计算机英语文章阅读

❶ 有关于计算机的英语文章吗带翻译的，5000字左右，有的话可以给分

电脑的学名为电子计算机，是由早期的电动计算器发展而来的。1946年，世界上出现了第一台电子数字计算机“ENIAC”，用于计算弹道。是由美国宾夕法尼亚大学莫尔电工学院制造的，但它的体积庞大，占地面积170多平方米，重量约30吨，消耗近100千瓦的电力。显然，这样的计算机成本很高，使用不便。1956年，晶体管电子计算机诞生了，这是第二代电子计算机。只要几个大一点的柜子就可将它容下，运算速度也大大地提高了。1959年出现的是第三代集成电路计算机。最初的计算机由约翰·冯·诺依曼发明(那时电脑的计算能力相当于现在的计算器)，有三间库房那么大，后逐步发展。 从20世纪70年代开始，这是电脑发展的最新阶段。到1970年，由大规模集成电路和超大规模集成电路制成的“克雷一号”，使电脑进入了第四代。超大规模集成电路的发明，使电子计算机不断向着 小型化、微型化、低功耗、智能化、系统化的方向更新换代。20世纪90年代，电脑向“智能”方向发展，制造出与人脑相似的电脑，可以进行思维、学习、记忆、网络通信等工作。 进入21世纪，电脑更是笔记本化、微型化和专业化，每秒运算速度超过100万次，不但操作简易、价格便宜，而且可以代替人们的部分脑力劳动，甚至在某些方面扩展了人的智能。于是，今天的微型电子计算机就被形象地称做电脑了。世界上第一台个人电脑由IBM于1981年推出。IBM推出以英特尔的x86为硬体架构，以微软公司的MS-DOS为操作系统的个人电脑，并制定以PC/AT为PC的规格。之后，由英特尔推出的微处理器以及微软推出的操作系统的发展几乎等同于个人电脑的发展历史。Wintel架构全面取代了IBM在个人电脑世界的主导地位。 通常说到“世界公认的第一台电子数字计算机”大多数人都认为是1946年面世的“ENIAC”，它主要是用于计算弹道。是由美国宾夕法尼亚大学莫尔电气工程学院制造的，它的体积庞大，占地面积170多平方米，重量约30吨，消耗近150千瓦的电力。显然，这样的计算机成本很高，使用不便。这个说法被计算机基础教科书上普遍采用,事实上在1973年根据美国最高法院的裁定,最早的电子数字计算机,应该是美国爱荷华州立大学的物理系副教授约翰·阿坦那索夫和其研究生助手克利夫·贝瑞(Clifford E. Berry ，1918-1963）于1939年10月制造的"ABC"(Atanasoff- Berry-Computer）。之所以会有这样的误会，是因为“ENIAC”的研究小组中的一个叫莫克利的人于1941年剽窃了约翰·阿坦那索夫的研究成果，并在1946年时，申请了专利。由于种种原因直到1973年这个错误才被扭转过来。（具体情况参阅网络----“约翰·阿坦那索夫”词条，希望大家记住ABC和约翰·阿坦那索夫，希望以后的教科书能够修改这个错误）。后来为了表彰和纪念约翰·阿坦那索夫在计算机领域内作出的伟大贡献，1990年美国前总统布什授予约翰·阿坦那索夫全美最高科技奖项----“国家科技奖”。

中国电脑 中国的算盘是最早的运算工具。在人类文明发展的历史上中国曾经在早期计算工具的发明创造方面写过光辉的一页。远在商代，中国就创造了十进制记数方法，领先于世界千余年。到了周代，发明了当时最先进的计算工具——算筹。这是一种用竹、木或骨制成的颜色不同的小棍。计算每一个数学问题时，通常编出一套歌诀形式的算法，一边计算，一边不断地重新布棍。中国古代数学家祖冲之，就是用算筹计算出圆周率在3.1415926和3.1415927之间。这一结果比西方早一千年。 珠算盘是中国的又一独创，也是计算工具发展史上的第一项重大发明。这种轻巧灵活、携带方便、与人民生活关系密切的计算工具，最初大约出现于汉朝，到元朝时渐趋成熟。珠算盘不仅对中国经济的发展起过有益的作用，而且传到日本、朝鲜、东南亚等地区，经受了历史的考验，至今仍在使用。 中国发明创造指南车、水运浑象仪、记里鼓车、提花机等，不仅对自动控制机械的发展有卓越的贡献，而且对计算工具的演进产生了直接或间接的影响。例如，张衡制作的水运浑象仪，可以自动地与地球运转同步，后经唐、宋两代的改进，遂成为世界上最早的天文钟。 记里鼓车则是世界上最早的自动计数装置。提花机原理与计算机程序控制的发展有过间接的影响。中国古代用阳、阴两爻构成八卦，也对计算技术的发展有过直接的影响。莱布尼兹写过研究八卦的论文，系统地提出了二进制算术运算法则。他认为，世界上最早的二进制表示法就是中国的八卦。 经过漫长的沉寂，新中国成立后，中国计算技术迈入了新的发展时期，先后建立了研究机构，在高等院校建立了计算技术与装置专业和计算数学专业，并且着手创建中国计算机制造业。 中国是在1956年研制成功国产计算机的。1958年和1959年中国先后自主研制成功国产小型和大型电子管计算机。60年代中期，中国研制成功一批晶体管计算机，并配制了ALGOL等语言的编译程序和其他系统软件。60年代后期，中国开始研究集成电路计算机。70年代，中国已批量生产小型集成电路计算机。80年代以后，中国开始重点研制微型计算机系统并推广应用；在大型计算机、特别是巨型计算机技术方面也取得了重要进展；建立了计算机服务业，逐步健全了计算机产业结构。 在计算机科学与技术的研究方面，中国在有限元计算方法、数学定理的机器证明、汉字信息处理、计算机系统结构和软件等方面都有所建树。在计算机应用方面，中国在科学计算与工程设计领域取得了显著成就。在有关经营管理和过程控制等方面，计算机应用研究和实践也日益活跃。
The scientific name for electronic computer by early computer, is developed from electric calculator. In 1946, the world appeared the first electronic digital computer "ENIAC", used for calculating trajectory. By the university of Pennsylvania electrician college manufacturing, Moore, the huge volume, but it occupies an area of more than one hundred seventy square meters, weight is about 30 tons, consumption by nearly 100 kilowatts of electricity. Obviously, this computer cost is high, difficult to use. In 1956, transistor electronic computer was born, this is the second generation of computers. Only a few bigger cabinet can will it hold, speed also greatly increased. 1959 appeared in the third generation integrated circuit computer. Early computer by John and von neumann invention (then the computing power of computer now, there are three calculators) is so large, warehouse after between graal development. From 20th century since the 1970s, this is the latest stage of computer development. To 1970, by large scale integrated circuit and vlsi circuits made of "no.1", make the computer clay into the fourth generation. The invention of vlsi, make the electronic computer constantly toward miniaturization, miniaturization, low power consumption, intelligent, systematic direction upgraded. During the 1990s, the computer to "smart" direction development, proce and the brain computer, can undertake similar thinking, learning and memory, network communication, etc. Entering the 21st century, the computer is notebook change, miniaturization and specialization, gigabits per second operation speed over 100 million times, not only operate simple, cheap, and can replace people part mental work, even in some ways expanded the human's intelligence. So, today's microcomputer is what has been aptly called computer. The world's first personal computers launched by IBM in 1981. Introction to Intel's x86 IBM for hardware structure, with Microsoft's ms-dos for the personal computer operating system and formulated to PC/AT for PC specification. Later, launched by Intel microprocessor and Microsoft introced the development of the operating system almost as fast as the development history of personal computers. Wintel architecture comprehensive replaced in the PC world of IBM's dominance. Usually said "the world recognized as the first electronic digital computer" most people think that is available in 1946, "it" ENIAC is mainly used for calculating trajectory. By the university of Pennsylvania is made of electrical engineering college Mohr, its huge volume, covers an area of more than one hundred seventy square meters, weight is about 30 tons, costs nearly 150 kilowatts of electricity. Obviously, this computer cost is high, difficult to use. This statement is widely used Computer basic textbooks in 1973, in fact, according to the United States Supreme Court ruled that the earliest digital electronic computers, should is the Iowa state university physics department associate professor John o SuoFu and its Tampa that graate assistant cliff Berry (Clifford Berry e., 1918-1963) in October 1939 manufacturing "ABC" (Atanasoff - Berry - Computer). Have this misunderstanding, because "ENIAC" one of the research team at Cleveland, called mo 1941, o John plagiarism SuoFu research achievements of the Tampa in 1946, and apply for a patent. Due to various reasons until 1973 this error is turn them around. (particular case refer to - "John o wikipedia entries and SuoFu" Tampa that hope everyone remember ABC and John o SuoFu, hoped later tantra that can modify this error of textbook. Later in order to commend and commemorative John o SuoFu in computer field tantra it within a great contribution in 1990, former U.S. President bush awarded Tampa SuoFu John o across the highest technology awards - "the state" eeffect ".
Chinese computer Chinese abacus is the earliest computing tools. In the history of the development of human civilization in China was once early computing tools invention aspects wrote a glorious page. Shang, China will have created a decimal numeration method, leading in more than 1,000 years. To the zhou dynasty, invented the most advanced computing tools - count chips. This is a kind of bamboo, wood or bone of different colors made of small stick. Computing every math problems, usually make up a set of GeJue forms of algorithm, side calculation, side constantly to cloth stick. Ancient Chinese mathematician zu chong, is calculated by numerical raised in 3.1415927 3.1415926 and between of PI. The results earlier than the west for a thousand years. Abacus plate is another original Chinese, but also in the history of computing tools in the first major inventions. This light and flexible, convenient to carry, and people's living close calculation tool, first emerged when YuHanChao maturity, to the yuan dynasty. Abacus in Chinese economy not only dish played beneficial effects of the development, and spread to Japan, Korea, southeast Asia and other regions, withstand the test of the history, are still in use. Chinese inventions, it was the direction-guiding cart in waterway written instrument, such as car, jacquard machine drums, not only to the development of automatic control machines have outstanding contributions to computing tools, and the evolution proced direct or indirect impact. For example, it was made of zhang heng waterway, can automatically instrument with earth in moving synchronization, by the tang, song after two generations of improvement, thus became the world's first world. The car is written in the world drum, the earliest automatic counting device. Jacquard machine principle and the development of the computer program control have indirect effects. Ancient Chinese Yao with Yang, Yin constitutes a gossip, and two of the development of computing technology have direct influence. Leibnitz wrote research papers, systematically tabloid forward binary arithmetic algorithms. He thinks, the world's first binary representation is China's gossip. After a long silence, after the founding of new China, Chinese computing entered the new developing period, has established a research organization, in universities and colleges to establish computing technology and device professional and computational mathematics, and hands to create China professional computer manufacturing. China is developed successfully in 1956 in home computer. In 1958 and 1959 China has successfully developed independently domestic small and large tube computer. In the mid 60, China has successfully developed computer, and configuration of the transistor such language ALGOL compiler and other system software. In the late 1960's, China began to study computer integrated circuits. In the 1970s, China has batch proction small integrated circuit computer. In the 1980s, China began after key development microcomputer system and popularized; In large computer, especially huge computer technology has also made important progress; Established computer services, and graally improve the computer instry structure. In computer science and technology research, China in finite element calculation method, mathematical theorems machine proof, Chinese information processing, computer system structure and software all aspects contribute. In computer applications, in Chinese scientific computing and engineering design fields have achieved remarkable success. In the related management and process control, computer application research and practice is increasingly active.

❷ 计算机英语短文

What is a Computer?

Computers are machines that can be used for performing calculations automatically. They can perform complex and repetitive proceres quickly, precisely and reliably and can quickly store and retrieve large amounts of data.

The physical components from which a computer is constructed (electronic circuits and input/output devices) are known as "hardware". Most computers have four types of hardware components: input, processor, storage (main memory, auxiliary storage) and output.

Input and output (I/O) devices allow the computer to communicate with the user and the outside world. The CPU (central processing unit) executes programs ("software") which tell the computer what to do.

The two principal characteristics of a computer are: It responds to a specific set of instructions in a well-defined manner. It can execute a prerecorded list of instructions (a program).

Classification of computers

Computers can be generally classified by size and power as follows:

• Personal computer: A small, single-user computer based on a microprocessor. In addition to the microprocessor, a personal computer has a keyboard for entering data, a monitor for displaying information, and a storage device for saving data.

• Workstation : A powerful, single-user computer. A workstation is like a personal computer, but it has a more powerful microprocessor and a higher-quality monitor.

• Minicomputer : A multi-user computer capable of supporting from tens to hundreds of users simultaneously.

• Mainframe : A powerful multi-user computer capable of supporting many hundreds to thousands of users simultaneously.

• Supercomputer : An extremely fast computer that can perform millions of instructions per second.

Generations of Computers

The history of computer development is often referred to in reference to the different generations of computing devices. Each generation of computer is characterized by a major technological development that fundamentally changed the way computers operate. It resulted in smaller, cheaper, and more powerful, efficient and reliable devices.

• First Generation- 1940-1956: Vacuum tubes were used and it relied on machine language to perform operations, and they could only solve one problem at a time.

• Second Generation - 1956-1963: Transistors were used and computers moved from cryptic binary machine language to symbolic, or assembly, languages, which allowed programmers to specify instructions in words.

• Third Generation - 1964-1971: Integrated circuits -Transistors were miniaturized and placed on silicon chips, called semiconctors. Users interacted through keyboards and monitors and interfaced with an operating system.

• Fourth Generation - 1971-Present: Microprocessors -The microprocessor brought the fourth generation of computers, as thousands of integrated circuits were built onto a single silicon chip.

• Fifth Generation - Present and Beyond: Artificial intelligence -Computing devices, based on artificial intelligence, are still in development, though there are some applications, such as voice recognition, that are being used today

IPSO

Most computers have four types of hardware components: input, processor, storage (auxiliary storage) and output. Input and output (I/O) devices allow the computer to communicate with the user and the outside world. The CPU (central processing unit) executes programs ("software") which tell the computer what to do.

IPSO Cycle

The diagram given explains the operations in the computer. First the data enters the computer through the input device, and then processing occurs at the processing unit. The processing unit is the microprocessor chip. Processing unit comprises of the control unit and arithmetic and logical unit and main memory. There are storage devices (auxiliary storage) which store the processed data and data can be retrieved at anytime. The processed data is sent out to the output devices for the user.

Input ----- Processing ------ Storage ----- Output

NEW WORDS AND EXPRESSIONS

automatically adv. 自动地

repetitive adj.各自的

retrieve v. 恢复，补救

physical adj.物理的，自然的

auxiliary adj.辅助的，附加的，副的 n.补助物

main memory 主存

auxiliary memory辅存

execute v.执行，实现

prerecord v.事先录音

microprocessor n.微处理器

in addition to adv.除…什么之外

monitor n.显示器

simultaneously adv.同时地

technological adj.科技的

fundamentally adv.基础地，根本地

Vacuum tube 电子管

transistor 晶体管

cryptic adj.秘密的，神秘的

binary adj.二进位的

symbolic adj.象征的，符号的

semiconctor n.半导体

artificial intelligence 人工智能

❸ 求一篇关于计算机病毒的英文文章

1、打开IE，地址栏输入www.google.cn。

2、搜索栏后面高级搜索。

3、搜索框输入ComputerVirus，下面文件格式选择pdf、doc格式。

4、回车

5、在搜索结果标题中右击使用迅雷下载，或者目标另存为。

外事问google，内事问网络。

❹ 急求一篇关于计算机用途的英语短文

Internet Virus Spreads 网络病毒的传播
Experts on cyberspace say the much feared code red computer 1)worm continues to spread through the internet. But so far, the electronic bug that was being considered a global threat to internet 2)traffic seems to have had little 3)impact.

No significant disruptions to traffic on the web have been reported since the code red bug was 4)unleashed early Wednesday. But experts warn the threat may be far from over. Bill Jones, the spokesman of California's Keynote Systems, the company which helps businesses with e-commerce ‘I haven’t said anything so far that we call unusual, but we certainly would… But the FBI says the code red worm is still spreading and has the potential to infect internet sites and cause 5)significant disruption to traffic on the world wide web.

"I would expect that the worm has probably not run its course. I would think that because it is a 6)geometric progression, as it infects machines and they infect other machines, you have the opportunity to see a slowdown over time. To have expected something immediately at 0000 UTC Wednesday I think was 7)unrealistic but over the next 24 hours and next few days we could certainly see a slowdown."

Last month, the worm attacked more than 350,000 computer systems running on Microsoft operating systems - including the White House website - and prompted the Pentagon to shut down sites then as well. But it seems that the advice issued by the FBI and cyber instry leaders for internet users to take precautions may have paid off. So far, more than a million people have downloaded a so-called 8)patch from Microsoft's website that prevents computers from being infected.

注释：

(1) worm [w:m] n.虫, 蠕虫

(2) traffic [5trAfIk] n.交通, 通行, 运输, 贸易, 交通量, 交易, 交往, 通信量

(3) impact [5ImpAkt] n.碰撞, 冲击, 冲突, 影响vt.撞击, 压紧, 对...发生影响

(4) unleash [Qn5li:F] v.释放

(5) significant [sI^5nIfEkEnt] adj.有意义的, 重大的, 重要的

(6) geometric progression n.[数]等比级数

(7) unrealistic [QnrIE5lIstIk] adj.不切实际的, 不实在的

(8) patch [pAtF] n.修补程序

转载的~~~~~
还有几个
Compter Networks
Modem networking applications require a sophisticated approach to carrying data from one machine to another. If you are managing a machine that has many users, each of whom may wish to simultaneously connect to remote hosts on a network, you need a way of allow-in them to share your network connection without interfering with each otherf~3. The approach that a large number of modern networking protocols use is called packet switching. A packet is a small chunk of data that is transferred from one machine to another across the network. The switching occurs as the datagram is carried across each link in the network. A packet-switched network shares a single network link among many users by alternately send-in packets from one user to another across that link.
When talking about TCP/IP networks you will hear the term datagram, which technical-lye has a special meaning but is often used interchangeably with packetE2~. In this section, we will have a look at underlying concepts of the TCP/IP protocols.
TCP/IP traces its origins to a research project funded by the United States Defense Ad-Vance Research Projects Agency (DARPA) in 1969. The ARPANET was an experimental network that was converted into an operational one in 1975 after it had proven to be a success.
In 1983, the new protocol suite TCP/IP was adopted as a standard, and all hosts on the network were required to use it. When ARPANET finally grew into the internet (with ARPANET itself passing out of existence in 1990), the use of TCP/IP had spread to net-works beyond the Intermit itself. Many companies have now built corporate TCP/IP net-works, and the Intermit has grown to a point at which it could almost be considered a main-stream consumer technology. It is difficult to read a newspaper or magazine now without see-in/reference to the Internet; almost everyone can now use it.
Another very important application in TCP/IP networks is NFS, which stands for Net-work File System. It is another form of making the network transparent, because it basically allows you to treat directory hierarchies from other hosts as if they were local file systems and look like any other directories on your hostc3J . For example, all users' home directories can be kept on a central server machine from which all other hosts on the LAN can mount them. The effect is that users can login to any machine and find themselves in the same home directory, Similarly, it is possible to share large amounts of data(such as database, documentation programs)among many hosts by maintaining one of the data on a server and allowing other hosts to access it.
Of course, these are only examples of what you can do with TCP/IP networks. We will now have a closer look at the way TCP/IP works. This information will help you understand how and why you have to configure your machine.
The World Wide Web is a hypertext-based system for finding and accessing Internet resources; it is a set of programs, standards, and protocols governing the way in which multimedia files are created and displayed on the Internet. It can provide access to a variety of Internet resources from the same interface ,including FTP, Gopher and Usenet newsgroups in addition to WWW sites.

作者： 218.200.247.* 2006-2-26 14:31 回复此发言

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2 计算机方面的英语资料，介绍一些计算机的英语短文，有兴趣的可以看
The World Wide Web is a distributed, multimedia and hypertext system, and thus a unique medium for communication and for publishing.
Documents for the WWW are written in HTML. The term is used to describe an interlinked system of documents in which a user may jump from one document to another in a nonlinear, associative way. The ability to jump from one document to the next is made possible through the use of hyperlinks. By click the hyperlink, the user is immediately connected to the document specified by the link. Multimedia files on the Internet are called hypermedia documents.
The explosion in use and popularity of Internet in the 1990s is most likely e to the graphics-intensive nature of the World Wide Web. Indivials, companies, and institutions use the Web in many ways. The most widely used tool on the Web is electronic mail, or E-mail, which is used to send written messages between indivials or groups of indivials, often geographically separated by large distances. As a very convenient and inexpensive way to transmit messages, E-mail has dramatically affected scientific, personal, and business communications.
World Wide Web has found application everywhere. E-commerce (business via the Internet) has grown out of businesses that started to advertise their presence via a Web site.
This has broadened into selling procts and services, not only to customers but between businesses themselves. The costs of commercial transactions are negligible, compared with using the traditional distribution and retail network. What is more revolutionary is that the Web can lead to greater political involvement in decision making for ordinary people, via devoting systems.
Web technology has also been extended to handle conferencing and real time communications, to enable it to act like groupware, which facilitates people collaborating over a net-work, especially over an Intranet. The future of the World Wide Web is certain; it will survive and grow. What is uncertain is how it will affect other areas of everyday life.
Wireless Access System ( I )
With its advantages including the short construction period, dispensability with the laying of conits and capability of both data and voice transmission, wireless access can partly or even entirely substitute for wire accessE13 . It is widely used by telecom carriers, which provide voice service largely, and newly emerging Internet service providers (ISPs) and potential local access providers as welled~ . The WA systems used in China have the following six types in terms of frequency bands used.
1. 450/460 MHz WA System: This system finds wide application in rural areas, re-mote suburbs, remote mountainous areas and islands. Some years ago, in order to achieve the objective of making every village accessible to telephone service, the Ministry of Posts and Telecommunications (MPT) extensively used WA systems of this frequency band, pro-mooting the rapid growth of the segments concerned TM . A dozen of manufacturers such ashamed, TCL and Dating proced such systems. However, since these are used mainly in rural areas, their economic efficiency is not as good as is expected. After China Telecom became an independent accounting unit, the development of WA service of this band began to slow down and face fierce competition. This band will not be reallocated; the government encourages telecom carriers to use it for rural communications.

作者： 218.200.247.* 2006-2-26 14:31 回复此发言

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3 计算机方面的英语资料，介绍一些计算机的英语短文，有兴趣的可以看
2. 1800 MHz WA System: This system uses 1800 - 1805 MHz and is based on TDD
molation. Now only the S-CDMA WA systems developed by Dating and deployed in many
places (like Changing) by China Telecom use this band. Owing to the fact that Internet access and mobile terminals are not yet to be introced, the growth of the relevant services impeded. Moreover, this band may possibly be withdrawn for the purpose of 3G generation mobile communications.
3. 1900 MHz WA System: This system is either based on FDD or TDD. The FDD-
based system uses 1880 ~ 1900 MHz/1960 ~ 1980MHz. It adopts CDMA, GSM and PACS.
Since these bands are inconsistent with those designated by the ITU for the use of 3G mobile
communications, in accordance with the regulations of the Radio Regulatory Bureau of theme, they can be used only in Beijing, Tianjin, Shanghai, Guangzhou, Shenzhen, Xiamen,Fuzhou,Cheng and Chongqing by the year 2002 and will be withdrawn and reallocated after that.
The TDD-based WA system uses 1900~1920 MHZ and falls into two types: mobile and fixed. The mobile system, which adopts either PHS or DECT technology, is well known as the radio telephone and mobile phone. The TDD-based fixed WA system uses 1907~1915MHZ and both the CDMA/TDMA molation modes. Now shanghai Bell proces Israel’s Beta-2000 system. This system is used in Ningxia province and part of Hunan province
Wireless Access System(Ⅱ)
4.Spread Spectrum WA System: This system uses 2400~2483.5MHZ/5725~5825MHZ and either direct spread spectrum molation or hopping frequency spread spectrum molation. It can be a normal point-to-point and point-to-multipoint spread spectrum data communications system or a wireless local area network(LAN), providing an emission power no more than 100 mw. The wireless LAN, also known as the wireless network bridge and wireless router , is mainly used for short-distance wireless data access to the Internet. With a directional antenna, the normal wireless spread spectrum data communications system provides a relatively long-distance transmission up to 5~10 kilometers. However, there being quite a lot of illegal systems in use within this frequency band, the electro-magnetic environment Is getting worse and interference occurs frequently. This has affected the further development of spread spectrum WA.
5. 3,5 MHz WA System: This system uses 3400 ~ 3430MHz/3500 - 3530MHz, ma-
inlay for midland and broadband WA. In view of the fact that the extended C-band for satellite communications also uses this band, and taking into account the potential trend of satellite communications, the 3.5 MHz WA is planned to use temporarily the frequencies of the2 x 30 MHz bandwidth. WA of this band is widely used in Europe whereas in the United States it is not open yet. Considering the limited frequency range that has been planned, theta -based WA system cannot use this band for the time being. It is estimated that each city or area can only accommodate a couple of WA operators eventually though many operators have made demand for the band. It is expected that the related frequency allocation and commercial experiments will be carried out in the first half of the year 2001.
6. Broadband WA: As demand for broadband services increases, recent years have seen the strong growth of broadband WA. People generally refer to the local multipoint distribution system (LMDS) as the broadband WA system. Because of its wide bandwidth, its frequencies can only be arranged in a higher band, which allows a short distance.
Generally speaking, because of its good propagation characteristics, the WA system un-deer 1000 MHz is suitable for rural areas, remote suburbs, mountainous areas and islands withal high cost of cable installation, a low teledensity and complex topography. The WA system above 1000 MHz can also serve as a means of installing telephone lines soon. Lacking for re-lasted global unified standards, the WA system is not able to provide roaming. So it is important to encourage the selection of appropriate technologies and systems for different subscribers in different areas and environments. Different WA systems may use different bands flexibly provided that they do not interfere with the operation of existing radio services.

❺ 关于计算机的英语作文

【要求】

在一次主题为“电脑时代”的学校征文活动中，你计划以“The Computer”为题写一篇文章参加评选，你的辅导老师帮助你制订了一个写作纲要，如下：

计算机正广泛被用于各行各业。

在过去的五十年中，计算机得到了迅猛的发展。

计算机最终还是由人来设计和控制。

【范文】

The Computer

The computer is widely used in all phases of society. In instry, business, ecation, medicine, nearly all walks of life, computers have made their appearance, providing great speed and accuracy for our work. Computers have been used in the home, offices, laboratories and research institutions, functioning as the most efficient and versatile instruments for calculating, sorting, filing, recording and distributing. Computers are indispensable to modern civilization. Without computers, our life and our society will undoubtedly suffer a big regression.

During the past five decades the computer has been rapidly advanced. Ever since the computer came into being, it has experienced the development of several generations, which are based respectively on vacuum tube, transistor and integrated circuit. Early computers were of great size, and had no match for the latest electronic computers in speed and accuracy. The Latter is capable of processing the most complicated information and reaching solution to problems in a fraction of time. At present, efforts are being made not only to bring the hardware to perfection, but also to improve the quality of the software.

作文的内容千变万化，这就要求我们丰富自己的知识，特别是各行业的最新动态。只有这样，才能自如地处理各种题材和内容。

Computers must be instructed and programmed by people. In spite of the remarkable skill of the computer, men can never become its slave. Computers are not creative. They work according to men's instructions. So the development of computers and their use will depend upon the ingenuity of men. Although there are times when computers seem to operate like a mechanical “brain”,their achievements are not comparable to what the minds of men are able to do
给分吧