I. Read and translate the text.
FUTURE OF ELECTRONICS
Electronics is believed to be a rather young and a very promising science. It has become a powerful means of progress. Electronics has widened our vision and given us the chance to see the microworld more clearly.
Electron-optical image converters using solid-state components penetrate deep into opaque2 materials, convert invisible radiations to visible, and pick up3 light of negligible intensity. Radiotelescopes are known to collect and to focus the radio waves emitted by celestial bodies4, revealing new facts about the universe. Of course, radio waves are not the only carriers of information in space.
Modern science knows many more media, which can be employed for this purpose. These are the infrared and ultraviolet radiations, X- and gamma rays, elementary particles and fields, ect. What role will electronics play in space travel? Above all, it will give a deep insight into the properties of outer space.
Radio is thought to help man to know more about the Suns atmosphere of many planets, the location, the speed of huge hydrogen clouds in space, and the processes accompanying the collisions galaxies5. Electronics is expected to enable the astronauts to locate their position in space.
Spaceships will be guided automatically just as planes are controlled by robots today. Electronics is sure to give the space pilots easy control for soft landing on other planets. Collision-warning radars will operate automatic control if there is a danger of meteor hitting the spaceship. Before all this can be accomplished, however, many complicated problems will have to be solved. One problem is that of extending the range of radio communication in outer. With proper refinements, radio communication is likely to be set up overdistances of 100 million kilometers or even more.
To ensure higher effectiveness and reliability of communication many thousands of scientific experiments were devoted to the investigations of these factors. All scientific achievements in the field of transmitting information over long distances being applied in the system of space communication, real possibilities are opened up transmitting tremendous amount of information over distances several hundred million kilometers.
It is expected that greater prospects for constructing even more effective systems for transmitting information in space will be opened with the application of methods and means of quantum electron and especially of quantum generators.
Vocabulary notes
1. converters n
2. pick up -
3. opaque adj , -pick up v
4. celestial bodies
5. collisions of galaxies
6. refinement n ()
II. Make the annotation.
TRANSISTORS
Transistors made it possible to design compact, small-dimensioned electronic devices which consume very little power. The transistors are used for direct transformation of heat energy into electrical energy by means of thermal elements. They are also used to transform radiant energy into electricity with the help of photocells or so called solar batteries. In later years light sources and lasers were built on the basis of transistors.
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Transistors revolutionized radio engineering and electronics. Having small size and other properties, transistors make it possible to produce devices which cannot be made with vacuum tubes. Transistors are extremely sensitive to external influences, thousandths of one per cent of admixtures changing their electrical conductive properties by hundreds of thousands times. They are very sensitive to the action of light, nuclear particles, pressure, etc.
Transistors being sensitive to light, engineers have to take this property into consideration. Some transistors act as insulators in the darkness, cadmium sulphide presenting one of them. But already under ordinary room temperature their resistances decrease millions of times. This property was used as the basis for making so called photoresistances. Some of them react not only to visible light but also to ultraviolet, infrared and X-rays, and radioactive radiation. At present such photoresistances, being very small in size, are successfully used as the main elements for various measuring instruments and automatic devices. The supply of transistors is inexhaustible. But up to now only a limited number of them is being used for engineering purposes. Semiconductors are germanium, silicon, selenium and some of the simple compounds, like lead sulphide and arsenic and phosphoruses with indium and gallium. The electrical properties of germanium may be changed, provided the latter is exposed to light.
A very fine technology has been developed for obtaining transistors with preset physical properties by introducing into them admixtures of gold, copper, nickel, zinc, etc. Scientists have had considerable success in developing special films which protect the transistor crystals from outer influences and change their properties, these films making it possible to create a new family of miniaturized instruments.
III. Translate the text in written form.
WHAT IS CYBERNETICS?
Cybernetics is hard to define. The word "Cybernetics" is known to have originated from the Greek meaning control. Cybernetics was defined by Wiener as "the science of control and communication, in the animal and the machine, coordination, regulation and control being its themes".
Scientists know cybernetics to be a theory of "machines", but it treats not things but ways of behaving. It does not ask: "What is this thing?" but "What does it do?"
Cybernetics started by being closely associated in many ways with physics. It deals with all forms of "behaviour" in so far as they are regular or determinated, or reproducible. It takes as its subject- matter the domain of "all possible machines". What cybernetic! is the framework1 on which all individual machines may be ordered, related and understood. It is known to have found many applications in different fields of science, technique and economics. It should be kept in mind2 that it offers a single vocabulary and single concepts suitable for representing the most diverse types of systems.
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Cybernetics offers one set of correspondences with each branch, science can thereby bring them into exact relation with one another. It has been found repeatedly in science that the discovery that branches are related leads to each branch helping in the development of the other, the result being often a markedly accelerated growth of both. The infinitesimal calculus3 and astronomy, the virus a protein molecules are examples that come to mind. Cybernetics is likely to reveal a great number of interesting and suggestive parallelisms between machine and brain and society. It can provide the common language by which discoveries in the branch can readily be made use of in the others.
Thus, cybernetics provides effective methods for the study, and control of systems that are intrinsically extremely complex. One function of cybernetics is to study the new techniques that are needed in order to enable the scientists to cope with the increasingly complex problems. It deals with ways of making machines; computers and systems operate similarly to the human brain or other biological systems in spite of the brain's being far more efficient than computers in solving certain problems.
Vocabulary notes
1 .framework n
2. it should be kept in mind
3. infinitesimal calculus
IV. Make the annotation.
HISTORY OF ELECTRONICS
Electronics is the science dealing with devices operated by cc of the movement of electric charges in a vacuum, in gases, or semiconductors; or with the processing of information or the control of energy by such devices. This definition covers the whole complex family of vacuum and gaseous electron tubes and their applications. It also includes metallic contact or semiconductor rectifiers and the transistors which utilize the control of electrons or positive charges (holes) to process information or to convert energy.
Electronics was born in the 19th century. Like hydrolysis chemistry has come into its own only recently. Electronics first established itself, however, in wireless telegraphy. Industrial applications of electronics include control gauging, counting, heating speed regulation, etc. But in a larger field, electronics leads to automatic control of large-scale industrial operations.
Today, electronics has started a new era. Electronic devices are doing simple, but human-like thinking. Some industries are controlled by electronic robots. Automation is the industrial keynote of the day. Planes and rockets are electronically controlled. Some radio telescopes work like radar to receive radio waves from outer space. Shortly speaking, electronics is not so much a new subject as a new way of looking at electricity.
V. Make the annotation.
SEMICONDUCTORS
A transistor is an active semiconductor device with three or more electrodes. By active we mean that the transistor is capable of current gain, voltage, amplification and power gain. A transistor is an electron device in which electronic conduction takes place within a semiconductor.
A semiconductor is an electric conductor with resistivity in the range between metals and insulators, in which the electrical charge carrier concentration increases with increasing temperature over some temperature range.
The resistivities of semiconductors and insulators decrease rapidly with rising temperatures, while those of metals increase relatively slowly. Unlike metals and insulators, the resistivity of semiconductors depends upon the direction of current flow. The direction of easiest current flow or lowest resistivity is called the forward direction, the direction of restricted current flow or highest resistivity is known as the reverse or back direction.
Semiconductors, such as the elements germanium and silicon, possess two types of current carriers, namely, negative electrons and positive holes. A hole is a mobile vacancy in the electronic valence structure of a semiconductor which acts like a positive electronic charge with a positive mass.
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VI. Translate the text in written form synoptically.
DIGIT THAT MEANS NOTHING
The introduction of the zero to the European mathematics was an essential contribution to modern technological development. The concept of symbolically representing "nothing" in a numerical system is considered to be one of man's greatest intellectual achievements.
Various peoples throughout the world have used systems of counting without having the zero. The classical Greeks used different letters of their alphabet to denote numbers from 1 to 10 and each of the multiples of 10. Any number not represented by a s symbol was expressed by the sum of the values of severs For example, the number 238 was indicated by writing symbols for 200, 30 and 8 adjacent to each other.
The Romans used fewer symbols to represent a more limited number of integers such as 1,5,10,50,100,500,1000 and the additive principle to a greater degree. Thus, in writing the number 238 nine individual symbols were required: CCXXXVIII
The zero of modern civilization had its origin in India A.D. By 800 A.D. its use had been introduced to Baghdad, from where it spread throughout the Moslem world. The zero with the rest of our "Arabic" numbers was known in Europe by the year of 1000 A.D., but because of the strong tradition of Roman numbers, there was considerable resistance to its adoption. The zero became generally used in Western Europe only in the IV century.
Including the Hindu the concept of the zero with its idea of positional value appears to have been independently arrived at in three great cultures which were widely separated in space and time. About 500 B.C. the Babylonians began to use a symbol to represent a vacant space in their positional value numbers. However, before the idea could be disseminated to other areas, its use apparently died out about 2000 years ago along with the culture that gave it birth.
The Mayas of Central America began using the zero beginning of the Christian era. They have been in possess zero for about a thousand years longer than the Spaniard general, the Mayas were more advanced in many as mathematics than their conquerors.
Modern civilization derives incalculable practical and theoretical benefits from the use of zero.
VII. Translate the text in written form synoptically.
FIRST MAN-MADE SATELLITES
For hundreds of years people have been dreaming flights. Yet the dream remained only a dream till 1957 when people sent up the first man-made satellites. The man-made satellites are flying laboratories, equipped with the latest instruments and apparatus. The purpose of these laboratories is to investigate various types of radiations as well as the effects of the state of weightlessness on the human organism in the upper layers of the atmosphere.
The satellites revolve round the Earth just like planets. Their motion is governed by the same laws that govern the Moon's revolution round the Earth and the motion of the Earth round the Sun. Had there been no Earth's gravitation, they would have moved through airless space in a straight line at a uniform speed. It is the gravitation that makes them move round the Earth.
The force of gravitation which affects the satellite has a definite value. To counter-balance this force the satellite must keep to its orbit if it moves at a given speed. This speed must be approximately eight kilometers per second if the satellite moves at a relatively small distance from the Earth's surface.
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The force of the Earth's gravitation decreases with the increase in the distance from the Earth. Therefore, a satellite moving along a higher orbit should have a lesser speed. If a satellite moved in different orbits all within a thousand kilometers from the Earth's surface the variations in the speed would be relatively small.
In order to be set on its orbit, the satellite has to be sent up at a great height and with the necessary speed. The satellite does not need any additional energy in order to move in its orbit. All it needs is the initial speed given it by the carrier rocket.
If the satellite's speed were much less than the necessary one, the satellite might drop and enter the denser layers of the atmosphere. It would lose its energy because of the friction of the air. If it dropped further and further, it would grow hotter and hotter and finally would burn up in the atmosphere.
The first satellite marked the beginning of the conquest of cosmic space. Now the day has come when manned space ships are leaving and will leave the Earth for distant planets, for distant worlds.
VIII. Translate the text in written form.
SUPERSONIC WAVES
The word "supersonic" means moving faster than sound. Sound waves travel with a definite speed in any elastic medium. A vibrating source of sound acts on the surrounding particles of the medium, creating compressions and rarefactions that spread out in alternate sequence through the whole area of the medium. The number of compressions and rarefactions following one another in the course of a second determine the pitch at which a sound is heard.
The human ear can register sounds to about 20,000 vibrations per second. Nature, however, has a much greater range of sounds than that. Science discovered the existence of these frequencies in the last century. They were called supersonic, and a method was worked out to produce them in laboratory conditions. At present, scientists in various countries are successfully creating instruments emitting supersonic waves of great intensity at frequencies of several hundred million vibrations per second.
One of the excellent properties of supersonic waves is their ability of penetrating metals, alloys and other materials to a great depth. With the help of supersonic detectors we can discover cavities, cracks and other internal faults in metal and ceramics at the depth of over 30 feet. The faults reflect supersonic waves that are recorded on the screen of an oscillograph in the form of an impulse indicating the position of the faults. By means of a supersonic apparatus the thickness of any ob can be measured with great accuracy. Special supersonic e sounders on board a ship help to determine the exact depth of sea, on every yard of the ship's course, underwater, rocks, reefs, and icebergs being discovered in the same way.
Supersonic waves may also be used to bore holes in hard brittle metals. Moreover, they are used of in breaking up and crushing various substances to produce fine emulsions of liquids and me such emulsions being now widely employed in different industries.
Supersonic waves are very sensitive, their speed changing if a medium contains even a small quantity of foreign matter. Special instruments having been constructed on this basis, it became possible to control chemical reactions and technological processes with great precision.
Under the influence of supersonic waves the minute particles of a hard substance in a gaseous medium join together, forming larger particles that fall out of the medium. This principle forms the basis of a method of cleaning smoky air.
Scientists are working on problems connected with the physical nature of supersonic waves and their application in science and everyday life. It is to be hoped that in a few years from now this will bring us many discoveries of still greater importance.
IX. Translate the text in written form synoptically.
RADAR
The word "radar" means Radio Determination and Ranging. Radar equipment is capable of determining by radio echoes the presence of objects, their direction, range and recognizing their character.
There are several types of radar sets, all of them consisting of six essential components, namely: a transmitter, a receiver, an antenna system, and an indicator), a timer, and, of course, a power supply.
A radar set detects objects by sending out short powerful pulses of ultrahigh frequency radio wave energy from a highpower transmitter. The directional antenna takes this energy from the transmitter and radiates it in a beam (similar to that of a searchlight).
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As the transmitted energy strikes an object, a portion of it is reflected back. The receiver picks up the returning echo through its antenna and translates it into visual readable signals on a fluorescent screen. The appearance of these signals shows the presence of an object within the field of view of radar.
The electron beam sweeps across the fluorescent screen in somewhat the same way as a hand sweeps across the face of a clock. Just as the hand of a clock completes its sweep in sixty seconds, the electron beam can be made to travel across any desired portion of the screen in some predetermined interval of time. It is the timer, which is the synchronizer of the whole system, that times the transmitter pulse and the indicator. The use of these timed pulses and the fact that the radio waves travel at the constant velocity of light gives a simple means of measuring range. The accuracy with which time is measured determines the accuracy of the range.
How then is the direction in which an object lies to be found? Both azimuth and elevation can be determined by means of the directional antenna. The antenna may be rotated as the pulses are sent out and the strongest signal appears on the screen when the antenna points directly at the object. The direction of the antenna enables the determination of azimuth and elevation. Thus, with the help of a radar set we can get a three-dimensional location of an object.
The wide use of radar sets in our everyday life will make air and sea entirely safe. Radars may be installed on every ship at sea as well as in every large harbour. They will prevent collisions in fog and aid a ship to sail safely into any harbour, regardless of night or weather. Similarly airplanes will be able to fly over mountain ranges in storms and effect blind landing during poor visibility.
X. Translate the text in written form synoptically.
SEMICONDUCTORS1
The term "semiconductor1" means "half-conductor", that is, a material whose conductivity2 ranges between3 that of conductors and non-conductors or insulators.
They include great variety of elements (silicon, germanium, selenium, phosphorus and others), many chemical compounds (oxides4, sulphides5) as well as numerous ores6 and minerals.
While the conductivity of metals is very little influenced by temperature, conductivity of semiconductors sharply increases with heating and falls with cooling. This dependence has opened great prospects for employing semiconductors in measuring techniques.
Light, as well as heat, increases the conductivity of semiconducting materials, this principle being used in creating photo resistances. It is also widely applied for switching on engines, for counting parts on a conveyer belt, as well as various systems of emergency signals7 and for reproducing sound in cinematography. Besides reacting to light, semi-conductors react to all kinds of radiations and they are therefore employing in designing electronic counters.
Engineers and physicists turned their attention8 to semiconductors more than fifty years ago, seeing in them the way of solving complicated engineering problems. Converting heat into electricity without using boilers or other machines was one of them. This could be done as means of metal thermocouples, but in this way impossible to convert more one per cent of the heat into electricity. The thermocouples made later of conductors more generated ten times as much electricity as the metal ones.
Sunlight like heat can feed our electric circuit. Photocells made of semiconducting materials are capable of transforming ten per cent; of sunray energy into electric power. By burning wood, which has accumulated the same amount of solar energy, we obtained only heat fractions of one per cent of electric power.
The electricity generated by semiconductor thermocouples can produce not only heat but also cold, this principle being used in, manufacturing refrigerators.
Semiconducting materials are also excellent means of maintaining a constant temperature irrespective of the surrounding temperature changes. The latter can vary over a wide range, for example, from 50 below 0 to 100 above 0.
Semiconductors are the youngest field of physical science. Yet even now they are determining the progress of radio engineering, automation, chemistry, electrical engineering and many other fields of science and technique.
Vocabulary notes
1. semiconductor n
2. conductivity n
3. range between ( )
4. oxide n .
5. sulphide n
6. ore n
7. emergency signal
8. to turn one's attention (to) - ( -)
XI. Make the annotation.
SOURCES OF POWER
The industrial progress of mankind is based on power; power for industrial plants, machines, heating and lighting system, transport. In fact, one can hardlyfind a sphere where power is not required.
At present most of the power required of obtained mainly, from two sources. One is from burning of fossil fuels1, i.e.2 coal, natural gas and oil, for producing heat that will operate internal- and external-combustion engines3. Many of these engines will actuate generators, which produce electricity. The second way of producing electricity is by means of generators that get their power from steam of water turbines. Electricity so produced then flows through transmission lines to houses, industrial plants, enterprises, etc.
It should be noted, however, that the generation of electricity by these conventional processes is highly uneconomic. Actually, only about 40 per cent of heat in the fuel is converted into electricity. Besides, the world resources of fossil fuels are not everlasting. On the other hand4, the power produced hydroelectric plants5, even if increased many times, will be able to provide for only a small fraction of the power required in near future.
Therefore much effort and thought are being given to other means of generating electricity.
One is the energy of hot water. Not long ago we began utilizing hot underground water for heating and hot water supply, and in some cases, for the generation of electric power.
Another promising field for the production of electricity is the use of ocean tides6.
The energy of the Sun, which is being used in various ways, represents a practically unlimited source.
Using atomic fuel for the production of electricity is highly promising. It is a well-known fact, that one pound of uranium contains as much energy as there million pounds of coal, such cheap power can be provided wherever it is required. However, the efficiency reached in generating power from atomic fuel is not high, namely 40 per cent
No wonder, therefore, that scientists all over the world are doing their best7 to find more efficient ways of generating electricity directly from the fuel (without using intermediate cycles). They already succeeded developing some processes, which are much more efficient as high as 80 per cent, and in creating a number of devices capable of giving a higher efficiency. Scientists are hard at work trying to solve all these and many other problems.
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1. fossil fuels
2. i.e. (id est)
3. internal- and external-combustion engines
4. on the other hand
5. hydroelectric plants
6. tide n
7. to do one's best
XII. Translate the text.
RADAR
Electromagnetic waves in the super high frequency range, that is waves of between about 1 and 10 centimeters in length, are reflected by large solid object in much the same manner as light. They are however, able to travel greater distances than light in the Earths atmosphere, because they are not reflected or diffused by small dust particles in the atmosphere. If, therefore, a transmitter sends out a beam of these centimetric waves, an adjacent receiver can be made to pick up any of the beam that is reflected back by a large solid object. In this way distant object that is not visible by light can be located. By suitable scanning arrangements, the position and shape of the object can be outlined on a cathode ray tube. Thus, electromagnetic waves of these frequencies, which are called radar frequencies, provide a method of seeing in the dark or in the fog.
XIII. Make the annotation.
ELECTRIC POWER
Electric power is generated by converting heat, light, chemical energy, or mechanical energy into electrical energy. Most electrical energy is produced in large power stations by the conversion of mechanical energy or heat. The mechanical energy of falling water is used to drive turbine generators in hydroelectric stations, and the heat derived by burning coal, oil, or other fossil fuels is used to operate steam turbines or internal-combustion engines that drive electric generators. Also, the heat from the fissioning of uranium or plutonium is used to generate steam for the turbine generator in a nuclear power station.
Electricity generated by the conversion of light or chemical energy is used mainly for portable power sources. For example, a photoelectric cell converts the energy from light to electrical energy for operating the exposure meter in a camera, and a lead-acid battery converts chemical energy to electrical energy for starting an automobile engine.
Electrical power produced in large power stations generally is transmitted by using an alternating current that reverses direction 25, 50, or 60 times per second. The basic unit for measuring electric power is the watt the rate at which work is being done in an electric circuit in which the current is one ampere and the electromotive force is one volt. Ratings for power plants are expressed in kilowatts (1,000 watts) or megawatts (one million watts). Electric energy consumption normally is given in kilowatt-hour that is, the number of kilowatts used times the number of hours of use. Electricity is clean, inexpensive, and easily transmitted over long distances. Since the 1880s, electricity has had an ever-increasing role in improving the standard of living. It now is used to operate lights, pumps, elevators, power tools, furnaces, refrigerators, air-conditioners, radios, television sets, industrial machinery, and many other kinds of equipment. It has been counted that in developed countries about 43% of the electric power is generally used for industrial purposes, 32% in homes, and 21 % in commercial enterprises.
XIV. Make the annotation.
LASERS
A device that has received a great deal of publicity is the laser (Light Amplification by Stimulated Emission of Radiation). This device produces a beam of light composed of waves that are both monochromatic (all of one wavelength) and coherent2 (all in the same phase that is, all the peaks coinciding3). These properties enable the beam to be used4 as a source of considerable energy at a sharply defined point, for welding, eye surgery, and similar applications. Because the beam is also extremely parallel, diverging5 very much less than ordinary light, it is used in space communications a laser beam that has traveled the quarter of a million miles to the moon is still narrow enough to be useful.
The principle on which the laser works derives from an earlier device called the maser, which operates at microwave frequencies6 rather than optical frequencies. This principle is based on simulated emission, that is, the emission of a photon by an atom in an excited state as the result of the impact of a photon from outside of exactly equal energy. In this way the stimulating photon is augmented7 by the photon from the excited atom.
Thus if an atom in a substance is excited it will emit a photon to bring it back to the ground state8. It is stimulated (hit) by a photon containing energy, equal to the difference between the excited and ground states. If a high proportion of the atoms in a substance is pumped to an excited state there is an avalanche effect9. A stimulating photon from outside is doubled the first time it hits an excited atom, the two photons resulting then go on to double10 again by impacts with other excited atoms, and so on. All the photons have exactly equal energy, and are therefore associated with waves of identical wavelength.
A laser consists of a solid or gaseous active medium in which the majority of the atoms can be pumped to an excited state by exposing them to electromagnetic radiation of a different frequency to the stimulating frequency. The active medium consist of (or in the case of a gas is contained in) a transparent cylinder which acts as a resonant cavitythe stimulated waves of the same frequency making repeated passages up and down the cylinder. One end of the cylinder has a reflecting surface, and the other has a partially reflecting surface through which the laser beam emerges.
In a ruby laser, for example, the electrons in the chromium atoms of a cylindrical ruby crystal are pumped to an excited level by radiation from a flash tube, thus producing a pulsed beam. Continuous wave lasers can also be made using mixtures of inert gases.
Vocabulary notes
1. monochromatic adj
2. coherent adj
3. that is, all the peaks coinciding
4. enable the beam to be used
5. diverge v ( )
6. frequency n
7. is augmented (.)
8. ground state
9. avalanche effect
10. two photons resulting then go on to double
XV. Make the annotation.
