专业英语重要翻译

Unit 6 ASamuel Morse developed the first electronic communications system in 1837. Morse used electr

Unit 6A Samuel Morse developed the first electronic communications system in 1837. Morse used electromagnetic induction to transfer information in the form of dots, dashes, and spaces between asimple transmitter and receiver using atransmission line consisting of alength of metallic wire. He called his invention the telegraph. In 1876 Alexander Graham Bell and Thomas A. Watson were the first successfully transfer human conversation over acrude metallic wire communications system, they called the telephone Samuel Morse 1837Morse 于年发明了第一个电子通信系统。利用电磁感应来传送用 点、破折号、空格表示信息，简易的发送机与接收机之间用金属传输线连接。他把他的发明 1876Alexander Graham Bell Thomas A. Watson 称为电报。年，和利用一个简陋的金属 线通信系统成功地传送了人的对话，他们把这个系统称为电话。 Guglielmo Marconi successfully transmitted the first wireless radio signals through Earth’ satmosphere in 1894, and in 1908 Lee Deforest invented the triode vacuum tube which provided the first practical means of amplifying electrical signals. Commercial radio began in 1920 when radio stations began broadcasting amplitude-modulated (AM) signals, and in 1933, Major Edwin Howard Armstrong invented frequency modulation (FM). Commercial broadcasting of FM began in 1936. Guglielmo Marconi 1894 Lee de 于年首次成功地通过大气层发送了无线电信号。 Forest1908 于年发明了真空三极管，为放大电信号提供了第一个实用手段。商用广播始于 1920AM1933 Edwin Howard Armstrong 年，当时采用的是调幅（）信号。年，发明了 FM1936 频率调制（），而商用调频广播始于年。 Although the fundamental concepts and principles of electronic communications have changed little since their inception, the methods and circuits used to implement them have undergone considerable change. In recent years, transistors and linear integrated circuits have simplified the design of electronic communications circuits, thus allowing for miniaturization, improved performance and reliability, and reduced overall costs. In recent years, there has been an overwhelming need for more and more people to communicate with each other. This tremendous need has stimulated a monumental growth in the electronic communications industry. Modern electronic communications systems include metallic cable systems, microwave and satellite radio systems, and optical fiber systems. 尽管电子通信的基本概念和原理自开创以来并没有多大变化，但实现的方法和电路已有 飞速发展。近年来，晶体管和线性集成电路已大大简化了电信通信电路的设计，并使其小型 化，提高了性能和可靠性，降低了成本。近来，越来越多的人对通信的强烈需求，刺激了通 信业的强烈需求，刺激了通信业空前迅猛的发展。现代通信系统已涵盖了电缆系统、微波系 统、卫星系统和光纤系统。 On an international basis, frequency assignments and technical standards are set by the International Telecommunications Union (ITU). The ITU is a specialized agency of the United Nations, and the ITU administrative headquarters are located in Geneva, Switzerland, with astaff of 700 persons. This staff is responsible for administering the agreements that have been ratified by the 184 member nations of the ITU. In 1992, the ITU was restructured into three sectors. The Radio Communication Sector (ITU-R) provides frequency assignments and is concerned with efficient use of the radio frequency spectrum. The Telecommunications Standardization Section (ITU-T) examines technical, operating, and tariff questions. It recommends