准确翻译英语口语.doc

第一章 Electronic amplifiers are used mainly to increase the voltage , current ,or power of a signal . 电子放大器主要是用来增强电压，电流或信号（信号功率）的强度 A linear amplifier provides signal amplification with little or no distortion , so that the output is proportional to the input .线性的放大器能几乎无失真地放大信号，从而使输出与输入相称 A nonlinear amplifier may produce a considerable change in the waveform of the signal .非线性放大器在信号的波形方面会产生相当大的变动 Linear amplifiers are used for audio and video signals , whereas nonlinear amplifier find use in oscillators , power electronics , modulators , mixers , logic circuits , and other applications where an amplitude cutoff is desired . 线性放大器用于音频信号，而非线性放大器用于振荡器，电力电子学，调节器，混音器，逻辑电路以及其他的要求振幅中断的器材 Although vacuum tubes played a major role in amplifiers in the past , today either discrete transistor circuits or integrated circuits are mostly used .尽管真空管在过去的放大器中充当了主要的角色，而如今最常用的是离散的晶体管电路或集成电路 第二章 Configurable computing is still an extremely young field .可配置计算仍然是极年轻的领域 Although Gerald Estrin of the University of California at Los Angeles proposed configurable computing in the late 1960s , the first demonstrations did not occur until a few years ago , and current FPGAs ,with up to 100,000 logic elements , still do not come close to exploiting the full possibilities of the technique . 虽然可配置计算是由洛杉矶加州大学的杰拉尔德艾斯特林在1960年代末期提出的，但是在几年前才首次展示给世人，甚至，含有十万个逻辑元件的电流FPGA（现场可编程门阵列）仍未能开发出其技术的全部潜力 Future FPGAs will be much larger , as with many other integrated circuits , the number of elements on a single FPGA has doubled roughly every 18 months . 正如许多其他的集成电路一样，未来的FPGA会（比目前的）大的多,单一的FPGA中的元件的数量约每隔一年半就会翻倍。 Before the decade is out , we expect to see FPGAs that have a million logic elements .十年之后，我们期盼着会出现含有一百万个逻辑元件的FPGA Such chips will have much broader application , including highly complex communications and signal-processing algorithms .这些芯片应用范围更广，包括应用于高度合成的通讯系统和信号加工算法。 第三章 Variable-length instructions are more difficult for a chip to process , though , and the longer CISC instructions are especial