电气工程及其自动化专业英语第二章课文翻译.docx

PAGE PAGE 1 第二章第一篇 To say that we live in an age of electronics is an understatement。 From the omnipresent integrated circuit to the equally omnipresent digital computer ， we encounter electronic devices and systems on a daily basis. In every aspect of our increasingly technological society — whether it is science, engineering， medicine， music, maintenance, or even espionage—the role of electronics is large， and it is growing。 谈论关于我们生活在一个电子学时代的论调是一种空泛的论调。从无处不在的集成电路到同 样无处不在的数字计算机，我们在日常活动中总会遇到电子设备和电子系统。在我们日益发 展的科技社会的方方面面——无论是在科学、工程、医药、音乐、维修方面甚至是在谍报方面—-电子学的作用是巨大的，而且还将不断增强. In general, all of the tasks with which we shall be concerned can be classified as ”signal-processing“tasks. Let us explore the meaning of this term 一般说来,我们将要涉及到的工作被归结为“信号——处理”工作，让我们来探究这个术语的含义吧。 A signal is any physical variable whose magnitude or variation with time contains information 。This information might involve speech and music, as in radio broadcasting, a physical quantity such as the temperature of the air in a room, or numerical data，such as the record of stock market transactions. The physical variables that can carry information in an electrical system are voltage and current. When we speak of signals”， therefore， we refer implicitly to voltages or currents. However, most of the concepts we discuss can be applied directly to systems with different information—carrying variables。Thus, the behavior of a mechanical system（in which force and velocity are the variables） or a hydraulic system (in which pressure and flow rate are the variables) can often be modeled or represented by an equivalent electrical system。 An understanding of the behavior of electrical systems， therefore, provides a basis for understanding a much broader range of phenomena. 信号就是其与时间有关的量值或变化包含信息的任何物理变量。这种信息或许像无线电广播的演讲和音乐,或许是像室内温度的物理量,或许像股市 交易记录的数字数据。在电气系统中能够载有信息的物理变量是电压和电流。因此当我们谈 到“信号”，我们不言而喻指的是电压和电流，然而，我们要讨论的大多数概念是可以被直接 应用于载有不同信息的变量的系统，因此，一个机械系统(在这个系统中力和速度是其变量） 或者液压系统（在这个系统中压力和流速是其变量）的性能通常可以用一个等效的电气系统 来模拟或表示。因此，我