section 2-1.ppt

* Chapter 2 Electronics Section 1 Introduction Text New Words and Expressions Exercises End Vocabulary Characteristic III New Words and Expressions electronics n. 电子学，电子仪器，电子设备，电子线路 understatement n. 轻描淡写，有节制的表达 omnipresent [?mn?prez(?)nt] a. 无处不在的，普遍存在的 electronic a. 电子（学）的 transaction n. ①交易，业务 ②办理，处理 digital a. 数字的，数字式的，计数的 espionage [esp??nɑ:?] n. 谍报，间谍活动，密探 New Words and Expressions signal-processing a. 信号处理的 analog n. ①模拟（量，装置，设备，系统） ②类似，类比，比拟 velocity [v?l?s?t?] n. 速度，速率 thermocouple [θ??m??k?p(?)l] n. 热电偶 discrete [d?skri?t] a. 离散的，不连续的，分散的 household a.; n. 家用的，普通的，一般用途的，家庭，家，户 thermostat [θ??m?st?t] n. 恒温器，定温器，温度自动调节器 New Words and Expressions preset [pri?set] v.; a. ①预定，预置，（预先）调整 ②安装程序，给定程序的 switch n. 开关； v. 接通或关断，转变，换接 A/D = Analog-to-Digital 模数转换，模数变换 D/A = Digital-to-Analog 数模转换，数模变换 transducer n. 传感器，变送器，发射器，换能器，换流器 excitation [,eks?te??(?)n] n. ①激励，激发，激磁 ②刺激，干扰 display v. 显示，显像，表现，陈列， 展览；n. 显示，指示，表现 Return Section 1 Introduction 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. In general, all of the tasks with which we shall be concerned(关注的) can be classified as signal-processing Section 1 Introduction tasks. Let us explore the meaning of this term. Signal 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