计算机网络外文翻译
附录
一、英文原文：
The NetWorks
Birth of the Net
The Internet has had a relatively brief, but explosive history so far. It grew out of an experiment begun in the 1960's by the U.S. Department of Defense. The DoD wanted to create a computer network that would continue to function in the event of a disaster, such as a nuclear war. If part of the network were damaged or destroyed, the rest of the system still had to work. That network was ARPANET, which linked U.S. scientific and academic researchers. It was the forerunner of today's Internet.
In 1985, the National Science Foundation (NSF) created NSFNET, a series of networks for research and education communication. Based on ARPANET protocols, the NSFNET created a national backbone service, provided free to any U.S. research and educational institution. At the same time, regional networks were created to link individual institutions with the national backbone service.
NSFNET grew rapidly as people discovered its potential, and as new software applications were created to make access easier. Corporations such as Sprint and MCI began to build their own networks, which they linked to NSFNET. As commercial firms and other regional network providers have taken over the operation of the major Internet arteries, NSF has withdrawn from the backbone business.
NSF also coordinated a service called InterNIC, which registered all addresses on the Internet so that data could be routed to the right system. This service has now been taken over by Network Solutions, Inc., in cooperation with NSF.
How the Web Works
The World Wide Web, the graphical portion of the Internet, is the most popular part of the Internet by far. Once you spend time on the Web,you will begin to feel like there is no limit to what you can discover. The Web allows rich and diverse communication by displaying text, graphics, animation, photos, sound and video.
So just what is this miraculous creation? The Web physically consists of your personal computer, web browser software, a connection to an Internet service provider, computers called servers that host digital data and routers and switches to direct the flow of information.
The Web is known as a client-server system. Your computer is the client; the remote computers that store electronic files are the servers. Here's how it works: Let's say you want to pay a visit to the the Louvre museum website. First you enter the address or URL of the website in your web browser (more about this shortly). Then your browser requests the web page from the web server that hosts the Louvre's site. The Louvre's server sends the data over the Internet to your computer. Your web
browser interprets the data, displaying it on your computer screen.
The Louvre's website also has links to the sites of other museums, such as the VaticanMuseum. When you click your mouse on a link, you access the web server for the VaticanMuseum.
The "glue" that holds the Web together is called hypertext and hyperlinks. This feature allow electronic files on the Web to be linked so you can easily jump between them. On the Web, you navigate through pages of information based on what interests you at that particular moment, commonly known as browsing or surfing the Net.
To access the Web you need web browser software, such as Netscape Navigator or Microsoft Internet Explorer. How does your web browser distinguish between web pages and other files on the Internet? Web pages are written in a computer language called Hypertext Markup Language or HTML.
Some Web History
The World Wide Web (WWW) was originally developed in 1990 at CERN, the European Laboratory for Particle Physics. It is now managed by The World Wide Web Consortium, also known as the World Wide Web Initiative.
The WWW Consortium is funded by a large number of corporate members, including AT&T, Adobe Systems, Inc., Microsoft Corporation and Sun Microsystems, Inc. Its purpose is to promote the growth of the Web by developing technical specifications and reference software that will be freely available to everyone. The Consortium is run by MIT with INRIA (The French National Institute for Research in Computer Science) acting as European host, in collaboration with CERN.
The NationalCenter for Supercomputing Applications (NCSA) at the University of Illinois at Urbana-Champaign, was instrumental in the development of early graphical software utilizing the World Wide Web features created by CERN. NCSA focuses on improving the productivity of researchers by providing software for scientific modeling, analysis, and visualization. The World Wide Web was an obvious way to fulfill that mission. NCSA Mosaic, one of the earliest web browsers, was distributed free to the public. It led directly to the phenomenal growth of the World Wide Web.
Understanding Web Addresses
You can think of the World Wide Web as a network of electronic files stored on computers all around the world. Hypertext links these resources together. Uniform Resource Locators or URLs are the addresses used to locate these files. The information contained in a URL gives you the ability to jump from one web page to another with just a click of your mouse. When you type a URL into your browser or click on a hypertext link, your browser is sending a request to a remote computer to download a file.
What does a typical URL look like? Here are some examples:
https://www.360docs.net/doc/143043058.html,/
The home page for study english.
ftp://https://www.360docs.net/doc/143043058.html,/pub/
A directory of files at MIT* available for downloading.
news:rec.gardens.roses
A newsgroup on rose gardening.
The first part of a URL (before the two slashes* tells you the type of resource or method of access at that address. For example:
·http - a hypertext document or directory
·gopher - a gopher document or menu
·ftp - a file available for downloading or a directory of such files
·news - a newsgroup
·telnet - a computer system that you can log into over the Internet
·WAIS* - a database or document in a Wide Area Information Search database ·file - a file located on a local drive (your hard drive)
The second part is typically the address of the computer where the data or service is located. Additional parts may specify the names of files, the port to connect to, or the text to search for in a database.
You can enter the URL of a site by typing it into the Location bar of your web browser, just under the toolbar.
Most browsers record URLs that you want to use again, by adding them to a special menu. In Netscape Navigator, it's called Bookmarks. In Microsoft Explorer, it's called Favorites. Once you add a URL to your list, you can return to that web page simply by clicking on the name in your list, instead of retyping the entire URL.
Most of the URLs you will be using start with http which stands for Hypertext Transfer Protocol*. http is the method by which HTML files are transferred over the Web. Here are some other important things to know about URLs:
· A URL usually has no spaces.
· A URL always uses forward slashes (//).
If you enter a URL incorrectly, your browser will not be able to locate the site or resource you want. Should you get an error message or the wrong site, make sure you typed the address correctly.
You can find the URL behind any link by passing your mouse cursor over the link. The pointer will turn into a hand and the URL will appear in the browser's status bar, usually located at the bottom of your screen.
Domain Names
When you think of the Internet, you probably think of ".com." Just what do those three letters at the end of a World Wide Web address mean?
Every computer that hosts data on the Internet has a unique numerical address. For example, the numerical address for the White House is 198.137.240.100. But since few people want to remember long strings of numbers, the Domain Name System (DNS)* was developed. DNS, a critical part of the Internet's technical infrastructure*, correlates* a numerical address to a word. To access the White House website, you could type its number into the address box of your web browser. But most people prefer to use "https://www.360docs.net/doc/143043058.html,." In this case, the domain name is https://www.360docs.net/doc/143043058.html,.
In general, the three-letter domain name suffix* is known as a generic top-level domain and describes the type of organization. In the last few years, the lines have somewhat blurred* between these categories.
.com - business (commercial)
.edu - educational
.org - non-profit
.mil - military
.net - network provider
.gov - government
A domain name always has two or more parts separated by dots and typically consists of some form of an organization's name and the three-letter suffix. For example, the domain name for IBM is "https://www.360docs.net/doc/143043058.html,"; the United Nations is "https://www.360docs.net/doc/143043058.html,."
If a domain name is available, and provided it does not infringe* on an existing trademark, anyone can register the name for $35 a year through Network Solutions, Inc., which is authorized to register .com, .net and .org domains. You can use the box below to see if a name is a available. Don't be surprised if the .com name you want is already taken, however. Of the over 8 million domain names, 85% are .com domains.
ICANN, the Internet Corporation for Assigned Names and Numbers, manages the Domain Name System. As of this writing, there are plans to add additional top-level domains, such as .web and .store. When that will actually happen is anybody's guess.
To check for, or register a domain name, type it into the search box.
It should take this form: https://www.360docs.net/doc/143043058.html,
In addition to the generic top-level domains, 244 national top-level domains were established for countries and territories*, for example:
.au - Australia
.ca - Canada
.fr - France
.de - Germany
.uk - United Kingdom
For US $275 per name, you can also register an international domain name with Net Names. Be aware that some countries have restrictions for registering names.
If you plan to register your own domain name, whether it's a .com or not, keep these tips in mind:
The shorter the name, the better. (But it should reflect your family name, interest or business.)
The name should be easy to remember.
It should be easy to type without making mistakes.
Remember, the Internet is global. Ideally, a domain name will "read" in a language other than English.
Decoding Error Messages
As you surf the Net, you will undoubtedly find that at times you can't access certain websites. Why, you make wonder? Error messages attempt to explain the
reason. Unfortunately, these cryptic* messages baffle* most people. We've deciphered* the most common ones you may encounter.
400 - Bad Request
Problem: There's something wrong with the address you entered. You may not be authorized* to access the web page, or maybe it no longer exists.
Solution: Check the address carefully, especially if the address is long. Make sure that the slashes are correct (they should be forward slashes) and that all the names are properly spelled. Web addresses are case sensitive, so check that the names are capitalized in your entry as they are in the original reference to the website.
401 - Unauthorized
Problem: You can't access a website, because you're not on the guest list, your password is invalid or you have entered your password incorrectly.
Solution: If you think you have authorization, try typing your password again. Remember that passwords are case sensitive.
403 - Forbidden
Problem: Essentially the same as a 401.
Solution: Try entering your password again or move on to another site.
404 - Not Found
Problem: Either the web page no longer exists on the server or it is nowhere to be found.
Solution: Check the address carefully and try entering it again. You might also see if the site has a search engine and if so, use it to hunt for the document. (It's not uncommon for pages to change their addresses when a website is redesigned.) To get to the home page of the site, delete everything after the domain name and hit the Enter or Return key.
503 - Service unavailable
Problem: Your Internet service provider (ISP) or your company's Internet connection may be down.
Solution: Take a stretch, wait a few minutes and try again. If you still have no luck, phone your ISP or system administrator.
Bad file request
Problem: Your web browser may not be able to decipher the online form you want to access. There may also be a technical error in the form.
Solution: Consider sending a message to the site's webmaster, providing any technical information you can, such as the browser and version you use.
Connection refused by host
Problem: You don't have permission to access the page or your password is incorrect.
Solution: Try typing your password again if you think you should have access.
Failed DNS lookup
Problem: DNS stands for the Domain Name System, which is the system that looks up the name of a website, finds a corresponding number (similar to a phone number), then directs your request to the appropriate web server on the Internet. When the lookup fails, the host server can't be located.
Solution: Try clicking on the Reload or Refresh button on your browser toolbar. If this doesn't work, check the address and enter it again. If all else fails, try again later.
File contains no data
Problem: The site has no web pages on it.
Solution: Check the address and enter it again. If you get the same error message, try again later.
Host unavailable
Problem: The web server is down.
Solution: Try clicking on the Reload or Refresh button. If this doesn't work, try again later.
Host unknown
Problem: The web server is down, the site may have moved, or you've been disconnected from the Net.
Solution: Try clicking on the Reload or Refresh button and check to see that you are still online. If this fails, try using a search engine to find the site. It may have a new address.
Network connection refused by the server
Problem: The web server is busy.
Solution: Try again in a while.
Unable to locate host
Problem: The web server is down or you've been disconnected from the Net.
Solution: Try clicking on the Reload or Refresh button and check to see that you are still online.
Unable to locate server
Problem: The web server is out-of-business or you may have entered the address
incorrectly.
Solution: Check the address and try typing it again.
二、英文翻译：
网络
网络的诞生
迄今为止，因特网的历史虽比较简短，但仍然是突破性的。在1960年代，因特网是在美国国防部的实验中产生的。DOD希望发明一种计算机网络，它能在类似原子核战争的重大灾难中发挥作用。如果网络的一部分遭到损害，或者是毁灭性的破坏，那么系统的其它部分仍能正常工作。那个网络就是阿帕网，它连接到美国的科学和学术研究人员。阿帕网是我们今天所用网络是始祖。
在1985年，全美科学基金会（全美科学财团）创建了NSFNET，这是一系列用于研究和教育交流用的网络。根据阿帕网议定书，NSFNET创建了国家支柱服务，即对任何美国研究是学术机构提供免费服务。同时，地区网络把私人机构和国家主干服务连接起来。
正如人们对其潜力的估计，也正由于使用起来更简单的新的软件的问世，
NSFNET迅速地成长起来。类似美国Sprint通讯公司和美国著名的MCI公司的一些公司也开始构筑他们自己的网络，这些网络连接到NSFNET上。
当商业公司是其它的地区网络提供商承担起主要网络动脉的管理是，NSF （全美科学财团）已经从主干商务中退了下来。
NSF也同一种叫做InterNIC的服务对等，InterNIC登记因特网上的所有的地址，以便数据能传送到正确的系统中。现在这项服务已由网络Sloution公司是全美科学财团合力承担了。
网络是如何工作的
世界万维网——因特网的一部分——是迄今为止因特网中最流行的部分。只要你肯花时间浏览网页，你将会发现网上没有你找不到的东西！网页通过展示文字，图画，动画，照片，声音和录象来使得通讯丰富多采。
那么什么是这奇迹般的创造呢？网络实际上包括你的个人电脑，网络浏览器软件，与INTERNET服务商的连接，被称为主数字数据和路由器，以及引导信息流的开关。
万维网已客户机系统著称。你的计算机是客户；储备电子文件的远程计算机是服务器。以下就是它的工作方式：
假设你要访问Louver博物馆的网点。首先在你的网络浏览器中输入这个网点的URL地址（等下还会有更多关于这的探讨）。然后你的浏览器象主管Louver 的网络服务器请求网页。Louvre的服务器通过因特网向你的计算机发送数据。你的网络浏览器翻译这些数据并把它们显示在屏幕上。
Louvre网点也有其它博物馆的站点的连接。当你在链接上单击鼠标时，你从网络服务器中取得焚蒂冈的博物馆的网页。
使得万维网联系在一起的“粘合剂”是超文本和超链接。这个特征允许网上的电子文件被链接因此你可以很容易的跳过它们。在网上，你可以选择你当时所感兴趣的页面来看，这通常被叫做浏览或者冲浪。
为了能上网浏览，你需要安装网络浏览器的软件，例如网景或者微软公司的Internet Explorer浏览器。那么你的网络浏览器是如何区分网上的Web页面和其它的文件的呢？网页是由超文本传输语言或HTML语言等计算机语言写成的。一些网络的历史
万维网（WWW）在1990年在CERN——粒子物理的欧洲实验室被开发。它现在由万维网国际财团管理，万维网财团也是著名的万维网机构。万维网国际财团向许多包括美国电话电报公司，阿道比系统公司，微软公司和Sun Microsystems公司在内的公司的社团的成员提供资金。其目的在于通过发展技术规格和对每个人都免费的参考软件来促进网络的发展。国际财团由麻省理工学院
和INRIA（法国国家为计算机科学的研究学会）运作，INRIA作为欧洲的主人，与CERN保持合作关系。
在厄巴纳-尚佩恩的伊利诺斯大学的国际超高速计算应用中心（NCSA），在早期的物理软件运用到由CERN创建的万维网的发展中起到了一定作用。NCSA 智力于通过提供给研究人员用于模拟，分析，和想象的软件来提高他们的生产率。明显的万维网就是完成那个使命的方法！
NCSA Mosaic——最初期的网络浏览器之一，已被广泛使用。是它导致了万维网的非凡的成长！
网址
World Wide Web可以被理解为存储在全世界计算机上的网络电子文件。超级链接将这些资源连接在一起。统一资源标示符或者URLs是定位这些文件的地址。包含在一个URL里的地址信息可以使你轻轻一点便从一个网页跳到其他页面上。当你在浏览器上键入URL地址或者点击超级链接，你的浏览器会立刻发一个请求到远端的主机去下载文件。
传统的URL是什么样的呢？这有几个例子：
https://www.360docs.net/doc/143043058.html,/
这是张英文学习的首页。
ftp://https://www.360docs.net/doc/143043058.html,/pub/
MIT学院主页下的一个文件下载路径
news:rec.gardens.roses
一个关于玫瑰园艺的新闻组
一个URL的第一部分（双斜杠之前的部份）为资源的类型或者这个地址的存取方法。
例如：
http- 表示一个超文本文档或路径
gopher- 表示一个gopher文档或菜单
ftp- 表示一个可以下载的文件或一个这种文件的路径
news- 表示一个新闻组
telnet- 表示一个通过Internet登陆的计算机系统
WAIS-表示一个广域信息搜索数据库的数据库或文档
file- 表示一个存储在本地硬盘上的文件（你的硬盘）
第二部分是放置数据或服务的一个典型计算机地址。其他部分可以为具体的文件名，连接的端口号，或者需要在数据库中查寻的文本。
你可以在网页浏览器的工具栏下的定位条里键入一个站点的URL。
大多数的浏览器通过把你访问过的URLS添加到一个特殊的菜单里将其记录下来，
以便以后再次使用。再Netcape的Navigator中，它叫书签。在Microsoft Explorer中，则叫做Favorites。一旦你添加一个URL到列表中，你可以通过简单的点击列表里的名字返回那个网页，而不用在此间如完全的URL.
你使用的大多数的URLs为http开头代表Hypertext Transfer Protocol。http 是一种将HTML转换为网页的方法。这有一些关于使用URLs应该注意的地方：一个URL通常不包括空格。
一个URL通常要到用双斜杠。
如果你输入的URL不正确的，你的浏览器将不能找到你想要的站点或资源。
你将会收到一个错误的信息或访问一个错误的网页，所以确保你键入地址的正确性。
当你将鼠标的光标放到一个链接上，在这个链接的URL将显现出来。鼠标的指针将变为手状而且URL将出现在浏览器屏幕的底端的状态条里。
域名
当你想到Internet,你可能会想到“.com”。这个WWW网址的最后三个字母到底实是什么意思呢？
在Internet的主机数据上，每个主机有一个独特的数字地址。例如，代表白宫的地址是198.137.240.100。因为很少人想去记那么一长串数字，所以域名系统被开发出来。DNS，作为一项Internet核心技术架构的一部分，将一个数字地址关联为一个词。要访问白宫的网站，你当然可以敲入那一串数字在地址栏里，但大多数人更愿意使用https://www.360docs.net/doc/143043058.html,来代替它。在这个例子中，域名为https://www.360docs.net/doc/143043058.html,。
通常，三个字母的后缀域名被作为通用顶级域名用来描述一个组织类型。在过去的几年中这种类之间的划分已经变得有些模糊了。
.com - 商业（金融）
.edu - 教育
.org- 非盈利
.mil- 军事
.net- 网络提供商
.gov- 政府
一个域名总是包括2个或更多被点分的部分，并且通常包括一个组织名字的某种形式和三个字母的后缀。例如，IBM的域名为“https://www.360docs.net/doc/143043058.html,”；联合国的域名为“https://www.360docs.net/doc/143043058.html,”。
一旦一个域名可用，它作为已存在商标不被侵犯，任何人可以通过Network Solutions,Inc.花35$注册一个“.com、.net或.org”的被授权的名字。你可在查询文本框中输入并确认你想要的域名是否可用。不要怀疑你想要的“.com”的域名已经有了。在超过800万的域名中85%为“.com”域。
ICANN，分配名字和号码的Internet公司管理DNS。当本文写到这里的时候，还有其他的域名被计划加入顶级域名的行列之中。如：.web和.store。人们其实早已猜出这些事情的发生。
为了检查或注册一个域名，将其键入查询框中。应该用这种形式：https://www.360docs.net/doc/143043058.html,
除了通用顶级域名之外，244个国家顶级域名被建立代表不同国家和领土。例如：
.au-Australia
.ca –Canada
.fr –France
.uk –United Kingdong
花上275$你还可注册一个带有Net Names的国际域名，但请注意，一些国家限制注册此类名字
如果你计划注册你自己的域名，无论是“.com”的还是其他的。请记住如下几条。
名字越短越好（但应反映你的姓氏，利益或生意）。
名字应该好记。
名字应该易于无错的输入。
切忌Internet的全球性。理论上，域名可以被读为除英语以外的其他语言。错误信息分析
当你在网上冲浪的时候，毫无疑问你会不时发现你不能访问某些页面。为什么，你会奇怪？错误信息试图解释这个原因，不幸的是，这些晦涩的信息往往会使大多数人感到困惑。
我们已经解释出你可能遇到的最普遍的问题。
400-Bad Request
问题：在你输入的地址中有一些错误，你也许没有访问此页面的授权，或者这页已经不存在了。
解决：键入地址时要小心，尤其当地址很长时。保证双斜杠要正确（他们应为前向双斜杠）并且所有名字要拼写恰当。网址是事件敏感的，因此要检查作为入口的名字，他们是网站的最原始的关联。
401-非授权
问题：你不能访问你个网站，因为你没在宾客列表中，你的密码是不合法的活着你输入的密码是错误的。
403-禁止
问题：本质上和401相同
解决：再次输入密码或换到其他网站。
404-未发现
问题：或者页面不存在服务器上了，或者这地方找不到了。
解决：仔细地检查地址或者再输入一遍，你可以看看这个站点有没有搜索引擎，使用它搜寻一下你要的文档。（当站点重新设计时，这种事情是很普遍的。）找到站点的首页，删除域名
后的所有东西然后键入回车。
503-服务不可用
问题：你的ISP或者你公司的Internet连接已经断掉。
解决：等一下，再试一下。如果还不成打电话给你的ISP或你的系统管理员。
错误的文件请求：
问题：你的浏览器可能不能解析你要访问的在线表格。也许这种表格有技术方面的错误。
解决：考虑给你的站点主管发一个信息，提供你所知道所有这方面的技术信息。比如：你使用浏览器的版本。
主机拒绝连接：
问题：你没有访问这个主页的权限或你的密码不正确。
解决：你认为可以到达的情况下重输你的密码。
DNS失败检索
问题：DNS代表域名系统，这个系统用来检索站点的名字，找一个相应的数字（类似电话号码），然后将它指向Internet上你需要访问的专有的网页的名字。当查找失。如败，主机服务器将不能被定位。
解决：试着点击你的浏览器工具栏上的重新装载或刷新按钮。如果还是不行，检查地址然后再输入一遍果所有这些都失败了，过一会儿再试试。
文件中无数据：
问题：这个站点没有网页。
解决：检查网址再输入一遍。如果你得到同样的错误信息，一会儿再试一下。
主机不可用：
问题：网页服务器断掉了
解决：试着点击你的浏览器工具栏上的重新装载或刷新按钮。如果还不行，过一会儿再试试。
主机未知：
问题：网页服务器断掉了，这个站点可能已经移动了，或者你已经离线了。
解决：试着点击你的浏览器工具栏上的重新装载或刷新按钮来检查你是否还在线。
如果还是失败，试着用浏览器找一下这个站点。它可能有了一个新的网址。
服务器网络连接拒绝：
问题：网页服务器忙。
解决：一会儿再试
不能定位主机
问题：网页服务器已经断掉或你已经离线。
解决：试着点击你的浏览器工具栏上的重新装载或刷新按钮来检查你是否还在线。
不能定位服务器：
问题：网页服务器已过载，或你输入的网址不正确。
解决：检查网址，在输入一下。
变速器论文中英文对照资料外文翻译文献
中英文对照外文翻译 汽车变速器设计 我们知道，汽车发动机在一定的转速下能够达到最好的状态，此时发出的功率比较大，燃油经济性也比较好。因此，我们希望发动机总是在最好的状态下工作。但是，汽车在使用的时候需要有不同的速度，这样就产生了矛盾。这个矛盾要通过变速器来解决。 汽车变速器的作用用一句话概括，就叫做变速变扭，即增速减扭或减速增扭。为什么减速可以增扭，而增速又要减扭呢？设发动机输出的功率不变，功率可以表示为 N = w T，其中w是转动的角速度，T 是扭距。当N固定的时候，w与T是成反比的。所以增速必减扭，减速必增扭。汽车变速器齿轮传动就根据变速变扭的原理，分成各个档位对应不同的传动比，以适应不同的运行状况。 一般的手动变速器内设置输入轴、中间轴和输出轴，又称三轴式，另外还有倒档轴。三轴式是变速器的主体结构，输入轴的转速也就是发动机的转速，输出轴转速则是中间轴与输出轴之间不同齿轮啮合所产生的转速。不同的齿轮啮合就有不同的传动比，也就有了不同的转速。例如郑州日产ZN6481W2G型SUV车手动变速器，它的传动比分别是：1档3.704:１；2档2.202:1；3档1.414:1；4档1:1；5档（超速档）0.802:1。 当汽车启动司机选择1档时，拨叉将1/2档同步器向后接合1档
齿轮并将它锁定输出轴上，动力经输入轴、中间轴和输出轴上的1档齿轮，1档齿轮带动输出轴，输出轴将动力传递到传动轴上（红色箭头）。典型1档变速齿轮传动比是3:1,也就是说输入轴转3圈，输出轴转1圈。 当汽车增速司机选择2档时，拨叉将1/2档同步器与1档分离后接合2档齿轮并锁定输出轴上，动力传递路线相似，所不同的是输出轴上的1档齿轮换成2档齿轮带动输出轴。典型2档变速齿轮传动比是2.2:1，输入轴转2.2圈，输出轴转1圈，比1档转速增加，扭矩降低。 当汽车加油增速司机选择3档时，拨叉使1/2档同步器回到空档位置，又使3/4档同步器移动直至将3档齿轮锁定在输出轴上，使动力可以从轴入轴—中间轴—输出轴上的3档变速齿轮，通过3档变速齿轮带动输出轴。典型3档传动比是1.7:1，输入轴转1.7圈，输出轴转1圈，是进一步的增速。 当汽车加油增速司机选择4档时，拨叉将3/4档同步器脱离3档齿轮直接与输入轴主动齿轮接合，动力直接从输入轴传递到输出轴，此时传动比1:1，即输出轴与输入轴转速一样。由于动力不经中间轴，又称直接档，该档传动比的传动效率最高。汽车多数运行时间都用直接档以达到最好的燃油经济性。 换档时要先进入空档，变速器处于空档时变速齿轮没有锁定在输出轴上，它们不能带动输出轴转动，没有动力输出。 一般汽车手动变速器传动比主要分上述1－4档，通常设计者首先确定最低（1档）与最高（4档）传动比后，中间各档传动比一
自动化外文翻译
景德镇陶瓷学院 毕业设计(论文)有关外文翻 译 院系：机械电子工程学院 专业：自动化 姓名：肖骞 学号： 201010320116 指导教师：万军 完成时间： 2014.5.8 说明
1、将与课题有关的专业外文翻译成中文是毕业设计（论文）中的一个不可缺少的环节。此环节是培养学生阅读专业外文和检验学生专业外文阅读能力的一个重要环节。通过此环节进一步提高学生阅读专业外文的能力以及使用外文资料为毕业设计服务，并为今后科研工作打下扎实的基础。 2、要求学生查阅与课题相关的外文文献3篇以上作为课题参考文献，并将其中1篇（不少于3000字）的外文翻译成中文。中文的排版按后面格式进行填写。外文内容是否与课题有关由指导教师把关，外文原文附在后面。 3、指导教师应将此外文翻译格式文件电子版拷给所指导的学生，统一按照此排版格式进行填写，完成后打印出来。 4、请将封面、译文与外文原文装订成册。 5、此环节在开题后毕业设计完成前完成。 6、指导教师应从查阅的外文文献与课题紧密相关性、翻译的准确性、是否通顺以及格式是否规范等方面去进行评价。 指导教师评语： 签名： 年月日
TMS320LF2407, TMS320LF2406, TMS320LF2402 TMS320LC2406, TMS320LC2404, MS320LC2402 DSP CONTROLLERS The TMS320LF240x and TMS320LC240x devices, new members of the ‘24x family of digital signal processor (DSP) controllers, are part of the C2000 platform of fixed-point DSPs. The ‘240x devices offer the enhanced TMS320 architectural design of the ‘C2xx core CPU for low-cost, low-power, high-performance processing capabilities. Several advanced peripherals, optimized for digital motor and motion control applications, have been integrated to provide a true single chip DSP controller. While code-compatible with the existing ‘24x DSP controller devices, the ‘240x offers increased processing performance (30 MIPS) and a higher level of peripheral integration. See the TMS320x240x device summary section for device-specific features. The ‘240x family offers an array of memory sizes and different peripherals tailored to meet the specific price/performance points required by various applications. Flash-based devices of up to 32K words offer a reprogrammable solution useful for: ◆Applications requiring field programmability upgrades. ◆Development and initial prototyping of applications that migrate to ROM-based devices. Flash devices and corresponding ROM devices are fully pin-to-pin compatible. Note that flash-based devices contain a 256-word boot ROM to facilitate in-circuit programming. All ‘240x devices offer at least one event manager module which has been optimized for digital motor control and power conversion applications. Capabilities of this module include centered- and/or edge-aligned PWM generation, programmable deadband to prevent shoot-through faults, and synchronized analog-to-digital conversion. Devices with dual event managers enable multiple motor and/or converter
机械毕业设计英文外文翻译436手动变速器 (2)
附录 附录A. Manual Transmission It’s no secret that cars with manual transmissions are usually more fun to drive than the automatic-equipped counterparts. If you have even a passing interest in the act of driving, then chances are you also appreciate a fine-shifting manual gearbox. But how does a manual transmission actually work? A history hows that manual transmissions preceded automatics by several decades. In fact，up until General Motors offered an automatic in 1938, all cars were of the shift-it-yourself variety. While it’s logical for many types of today’s vehicles to be equipped with an automatic――such as a full-size sedan, SUV or pickup――the fact remains that nothing is more of a thrill to drive than a tautly suspended sport sedan, snort coupe or two-sealer equipped with a precise-shifting five-or six-speed gearbox． We know whicn types or cars have manual trannies. Now let’s take a look at how they work. From the most basic four-speed manual in a car from the’60s to the most high-tech six-speed one in a car of today, the principles of a manual gearbox are the same. The driver must shift from gear to gear. Normally, a manual transmission bolts to a clutch housing (or bell housing）, in turn, bolts to the back of the engine. If the vehicle has front-wheel drive,
外文文献翻译：汽车的发展
The development of automobile As the world energy crisis and the war and the energy consumption of oil -- and are full of energy in one day someday it will disappear without a trace. Oil is not inresources. So in oil consumption must be clean before finding a replacement. With the development of science and technology the progress of the society people invented the electric car. Electric cars will become the most ideal of transportation. In the development of world each aspect is fruitful especially with the automobile electronic technology and computer and rapid development of the information age. The electronic control technology in the car on a wide range of applications the application of the electronic device cars and electronic technology not only to improve and enhance the quality and the traditional automobile electrical performance but also improve the automobile fuel economy performance reliability and emission spurification. Widely used in automobile electronic products not only reduces the cost and reduce the complexity of the maintenance. From the fuel injection engine ignition devices air control and emission control and fault diagnosis to the body auxiliary devices are generally used in electronic control technology auto development mainly electromechanical integration. Widely used in automotive electronic control ignition system mainly electronic control fuel injection system electronic control ignition system electronic control automatic transmission electronic control ABS/ASR control system electronic control suspension system electronic control power steering system vehicle dynamic control system the airbag systems active belt system electronic control system and the automatic air-conditioning and GPS navigation system etc. With the system response the use function of quick car high reliability guarantees of engine power and reduce fuel consumption and emission regulations meet standards. The car is essential to modern traffic tools. And electric cars bring us infinite joy will give us the physical and mental relaxation. Take for example automatic transmission in road can not on the clutch can achieve automatic shift and engine flameout not so effective improve the driving convenience lighten the fatigue strength. Automatic transmission consists mainly of hydraulic torque converter gear transmission pump hydraulic control system electronic control system and oil cooling system etc. The electronic control of suspension is mainly used to cushion the impact of the body and the road to reduce vibration that car getting smooth-going and stability. When the vehicle in the car when the road uneven road can according to automatically adjust the height. When the car ratio of height low set to gas or oil cylinder filling or oil. If is opposite gas or diarrhea. To ensure and improve the level of driving cars driving stability. Variable force power steering system can significantly change the driver for the work efficiency and the state so widely used in electric cars. VDC to vehicle performance has important function it can according to the need of active braking to change the wheels of the car car motions of state and optimum control performance and increased automobile adhesion controlling and stability. Besides these appear beyond 4WS 4WD electric cars can greatly improve the performance of the value and ascending simultaneously. ABS braking distance is reduced and can keep turning skills effectively improve the stability of the directions simultaneously reduce tyre wear. The airbag appear in large programs protected the driver and passengers safety and greatly reduce automobile in collision of drivers and passengers in the buffer to protect the safety of life. Intelligent electronic technology in the bus to promote safe driving and that the other functions. The realization of automatic driving through various sensors. Except some smart cars equipped with multiple outside sensors can fully perception of information and traffic facilities
自动化制造系统与PLC关系---自动化外文翻译5000字
自动化制造系统与PLC关系 控制工程随着时间的演变。过去的人们主要致力于控制方面研究。最近电力已被应用于控制,早期电气控制是基于继电器的。这些继电器使其可以在没有机械开关的情况下被开动和关闭。这是通常使用继电器进行简单的逻辑控制的方法。低成本计算机的发展带来了新的革命,可编程逻辑控制器(PLC)出现于70年代,它已成为制造控制的最常见选择。PLC的功能受到越来越多的工厂欢迎并可能作为主要控制手段再今后的一段时间内。而这其中绝大部分原因是因为PLC 它的优点很多。 1.1梯形逻辑 梯形逻辑编程法是主要的PLC编程方法。正如之前所说,梯形逻辑已发展到模仿继电器逻辑。通过选择简单的梯形逻辑编程法,培训工程师和商人所需要的金钱极大的减少。现代控制系统仍然包括继电器,但这些都是很少的逻辑使用。字母a继电器是一个简单的装置,它使用一个磁场来控制开关,如图图1.1。当电压作用于输入线圈产生的磁场,产生电流领域。拉起磁场的金属开关,再实现它的接触和联系,关闭开关。 图1.1 简单的布局和继电器电路图 继电器的工作方式,让一个电源开关关闭另一(通常是高电流)电源,同时保持他们孤立。一个简单的例子,控制继电器应用,见图 1.2。在这方面,左边第一个接力是通常使得系统关闭,并允许电流流动,直到电压加到输入端甲,第二个中继器通常是开放的,不会允许目前的速度,目前的输入二是流经前两个继电器
然后电流流通过在第三继电器线圈,并关闭输出 C.此电路的开关会通常应用在制定阶梯逻辑形式。这可以被解释为将C逻辑作用,如果A关闭B合上的话。 图1.2一个简单的继电器控制器 图1.2中的例子没有显示整个控制系统,只有逻辑。当我们考虑一个PLC 有输入,输出,和逻辑。图1.3显示的更全面。这里有两个按钮的输入。我们可以想像激活24V直流在PLC继电器线圈的输入。反过来驱动器是一个输出继电器,开关115伏交流电,结果打开了一盏灯。请注意,在实际情况下PLC的输入继电器,常常又是输出继电器。PLC梯形图逻辑其实一种计算机程序,用户可以输入和更改它。注意,两个输入的推按钮常开,但里面的PLC梯形图逻辑有一个常开触点,和一个常闭触点。在PLC梯形逻辑图不需要匹配输入或输出。许多初学者会被抓住这点试图使阶梯逻辑匹配它的输入类型。 图1.3继电器PLC的简图 许多继电器也有多个输出(抛出),这允许输出继电器可以同时输入。图1.4所示的电路是一个例子,它是在电路里称为印章。此电路的电流流过两个电路的分支,通过接触标签A或B的输入端,B只相对乙输出。如果B是关闭的,而A 是通电,那么B将打开。如果B打开,然后输入,B将打开。打开后,乙在输出,乙将不会关闭。 图1.4电路 1.2编程
外文翻译--一个控制器使门式起重机和减摇桥精确定位
A controller enabling precise positioning and sway reduction in bridge and gantry cranes Khalid L. Sorensen, William Singhose, Stephen Dickerson The George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, 813 Ferst Dr., MARC 257, Atlanta, GA 30332-0405, USA Received 28 September 2005; accepted 30 March 2006 Available online 5 June 2006 一个控制器使门式起重机和减摇桥精确定位 Khalid L. Sorensen, William Singhose, Stephen Dickerson, 乔治亚机械工程学院，乔治亚技术学院， Ferst博士813，MARC 257 ,亚特兰大，GA 30332-0405,美国，2005年9月28日收到，2006年3月30日接受，2006年6月5日可在线使用.
一个控制器使门式起重机和减摇桥精确定位 摘要 起重机是很难精确操纵载荷的。振荡,可以诱导成大桥或手推车的阻尼系统轻度运动,并且还对环境造成滋扰. 为解决上述两种振荡的来源,结合反馈和输入整形控制器的发展。该控制器是由三个不同的模块组成，反馈模块的检测和定位误差补偿; 第二反馈模块侦测并拒绝振动; 使用塑料造填充的第三个模块,以减轻振荡。一个使用精确的模型矢量驱动的交流感应马达，为典型的大型起重机, 用同一个褶分析技术,将非线性动力学起重机器分为对照设计。在佐治亚技术学院实验10吨桥式起重机控制器。该控制器具有良好的定位精度和性能以减少摆动.。 关键词:输入整形；指挥整形；起重机控制；振动控制；防摇；桥式起重机；龙门吊床 1. 绪论 桥、门式起重机在工业生产中占据了关键地位。它们被使用在世界各地数以千计的船场、建筑工地、钢铁厂、仓库、核电厂及废料储存设施，以及其他工业园区。这种操纵系统的及时性和有效性为工业生产力起了重要贡献。因此，可以提高企业经济效益的起重机是极其宝贵的。这些结构，见图一。1.被给予高度评价的压电性质.、抗外部干扰，如风力或气压 (例如桥梁或小车) 能造成载荷振动。在许多实际生产中，这些振动产生了不良后果。摇动使得有效载荷或钩的精确定位在一人操作的时候费时费力；此外，当载荷或周边障碍有是一个危险和脆弱的时候，振荡可能存在安全风险。广泛使用的桥、门式起重机，再加上要控制不必要的振荡，使得大量的研究与控制这些结构有了干劲。工程师们正试图改善其易用性，以增加经济效益，并减轻安全上的顾虑，起重机系统的三个主要要解决的方面: (1)运动诱发的振荡；(2)扰动诱发的振荡；(3)定位能力。一个15吨的桥式起重机采用鲁棒输入整形技术来减少运动诱发的振荡(Singer,Singhose, & Kriikku,1997)。莱利建议控制小车位置和振荡通过比例-微分( PD )控制，在这之间的耦合电缆角和运动的小车将被增加(Fang,Dixon, Dawson, & Zergeroglu, 2001)。Piazzi提出了动态基于逆控制以降低瞬态和残余运动诱发振荡(Piazzi & Visioli, 2002)。金大中推行了极点配置策略,对一个真正的集装箱起重机运动控制和振荡以及定位(Kim, Hong, & Sul, 2004) 。 Moustafa今日发达非线性控制载荷轨迹律跟踪基于Lyapunov的稳定性分析((Moustafa, 2001) 。奥康纳制定了控
二轴式手动变速器外文翻译
外文翻译 文章出处《Tribology International》, 2009, 42(5):714-723 译文： 有限元热分析的陶瓷离合器 1 引言 磨料空转车辆离合器是力封闭联轴器。扭矩和高速传输被压紧表面之间产生的摩擦力所保证。应用陶瓷是因为它作为摩擦介质具有好耐热和耐磨损性能，提供了机会以驱动更高的压力，以及一个低的密度。因此，一个提功率密度启用了一个平行的最小化建筑空间。 测量使用陶瓷饰面离合器盘的第一个原型在卡尔斯鲁厄大学的一个实验室专门从事客车驱动系统进行了测试执行。在分析过程中的有限元（FE）模型是将与测量数据和测量条件的知识所构成。计算的目的是要确定在离合器盘上温度的分布以及环境中的在每一时刻的及时测量目。至关重要的是熟悉的温度范围，为了检验该系统的耐磨特性。因此，重要信息从测量数据中得出。在临界负载的情况下，预计最高温度必须在时间和空间上进行预测，为保护接近发热体的位置测量工具的。 本研究的目的是分析和修改该离合器系统通过改进，以提供更好的工作条件热传导和系统或增加转化成摩擦热的能量的对流。此外，人们希望找到更有效的更好的离合器系统设计方案。 计算是由宇宙星空的设计的软件进行的。在模型开发阶段，非常谨慎，必须采取几何元素，选择适当的简化尺寸，并且由于正确调整的时间步长大量的硬件要求瞬态计算。热物性参数的改变，如表面热对流化系数和热负荷，必须考虑到到在一个持续的基础上在时间和地点方面。离合器系统的分析测试这两方面，只能通过加热隔板连接的两个独立的模型来管理，根据该假说认为，接触温度必须是在两个相同的双方，同时他们要有适当接触，其价值需通过迭代来进行调整。计算显示，该热分区按周期变化，它沿不同的内，外接触环。在不同的冷却特性下，在陶瓷和钢之间的结果是不同的，热流从陶瓷侧面向钢侧流动。此热流也通过迭代确定;它的价值也改变了周期和不同沿着所述内和外接触环。 2 采用工程陶瓷作为摩擦材料的第一个原型机 这款检查过的离合器盘是根据“特定的陶瓷”产品而开发的，此材料的研发过程在流程在卡尔斯鲁厄大学的Institute for Product Development (IPEK)杂志上发表过。此开发过程已经具有的可能性，用于连接到一个真实的传动轴；甚至，它为面板有一个好的初始行为起到一个很好的缓冲作用。磨料配件必须符合以下基本要求：
3-电气工程及其自动化专业_外文文献_英文文献_外文翻译_plc方面
1、 外文原文 A: Fundamentals of Single-chip Microcomputer Th e si ng le -ch i p mi cr oc om pu ter is t he c ul mi nat i on o f bo th t h e d ev el op me nt o f th e d ig it al com p ut er an d t he int e gr at ed ci rc ui t a r gu ab ly th e t ow m os t s i gn if ic ant i nv en ti on s o f t h e 20t h c en tury [1]. Th es e to w typ e s of a rc hi te ctu r e ar e fo un d i n s in gl e -ch ip m i cr oc om pu te r. So m e em pl oy t he sp l it p ro gr am /d ata me mo ry o f th e H a rv ar d ar ch it ect u re , sh ow n in Fi g.3-5A-1, o th ers fo ll ow t he p h il os op hy , wi del y a da pt ed f or ge n er al -p ur po se co m pu te rs a nd m i cr op ro ce ss o r s, of ma ki ng no lo gi c al di st in ct io n be tw ee n p ro gram a n d da ta m em or y a s i n th e Pr in cet o n ar ch it ec tu re, sh ow n in F i g.3-5A -2. In g en er al te r ms a s in gl e -chi p m ic ro co mp ut er i s c h ar ac te ri ze d b y th e i nc or po ra tio n o f al l t he uni t s o f a co mp ut er i n to a s in gl e d ev i ce , as s ho wn in Fi g3-5A -3. Fig.3-5A-1 A Harvard type Fig.3-5A-2. A conventional Princeton computer Program memory Data memory CPU Input& Output unit memory CPU Input& Output unit
基础防雷外文资料翻译 精品
毕业设计(论文)外文资料翻译 系（院）：电子与电气工程学院 专业：电气工程及其自动化 姓名： 学号： 外文出处： (用外文写)Baidu library 附件： 1.外文资料翻译译文；2.外文原文。 注：请将该封面与附件装订成册。
附件1：外文资料翻译译文 基础防雷 简介 闪电是一个反复无常，随机和不可预测的事件。它的物理特征包括：电流超过400 kA；温度超过50000华氏度，速度接近或超过三分之一的光速。自2000年以来持续雷击地球约100次每秒。美国保险公司的资料显示每57索赔有一次是因为雷击损坏。这些数据还不包括商业，政府和工业雷电造成的损失。在美国每年因雷电造成的火灾超过26000起，财产损失在5-6亿美元。 地球上的雷击现象，按目前的技术角度来看，遵循一个近似的规律： 1。从顶层雷云朝地球的向下脉冲，寻求电气地面目标。 2。地基对象（围栏，树木，草叶，建筑，避雷针，等等）对此事件发出不同程度的电力活动。从这些地基对象向上发送电力波动，在离地面几十米的位置，会出现一个“聚集区”加剧当地的电场。 3。当带有异种电荷的雷云相遇，相当于电路“开关”被关闭，于是有电流流过。我们就会看到闪电。 闪电效果可以直接也可能是间接的。直接影响是有电阻发热，出现电弧并可能燃烧起来。间接影响是，多数时候对电容，电感出现电磁影响。在绝对意义上实现闪电的防护是不可能的，只能使其产生的影响减少，可以由一个整体性，系统性的风险缓解办法来实现保护。下面对通用条款进行描述。 避雷针 从富兰克林研究雷电开始，就使用避雷针进行建筑物防雷并引流接地。避雷针，是现在最常用的防雷装置，根据建筑物不同的地点，高度和形状，使用合适类型的避雷针来达到设计要求。一些公共事业如架空线、变电所喜欢屏蔽电线。在某些情况下，没有任何避雷装置的使用是最适当的。 高空避雷装置的使用可能会改变闪电的动作。在等效电力场所，钝尖杆被看作是一种有效的避雷针类型。高空防雷装置的设计和性能是一个有争议的并尚未解决
汽车变速器外文翻译
外文翻译 Auto Transmission First, an overview of automotive transmission and the development trend Automobile available more than a century, especially from the mass production of motor vehicles and the automotive industry since the development of large, Car has been the economic development of the world for mankind to enter the modern life and have had a tremendous impact on the immeasurable, The progress of human society has made indelible contributions to the great, epoch-making set off arevolution. From From the vehicle as a power plant using internal combustion engine to start, auto transmission has become an important component. Is Generation is widely used in automotive reciprocating piston internal combustion engine with a small size, light weight, reliable operation and the use of The advantages of convenience, but its torque and speed range of smaller changes, and complex condition requires the use of motor vehicles Traction and the speed can be considerable changes in the scope. Therefore, its performance and vehicle dynamics and economy of There are large inter-contradictions, which contradictions of modern automotive internal combustion engine by itself is insoluble. Because Here, in the automotive power train set up the transmission and main reducer in order to achieve the purpose of deceleration by moment. Speed The main function of performance: ⑴ change gear ratio of motor vehicles, and expand the wheel drive torque and rotational speed of the Fan Wai, in order to adapt to constantly changing driving cycle, while the engine in the most favorable conditions within the scope of work; ⑵no change in the direction of engine rotation, under the premise of the realization of cars driving back; ⑶the realization of the free, temporary Interruption of power transmission, in order to be able to start the engine, idling, etc.. V ariable-speed drive transmission by the manipulation of institutions and agencies. Change the transmission ratio by way of transmission is divided into There are class-type, non-stage and multi-purpose three. Have class most widely used transmission. It uses gear drive, with a number of transmission ratio setting. Stepless transmission Continuously V ariable Transmission (CVT) transmission ratio of a certain The framework of multi-level changes may be unlimited, there is a common type of power and torque (dynamic fluid-type) and so on. Continuously V ariable Transmission Transmission development is the ultimate goal, because only it can make the most economical engine in working condition Can provide the best vehicle fuel economy and optimal power in order to provide the most comfortable By the feeling. Today's CVT is a typical representative of the CVT
变速器设计,中英文带翻译
原文： Transmission design As we all know automobile engine to a certain speed can be achieved under the best conditions, when compared issued by the power, fuel economy is relatively good. Therefore, we hope that the engine is always in the best of conditions to work under. However, the use of motor vehicles need to have different speeds, thus creating a conflict. Transmission through this conflict to resolve. Automotive Transmission role sum up in one sentence, called variable speed twisting, twisting or slow down the growth rate by increasing torsional. Why can slow down by twisting, and the growth rate but also by twisting? For the same engine power output, power can be expressed as N = WT, where w is the angular velocity of rotation. When N fixed, w and T is inversely proportional to the. Therefore, the growth rate will reduce twisting, twisting slowdown will increase. Automotive Transmission speed gear based on the principle of variable twisted into various stalls of different transmission ratio corresponding to adapt to different operational conditions. General to set up a manual gearbox input shaft, intermediate shaft and output shaft, also known as the three-axis, as well as Daodang axis. Three-axis is the main transmission structure, input shaft speed is the speed of the engine, the output shaft speed is the intermediate shaft and output shaft gear meshing between different from the speed. Different gears are different transmission ratio, and will have a different speed. For example Zhengzhou richan ZN6481W2G manual transmission car-SUV, its transmission ratio are: 1 File 3.704:1; stalls 2.202:1; stalls 1.414:1; stalls 1:1 5 stalls (speeding file) 0.802: 1. When drivers choose a launch vehicle stalls, Plectrum will be 1 / 2 file synchronization engagement with a back stall gear and output shaft lock it, the power input shaft, intermediate shaft and output shaft gear of a stall, a stall the output shaft gear driven, and the output shaft power will be transmitted to the drive shaft (red arrow). A typical stall Biansuchilun transmission ratio is 3:1, that is to say three laps