New Works in the Field of Semiconductors
We consider semiconductors to occupy an intermediate1 place between metals and insulators. Academician Joffe, a famous Soviet scientist, found transistors to be of great interest not only for physics, but also for future technology
Transistors made it possible to design compact, small-dimensioned electronic devices, which consume very little power.
The transistors are successfully used for direct transformation of heat energy into electrical energy by means of thermal elements. We know them to be 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.
Transistors revolutionized radio engineering and electronics. Because of their small size, the absence of incandescence and other properties, transistors make it possible to produce designs which cannot be achieved with vacuum lamps.
Transistors are extremely sensitive to external influences. Even thousandths of one per cent of admixtures change their electrical conductive properties by hundreds of thousands of times. They are very sensitive to the action of light, nuclear particles, pressure, etc
Пояснение к тексту
1. intermediate— промежуточный
XIV. Переведите, пользуясь словарем:
Nuclear Fusion and Nuclear Fission
One knows fission to be a process by which a heavy nucleus is bombarded with free neutrons which cause it to divide or fission into two or more smaller nuclei. The smaller nuclei have a greater total binding energy and, consequently, a smaller total mass (about one tenth of one per cent less) than the heavy nucleus which fissioned. Therefore, there is a release of energy when an atom fissions.
We know nuclear fusion to occur when two light nuclei combine or fuse to form a single nucleus with a greater mass. The large nucleus will have a stronger binding energy and a mass that is about one half of one per cent smaller than the total mass of the two small nuclei. Thus, a fusion reaction releases several times as much energy as a fission reaction.
We have not yet learned how to control nuclear fusion well enough to reutilize it as a source of commercial power, although a fusion process is used in hydrogen bombs. The greatest problem is that each nucleus bears a positive electrical charge and two nuclei therefore repel one another at ordinary temperatures. However, when the nuclei are heated to a very high temperature, they no longer repel one another and so are able to meet and fuse. Because they require such high temperatures, fusion reactions also are called "thermonuclear reactions". The high temperatures required — several million degrees Fahrenheit — are too great for any known material to withstand. Research is now in progress to develop a method to contain the high temperature fusion materials within a magnetic field, rather than1 in a material container.
Пояснение к тексту
1. rather than – а не
УРОК 8
ПРЕДТЕКСТОВЫЕ УПРАЖНЕНИЯ
I. Прочтите предложения, укажите в них оборот «именительный падеж с инфинитивом» и переведите предложения:
1. Electronics is thought to be a young science.
2. The electric generator is known to be a machine that converts mechanical energy into electrical energy.
3. Alpha rays are considered to be positively charged helium atoms.
4. An electric cell is believed to consist of an electrolyte and two electrodes.
5. This voltage source was supposed to supply current for this circuit.
6. The value of the output voltage of the cell was found to depend only on the materials used.
7. Due to these experiments this substance was shown to be a good conductor.
8. The secondary coil of the transformer is assumed to have more turns than the primary one.
9. Cadmium was reported to be very useful for application in transistors.
10. This scientist is expected to make a report on the fundamentals of radio engineering.
11. The designer is said to construct a new device by using semiconductors.
12. The antenna was found to receive only a small part of energy radiated by the transmitter.
13. Atomic nuclei are believed to be composed of protons and neutrons.
14. An electric cell is known to be used for electric energy production.
15. The efficiency of these tubes is reported to be perfected.
16. Radio engineering in the USSR is considered to have made considerable progress.
17. The engineer is expected to have finished the experiment.
18. The engineers are said to have discovered new means of testing the equipment.
19. The students are said to have obtained very important data on the conductivity of a new substance.
II. а) Найдите в словаре глаголы и сочетания и запомните их значения:
to seem, to appear, to prove, to turn out, to happen, to be likely, to be unlikely, to be certain, to be sure
б) Прочтите и переведите предложения, обращая внимание на перевод сказуемого:
1. This substance proved to be a good conductor.
2. The engineer seems to work at the problem of waves traveling.
3. The laboratory appears to investigate this phenomenon.
4. The substance turned out to be unique in its properties.
5. The engineer happened to carry out this very important experiment.
6. Nuclear energy is certain to be the prime source of heat energy.
7. The cyclotron is likely to be the simplest and oldest type of accelerator.
8. He is sure to analyze the results of the test.
9. The rays from uranium compounds proved to differ from X-rays.
10. The dimensions of the body are likely to change under different temperature conditions.
11. These experiments appeared to be carried out in our laboratory.
12. The network of transmitting stations seems to be built in this region.
13. The laboratory is certain to be equipped with perfect measuring instruments.
14. This energy source is unlikely to be used in this system.
15. The application of new superconductive materials seems to be suitable for this device
III. Прочтите слова и группы слов:
micro [ai], microelement, microworld; image , electron-optical image, electron-optical image converters; opaque [ou'peik], opaque materials, to penetrate into opaque materials; negligible , negligible radiation, negligible intensity; celestial , celestial body, waves emitted by celestial bodies; the universe , facts about the universe; ultra-short waves; ultra-violet radiations; (to) collide [ai], collision , collisions of bodies, collisions of galaxies ; aircraft , aircraft location; a meteor , meteors collisions; (to) ensure , (to) ensure radio contact, to ensure reliability of communication
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