计算机英语sectionA课文及对应中文翻译.docx

1、计算机英语sectionA课文及对应中文翻译 第七单元Telecommunications enables people to send and receive personal messages across town, between countries, and to and from outer space. It also provides the key medium for news, data, information and entertainment.When a signal reaches its destination, the device on the recei

2、ving end converts the electronic signal back into an understandable message, such as sound over a telephone, moving images on a television, or words and pictures on a computer screen. 电信使世界各地的人们得以互相联系，即刻获 取信息，并从边远地区实施通信。电信通常涉及一个信息发送者和一个或多个接收者，他们通过电话系统等把信息从一地发送到另一地的技术相联系。电信设备将不同类型的信息，如声音和图像，转换成电子信号。然

3、后，这些信号就可以通过电话 线或无线电波等媒介进行发送。信号到达目的地后，接收端的设备将电子信号转换 回可以理解的信息，如电话中的声音、电视上的活动图像或计算机屏幕上的文字和 图片。电信使人们能够在城镇不同地方、国家之间以及向外层空间和从外层空间发送和接收个人信息。电信也为新闻、数据、信息和娱乐提供了关键的媒介。Telecommunications messages can be sent in a variety of ways and by a wide range of devices. The messages can be sent from one sender to a sing

4、le receiver (point-to-point) or from one sender to many receivers (point-to-multipoint). Personal communications, such as a telephone conversation between two people or a facsimile (fax) message, usually involve point-to-point transmission. Point-to-multipoint telecommunications, often called broadc

5、asts, provide the basis for commercial radio and television programming. 电信信息可通过各种方式和设备发送。信息可由一个发送者发送给一个接收者（点对点）， 或者由一个发送者发送给多个接收者（点对多点）。个人通信，如两个人之间的电话对话或传真信息，通常涉及点对点的传输。通常称为广播的点对多点电信传输，为商业无线电和电视节目播送提供了基础。Telecommunications begin with messages that are converted into electronic signals. The signals

6、are then sent over a medium to a receiver, where they are decoded back into a form that the person receiving the message can understand. There are a variety of ways to create and decode signals, and many different ways to transmit signals.电信以信息转换为电子信号为 开端。然后，这些信号通过媒介发送到接收机，并在那里解码，恢复为接收信息的 人能够理解的形式。有

7、各种方法可以生成并解译信号，也有许多不同方法可以传输 信号。Devices such as the telegraph and telephone relay messages by creating modulated electrical impulses, or impulses that change in a systematic way. These impulses are then sent by wires, radio waves, or other media to a receiver that decodes the modulation. 电报机与电话机等设备，通过

8、生成调制电脉冲或以系统化方式变化的脉冲，来传递信息。接下来，这些脉冲通过导线、无线电波或其他媒介发送给接收机，并由其进行解调。The telegraph, the earliest method of delivering telecommunications, works by converting the contacts (connections between two conductors that permit a flow of current) between a telegraph key and a metal conductor into electrical impuls

9、es.hese impulses are sent along a wire to a receiver, which converts the impulses into short and long bursts of sound or into dots and dashes on a simple printing device.电报机是最早的传递电信信息的方法，它通过将电报电键与金属导 体之间的接触（使电流得以流动的两个导体之间的连接）转换成电脉冲而进行工 作。这些脉冲沿着导线发送到接收机，而接收机则将这些脉冲转换成长与短的声音脉冲串，或者在简单的打印设备上打印出来的点与划。T Sp

10、ecific sequences of dots and dashes represent letters of the alphabet. In the early days of the telegraph, these sequences were decoded by telegraph operators. In this way, telegraph operators could transmit and receive letters that spelled words. Later versions of the telegraph could decipher lette

11、rs and numbers automatically. Telegraphs have been largely replaced by other forms of telecommunications, such as fax machines and electronic mail (e-mail), but they are still used in some parts of the world to send messages.特定的点与划序列代表字母 表中的字母。在早期的电报中，这些序列由电报机操作员进行解译。这样，电报机 操作员就可以发送和接收可拼成词语的字母。后来的电报

12、机能自动解译字母和数 字。电报机在很大程度上已被其他的电信形式所取代，如传真机和电子邮件，但在 世界有些地方，电报机仍然用来发送信息。Telegraphs, telephones, radio, and television all work by modifying electronic signals, making the signals imitate, or reproduce, the original message. This form of transmission is known as analog transmission. Computers and other ty

13、pes of electronic equipment, however, transmit digital information. 电报机、电话机、无线电和电视都是通过修改电子信号，使其模拟或再现原来的信息，来进行工作的。这种传输称为模拟传输。然而，计算机和其他类型的电子设备是传输数字信号的。数字技术将信息转换成电子形式。其方法首先是多次测量信息的不同特性，如语音的音高和音量。 Digital technologies convert a message into electronic form first by measuring different qualities of the m

14、essage, such as the pitch and volume of a voice, many times. These measurements are then encoded into multiple series of binary numbers, or 1s and 0s.数字技术将信息转换成电子的形式。其方法首先是多次测量信息的不同特性，如语音的音高和音量。然后，这些测量值被编译成多个系列的二进制数或1与0。 Finally, digital technologies create and send electrical impulses that correspo

15、nd to the series of 1s and 0s. Digital information can be transmitted faster and more clearly than analog signals, because the electrical impulses only need to correspond to two digits and not to the full range of qualities that compose the original message, such as the pitch and volume of a human v

16、oice. 最后，数字技术生成并发送与这些系列的1和0相对应的电脉冲。与模拟信号比较起来，数字信息可以更快、更清晰地传输，因为电脉冲仅需与两个数字对应，而不是构成原信息的所有特性，如人的说话声的音高和音量。 While digital transmissions can be sent over wires, cables or radio waves, they must be decoded by a digital receiver. New digital telephones and televisions are being developed to make telecommun

17、ications more efficient.数字传输可以通过导线、电缆或无线电波发送，但必须由数字接收机进行解译。新型数字电话和电视正在开发中，以提高电信的效率。 Most personal computers communicate with each other and with larger networks, such as the Internet, by using the ordinary telephone network. Since the telephone network functions by converting sound into electronic s

18、ignals, the computer must first convert its digital data into sound. Computers do this with a device called a modem, which is short for modulator/demodulator.大多数个人计算机通过使用普通电话网，来进行彼此间的和与因特网等大型网络的通信。因为电话网是通过将语音信号转换成电子信号来工作的，计算机必须首先将其数字数据转换成语音信号。计算机使用被称为调制解调器的设备完成这项工作。调制解调器是调制器/解调器的缩略。 A modem converts

19、 the stream of 1s and 0s from a computer into an analog signal that can then be transmitted over the telephone network, as a speakers voice would. The modem of the receiving computer demodulates the analog sound signal back into a digital form that the computer can understand. 调制解调器将计算机输出的1和0的数字流转换成

20、模拟信号，而模拟信号可随后通过电话网传输，就像通话者的声音那样。接收端的计算机的调制解调器将模拟语音信号解调还原为计算机能理解的数字形式。Telecommunications systems deliver messages using a number of different transmission media, including copper wires, fiber-optic cables, communication satellites, and microwave radio. One way to categorize telecommunications media i

21、s to consider whether or not the media uses wires. 电信系统传输信息，使用的是许多不同的传输媒介，包括铜线、光缆、通信卫星和微波。划分电信媒介的一种方法是看媒介是否使用导线。 Wire-based (or wireline) telecommunications provide the initial link between most telephones and the telephone network, and are a reliable means for transmitting messages.基于导线（或有线）的电信提供了大

22、多数电话与电话网之间的初期链路，是一种可靠的信息传输方式。 Telecommunications without wires, commonly referred to as wireless communications, use technologies such as cordless telephones, cellular radio telephones, walkie-talkies, citizens band (CB) radios, pagers, and satellites. Wireless communications offer increased mobilit

23、y and flexibility.无线电信，通常称作无线通信，使用无绳电话、蜂窝式无线电话、步话机、民用波段无线电台、寻呼机和卫星等技术。无线通信提供了更高的机动性和灵活性。 Individual people, businesses, and governments use many different types of telecommunications systems. Some systems, like the telephone system, use a network of cables, wires, and switching stations for point-to

24、-point communication. 个人，商业和政府使用不用方式的通讯系统。有些系统，如电话系统，使用由电缆、导线和交换台组成的网络，来进行点对点的通信。 Other systems, such as radio and television, broadcast signals through space, which can be received by anyone who has a device to receive them. For example, a telephone call may travel by means of copper wire, fiber-op

25、tic cable, and radio waves as the call is sent from sender to receiver. All telecommunications systems are constantly evolving as telecommunications technology improves.其他系统，如无线电台与电视台，通过空间来播出信号，任何拥有接收设备的人都可以接收。例如，当我们打电话的时候，电话可以通过铜线，光缆和无线电波从发送人传送到接收人。随着通信科技的提升，通信系统也在不断地进步。Computer telecommunications,

26、 with the ability to send and receive audio, video, text, software, and multimedia, is one of the fastest-growing segments of the telecommunications market. 计算机远程通信具有发送和接收音频信号、视频信号、文本、软件和多媒体的能力，是电信市场发展最快的部分之一。Computer telecommunications takes advantage of existing telephone connections to transmit d

27、igital data. This type of transmission is frequently done over the Internet, a decentralized network of personal, business, government, educational computers, and sources of information. 计算机远程通信利用现有的电话连接来传输数字数据。这种传输常常通过因特网进行，而因特网是一个由个人、工商企业、政府和教育机构所用的计算机以及信息源构成的分散式网络。 Some computers connect directly

28、 to the digital portion of the telephone network using the Integrated Services Digital Network (ISDN), but this requires the installation of special devices and telephone line conditioning. An improved modem system for regular phone lines, called Digital Subscriber Line (DSL), is being developed to

29、increase modem speed tremendously. 有些计算机使用综合业务数字网直接连接到电话网的数字部分，但是这需要安装专用设备和进行电话线调整。为了大幅度提高调制解调器的速率，目前正在开发一种供常规电话线使用的改进型调制解调器系统，称为数字用户线路。Electronic mail, or e-mail, is a key attraction of the Internet and a common form of computer telecommunications. E-mail is a text-based message delivery system tha

30、t allows information such as typed messages and multimedia to be sent to individual computer users. Local e-mail messages (within a building or a company) typically reach addressees by traveling through wire-based internal networks. 电子邮件是因特网吸引人的一个亮点，也是计算机远程通信的常见形式。电子邮件是基于文本的信息传输系统，它能将键入的信息和多媒体信息等发送给

31、个人计算机用户。（一幢建筑或一家公司内的）本地电子邮件通常经由基于导线的内部网传送给收件人。 E-mail that must travel across town or across a country to reach the final destination usually travels through the telephone network. Other computer telecommunications technologies that businesses frequently use include automated banking terminals and d

32、evices for credit card transactions that bill charges directly to a customers bank account.必须横穿城市或国家才能到达最终目的地的电子邮件，通常通过电话网进行传输。工商企业经常使用的其他计算机远程通信技术包括自动银行终端和设备，用来处理将费用直接从顾客银行帐户上扣除的信用卡业务。 Personal computers have pushed the limits of the telephone system as more and more complex computer messages are b

33、eing sent over telephone lines, and at rapidly increasing speeds. This need for speed has encouraged the development of digital transmission technology. 随着越来越复杂的计算机信息以快速增长的速度通过电话线发送，个人计算机拓展了电话系统的作用范围。提高速度的需要促进了数字传输技术的发展。 Innovations in fiber-optic technology will hopefully keep up with the growing use