The First Supersonic Plane in the World

The TU-144, the first supersonic passenger plane in the world, can fly at twice the speed of sound, its cruising speed¹ being 2,500 kph.

The air conditioning system is known to be of great impor­tance for a supersonic plane. In the turbojet planes the air in the cabins had to be heated but in supersonic types it had to be cooled. This is much more complicated than heating, for, besides the heat emitted by the passengers and electronic equip­ment, it is also necessary to cool the heat which penetrates the walls of the fuselage. At a speed of 2,500 kph the outer shell of the TU-144 heats up to 150° C. At an altitude of 20,000 metres the pressure in the passenger cabine of the TU-144 is maintained at the level of 2,400 metres.

The supersonic airliner is certain to occupy a leading place in passenger transport. This type of transportation has great advantages since it provides a high degree of comfort for passen­gers. One shouldn't forget that it takes no more than three hours to fly great distances.

It is precisely from this moment that the age of supersonic airliners begins.

Пояснение к тексту

1. cruising speed -крейсерская скорость

УРОК 9

ПРЕДТЕКСТОВЫЕ УПРАЖНЕНИЯ

I. Прочтите предложения, укажите в них формы сослагательного наклонения и переведитепредложения.

1. It is necessary that the temperature be constant. 2. It is desirable that this device be tested before the expe­riment.

3. It is required that a spaceship be directed towards the
planet.

4. It is important that any student know the fundamentals
of electrical engineering.

5. If the magnetic circuit consisted of non-magnetic material, the field would be proportional to the current.

6. If the temperature were higher, the results of the test
would be better,

7. If. the tube acted as a simple resistor, the relation between
the plate current and the plate voltage would follow Ohm's Law.

8. Without the radio we would nave very great difficulty
in observing man-made satellites

9. Had the pipe a small cross-section, the water flow per
second would be small.

10.Had a coil more turns, the induced emf would be larger. 11 Were a directional antenna used, the system would ope­rate much better.

12. Were the plates connected together through an external circuit, a current would result and chemical reactions would take place in the cell.

13. If we had used a coil with half the number of turns du­ring our last experiment, we should have got a much lower emf.

14. If we had had more powerful equipment, we should have
carried out our research much earlier.

15. Were there a conducting wire between both points of
unequal potential, the electrons could flow from one of the
points to the other.

16. He suggested that we should use this equipment.

II. Прочтите и переведите предложения, определив тип бессоюзного придаточного предложения:

1. The experiments showed this substance was unique in its
properties.

2. We know the value of voltage is the same in all the ele­ments of a parallel circuit.

3. The weight of an atom depends on the number of protons
and neutrons it contains.

4. The test we have made is of great importance for our
laboratory.

5. The problem we shall deaf with is connected with new
electronic devices.

6. The devices we are speaking about are constructed on
the basis of photoemission.

7. The computer the engineer is testing was produced in
Minsk.

8. The transmitter we have spoken about is suitable for
this system.

9. We think cadmium is very useful for the application in
transistors.

10. The rays he referred to differ from X-rays.

III. Прочтите слова и группы слов:

(to) rectify [ai], rectifier, rectifying, rectification; charac­teristic , linear characteristics; symmetrical, symmetrical characteristics; (to) permit, (to) permit easy flow; a surface , on the surface of the contact; some features [i:], some typical features; to oppose, opposing, opposite [zit], the opposite flow; through , through the surfaces, imme­diate immediately, immediately connected; adjacent , adjacent surfaces, immediately adjacent; ideal , an ideal rectifier; infinite ['infinit], infinite conduc­tance

TEXT

varistors

I. A solid rectifier or diode is a varistor having a volt-current characteristic which is not only non-linear but also non-symmetrical about the origin of currents and voltages.

2. The shape of a rectifier characteristic permits easy flow of current through the device in one direction but presents high resistance to current flow in the opposite direction. 3. The device we are speaking about is called a non-symmetrical varis-tor.4. A semiconductor contact rectifier, whatever its size, or electrical properties, consists of a layer of the semiconductor material with two metal contacts on its surface or surfaces. 5. If both of these contacts were rectifying, then the device would really be a series combination of two rectifiers in series opposing.6. In order to use the properties of the device in the best way, it is necessary that the rectification at one of these contacts be as ideal as possible. 7. It is also necessary that the •rectification at the other contact would be eliminated at the same time.

8. This can be done through the proper choice of a nonrectifying metal for the second contact or through suitable rectification-destroying treatment of the semiconductor surface before applying the contact metal. 9.The place of the rectification at the non-ohmic contact is often called the barrier layer or blocking layer l0. It consists of a very thin layer of semiconductor, immediately adjacent to the metal contact in which the local resistivity is many times greater than in the bulk material. II. The magnitude of the local resistivity, as well as the thickness of the layer itself, depends upon the direction and the magnitude of the voltage applied across the contact. 12. Typical barrier layer thickness runs from 10-6 to 10-³ cm. 13. The primary function of a rectifier is to serve as one-way valve allowing current to flow easily in one direction and only with great difficulty in the other. 14. The ideal rectifier would of course present infinite conductance in one direction and infinite resistance in the other.

15. Rectifying devices of various kinds using contacts between metals and semiconductors approach this ideal with certain characteristic features which are more or less common to all such devices.

16. The features we have just mentioned above must be discussed in details if one wants to understand the operation of these devices much better.

Слова для запоминания

п feature, origin, rectifier, surface, thickness, treatment

v destroy, mention, permit, rectify, serve

a adjacent, local, solid

adv immediately

prep as well as

Слова для повторения

n layer, magnitude, shape

v allow, approach, eliminate, present, run (ran, run)

a opposite, thin

УПРАЖНЕНИЯ

IV. * Прочтите предложения, укажите номера предложений со сказуемым в сослагательном наклонении и переведите все предложения;

1. Some materials could conduct electricity if their temperature were increased.

2. It is possible to find out the resistance of the conductor at any given temperature if the resistance at one temperature is known.

3. A redistribution of charges would take place if two
charged conductors were connected by a wire.

4. Potential in a point is equal to the work that would be
required to transfer that unit charge from infinity to that point.

5. If both metal contacts in a semiconductor contact rectifier were rectifying, the device would be, a series combination of two rectifiers in series opposing.

6. It is necessary that the electrical characteristics of semiconductor materials be changed.

7. If the wire is a large one and the current is a small one should use a thermometer to detect the developed heat.

8. If the structure were perfectly regular, all atoms would be in their proper places and no extra atoms would be present.

9. If placed in a different surrounding medium this device operated differently.

10. Were the vapors emitted collected they would be found to consist largely of water.

11. If the semiconductor had been disposed in a thick layer, the photoelectric increase of conductivity would have taken place only in the surface layers near where the light is absorbed.

12. Were the rectification at one contact ideal, we could use this material.

13. If the student had known the main features of this receiver, he could have used it in his experiment.

14. The engineer ordered that the test should be repeated.

V. Прочтите и переведите группы слов:

1. a rectifier characteristic; 2. the rectifier characteristic investigation; 3. a surface layer; 4. surface layer features; 5. the barrier layer application; 6. the barrier layer investigation; 7. the barrier layer thickness; 8. the resistivity magnitude; .9. an adjacent contact shape; 10. the adjacent contact shape features; 11. a semiconductor resistance; 12. a semiconductor resistance thermometer; 13. a rectifier contact area; 14, a recti­fier barrier capacitance

VI. * Определите по суффиксам, к какой части речи относятся
слова, и переведите их:

1. rectify; 2. rectifier; 3. rectification; 4. local; 5. locality; 6. immediately; 7. destruction; 8. destructive; 9. eliminate; 10. elimination; 11, original; 12. originally; 13. opposition

VII. * Прочтите и переведите сочетания слов:

1. rectifying contacts; 2. to employ these rectifiers; 3. to employ heat treatment; 4. to accomplish heat treatment; 5. to decrease the layer thickness; 6.to mention the typical features of this device; 7. to study the origin of this phenomenon; 8. to destroy the rectification; 9. to destroy the equipment; 10, a dan­ger of destruction; 11. destructive forces accompanying the explosion; 12. to penetrate through the surface; 13, to permit easy flow of current; 14. to permit the voltage to increase; 15 tо sегvе as a semiconductor; 16. a layer adjacent to the metal contact; 17. adjacent surfaces; 18. local changes; 19. a solid rectifier; 20. immediately adjacent contacts; 21, as well as these surfaces; 22. as well as these magnitudes; 23. to mention typical features

VIII.Прочтите и переведите предложения:

1. Properties of steel depend also on heat treatment the
metal has been subjected to.

2. It is desirable that heat treatment be used in this case.

3. A valve voltmeter is known to be one of the most useful
measuring instruments the radio engineer can possess,

4. It is necessary that this rectifier would serve as one-way
valve permitting current to flow easily in one direction and
with great difficulty in the other,

4. The blocking layer is known to consist of a very thin layer
of semiconductor, immediately adjacent to the metal contact.

5. The transmitter he will construct must operate on various
frequencies.

6. Were the wire a large one and the current were small we
should have to use a sensitive thermometer to detect the developed heat.

7. If the wire had been very thin and the current had been
large, the amount of generated heat would have been much
greater than that developed in the thick wire.

8. The way of current generation we are speaking about is
widely used in industry.

10. It is required that the rectification at one of these contacts

be as ideal as possible. •

11. We know the place of rectification at the non-ohmic
contact to be called the barrier layer or blocking layer.

12. If we had taken into consideration the properties of this
substance, we should have been careful when working with it.

13. The non-symmetrical varistors characteristics are considered

to depend upon the direction the voltage is applied in.

14. The object of this treatment is to increase the photosensitivity

of the lead sulfide layer in photoconductivity.

15. The magnitude of the local resistivity, as well as the
thickness of the layer itself is believed to depend upon the direction

and the magnitude of the voltage applied across the
contact.

IX. * Укажите дробью номер вопроса (числитель) и номер предло­жения из текста, которое является ответом на него (знаменатель):

1. What is the place of the rectification at the non-ohmic
contact called?

2. What does the magnitude of the local resistivity depend
upon?

3. What is a solid rectifier?

4. What does a semiconductor contact rectifier consist of?

5. What would happen if both of the semiconductor contacts
were rectifying?

6. What does a blocking layer consist of?

7. What is the primary function of a rectifier?

8. What is necessary in order to use the properties of the con­
tact rectifier in the best way?

X. Переведите, не пользуясь словарем:

Heat Detection In a Wire

A current carrying wire will almost always be at a higher temperature than the temperature of the same wire when a current is only flowing through it. It means that the electric current passing through a wire will heat that wire. Thus, this current can be detected due to the heat it produces when it is flowing through the wire. If the wire were a large one and the current were small, the only way to detect the developed heat would be using a sensitive thermometer because the heating were very weak for the detection by other means. But when the wire is very thin and the current is large, the amount of generated heat is much greater than that developed in the thick wire.

• "

XI.Переведите, пользуясь словарем:

I. The Magnetic Loudspeaker

We know the moving diaphragms of the earphones to cause the air next to them to move. Thus they produce the sound you hear. Were this sound loud enough, you could lay the ear­phones on the table and would not wear them on your head.

If you were to make one of the diaphragms larger it would move a greater quantity of air and thus produce a louder sound. For practical reasons a diaphragm cannot be made very large, and so another scheme was developed. One end of a stiff wire is fastened to the center of the diaphragm. To the other end of the wire a large paper cone is fastened. The fluctuating dia­phragm moves the wire; the wire in turn moves the paper cone. This in turn sets a large amount of air in motion, creating a loud sound. This device is called the magnetic loudspeak

Short-Wave Converter

When the first sputnik was launched with its 1-watt trans­mitters, operating at approximately 20 mc and 40 mc (mega­cycles), most owners of short-wave receivers were able to tune to the lower frequency, and with moderately good antennas pick up the signals from the satellite, especially when it passed over at some minimum angle above the horizon. However, many ordinary short-wave receivers would not tune to 40 mc, and the need for converters or new receivers was apparent.

A popular solution to the matter was to construct a converter. This unit could be provided in a very stable form by using a crystal-controlled oscillator at a frequency, which when fed into its mixer — either as a fundamental or a harmonic — would provide a signal which could be tuned in by the main receiver. Good signal-to-noise ratios were obtained by using a cascode radio frequency amplifier ahead of the converter mixer. The output of the mixer can be established at some relatively low frequency, such as 3 to 4 mc, so that good stability will be realized in the main receiver.