Properties of Materials in Space
1. While exploring space scientists came across1 some problems concerning the behaviour of materials used in space equipment. These are too high or too low temperatures, low pressures and solar radiation. These factors were found to alter the physical and mechanical properties of the material used.
2. The behaviour of some materials under vacuum conditions had been studied. It was found that such widely used coatings2 as cadmium and zinc, would be easily evaporated in vacuum when heated. The phenomenon of evaporation of materials may cause trouble to electronic equipment and devices. Cadmium, zinc and magnesium are the most dangerous in this respect. That is why they cannot be used in the construction of vehicles launched into space.
3. Some polymeric materials proved to change their properties under such conditions as well. This is mostly due to the rapid evaporation of components the polymers are made of. The use of new protective films and the proper selection of the necessary materials is the only means to ensure high reliability of instruments operating under low pressures.
4. Radiation damage caused by protons and electrons is another factor to be taken into consideration3 in selecting the material. Radiation results in4 changing optical properties of a material. Some glasses grow darker, when bombarded by high-energy particles. For example, such a material as plexiglass gets covered with a dull untransparent film5. Those factors gave rise6 to developing special grades of glasses which do not alter their properties when subjected to prolonged radiation.
5. Scientists consider polyamides to be the best polymeric materials. Thermoplastic polyamides possess good technological properties and good casting ability. Because of small shrinkage it is possible to directly cast precision parts of complex shapes.
6. The materials mentioned above can be used in industries as light and strong engineering materials7. Their application in electric equipment enables us to considerably increase the reliability and life-time8 of machines operating under severe conditions. Besides, the weight of electronic equipment is essentially reduced which is of great importance for aviation and space engineering.
Notes
1to come across - встречаться с чем-либо
2coating n - покрытие
3to take into consideration - принимать во внимание
4to result in - приводить к ...
5a dull untransparent film - матовая, непроницаемая пленка
6to give rise (to) - способствовать чему-либо
7engineering materials - технические материалы
8lifetime n - срок службы
VII. Выпишите и переведите из 3-го абзаца предложение, содержащее инфинитив в функции определения, а из 5-го абзаца – предложение, содержащее инфинитив в функции подлежащего.
VIII. Прочтите 6-й абзац и вопрос к нему. Из приведенных вариантов ответа укажите номер предложения, содержащего правильный ответ на поставленный вопрос:
What additional advantage can we get using the new materials?
1. ... we can decrease the lifetime of the equipment.
2. ... we can increase the weight of the equipment.
3. ... we can decrease the weight of the equipment.
Вариант 2
I. Перепишите предложения, определите в каждом из них видо-временную форму и залог глагола-сказуемого (см. образец). Переведите предложения на русский язык:
1. The construction of the dam was completely mechanized.
2. I saw the power station which had been described in this article.
3. Mendeleyev predicted that the vacant places in his table would be filled by yet unknown elements.
4. While a current is flowing through a wire, the latter is being heated.
II. Перепишите следующие предложения и переведите их, учитывая значения слов it, that, one:
1. January is the first month of the year and December is the last one.
2. Natural rubber is of higher quality than that produced artificially.
3. It was expected that our engineer would return before the New Year.
4. It is understood that the new power plant will be soon constructed.
III. Перепишите предложения и переведите их, имея в виду различные значения глаголов to be, to have, to do:
1. We see that you are busy.
2. The designs have to be examined and approved of by experts.
3. Do you live in the same street?
4. They say that our professor is in the laboratory.
5. He told us that he was writing an article about Russian music.
6. They do their home tasks after their work is over.
IV. Перепишите следующие предложения и переведите их, обращая внимание на бессоюзное подчинение:
1. We hoped the students had finished their experiment.
2. He thought everybody knew about his invention.
V. Перепишите следующие предложения и переведите их, обращая внимание на функции инфинитива:
1. This method is designed to eliminate costly tower cranes.
2. To read ancient mathematical tables was very difficult.
VI. прочтите и устно переведите 1-6-й абзацы текста. Перепишите и письменно переведите 1, 3, 4 и 6-й абзацы текста:
Acoustics in Buildings
1. In designing a concert hall or theatre the architect not only has to take into account1 the number of people to be seated and the arrangement of the seats in relation to one another, the position of doors and details of ventilation and illumination. He should also give careful consideration to2 the acoustics of the building.
2. Sound waves are known to travel in straight lines. They go out from their source in all directions. In much the same way as with light, sound waves can be reflected or absorbed by surfaces which they strike.
3. As the sound absorption properties of a particular substance vary for different frequencies, it is desirable that sound should have a free path from the source directly to each member of the audience. For this reason pillars and other obstacles in the halls should be avoided if it is possible.
4. The final tonal quality of the sounds depends largely upon the portion of the sound waves reaching the listener by reflection. Each time a sound wave is reflected, some of the sound is lost due to absorption. Thus after it has been reflected a few times, the sound will die away3 completely. There will always be a slight time lag4 during which the sound gradually dies away even if the source is stopped suddenly. This time lag for concert halls of moderate size is known to be about 2 seconds.
5. The extent of the reflections will depend not only upon the shape and size of the auditorium, but also upon the nature and relative proportions of the reflecting and absorbing surfaces. Irregularities in the walls and ceilings can cause unwanted reflections and are to be avoided. The form and height of the roof of the concert hall have to be carefully chosen in order that the sound waves it collects could be reflected back over as large an area of the auditorium as possible.
6. At the design stage the architect has to check the acoustic properties of a concert hall by means of calculations based on the reflection of sound. The improvements in the acoustics will depend largely upon the interior decoration of the hall.
7. Various reflectors may be attached to the walls and ceilings to turn the sound waves in the most desirable directions. The acoustic properties of paints used for wall coverings are at least as important as their decorative value. The use of carpets on the floors, of absorbent materials on the walls and ceilings and of suitably upholstered5 seats will help to solve this problem.
Notes
1to take into account - принимать во внимание
2to give consideration to - уделять внимание чему-либо
3to die away - затухать
4time lag - запаздывать
5to upholster - обивать мебель
VII. Выпишите из текста предложения, содержащие следующие грамматические формы и обороты: из 2-го абзаца – предложение, содержащее страдательный залог; из 5-го абзаца – предложение, содержащее бессоюзное подчинение. Переведите эти предложения на русский язык.
VIII. Прочтите 7-й абзац и вопрос к нему. Из приведенных вариантов ответа укажите номер предложения, содержащего правильный ответ на поставленный вопрос:
What helps to improve the acoustics of a concert hall?
1. the decorative value of wall coverings...
2. absorbent materials on the walls...
3. the use of pillars in the hall...
Вариант 3
I. Перепишите предложения, определите в каждом из них видо-временную форму и залог глагола-сказуемого (см. образец). Переведите предложения на русский язык:
1. The delegates will be met at the station.
2. Scientists have worked out special equipment for this purpose.
3. Splendid new buildings have changed the city’s appearance.
4. Beautiful houses of concrete and glass are being built in our district.
II. Перепишите следующие предложения и переведите их, учитывая значения слов it, that, one:
1. Everybody knows this man.
2. This book is more interesting than the one we read last week.
3. There is a new machine in our shop similar to that described in the magazine.
4. You must close the window for it is rather cold.
III. Перепишите предложения и переведите их, имея в виду различные значения глаголов to be, to have, to do:
1. She did not come because she was ill.
2. Your task is to do your work well.
3. He is to finish this experiment by the next Monday.
4. They had to bring the results of their work yesterday.
5. They have much work to do.
6. Do they like visiting exhibitions?
IV. Перепишите следующие предложения обращая внимание на бессоюзное подчинение:
1. He said he would not be able to come.
2. My friend told us he had taken part in the construction of that power station.
V. Перепишите следующие предложения и переведите их, обращая внимание на функции инфинитива:
1. This new method can be used to produce houses of any number of storeys.
2. To design the plans of buildings is the work of architects.
VI. Прочтите и устно переведите 1-4-й абзацы текста. Перепишите и письменно переведите 1 и 2-й абзацы:
Solar Energy
1. Solar energy has proved to be an ideal source of power. Man had learned to obtain electric power directly from the sun. In a climate where continuous sunshine can be guaranteed for long periods of the year architects have designed and built houses to be heated by solar radiation. The solar collector built into the roof consists of a number of blackened metal plates with spaces between them. Air is circulated between the plates and when heated, it passes through a large container filled with gravel1. During the day the gravel heats up, and at night cold air is passed through the hot gravel and then to the rooms where warmth is required. A surprising feature of such a system is that under suitable conditions solar radiation can greatly raise the temperature of the air.
2. The simple principle of focusing the sun’s rays by mirrors has been applied to create a very-high-temperature furnace for melting metal alloys. To obtain a really high temperature for such furnaces by traditional methods is not easy. There is a limit of the temperature that can be achieved by combustion of fuels. Solar installations have no such limitations. Furnaces of this type are now under construction in many countries.
3. The device employed for converting solar energy into useful power is the solar cell. This is somewhat like thermocouple2 which consists of two dissimilar metals joined together. In the solar cell the junction is of two different kinds of semiconductors and the cell is energized not by heat but by light. The basic semiconductor employed in the solar cell is silicon in the form of a single crystal.
4. We know the solar energy to be produced by fusion3 of hydrogen atoms into helium atoms. The reaction that takes place in the sun is made possible due to extremely high temperatures – millions of degrees. Now the highest temperature commonly reached on earth can be measured in thousands of degrees. An electric arc, for instance, has the temperature of about 30000C. There are good prospects that this reaction of fusion can be reproduced artificially and in a controlled way on earth. If we had succeeded in4 doing it we should have found a complete solution to energy problems, for we have a vast store of hydrogen in the oceans, enough to satisfy the world’s power requirements for thousands, if not millions of years.
Notes
1gravel - гравий
2thermocouple - термопара
3fusion - синтез
4to succeed in - удаваться что-либо сделать