Power Engineering. Соколова Е.В. - 15 стр.

known in the whole world. 12. We were told about their having studied a number of
problems connected with the development of radio electronics.

      5 Lesson 5

      5.1 Прочтите слова согласно транскрипции

     phenomena, .associate , interaction , medium, infinity , equation , nonuniform,
conventional, parametric

      5.2 Прочтите слова, обращая внимание на смещение ударения

      electron - electronic; associate - association; responsible - responsibility; pro-
gress-progress; increases-increase; parameter - parametric; distribute - distribution.

      5.3 Сгруппируйте эквиваленты

       phenomtnon, dominant, certain, infinity, equation, conventional, responsible,
transfer, distribute

      бесконечность, уравнение, перенос, явление, господствующий, распреде-
лять, общепринятый, определенный, ответственный

      5.4 Сгруппируйте синонимы

      involve , govern, amplify , vacuum tube, basic association , main , increase, in-
clude, control, connection, valve

      5.5 Прочтите и переведите текст

                                       Electron tubes

       1. For the last half century, electron tubes have been the dominant devices in
the electronic field. Two basic phenomena are involved in electron tubes: electron
emission and physical interaction between free electrons and associated circuitry The
active medium of the "material" responsible for energy transfer is the free electron,
which does not manifestate until emitted from a suitable material under the proper
conditions. To move an electron in a metal from the Fermi level to "infinity", a cer-
tain amount of work is necessary. This work together with the kinetic energy of the
electron, is given in the Richardson-Dushman equation which governs electron emis-
sion.
       2.Electron emission has been found to be dependent upon the surface condi-
tions of the emitter particularly as far as surface films and nonuniform surfaces are
concerned. To achieve satisfactory emission, the emitter must be in a good vacuum.

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