АвтомобилиАстрономияБиологияГеографияДом и садДругие языкиДругоеИнформатикаИсторияКультураЛитератураЛогикаМатематикаМедицинаМеталлургияМеханикаОбразованиеОхрана трудаПедагогикаПолитикаПравоПсихологияРелигияРиторикаСоциологияСпортСтроительствоТехнологияТуризмФизикаФилософияФинансыХимияЧерчениеЭкологияЭкономикаЭлектроника
Прочитайте текст и расскажите о практическом применении лазеров.
An Encyclopedia on a Tiny Crystal
Scientists have discovered that a laser beam can be effectively used to record alphanumeric data and sound on crystals. According to Russian researchers a method for recording information on crystals by means of a laser has already been developed, but advanced technologies are needed to make it commercially applicable.
At present researchers are looking for the most suitable chemical compounds to be used as data storages and trying to determine optimum recording conditions. Theoretically, the entire «Great Soviet Encyclopedia» can be recorded on a single tiny crystal.
As far back as 1845, Michael Faradey discovered that a light beam reverses its polarization as it passes through a magnetized crystal. Scientists of our day have used this phenomenon to identify crystalline materials capable of storing information. Lasers have been successfully employed to record information on and read it off.
No ideal data storage crystal has yet been found, but it is obvious now that the future of computer engineering lies in lasers and optoelectronics.
Прочитайте текст и найдите примеры все возрастающей тенденции к более тесному международному сотрудничеству. Почему такое сотрудничество необходимо? Назовите страны-участницы такого сотрудничества. Запомните произношение названий стран.
Science and International Cooperation
One of the most striking features of modern science is the increasing tendency towards closer cooperation between scientists and scientific organizations (institutions) all over the world. In
fact, it is becoming more and more evident that many of the problems that affect the world today cannot be solved without joining scientific efforts and material resources on a wo rid-wide scale. The exploration of space, world finance, global environment protection problems and the development of new sources of power are the examples of areas of scientific research which are so costly and complicated that it is difficult for a single country to solve them efficiently and in a short period of time. The renewal of international scientific cooperation was demonstrated in the sharing of data which were obtained by Russian, Japanese and European space probes in 1986 on Halley's comet.
Many countries were successfully cooperating on a programme called Intercosmos in launching a large number of vertical geophysical rockets and satellites. Space exploration programmes were being conducted between Russia and Austria, India, France, Sweden and other countries. Joint manned flights by Russian and foreign cosmonauts included citizens from numerous countries. Many international crews have worked on orbit and carried out a lot of scientific experiments,
Russian and the U.S. engineers are now working side by side on the International Space Station, the largest peacetime engineering project in history.
Launched from opposite sides of the world, the first International Space Station components Zarya and Unity have begun a new era of exploration as 16 nations joined their scientific and technological resources in the first truly international space program to improve life on Earth. Even before its launch, the International Space Station has opened new spheres of research on Earth by overcoming barriers of language, culture and technological differences worldwide.
Indeed, it represents unprecedented (беспрецедентный, беспримерный) global cooperation and trust. There is no doubt that it is the first step towards a unified «planetary civilization» that will explore space as citizens of Earth, not of individual nations.
Упражнение 1. А.Прочитайте словосочетания из текста 10А и постарайтесь понять значения выделенных слов.
1. time to disintegrate
2.the durationof the pulse
3. to be encountered
4.in justa fraction of a second
В. Подберите к каждому выделенному в А слову соответствующее ему по значению.
a. to meet unexpectedly
b. only, merely
с break up into small parts
d. time during which smth lasts or exists
Упражнение 2. А.Прочитайте текст и постарайтесь понять значение словосочетания off-the-shelf item. Дайте определение или объяснение этому термину.
Another approach is to absorb laser light in a plasma «flame» sustained by laser light focused in the center of a flowing stream of propellant gas. Thrust levels as high as 10,000 N with a specific impulse (удельный импульс) of 1,000 sec appear achievable using hydrogen as the propellant gas. Laser power as low as 1 MW would be useful for low Earth orbit launching without relay optics. 10-100 MW lasers can launch small payloads from the ground. With up to 100 launches a day, a 20 MW launcher weighing 20 kg could place several hundred tons in orbit per year. Low-gigawatt lasers could launch multi-ton spacecraft with the same ease that present multi-gigawatt chemical rockets do. Laser rockets will have much better payload fraction since the heavy power plant is left on the ground and the higher specific impulse results in lower propellant fraction. Although gigawatt lasers are not off-the-shelf items, there is no doubt they could be built if the need were strong enough.
В. Выберите соответствующие контексту А значения выделенных слов.
Дата добавления: 2014-11-13; просмотров: 33; Нарушение авторских прав