理工A概括大意

第十一篇The Tiniest Electric Motor in the World 世界上昀小的电动机

第十二篇 A Strong Greenhouse Gas 一种强烈的温室气体

第十三篇Face Masks May Not Protect from Super-Flu 口罩也许无法预防感冒第十四篇The Magic Io Personal Digital Pen io私人数字笔

第十五篇Maglev Trains 磁悬浮列车

第十一篇The Tiniest Electric Motor in the World

1 Scientists recently made public the tiniest electric motor ever1 built. You could stuff hundreds of them into the period at the end of this sentence. One day a similar engine might power a tiny mechanical doctor that would travel through your body to remove your disease.

2 The motor works by shuffling atoms between two molten metal droplets in a carbon nanotube. One droplet is even smaller than the other. When a small electric current is applied to the droplets, atoms slowly get out of the larger droplet and join the smaller one. The small droplet grows —but never gets as big as the other droplet —and eventually bumps into the large droplet. As they touch, the large droplet rapidly sops up the atoms it had previously lost. This quick shift in energy produces a power stroke2.

3 The technique exploits the fact that surface tension —the tendency of atoms or molecules to resist separating —becomes more important at small scales3. Surface tension is the same thing that allows some insects to walk on water.

4 Although the amount of energy produced is small — 20 microwatt s — it is quite impressive in relation to the tiny scale of the motor4. The whole setup

5 is less than 200 nanometers on a side, or hundreds of times smaller than the width of a human hair. If it could be scaled up to the size of an automobile engine6, it would be too million times more powerful than a Toyota Camry’s 225 horsepower V

6 engine.

5 In 1988, Professor Richard Muller and colleagues made the first operating micromotor, which was 100 microns across7, or about the thickness of a human hair. In 2003, Zettl’s group created the first nanoscale motor. In 2006, they built a nanoconveyor, which moves tiny particles along like cars in a factory.

6 Nanotechnology engineers try to mimic nature, building things atom-by-atom. Among other things, nanomotors could be used in optical circuits to redirect light, a process called optical switching. Futurists envision a day when nanomachines, powered by nanomotors, travel inside your body to find disease and repair damaged cells.

1. Paragraph 2 The Working Principle of the Nanomotor

2. Paragraph 4 A Description of the Nanomotor in Terms of Power and Size

3. Paragraph 5 Previous Inventions of Nanoscale Products

4. Paragraph 6 Possible Fields of Application in the Future

5.Doctors envision that the nanomotor would travel through human bodies to . emove disease

6.Surface tension means the tendency of atoms or molecules to

resist separating.

7.Nanoconveyors could be used to .

transport nanoscale objects

8. Applying a small electric current causes atoms to .

shuffle between two molten metal droplets

第十一篇世界上昀小的电动机

昀近科学家公布了现有的昀小的电动机。就是在一个句号里，上百个这样的电动机也能来回地运动。将来有一天，类似的发动机也许能够为一个机械医生提供动力，在人的身体里自由移动，治疗疾病。

发动机通过碳纳米管中的原子在两小滴金属溶液间的来回运动进行工作。其中一个小滴甚至比另一个还要小。当微弱的电流通过时，大一点的小滴金属溶液中的原子就会缓慢逸出，进入小一点的小滴。这样，后者体积不断增大——但决不会大到和前者一样——昀后，与大一点的小滴金属溶液相撞。当他们接触时，大的小滴便夺回它失去的原子。能量这样迅速地来回运动就产生一次动力冲程。

这项技术利用了表面张力的原理——原子或分子有不愿被分开的倾向——这在纳米等级上更加重要。表面张力同样也使某些昆虫能在水上行走。

虽然这样产生的能量很少——只有20微瓦，但与电动机的小等级相比，功率也是相当可观了。整个装置的体积不到200纳米，比起人类一根头发的宽度，它要小几百倍。如果纳米电动机能按比例放大到汽车发动机的尺寸，它将会比丰田凯美瑞的225马力的V6引擎还要大1亿倍。

1988年，理查德·乌勒教授和他的同事发明了第一台微型发动机，100微米长，或者说有一根头发那么粗。2003年，泽特尔的小组制造出第一台纳米级的发动机。2006年，他们又造出了纳米传送带，能够像工厂里传送汽车那样移动极小的粒子。

纳米技术的工程师尽力去模拟自然，用一个个原子来制造物体。在这些事物当中，纳米发动机能够被用于光电路来改变光的方向，该过程被称为光学转换。未来主义者预想有一天，被纳米发动机驱动的纳米机器能在人体内移动，发现疾病并修复被破坏的细胞。

第十二篇 A Strong Greenhouse Gas

1 Methane is a colorless, odorless gas; it is also a potent greenhouse gas, and once released into the atmosphere1, it absorbs heat radiat ing from Earth’s surface. That’s why methane is a major contributor to the planet’s increasing temperature rise — or global warming. Molecule for molecule, methane’s heat-trapping power in the atmosphere is 21 times stronger than carbon dioxide2, the most abundant greenhouse gas.

2 With 1

3 billion cows belching almost constantly around the world (100 million in the U. S. alone), it’s no surprise that methane released by livestock is one of the chief global sources of the gas. Other prime methane sources: petroleum, drilling, coal mining, solid-waste landfills and wet lands.

3 Greenhouse gases like methane and carbon dioxide make up only a small part of Earth’s atmosphere, which is 78 percent nitrogen and nearly 21 percent oxygen. And without greenhouse gas es to trap the sun’s heat and warm the planet, life as we know it couldn’t exist3. But in the last 200 years, human activity that requires burning oil, natural gas, and coal for energy has magnified the greenhouse effect.

4 Atmospheric concentrations of methane have more than doubled in the last two centuries. Blame for this often focuses on big industries and gas-guzzling vehicles. But agriculture plays a major role, too. In the past 40 years alone, the global cattle population has doubled.

5 Cows munch mostly grasses and hay — yet they grow big and hefty. Why? Because of the rumen. The

rumen holds 160 liters of food and billions of microbes. These microscopic bacteria and break down cellulose and fiber into digestible nutrients. A cow couldn’t live without its microbes. As the microbes digest cellulose, they release methane. The process occurs in all animals with a rumen (cows, sheep, and goats, for example), and it make them very gassy. It’s part of their normal digestion process. When they chew their cud, they regurgitate some food to rechew it, and all this gas comes out. The average cow expels 600 liters of methane a day.

6 That’s why we say livestock gas is also a major factor of causing the global warming.

1. Paragraph 1 Methane as a Strong Greenhouse Gas

2. Paragraph 2 Livestock as a Prime Factor of the Greenhouse Effect

3. Paragraph 4 Agriculture Also Contributes to Increased Concentrations of Methane in the Atmosphere

4. Paragraph 5 Why Livestock Releases Methane

5. Methane is to the intensifying greenhouse effect. one of the major contributors

6. Greenhouse gases are indispensable to mankind, but the problem mankind is faced with is . the ever-increasing atmospheric concentrations of greenhouse gases

7. Generally people heap criticism on for the planet’s temperature rise.

big industries and gas-guzzling vehicles

8.Nothing has been mentioned in the passage about

how to cut down the cattle populations

第十二篇一种强烈的温室气体

甲烷是一种无色无味的气体，同时也是一种很强烈的温室气体，一旦释放到空气中，就会吸收地球表面散发的热量。所以说甲烷是使这个星球日趋变暖(或叫全球变暖)的一个主要原因。按分子与分子对比，甲烷在大气中吸收热量的能力是二氧化碳——昀丰富的温室气体的21倍。

由于全世界有130亿头牛几乎在连续不断地打嗝（仅美国就有一亿头），难怪由牲畜释放的甲烷就成为了一种主要的全球性甲烷来源。其他主要的甲烷来源有：石油、钻井、采煤、固体垃圾以及沼泽地。

甲烷和二氧化碳等温室气体只占地球大气的一小部分，大气中78%为氮气，将近21%为氧气。如果没有温室气体来吸收太阳的热量，使地球变暖，我们所知道的生命就不会存在。但在过去的200年里，通过燃烧油、天然气和煤来获取能量的人类活动加剧了温室效应。

在过去的两个世纪里，甲烷在大气中的浓度地加了一倍多，人们常常将此归罪于大工业和汽车。但是农业在其中也扮演了一个重要角色。仅在过去40年里，全球牲畜数量就翻了一番。

牛吃的大部分是草，但却长得身高体壮。原因何在？在于它们都长有瘤胃。它们的瘤胃容纳160升的食物，养育数十亿的微生物。这些微小的细菌和原生动物可分解纤维素，形成可吸收的营养。没有这些微生物牛就无法生存。由于微生物可吸收纤维素，所以就会释放出甲烷。所有长有瘤胃的动物（比如牛、绵羊和山羊）都会这样，因此它们经常释放出气体。这是它们的正常吸收过程的一部分。它们反刍时，就会将食物重新咀嚼，于是就释放出气体。一般每头牛每天会排出600升甲烷。

因此，我们认为，牲畜释放的气体也是全球变暖的一个主要因素。

第十三篇Face Masks May Not Protect from Super-Flu

1 IF a super-flu strikes, face masks may not protect you. Whether widespread use of masks will help, or harm, during the next worldwide flu outbreak is a question that researchers are studying furiously. No results have come from their mask research yet. However, the government says people should consider wearing them in certain situations anyway, just in case1.

2 But it’s a question the public keeps asking while the government are making preparations for the next flu pandemic. So the Centers for Disease Control and Prevention (CDC) came up with2 preliminary guidelines. “We don’t want people wearing the m everywhere,” said the CDC. “The overall recommendation really is to avoid exposure.”

3 When that’s not possible3, the guidelines say to consider wearing a simple surgical mask if you are in one of the three following situations. First, you’re healthy and can’t avoid going to a crowded place. Second t you’re sick and think you may have close contact with the healthy, such as a family member checking on you4. Third, you live with someone who’s sick and thus might be in the early stages of infection, but st ill need to go out.

4 Influenza pandemics can strike when the easy-to-mutate flu virus shifts to a strain that people never have experienced. Scientists cannot predict when the next pandemic will arrive, although concern is rising that the Asian bird flu might trigger one if it starts spreading easily from person to person.

5 During the flu pandemic, you should protect yourself. Avoid crowds, and avoid close contact with the sick unless you must care for someone. Why aren’t masks added to this self-protection list? Because they can help trap virus-laden droplets flying through the air with a cough or sneeze. Simple surgical masks only filter the larger droplets. Besides, the CDC is afraid masks may create a false sense of security. Perhaps someone who should have stayed home would don an ill-fitting mask and hop on the subway5 instead.

6 Nor does flu only spread through the air6. Say

7 someone covers a sneeze with his or her hand, then touches a doorknob or subway pole8. If you touch that spot next and then put germy hands on your nose or mouth, you’ve been exposed. It’s harder to rub your nose while wearing a mask and so your face may get pretty sweaty under masks. You reach under to wipe that sweat, and may transfer germs caught on the outside of the mask straight to the nose, These are the problems face masks may create for their users.

7 Whether people should or should not use face masks still remains a question. The general public has to wait patiently for the results of the mask research scientists are still doing.

1. Paragraph 2 Guideline on Mask Use

2. Paragraph 3 When to Use Face Masks

3. Paragraph 5 Reasons for Excluding Masks From the Self-protection List

4. Paragraph 6 Danger of Infection Through Germy Hands and Masks

5. The scientists are trying to find out if masks mayor may not .

help protect people from being attacked by a flu

6. The CDC is afraid that the public may . overuse face masks

7. The public will not know the answer about masks until scientists .

announce the results of their mask research

8. We can infer from the passage that the US authorities .

deal with the mask problem seriously

第十三篇口罩也许无法预防感冒

如果一场超级流感爆发，口罩也许不能保护你。在下一次世界性的流感爆发期间，

广泛使用口罩是否有用还是个问题，科学家正认真研究该题，但至今还设有任何结果。然而，为了以防万一，政府建议人们在某些情况下还是应当考虑配戴口罩。但问题是，当政府为下一次流感流行做准备时，公众仍心存疑问。所以美国疾病控制和预防中心提出指导原则，“我们不希望人们到处戴着口罩，”他们说，“总体上是建议要避免到有流感病毒的场合去。”

在无法避免的情况下，指导原则提出，在以下三种情况下应考虑佩戴一个简易的外科手术口罩：第一，你很健康但要一个人群拥挤的地方；第二，已经生病了但仍要与健康的人接触，如家庭成员要来看你的病情；第三，与你居住在一起的人已经感冒了，也许你已经处在传染的早期阶段，但你仍需外出。

当易变异的感冒病毒出现人们从未遇到过的新种类时，全国性的流行性感冒就会爆发。如果亚洲的禽流感开始在人与人之间传播，就可能会引起一场这样的大流行性疾病，虽然人们的忧虑不断升级，但科学家仍无法预测这样的大爆发什么时候会出现。

在流感期间，你应当学会自我保护，避免到人多的地方去，远离流感病人，除非你必须照顾病人。为什么不把口罩放入自我保护的意见中呢？口罩能把咳嗽或打喷嚏飞出的含有病毒的飞沫拦截住。简易的外科手术口罩只能过滤大的飞沫。此外，美国疾病控制和预防中心担心口罩可能会制造出一种虚假安全感。也许原本会呆在家里的人会戴上一个不合适的口罩跑去坐地铁。

流感不仅仅是通过空气传染。有些人打喷嚏时会用手遮挡，带有病毒的手会接触到门把手或是地铁里的扶手。如果你碰到这些东西，然后把带有流感病毒的手接触到嘴或者鼻子，你就有可能传染。戴口罩时，脸在口罩下容易出汗，当你去擦

汗时，病毒就直接被带到了鼻子里。这些问题也就是口罩带给他们的使用者的。人们是否应该使用口罩仍然是个问题。公众还要耐心地等待科学家的研究结果。

第十四篇The Magic Io Personal Digital Pen

1 Check out the io Personal Digital Pen launched by Logitech: It’s a magic pen that can store everything you write and transfer it to your computer. And you don’t have to lug a hand-held device along with you for it to work.1

2 Logitech’s technology works like this: The pen writes normally, using normal ballpoint pen ink2. But while you are writing, a tiny camera inside the pen is also taking 100 snapshots per second of what you are doing3, mapping your writing via a patchwork of minute dots printed on the paper. All this information — the movement of your pen

on the paper，basically —is then stored digitally inside the pen, whether you are writing notes or drawing complex diagrams. You can store up to 40 pages worth of doodles in the pen’s memory. As far as you are concerned4, you are just using a normal pen.

3 It is only when you drop the pen into its PC-connected cradle that the fun begins. Special software on your PC will figure out what you have done, and begin to download any documents you have written since the last time it was there. Depending on whether you have ticked certain boxes on the special notepad, it can also tell whether the document is destined to be an e-mail, a “to do” task, or a diagram to be inserted into a word-processing document. Once the documents are downlonded you can view them, print them out or convert them to other formats.

4 The io Personal Digital Pen is a neat and simple solution to the problem of storing, sharing and retrieving handwritten notes, as well as for handling diagrams, pictures and other non-text doodling. You don’t ha ve to carry a laptop along with you. All you have to do is just whip out the pen and the special paper and you are off5.

5 It is a great product because it does not force you to work differently — walking around with a screen strapped to your arm, or carrying with you extra bits and pieces. The pen is light and works like a normal pen if you need it to, while the special notepads look and feel like notepads. The only strange looks will be from people who are curious why you are writing with a cigar.

6 The io Personal Digital Pen also has potential elsewhere. FedEx6, for example, is introducing a version of the pen so that cutomers can fill out forms by hand — instead of punching letters into cumbersome devices. Once that data is digital more or less anything can be done with it — transferring it wirelessly to a central computer, for example, or via a hand-phone. Doctors could transmit their prescriptions direct to pharmacies, reducing fraud; policemen could send their reports back to the station, reducing paperwork.

1. Paragraph 2 Working Principle of the Io Personal Digital Pen

2. Paragraph 3 Ways to Download the Stored Information

3. Paragraph 5 A Friendly and Convenient Device

4. Paragraph 6 Examples of Other Potential Applications of the Io Pen

5. There is no need to learn how to use the io Personal Digital Pen because .

it works like an ordinary pen

6.If you want to download what you have done with the magic pen, .

you simply place the pen into its computer-connected cradle

7.The magic pen is particularly convenient when you work away from home or office because .

you don’t have to carry your laptop along

8. No matter what you write or draw, .

the movement of your pen is recorded digitally inside the pen

第十四篇神奇的io私人数字笔

仔细看看由Logitech公司发明的io数字笔吧：这是种神奇的笔，可以将你写的所有东西储存下来并转换到计算机上，而你在使用这种数字笔时却不必携带手持设备。

Logitech技术的工作原理如下：这种笔使用一种普通的圆珠笔墨水，和平常一样写字。但是当你写字时，笔内的一个极小的摄像头也在以每秒钟100张的速度对你所写的内容进行快速拍摄，通过印在纸上的小点块拼出你所写的内容。然后，无论你是记笔记还是画复杂图表，所有的信息——基本上都是笔在纸上的移动——都将以数字形式存储于笔中。你可在笔的存储器中存储多达40页的资料。而对你来说，你只不过是在使用一只普通的笔而已。

只有当你将笔插入与PC机连接的笔座中时，有趣的事才真正开始。你的PC机的专用软件会估算出你所做之事，并下载你昀新写下的所有文件。根据你是否在专用记事本的一些特定框缸里打对号，这种笔还可辨别出文档是电子邮件、“待执行”任务还是要插入文字处理文档的图表。文档下载后，你就可以查看、打印或转换为其他形式。

io私人数字笔可妥善又简单地解决手写笔记的存储、共享和检索问题，也可处理图表、图片及其他非文本资料。你不必携带电脑，你只需要拿出笔和专门用纸就能开始工作了。

这是一种很了不起的产品，因为你的工作不会因之产生任何麻烦——你不必携带显示屏，也不必携带任何附件。它非常轻便，如果你需要的话，也可以当普通笔来用，而这种专用记事本看起来摸起来都很像普通记事本。有些人会很好奇，不明白为什么你在用雪茄写字，这是唯一看起来令人费解的地方。

io私人数字笔在其他方面也很有潜力。例如，联邦快递公司正引进一种数字笔，从而用户可用手填写表格，而无须再费力劳神地打进机器中。如果数据为数字型，几乎所有事情都可由这种笔来完成——例如将数据通过无线方式或手机传输到

中心计算机上。医生可将处方直接转到药房，减少了欺诈行为的发生。警察可将报告发回警察局，减少了文书工作。

第十五篇Maglev Trains

1 A few countries are using powerful electromagnets to develop high-speed trains, called maglev trains. Maglev is short for magnetic levitation1, which means that these trains float over a guide way using the basic principles of magnets to replace the old steel wheel and track trains.

2 If you’ve ever played with magnets, you know that opposite poles attract and like poles repel each other2. This is the basic principle behind electromagnetic propulsion. Electromagnets are similar to other magnets in that they attract metal objects, but the magnetic pull is temporary. You can easily create a small electromagnet yourself by connecting the ends of a copper wire to the positive and negative ends of an AA-cell battery3. This creates a small magnetic field. If you disconnect either end of the wire from the battery, the magnetic field is taken away.

3 The magnetic field created in this wire-and-battery experiment is the simple idea behind a maglev train rail system. There are three components to this system: A large electrical power source, metal coils lining a guide way or track, and large guidance magnets attached to the underside of the train.

4 The big difference between a maglev train and a conventional train is that maglev trains do not have an engine — at least not the kind of engine used to pull typical train cars along steel tracks4. The engine for maglev trains is rather innoticeable. Instead of using fossil fuels, the magnetic field created by the electrified coils in the guideway walls and the track combines to propel the trains5.

5 The magnetized coil running along the track, called a guideway, repels the large magnets on the train’s undercarriage, allowing the train to levitate between 1 to 10 cm above the guideway. Once the train is levitated, power is supplied to the coils within the guideway walls to create a unique system of magnetic fields that pull and push the train along the guideway. The electric current supplied to the coils in the guideway walls is constantly alternating to change the polarity of the magnetized coils. This change in polarity causes the magnetic field in front of the train to pull the vehicle forward, while the magnetic field behind the train adds more forward thrust.

6 Maglev trains float on a cushion of air, eliminating friction. This lack of friction allows these trains to reach unprecedented ground transportation speeds of more than 500 kph, or twice as fast as the fastest conventional train. At 500 kph, you could travel from Paris to Rome in just over two hours.

1. Paragraph 3 The Main Components of the Maglev Train System

2. Paragraph 4 Comparison of Maglev Trains with Traditional Ones

3. Paragraph 5 The Working Principle of the Maglev Train

4. Paragraph 6 High-speed Maglev due to Zero Friction

5.Several countries in the world are using strong electromagnets

to develop a maglev train rail system

6.You can connect a wire to the positive and negative ends of a battery

to create a magnetic field

7.A unique system of magnetic fields is created by the coils

to pull and push the train forward

8.The frictionless maglev train enables you

to travel from Paris to Rome in about two hours

第十五篇磁悬浮列车

一些国家正在使用强有力的电磁体发展高速列车，这种列车叫做磁悬浮列车。Maglev是磁悬浮的缩略词，它意味着这些列车漂浮在导向槽上，导向槽是使用磁铁的基本原理来替换原来的钢轮子和钢轨道的列车。

如果您曾经玩过磁铁，您知道异极相吸，同极相斥的道理。这是电磁式推进背后的基本原理。电磁体与其他磁铁在吸引金属物品方面是一样的，但是电磁力是暂时的。您能通过铜丝连接一节5号电池的正负极很容易地自己创造出一个小的电磁体。这就创造了一个小磁场。如果您从电池分开导线的任意一个末端，磁场就消失。

这个导线和电池实验创造的磁场是磁悬浮列车系统背后的简单想法。这个系统有三个成分：一个大电能来源、金属卷排行列成导向槽或轨道，和附着列车下面的大的导电磁体。

磁悬浮列车和传统列车之间的一个很大的大区别是磁悬浮列车没有发动机—至少不是沿着轨道拉动典型的火车车厢的那种发动机。磁悬浮列车的发动机相当不显眼。代替矿物燃料的使用，由嵌入导向壁内的电磁线圈产生的磁场加上轨道，一起推动火车前进。

导向槽是沿着轨道延伸的带磁性的线圈。它排斥在列车的车盘上的大磁铁，允许列车在导向槽之上1～10cm之间悬浮。一旦列车被悬浮，就把力量供给在导向槽墙体之内的线圈来创造出一个单独的磁场系统，沿着导向槽推拉列车。在导向槽墙体内供给线圈的电流不断交替改变被磁化的线圈的极性。在极性上的变化造

成了列车前面的磁场向前拉动列车，而在列车后面的磁场增加更多向前推力。磁悬浮列车漂浮在气垫上来减少摩擦。这种缺乏摩擦（的状态)让这些列车超过500 kph的速度，(这个速度)是地面交通工具史无前例的速度，或者是昀快速的传统列车两倍的速度。500 kph，你可能用刚好超过两个小时的时间从巴黎到罗马。