 1833 Michael Faraday reported that silver sulfide exhibited a negative temperature coefficient of resistance. Another interesting date is 1873, when a technical assistant of W. Smith, testing underwater telegraph cables, found that the high resistance he was using varied considerably according to the amount of light falling on it.

The resistor was made of semiconductor selenium. And so it was discovered that selenium conducts electricity better in light than in darkness.

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The late 1920s (nineteen twenties) and middle thirties saw the appearance of selenium power rectifiers. The 1930s and early forties witnessed the development of thermistors, several types of diodes, rectifiers and photocells and the greatly increased application of all these devices. A great contribution to the study of semiconductor physics has been made by the prominent Soviet and Russian scientist A.P. Ioffe. It was in 1930s that Ioffe and his co-workers started a systematic research of semiconductor physics. Ioffe put forward the supposition that semiconductors could be used for the direct conversion of heat and light into electric power.

A new industry – helioengineering – has emerged. Nowadays solar batteries are successfully operating on sputniks and spaceships. Having contributed much to the theory of semiconductors Ioffe showed the continuously increasing technical importance of semiconductor devices. The most important among the semiconductor devices, the transistor, was invented in 1948. The invention and continuing development expanded the use of semiconductor devices of all kinds. Semiconductor devices are used in measuring technique, automatics, computers, radio and TV sets, etc., with greater economy of cost, space and power, than other devices such as vacuum tubes and relays.

Ex. 4. Complete the following statements by choosing the answer which you think fits best. Explain your choice.

1.Semiconductors are not new as they have been widely studied and developed since

a)1873;

b)the early forties of the 20th century;

c)the late nineteen twenties.

2.W. Smith’s technical assistant discovered that the high resistance he was using while testing the cable varied according to

a)the increase of temperature;

b)the increase of pressure;

c)the increase of illumination.

3.The greatly increased application of rectifiers, photocells, several types of diodes began in

a)1833;

b)the early forties;

c)the middle thirties.

4.In 1930 Ioffe and his co-workers began a systematic research of

a)a negative temperature coefficient of resistance;

b)electrical properties of selenium in light;

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c) physics of semiconductors.

5. Ioffe put forward the idea that semiconductors could be used for

a)transforming heat and light into electric power;

b)testing underwater telegraph cables;

c)exhibiting a negative temperature coefficient of resistance.

Ex. 5. Here are some answers to some questions about the text. Work out the questions.

1. It is mainly since the Second World War that semiconductors have been developed on a large scale. 2. Yes, solar batteries are successfully operating an sputniks and spaceships nowadays. 3. No, the transistor, the most important among the semiconductor devices was invented in 1948. 4. It was discovered that selenium conducts electricity better in light than in darkness. 5. Selenium power rectifiers appeared in the late nineteen twenties. 6. No, Ioffe and his co-workers started a systematic research of semiconductor physics only in 1930. 7. Nowadays semiconductor devices are widely used instead of vacuum tubes due to their greater economy of cost, space and power.

Ex. 6. Answer the questions, then render the text.

1. What scientists studied the properties associated with semiconductors? 2. What did Michael Faraday report in 1833? 3. Why were the first resistors made of semiconductor selenium? 4. When did the first semiconductor devices appear? 5. Who made a great contribution to the study of semiconductor physics? 6. Why are semiconductor devices widely used nowadays?

Text 4. SOME FACTS ABOUT CRYSTALS

Read the text and find out

1)the differences between the modifications of a simple cubic lattice;

2)the requirements that a good quality crystal must meet.

A characteristic feature of semiconductors is that they are crystalline. The atoms or molecules making up a crystalline structure are grouped according to definite geometrical patterns. This pattern is known to be a space cubic lattice. The simple cubic lattice contains atoms lying in the corners of a cube and at no other position.

There are modifications of this simple system: one is known as the body-centered cubic lattice, the other is the face-centered cubic lattice. In the former atoms are located in the corners of the cube and one atom is in its center. In the latter atoms are located in the corners of the cube and at

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the center of each face. Crystal particles are held together in the spacing by strong attractive forces. Besides those common types of relatively simple structures there exist a number of more complex ones having a cubical unit cell. The most important of these is the diamond cubic which is the structure taken by silicon, germanium and gray tin as well as by diamond. The basic bond pattern is a tetrahedral bond so that each atom has four nearest neighbours bound to it by valence-binding forces.

A good quality crystal must meet certain prescribed standards. A crystal may be considered good if it is clear with no inclusions, cracks, twinned growth structures or any other growth faults. The crystal surface must be planar and smooth without steps. Besides these general requirements there are also some special demands connected with the purpose of growing crystals. Accordingly, the crystals may be semiconductors, piezoelectric crystals or crystals with special mechanical, optical, electrical or electron optical properties.

The techniques that have been used most successfully for growing semiconductor crystals can be divided into three groups: growth from the melt, from the solution and from the vapour phase.

Ex. 7. Agree or disagree with the statements given below.

1. The atoms and molecules making up a semiconductor are grouped according to the definite patterns. 2. In the simple cubic lattice atoms lie in the center of the cube. 3. In the body-centered cubic lattice the atoms are located only at the corners of the cube. 4. Silicon and germanium have a cubical unit cell in which the basic bond pattern is a tetrahedral bond. 5. In tetrahedral bond atoms are located at the corners of the cube and at the center of each face. 6. A crystal is considered to be good if it meets certain prescribed standards. 7. There exhibits only one technique of crystal growth namely growth from the solution.

Ex. 8. Answer the following questions.

1. What is a characteristic feature of semiconductors? 2. How are atoms and molecules arranged in a crystalline structure? 3. What is the arrangement of atoms in a simple cubic lattice and in its modifications? 4. What structure do silicon and germanium have? 5. How are the atoms arranged in the tetrahedral bond? 6. What standards must a good quality crystal meet? 7. What techniques of crystal growth are used?

Ex. 9. Make up the plan of text 4. Render the text using the key-words given below.

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A characteristic feature, to make up, to be grouped, to be arranged, according to, a definite geometrical pattern, a space cubic lattice, in the corners of the cube, at the center of each face, to be located, the diamond cubic structure, a tetrahedral bond, to meet certain standards, a good quality crystal, the techniques of crystal growth.

Text 5. RADAR

Translate the text in writing using a dictionary if necessary.

An interesting application of lasers appears to be in the field of aviation safety. A serious hazard to flight is clear air turbulence (CAT) – powerful air currents or waves in the atmosphere that can toss a plane out of control. This type of clear air turbulence cannot be seen on the pilot’s radar scope since his radar is sensitive to storm turbulence. However, there are minute particles of dust and ice crystals concentrated in the turbulent clear air that might be detectable by a laser beam. They are too small to reflect the waves of a normal radar but they would reflect the much shorter wavelength of a laser beam. Thus an airplane equipped with a laser radar could detect CAT from a safe distance.

An important operation in space travel is the meeting or docking of two spacecraft. They cannot be brought together with a lot of bumps or they are likely to be knocked out of orbit. A very precise knowledge of the relative speeds of the vehicles is required and they must be brought together slowly. Claims have been made that with a laser radar, velocities can be measured precisely from 5 miles per second to 0.0001 inch per second. This is accurate enough to permit the space vehicles to dock softly enough to prevent any harmful bumping.

Text 6. LASER APPLICATIONS

Read the text and find the answers to the following questions.

1.What fields of industry can lasers be used in?

2.Why is laser so effective for welding and metal cutting?

3.What are the advantages of using laser for metal cutting and spot welding?

The varied applications of lasers by no means indicate the limits to which this device will be used but rather show the many areas of technology affected. The laser in particular is being applied in so many areas that applications given can only partially indicate its usefulness. In its short lifetime it has been applied in many fields including the following: com-

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munications, surgery, metal cutting and welding, radar, physics, power transmission, photography, high temperature studies, ignition system.

Welding and Metal Cutting. Experiments have shown that the laser can be used effectively for welding. By passing the laser beam through a lens system, an extremely high energy density can be focused in a very small area. The coherency of the light beam permits this high degree of focusing. It appears that the laser will be most useful for spot welding with the electronic beam welder or resistance welder continuing to perform seam welds. Some of the advantages in using the laser for spot welding are: 1) no physical contact with the material being welded, 2) welding can be accomplished in air (electron beam welding requires a vacuum), 3) very little rise in temperature in the area surrounding the weld and 4) a variety of metals have been successfully welded. Spot welding demanding a precise and delicate connection is natural for the laser. Welding transistor junctions, thermocouples and electronic micromodules are examples of the precise work which the laser can perform. Another interesting aspect of welding with the laser is that it is possible to weld a joint even after the joint has been sealed inside a glass envelope.

With some minor change in control, the same types of laser that perform welding can be used for cutting and burning metal just as in the welding application.

The main uses for the laser in metal cutting are in precision work. Experiments have succeeded in punching holes on the order of 005-inch diameter in sheets of metal. The laser has also succeeded in cutting holes in diamond, one of the hardest materials.

The application of the laser to metal working has made possible welding and cutting that previously was performed only by complicated electron beam devices or photographic etching. Eventually the lasers will be safer, quicker, cheaper and easier.

Text 7. PLASTICS AS ELECTRICAL CONDUCTORS

Translate the text in writing using a dictionary if necessary.

Semiconduction has been observed in more than 200 types of plastics or polymers. Plastics, long considered excellent electrical insulators, have now been made to conduct electricity even as well as some metals.

Midway between the metals carrying an electric current very well and insulators not carrying it at all, the new semiconducting plastics have properties used in certain electronic devices, particularly those operating at high temperatures.

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Desalting of seawater and other large scale chemical transformations may be possible with semiconducting polymers because of their unique combination of large surface area, semiconducting properties and the reactive chemical sites along their chainlike molecules. They could operate much as a water softener does in removing salts from water.

Semiconduction occurs in the new materials by a fundamentally different process from that occurring in the materials in common use as transistors. This difference is shown by their insensitivity to small amounts of impurities.

Best known polymers in the form of plastics and synthetic fibers are compounds with extremely long molecules. Molecules of the new polymers have many units of unsaturation (like those in unsaturated fats) arranged in a special way which permits them to carry an electric current.

Materials synthesized in the present study are not the semiconducting polymers to be prepared. However, the present work represents the first extensive study of a whole family of polymers of known structure and good ability to carry a current.

Text 8. ELECTRONIC INK – REVOLUTION IN

INFORMATION TECHNOLOGY

Scan the text and find the answers to the following questions.

1.How did the invention of paper influence the development of mankind?

2.Does paper have any advantages over computers?

3.What is the objective of creating E-Ink?

With a world full of electronic displays made with liquid crystals, light-emitting diodes and gas plasma, we probably don’t think of paper as being a revolutionary display technology, but the Chinese invention of paper in 105 A.D. forever changed the way the world communicates. Without it, books might still be printed on silk rolls, making literacy an expensive skill. It would be nearly impossible to live one day without coming into contact with paper in some form. This year, for example, the world will consume an estimated 280 million tons of paper.

For nearly 2 000 years, ink on paper was the only way to display words and images, and it still beats computer displays when it comes to portability and price. Paper also doesn’t require an external power supply. Yet it does have some limitations: once printed on paper, words cannot be changed without at least leaving some marks, and it is also difficult to carry around a large number of books.

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Scientists are developing a revolutionary technology that could replace paper, called electronic ink. It will allow us to carry a whole library in one book. E-Ink technology aims at creating a digital book that can type-set itself and that readers could leaf through just as if it were made of regular paper. Such a book could be programmed to alternate between up to 10 books stored on the device. Just as electronic ink could readily change the way we read books, it could change the way we receive our daily newspaper. Simply pressing a button on the delivery computer will simultaneously update thousands of electronic newspapers each morning.

Electronic ink has several advantages over current display technology, including: low power usage, flexibility and readability. E-Ink uses 50 to 100 times less power than liquid crystal displays because it only needs power when changing the display. E-Ink can be printed on any surface, including walls, product labels and T-shirts. We shall soon be able to change our digital wall paper by sending a signal to the electronic ink painted on the walls. Another advantage electronic ink has over traditional computer displays is its readability. It looks more like printed text, so it’s a lot easier on the eyes. Moreover, it saves trees by cutting the demand on paper!

Text 9. HOW E-INK WILL WORK

Translate the text in writing using a dictionary if necessary.

Electronic ink is a new material that will have far-reaching impact on how society receives its information. This patented material is processed into a film for integration into electronic displays. The principal components of electronic ink are millions of tiny microcapsules, about the diameter of a human hair. Each microcapsule contains positively charged white particles and negatively charged black particles suspended in a clear liquid.

When a negative electric field is applied, the white particles move to the top of the microcapsule where they become visible to the user. This makes the surface appear white at that spot. At the same time, an opposite electric field pulls the black particles to the bottom of the microcapsules where they are hidden. By reversing this process, the black particles appear at the top of capsule, which now makes the surface appear dark at the spot. To form an E-Ink electronic display, the ink is printed onto a sheet of plastic film that is laminated to a layer of circuitry. The circuitry forms a pattern of pixels controlled by a display driver. These microcapsules are suspended in a liquid ‘carrier medium’ allowing them to be printed onto

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