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1、第10章 Network,本章要点 What is a Network? Words and Expressions How To Do: A Search Tool How To Work：Security suites Grammar Focus：倒装句及句子种类 Text in Chinese：网络 Reading Selection: A Home (Page) of Your Own 科技英语翻译方法与技巧（） Practical Writing：标点符号,What is a Network?,Throughout the world, your microcomputer can

2、connect to other microcomputers, to the Internet, and to larger computers through the electronic communication systems. The electronic communication systems transmit information over communication lines of cable and air from one location to another. Such electronic communication lines are known as n

3、etworks (Figure 10-1). A network can be arranged in several different ways to meet different users needs. The network arrangement is called the networks topology. The four principal topologies are star, bus, ring, and hierarchical. In a star network, a number of small computers or peripheral devices

4、 are linked to a central unitmaybe a host computer or a file server. The host computer maintains its control by asking whether each connected device has messages to send. One advantage of the star network is that several users can share resources on a central host computer (Figure 10-2). In a bus ne

5、twork, there is no host computer, and instead each device in the network handles its own communication control. All communications travel along a common connecting cable called a bus and as the information passes along the bus, each device examines to see if the information is intended. *,What is a

6、Network?,This arrangement is common for sharing data stored on different microcomputers but not as efficient as the star network for sharing common resources (See Figure 10-3).,Figure 10-1 Figure 10-2 Figure 10-3,What is a Network?,In a ring network, each device is connected to two other devices, fo

7、rming a ring. There is no central computer or file server. Messages are passed around the ring until they reach the correct destination. With microcomputers, the ring arrangement is the least frequently used of the four networks. It is often used to link mainframe computers, especially over wide geo

8、graphical areas (See Figure 10-4). * The hierarchical network consists of several computers linked to a central host computer, just like a star network, but these other computers are also hosts to other smaller com- puters. A hierarchical network is useful in centralized organizations. * For example

9、, different departments within an organization may have individual microcomputers connected to departmental minicomputers and the minicomputers in turn may be connected to the corporations mainframe, which contains data and programs accessible to all (See Figure 10-5).,What is a Network?,Figure 10-4

10、 Figure 10-5,What is a Network?,Figure 10-6 Geographically, using both cable and air connections, networks range from home to citywide and even international. Here let us have some idea of three types: local area networks, metropolitan area networks, and wide area networks (See Figure 10-6). Network

11、s with computers and other devices in close physical proximitywithin the same building, or on the same campus, for instanceare called local area networks (LANs). Linked by cabletelephone, co-axial, or fiber-opticLANs often use a bus form of organization. A LAN may be linked to other LANs or to large

12、r networks. Figure 10-7-2Figure 10-7-1 A step up from the LAN is the MANthe metropolitan area network. These networks are used as links between office buildings in a city. Cellular phone systems expand the flexibility of MANs by allowing links to car phones and portable phones. Wide Area Networks (W

13、ANs) are countrywide and worldwide networks. Besides cables, they use microwave relays and satellites to reach users over long distances. The widest of all WANs is the Internet, which spans the entire globe (See Figure 10-7-1; Figure 10-7-2).,What is a Network?,Notes: 1“This arrangement is common fo

14、r sharing data stored on different microcomputers but not as efficient as the star network for sharing common resources.” 本句中，“but not as efficient as the star network for sharing common resources” 等于 but the arrangement is not as efficient as the star network in regard to sharing common resources.本

15、句意为：这种网络结构常见于相互间分享存储于不同微机上的信息，对于公有信息共享效率不如星型网络。 2“The hierarchical network consists of several computers linked to a central host computer, just like a star network, but these other computers are also hosts to other smaller computers.”本句中，“consist of”意为：由组成，由构成，“linked to a central host computer”作“s

16、everal computers” 的后置定语，“theses other computers” 指除了中心计算机以外的“several computers”.本句意为：树型（分级型）网络由几个计算机连接到一个中央主机上，像星型网络一样，但是这些连网的计算机同时又是其他更小计算机的主机。,What is a Network?,3“For example, different departments within an organization may have individual microcomputers connected to department minicomputers and

17、 the minicomputers in turn may be connected to the corporations mainframe, which contains data and programs accessible to all.”本句中，“in turn” 意为：按次序，依次。“which”引导的非限制性定语从句对“the corporations mainframe”作补充说明。本句意为：例如，一个公司的各个部门可以让本部门的个人微机连网到部门的主机微机上，部门主机又可以连网到公司的大型主机上，大型主机存有数据和程序供本公司所有连网微机使用。,What is a Ne

18、twork?,Choose the best answer to each question with the information from the passage. 1What is the star network? AEach computer handles its own communications along a common connecting cable. BEach computer links to a central unit and is controlled by this central unit. CEach computer connects to tw

19、o other devices forming a circle. DSmaller computers connect to a central host. 2What is the local area network? AIt is used to link office buildings within a city. BIt spans countries, or forms worldwide networks. CIt connects devices that are close to one another, in the same office, for example.

20、DIt is larger than a metropolitan area network and smaller than the Internet.,What is a Network?,3Which of the following expressions is true about the Internet? AThe Internet is the largest network in the world and everyone who connects his computer to the Internet can share information and make com

21、munication throughout the globe. BThe Internet is just the wide area network that spans countries to load information and deliver messages. CThe Internet is a network server to control countless computers and other devices that have connected to it. DThe Internet is not as competent as WWW (World Wi

22、de Web) for electronic communications. 4What is a communication system? AAny system that can transmit data from one location to another. BAn electronic system that transmits data over communication lines from one location to another. CCables that span over countries to send messages from one locatio

23、n to another. DA system of electronic signals sending and receiving information through telephone lines.,What is a Network?,Grammar Focus：倒装句及句子种类 倒装句：英语中的陈述句一般使用正常语序，即“主语+谓语”。有时由于结构或修辞的需要，将谓语放在主语前面，这就形成了倒装句。倒装句的结构可分为部分倒装和全部倒装。 句子种类： 1句子按使用目的可分为 1）陈述句：说明一个事实或陈述一种看法。 2）疑问句：提出问题，有以下4种。 a一般疑问句：Can you

24、finish the work in time? 你能及时完成任务吗？ b特殊疑问句：Where do you live?你住那儿？ c选择疑问句：Do you want tea or coffee? 你是要茶还是要咖啡？ d反意疑问句：He doesnt know her, does he?他不认识她，对不对？ 3）祈使句：提出请求、建议或命令。 4）感叹句：表示说话人惊奇、喜悦、愤怒等情绪。 2句子按其结构可以分为 1）简单句：只包含一个主谓结构的句子叫简单句。例如： She is fond of collecting stamps. 她喜欢集邮。,What is a Network?,2

25、）并列句：包含两个或两个以上主谓结构的句子叫并列句，句与句之间通常用并列连词或分号来连接。例如： The food was good, but he had little appetite. 食物很精美，但他却没什么胃口。 （主） （谓） （主）（谓） 3）复合句：包含一个主句和一个或几个从句的句子叫复合句，从句由从属连词引导，例如： The film had begun when we got to the cinema.我们到达电影院的时候，电影已经开演了。 主句 从句,What is a Network?,Point out the types of the following sent

26、ences . 1“Did he study much?” 2Whos going to look after her? 3Tom pushed back his chair as quietly as possible gathering up his pad and pencil as he backed away from the table. 4Shall I do it or will you do it yourself? 5Come on, heres our bus. Lets go on top. 6Really! I dont believe it. 7“Oh, Lucy,

27、” she burst out, after kissing her, “Youll stay with Tom and me, wont you?” 8Nancy finding my passport in the refrigerator! 9Dont go near it! 10As we drove along, my spirits revived again.,What is a Network?,Point out the types of interrogative sentences. 1Does she have sisters? 2Her family once liv

28、ed there, didnt they? 3Which way are you going home, Tom? 4Is she in town or has she going to the country? 5Can you type? 6Is he married or single? 7You dont think we have lost our way, do you? 8Where do you sail from? 9Are you happy over here, or do you to go back to France? 10Why didnt you speak t

29、o my father yourself on the boat?,What is a Network?,Text in Chinese：网络 通过电子通信系统，你的计算机能够连接世界范围内的其他计算机，连接因特网和更大型的计算机。电子通信系统通过有线和无线通信线路在世界各地间传输信息。这样的电子通信线路称为网络。 网络可以安排成几种不同的连接方式，称为网络结构或拓扑。4种主要的网络结构有：星型、总线型、环形、树型或分级型。 星型网络由许多小型计算机或外围设备连接到一个中央单元（主机或文件服务器）。主机进行总控制，询问每个连网的计算机是否有信息要传递。星型网络的一大优势是几个用户可以共享中央主

30、机的资源。 在总线型网络中，没有主机，连网的每个设备处理自己的通信。所有通信沿着同一个总线电缆传输，随着信息沿着总线传输，每个设备都在检索需要的信息。这种网络结构常用于相互间分享存储在不同微机上的信息，但是对于公有信息共享效率不如星型网络。 环型网络中，每个设备与另外两个设备连接，形成一个环。环型网络没有主机或文件服务器。信息绕着环网传输直到到达正确的目的地。对于微型计算机，环网是4种网络连接中最少使用的类型。环网经常用于连接大型计算机，特别适于地理跨度大的网络。,What is a Network?,树型网络由几个计算机连接到一个中央主机上，像星型网络一样，但是这些连网的计算机同时又是其他更

31、小的计算机的主机。树型网络多应用于集中的组织团体中。例如， 一个公司的各个部门可以让本部门的个人微机连网到部门的主机微机上，部门主机又可以连网到公司的大型计算机主机上，大型主机存有数据和程序供本公司所有连网微机使用。 地域上讲，使用有线和无线连接的网络覆盖范围可从一个城市到全世界。这里简介三种网络覆盖类型：局域网、城域网和广域网。 连网的计算机和其他设备地理分布临近，例如在一个建筑内，或某一大学校园内，这样的网络称作局域网。局域网由电缆（电话线、co-axial 或 光纤）连接，常采用总线连接结构。局域网可以连接到其他局域网或大型网络上。 城域网规模大于局域网，用于连接一个城市内的各个办公楼区

32、。移动电话系统利用局域网，开通汽车电话和手机业务。 广域网指国家或世界范围的网络。广域网除了使用电缆连接外，还使用微波传递和卫星传递到达远程的用户。最广泛使用的广域网就是覆盖全球的因特网了。,What is a Network?,Reading Selection: A Home (Page) of Your Own In the 60s, people asked about your astrological sign. In the 90s, they want to know your URL. These days, having a web address is almost as

33、 important as a street address. Your Website is an electronic meeting place for your family, friends and potentially*, millions of people around the world. Building your digital domain can be easier than you may think. Best of all, you may not have to spend a cent. The Web brims with all kinds of fr

34、ee services, from tools to help you to build your site, to free graphics, animation and site hosting. All it takes is some time and creativity. Think of your home page as the starting point of your Website. Like the table of contents of a book or magazine, the home page is the front door. Your site

35、can have one or more pages, depending on how you design it. If there isnt a lot of information just yet, your site will most likely have only a home page. But the site is sure to grow over time. While Web pages vary dramatically in their design and content, most use a traditional magazine layout. At

36、 the top of the page is a banner graphic. Next comes a greeting and a short description of the site. Pictures, text, and links to other Websites follow.,What is a Network?,If the site has more than one page, theres typically a list of itemssimilar to an indexoften with a brief description. The items

37、 in the list link to other pages on the Website. Sometimes these links are highlighted words in the body of the text. It can also be a combination of both. Additionally, a Web page may have images that link to other content. Before you start building your site, do some planning. Think about whom the

38、 site is for and what you want to say. Next, gather up the material that you want to put on the site: write the copy, scan the photos, design or find the graphics. Draw a rough layout on a sheet of paper. While there are no rules you have to follow, there are a few things to keep in mind. Start simp

39、ly: If you are too ambitious at the beginning, you may never get the site off the ground. You can always add to your site. Less is better: Most people dont like to read a lot of text online. Break it into small chunks.,What is a Network?,Use restraint: Although you can use wild colors and images for

40、 the background of your pages, make sure your visitors will be able to read the text easily. Smaller is better: Most people connect to the Internet with a modem. Since it can take a long time to download large image files, keep the file sizes small. Have the rights: Dont put any material on your sit

41、e unless you are sure you can do it legally. Now its time to roll up your sleeves and start building. Learn the Net Communities provides tools to help you to build your site, free Web hosting, and a community of other homesteaders.,What is a Network?,科技英语翻译方法与技巧（） 英语中句型的翻译 1被动语态 被动语态是科技语体特点之一。在科技英语文

42、献中，会经常碰到的语法现象。下面简要介绍一下如何正确地理解和翻译这种句子。 1）将原有的被动句译成汉语的被动句 若当英语被动句在语义上着重谓语动词本身的意义，可直接用汉语被动结构来翻译。 例如： The telephone was invented by Graham Bell. 电话为葛雷姆贝尔发明。 As with ordinary algebra，the operator symbo1 () can be omitted 正如普通代数一样，运算符()可被省略。,What is a Network?,2）将被动句译成汉语的主动句 汉语的被动句没有英语被动句运用得广泛。在翻译英语被动句时，可

43、在保持原文意思不变的基础上，根据句子整体结构将被动句转换成汉语的主动句进行翻译。被动句转译成汉语的主动句关键是如何确定汉语主动句的主语。一般有以下几种方法： 被动句不含动作执行者，可加入“有人，大家，人们，我们”等。 例如： A woman was heard moaning after midnight. 有人在深夜听到一女人呻吟。 但被动句中的动作承受对象含有物主代词，可根据物主代词所表示的人称来确定译句的主语。 例如：Being asked to give a performance, she could not refuse. 大家请她表演个节目，她不能拒绝。 Our calculat

44、ion must be checked and rechecked. 我们必须把数字再核对几次。,What is a Network?, 当被动句含有 by 短语时，只要不违反原文意思，并又更能合乎中文语法，可直接将 by 短语改做主语。 例如： English is spoken by many people. 许多人讲英语。 Large quantities of fuel are used by modern industry. 现代工业耗用大量燃料。 当原被动结构在语义上表示义务时，可直接译成汉语的主动句。 例如： The matter must be investigated car

45、efully. 这件事应仔细调查。 当被动结构的谓语在语义上接近不及物动词时，可直接译成汉语的主动句。 例如： Troops were dismissed when the parade was over. 游行结束后， 队伍就解散了。,What is a Network?,3）将被动句译成汉语的无主句 当遇到不带by的短语，并含有情态动词的英语被动句时，我们可以转译成汉语的无主句。 例如： Therefore logic must be used when making decisions，or when calculating or processing data 因此，在做判定或者计算或

46、处理数据时，必须采用逻辑。 Life cant be understood without much charity. 没有爱心，就无法了解生活。 4）固定译法 科技英语中有不少常用的被动结构，已经有了习惯译法。 例如： It should be pointed out that 应当指出 It should be Obvious that 很明显 It is very important that 是很重要的 It is said that 据说,What is a Network?,2非谓语动词 在英语中，动词可分为限定动词和非限定动词两大类。限定动词在句子中做谓语，它受到主语的限制。而非

47、限定动词在句子中不能独立作谓语，但可以和助动词或情态动词等构成谓语，还可以在句中充当主语、宾语、定语、状语等。因此，非限定动词的句子复杂些，翻译时有一定的难度。这里，就非限定动词的若干翻译技巧做一些探讨。非限定动词有三种形式： 1）不定式（the Infinitive） 不定式在科技文章中用的很多,它是一种非限定形式，通常前面带有小品词“to”，有时也可不带“to”。它在句中做主语、宾语、表语、定语、状语等。翻译成中文时应根据其在句子中所起的作用及上下文，而“酌情”予以翻译。 例如： To ignore this would be a mistake. 忽视这一点是错误的。（做主语） It o

48、nly took us a year to complete the work. 完成这个工作只花了我们一年时间。（间接做主语） 在许多情况下，常常用代词“it”来带做主语，这是为了使句子比较平稳。这种结构在科技文献中是经常出现的。,What is a Network?,I didnt think to find you here. 没想到在这儿碰到你。（做宾语） I think it better to translate it this way. 我觉得这样译更好些。（间接做宾语） Efforts to standardize high-level languages and compil

49、ers have received much attention in recent years. 使高级语言及编译程序标准化的努力，近年来已经受到人们的很大关注。（做定语） 不定式做定语时一般放在它所修饰的名词后面。可译成“的”。 His job is to clean the classroom. 它的工作是打扫教室。（做表语） To create different colors，the intensity of each of the three electron beams is varied.（做状语） 为了生成不同的颜色，三种电子束中的每一种的强度均是可变的。 Computers

50、 can connect to these networks to use resources in another city or country.（做状语） 计算机可以连接到这些网络上，以便使用另一城市或另一国家的资源。 动词不定式作目的状语时可译成“为了”，“以便”等。但有时不太容易看出，需根据上下文来判断。一般放在句首，译为“为了”；放在句末，译为“以便”。,What is a Network?,2）动名词 动名词是一种非限定动词，它在句中起名词作用，也可以用来构成名词。但它具有动词的若干性质，在句中用做主语、表语和宾语等。 例如： Developing an LSI circuit

51、requires a great deal of engineering research and development 开发大规模集成电路需要大量的工程研究和工程发展工作。（做主语） The real problem is getting to know the instructions of using the computer. 真正的问题是了解使用计算机的指令。（做表语） The RAM capacity can sometimes be expanded by adding extra chips RAM的容量有时可以通过附加额外的芯片来加以扩展。（做宾语）,What is a N

52、etwork?,3）分词 分词在科技英语文章中也是一种很常见的语法现象，它有两种形式：现在分词和过去分词。它主要起形容词和副词作用。一般地说，分词短语在句子中所起的具体作用为表语、定语、状语等等。 例如： He looked disappointed. 他显得很失望。（做表语） Barking dogs seldom bite. 爱叫的狗很少咬人。（做定语） Working in the background，the operating system manages，coordinates，and controls the computer hardware，input and output tasks，and storage system. 在此背景下工作时，操作系统管理、协调及控制计算机的硬件、输入及输出任务，以及存储系统。（做状语）,What is a Network?,Translate the passage. Modern computers are often designed as a related series so that each processor in the series is compatible with the others. Compatibility is a design technique which enables any