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1、第10章 Network,本章要點 What is a Network? Words and Expressions How To Do: A Search Tool How To Work：Security suites Grammar Focus：倒裝句及句子種類 Text in Chinese：網(wǎng)絡(luò) Reading Selection: A Home (Page) of Your Own 科技英語翻譯方法與技巧（） Practical Writing：標(biāo)點符號,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、句意為：這種網(wǎng)絡(luò)結(jié)構(gòu)常見于相互間分享存儲于不同微機上的信息，對于公有信息共享效率不如星型網(wǎng)絡(luò)。 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”意為：由組成，由構(gòu)成，“l(fā)inked to a central host computer”作“s

16、everal computers” 的后置定語，“theses other computers” 指除了中心計算機以外的“several computers”.本句意為：樹型（分級型）網(wǎng)絡(luò)由幾個計算機連接到一個中央主機上，像星型網(wǎng)絡(luò)一樣，但是這些連網(wǎng)的計算機同時又是其他更小計算機的主機。,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” 意為：按次序，依次?！皐hich”引導(dǎo)的非限制性定語從句對“the corporations mainframe”作補充說明。本句意為：例如，一個公司的各個部門可以讓本部門的個人微機連網(wǎng)到部門的主機微機上，部門主機又可以連網(wǎng)到公司的大型主機上，大型主機存有數(shù)據(jù)和程序供本公司所有連網(wǎng)微機使用。,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：倒裝句及句子種類 倒裝句：英語中的陳述句一般使用正常語序，即“主語+謂語”。有時由于結(jié)構(gòu)或修辭的需要，將謂語放在主語前面，這就形成了倒裝句。倒裝句的結(jié)構(gòu)可分為部分倒裝和全部倒裝。 句子種類： 1句子按使用目的可分為 1）陳述句：說明一個事實或陳述一種看法。 2）疑問句：提出問題，有以下4種。 a一般疑問句：Can you

24、finish the work in time? 你能及時完成任務(wù)嗎？ b特殊疑問句：Where do you live?你住那兒？ c選擇疑問句：Do you want tea or coffee? 你是要茶還是要咖啡？ d反意疑問句：He doesnt know her, does he?他不認(rèn)識她，對不對？ 3）祈使句：提出請求、建議或命令。 4）感嘆句：表示說話人驚奇、喜悅、憤怒等情緒。 2句子按其結(jié)構(gòu)可以分為 1）簡單句：只包含一個主謂結(jié)構(gòu)的句子叫簡單句。例如： She is fond of collecting stamps. 她喜歡集郵。,What is a Network?,2

25、）并列句：包含兩個或兩個以上主謂結(jié)構(gòu)的句子叫并列句，句與句之間通常用并列連詞或分號來連接。例如： The food was good, but he had little appetite. 食物很精美，但他卻沒什么胃口。 （主） （謂） （主）（謂） 3）復(fù)合句：包含一個主句和一個或幾個從句的句子叫復(fù)合句，從句由從屬連詞引導(dǎo)，例如： The film had begun when we got to the cinema.我們到達(dá)電影院的時候，電影已經(jīng)開演了。 主句 從句,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：網(wǎng)絡(luò) 通過電子通信系統(tǒng)，你的計算機能夠連接世界范圍內(nèi)的其他計算機，連接因特網(wǎng)和更大型的計算機。電子通信系統(tǒng)通過有線和無線通信線路在世界各地間傳輸信息。這樣的電子通信線路稱為網(wǎng)絡(luò)。 網(wǎng)絡(luò)可以安排成幾種不同的連接方式，稱為網(wǎng)絡(luò)結(jié)構(gòu)或拓?fù)洹?種主要的網(wǎng)絡(luò)結(jié)構(gòu)有：星型、總線型、環(huán)形、樹型或分級型。 星型網(wǎng)絡(luò)由許多小型計算機或外圍設(shè)備連接到一個中央單元（主機或文件服務(wù)器）。主機進(jìn)行總控制，詢問每個連網(wǎng)的計算機是否有信息要傳遞。星型網(wǎng)絡(luò)的一大優(yōu)勢是幾個用戶可以共享中央主

30、機的資源。 在總線型網(wǎng)絡(luò)中，沒有主機，連網(wǎng)的每個設(shè)備處理自己的通信。所有通信沿著同一個總線電纜傳輸，隨著信息沿著總線傳輸，每個設(shè)備都在檢索需要的信息。這種網(wǎng)絡(luò)結(jié)構(gòu)常用于相互間分享存儲在不同微機上的信息，但是對于公有信息共享效率不如星型網(wǎng)絡(luò)。 環(huán)型網(wǎng)絡(luò)中，每個設(shè)備與另外兩個設(shè)備連接，形成一個環(huán)。環(huán)型網(wǎng)絡(luò)沒有主機或文件服務(wù)器。信息繞著環(huán)網(wǎng)傳輸直到到達(dá)正確的目的地。對于微型計算機，環(huán)網(wǎng)是4種網(wǎng)絡(luò)連接中最少使用的類型。環(huán)網(wǎng)經(jīng)常用于連接大型計算機，特別適于地理跨度大的網(wǎng)絡(luò)。,What is a Network?,樹型網(wǎng)絡(luò)由幾個計算機連接到一個中央主機上，像星型網(wǎng)絡(luò)一樣，但是這些連網(wǎng)的計算機同時又是其他更

31、小的計算機的主機。樹型網(wǎng)絡(luò)多應(yīng)用于集中的組織團體中。例如， 一個公司的各個部門可以讓本部門的個人微機連網(wǎng)到部門的主機微機上，部門主機又可以連網(wǎng)到公司的大型計算機主機上，大型主機存有數(shù)據(jù)和程序供本公司所有連網(wǎng)微機使用。 地域上講，使用有線和無線連接的網(wǎng)絡(luò)覆蓋范圍可從一個城市到全世界。這里簡介三種網(wǎng)絡(luò)覆蓋類型：局域網(wǎng)、城域網(wǎng)和廣域網(wǎng)。 連網(wǎng)的計算機和其他設(shè)備地理分布臨近，例如在一個建筑內(nèi)，或某一大學(xué)校園內(nèi)，這樣的網(wǎng)絡(luò)稱作局域網(wǎng)。局域網(wǎng)由電纜（電話線、co-axial 或 光纖）連接，常采用總線連接結(jié)構(gòu)。局域網(wǎng)可以連接到其他局域網(wǎng)或大型網(wǎng)絡(luò)上。 城域網(wǎng)規(guī)模大于局域網(wǎng)，用于連接一個城市內(nèi)的各個辦公樓區(qū)

32、。移動電話系統(tǒng)利用局域網(wǎng)，開通汽車電話和手機業(yè)務(wù)。 廣域網(wǎng)指國家或世界范圍的網(wǎng)絡(luò)。廣域網(wǎng)除了使用電纜連接外，還使用微波傳遞和衛(wèi)星傳遞到達(dá)遠(yuǎn)程的用戶。最廣泛使用的廣域網(wǎng)就是覆蓋全球的因特網(wǎng)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?,科技英語翻譯方法與技巧（） 英語中句型的翻譯 1被動語態(tài) 被動語態(tài)是科技語體特點之一。在科技英語文

42、獻(xiàn)中，會經(jīng)常碰到的語法現(xiàn)象。下面簡要介紹一下如何正確地理解和翻譯這種句子。 1）將原有的被動句譯成漢語的被動句 若當(dāng)英語被動句在語義上著重謂語動詞本身的意義，可直接用漢語被動結(jié)構(gòu)來翻譯。 例如： The telephone was invented by Graham Bell. 電話為葛雷姆貝爾發(fā)明。 As with ordinary algebra，the operator symbo1 () can be omitted 正如普通代數(shù)一樣，運算符()可被省略。,What is a Network?,2）將被動句譯成漢語的主動句 漢語的被動句沒有英語被動句運用得廣泛。在翻譯英語被動句時，可

43、在保持原文意思不變的基礎(chǔ)上，根據(jù)句子整體結(jié)構(gòu)將被動句轉(zhuǎn)換成漢語的主動句進(jìn)行翻譯。被動句轉(zhuǎn)譯成漢語的主動句關(guān)鍵是如何確定漢語主動句的主語。一般有以下幾種方法： 被動句不含動作執(zhí)行者，可加入“有人，大家，人們，我們”等。 例如： A woman was heard moaning after midnight. 有人在深夜聽到一女人呻吟。 但被動句中的動作承受對象含有物主代詞，可根據(jù)物主代詞所表示的人稱來確定譯句的主語。 例如：Being asked to give a performance, she could not refuse. 大家請她表演個節(jié)目，她不能拒絕。 Our calculat

44、ion must be checked and rechecked. 我們必須把數(shù)字再核對幾次。,What is a Network?, 當(dāng)被動句含有 by 短語時，只要不違反原文意思，并又更能合乎中文語法，可直接將 by 短語改做主語。 例如： English is spoken by many people. 許多人講英語。 Large quantities of fuel are used by modern industry. 現(xiàn)代工業(yè)耗用大量燃料。 當(dāng)原被動結(jié)構(gòu)在語義上表示義務(wù)時，可直接譯成漢語的主動句。 例如： The matter must be investigated car

45、efully. 這件事應(yīng)仔細(xì)調(diào)查。 當(dāng)被動結(jié)構(gòu)的謂語在語義上接近不及物動詞時，可直接譯成漢語的主動句。 例如： Troops were dismissed when the parade was over. 游行結(jié)束后， 隊伍就解散了。,What is a Network?,3）將被動句譯成漢語的無主句 當(dāng)遇到不帶by的短語，并含有情態(tài)動詞的英語被動句時，我們可以轉(zhuǎn)譯成漢語的無主句。 例如： Therefore logic must be used when making decisions，or when calculating or processing data 因此，在做判定或者計算或

46、處理數(shù)據(jù)時，必須采用邏輯。 Life cant be understood without much charity. 沒有愛心，就無法了解生活。 4）固定譯法 科技英語中有不少常用的被動結(jié)構(gòu)，已經(jīng)有了習(xí)慣譯法。 例如： It should be pointed out that 應(yīng)當(dāng)指出 It should be Obvious that 很明顯 It is very important that 是很重要的 It is said that 據(jù)說,What is a Network?,2非謂語動詞 在英語中，動詞可分為限定動詞和非限定動詞兩大類。限定動詞在句子中做謂語，它受到主語的限制。而非

47、限定動詞在句子中不能獨立作謂語，但可以和助動詞或情態(tài)動詞等構(gòu)成謂語，還可以在句中充當(dāng)主語、賓語、定語、狀語等。因此，非限定動詞的句子復(fù)雜些，翻譯時有一定的難度。這里，就非限定動詞的若干翻譯技巧做一些探討。非限定動詞有三種形式： 1）不定式（the Infinitive） 不定式在科技文章中用的很多,它是一種非限定形式，通常前面帶有小品詞“to”，有時也可不帶“to”。它在句中做主語、賓語、表語、定語、狀語等。翻譯成中文時應(yīng)根據(jù)其在句子中所起的作用及上下文，而“酌情”予以翻譯。 例如： To ignore this would be a mistake. 忽視這一點是錯誤的。（做主語） It o

48、nly took us a year to complete the work. 完成這個工作只花了我們一年時間。（間接做主語） 在許多情況下，常常用代詞“it”來帶做主語，這是為了使句子比較平穩(wěn)。這種結(jié)構(gòu)在科技文獻(xiàn)中是經(jīng)常出現(xiàn)的。,What is a Network?,I didnt think to find you here. 沒想到在這兒碰到你。（做賓語） I think it better to translate it this way. 我覺得這樣譯更好些。（間接做賓語） Efforts to standardize high-level languages and compil

49、ers have received much attention in recent years. 使高級語言及編譯程序標(biāo)準(zhǔn)化的努力，近年來已經(jīng)受到人們的很大關(guān)注。（做定語） 不定式做定語時一般放在它所修飾的名詞后面?？勺g成“的”。 His job is to clean the classroom. 它的工作是打掃教室。（做表語） To create different colors，the intensity of each of the three electron beams is varied.（做狀語） 為了生成不同的顏色，三種電子束中的每一種的強度均是可變的。 Computers

50、 can connect to these networks to use resources in another city or country.（做狀語） 計算機可以連接到這些網(wǎng)絡(luò)上，以便使用另一城市或另一國家的資源。 動詞不定式作目的狀語時可譯成“為了”，“以便”等。但有時不太容易看出，需根據(jù)上下文來判斷。一般放在句首，譯為“為了”；放在句末，譯為“以便”。,What is a Network?,2）動名詞 動名詞是一種非限定動詞，它在句中起名詞作用，也可以用來構(gòu)成名詞。但它具有動詞的若干性質(zhì)，在句中用做主語、表語和賓語等。 例如： Developing an LSI circuit

51、requires a great deal of engineering research and development 開發(fā)大規(guī)模集成電路需要大量的工程研究和工程發(fā)展工作。（做主語） The real problem is getting to know the instructions of using the computer. 真正的問題是了解使用計算機的指令。（做表語） The RAM capacity can sometimes be expanded by adding extra chips RAM的容量有時可以通過附加額外的芯片來加以擴展。（做賓語）,What is a N

52、etwork?,3）分詞 分詞在科技英語文章中也是一種很常見的語法現(xiàn)象，它有兩種形式：現(xiàn)在分詞和過去分詞。它主要起形容詞和副詞作用。一般地說，分詞短語在句子中所起的具體作用為表語、定語、狀語等等。 例如： He looked disappointed. 他顯得很失望。（做表語） Barking dogs seldom bite. 愛叫的狗很少咬人。（做定語） Working in the background，the operating system manages，coordinates，and controls the computer hardware，input and output tasks，and storage system. 在此背景下工作時，操作系統(tǒng)管理、協(xié)調(diào)及控制計算機的硬件、輸入及輸出任務(wù)，以及存儲系統(tǒng)。（做狀語）,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