英语科普文选合集-中英文对照(计算机,互联网,通信)[优质文档]

英语科普文选（中英对照）

计算机与因特网插件指南

Life on-line can be a much richer experience when you aren't restricted to just written words and still pictures. Even if you're new to the Net, you've probably heard aobut multimedia

on-line--listening to audio, watching animations and videos, even playing in

three-dimensional space. Sound and movement make information come alive.

To experience it, you'll need special pieces of software called plug-ins. The term "plug-in" refers to a small, add-on piece of software which extends the capabilities of your web browser, like Netscape Navigator or Microsoft Explorer, turning your computer into a radio or TV.

When you arrive at a web page which contains a file requiring a plug-in which you don't have, you will usually receive a message asking if you want to get it by downloading it and installing it into your computer. Most of the time, the installation will be automatic.

Occasionally, you'll run into a downloaded file which needs to be decompressed or

un-zipped before installation. Once installed, plug-ins run automatically, without you having to do anything.

Many multimedia controls still need to be obtained from the developer but are installed automatically.

Shockwave is a good example of this. All you need to do is go to the Macromedia site and click on the link to install the ActiveX control. The rest happens automatically. The next time you go to a "Shocked" website, the Shockwave control loads and plays the movie.

Most plug-ins and controls can be downloaded for free on the Internet, although not all will work with every system. Some of them, for instance, only work with windows95.

当你不再仅仅限于文字和静止图片时，网上生活会丰富多彩得多。即使是个因特网新手，你也许听说过在线式多媒体——听音乐、看动画和录像，甚至玩三维游戏。声音和活动画面使信息变得活灵活现。

要体验这些，你需要叫作“插件”的特殊软件。术语“插件”指的是一个附加的小软件，他能够扩展你的网络浏览器（比如网景的导航者或微软的探索者）的功能——把你的计算机变成一台收音机或电视机。

当你进入的网页含有需要使用插件程序的文件，而你却又没有这个程序时，通常你会收到一个信息，询问你是否需要下载该程序并安装到你的电脑里。多数情况下安装是自动运行的。

有时候，你会碰到一个需要在安装前先进行解压缩的下载文件。一旦安装完毕，插件就会自动运行，无需你做任何事。

许多多媒体的控制程序仍需从开发商处索取，不过都是自动安装的。

Shockwave 就是这方面一个很好的例子。你所需要做的就是到Macromedia网站上点击链接来安装ActiveX控制程序，剩下的事自动就会完成。下次再到一个需要使Shockwave 的网站时，Shockwave 控制程序就会自动装载并播放电影。

大多数插件和控制程序可以从因特网上免费下载，尽管并非所有这些程序都会在每一个系统上正常运行。例如有些就只适用于视窗95。

Local Area Network(局域网)

There are two categories of networks: local area networks (LANs) and wide area networks (WANs). Here I'd like to mainly talk about LAN.

A LAN is a system of computers and associated peripherals such as Printers that are physically connected by cable within a limited geographical area-typically in an office building or on a college campus. The topology of the network may be ring, star or bus. LANs use fiber optics or coaxial cable to connect computers, and each computer must have special communications software installed oil its hard disk. Software has been developed that allows computers with different platforms to coexist and exchange data on the same LAN.

A File Server

Many networks are managed by a computer called a file server.A file server has a large －capacity hard disk and special software that manages access to flies on the network. It controls how data and database are shared among users on the network and how users access master copies of data and application software on the centralized hard disk. It is the file server's job to make sure that users don't accidentally try to update a file at the same time and scramble the data. The file server may also manage the access to an expensive piece of hardware such as a laser printer.

When a file server is used on a LAN, large databases are stored on the server and users may store all of their work flies there as well.This operation is analogous to someone's manually collecting all the data each day placing them in a file drawer, and then redistributing these data to the workers as needed.

The LAN Operating System--Net Ware

Novell's Net ware has become the strongest competitor to IBM's own network operating environment and predates IBM in its support for LANs. In fact,IBM now markets Net ware for both the PC Network and for Token Ring in addition to its own software.The key to Net ware is the file server software and directories on the server are mapped to network drives, thus operating like virtual diskettes from a user's perspective. The server software is a multitasking operating system with a file structure consistent with DOS 2.x and DOS 3.x. The