職稱英語 理工A概括大意與完成句子 字典版
32FJ gong-a 第十一篇The Tiniest Electric Motor in the World1 Scientists recently made public the tiniest electric motor ever 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 stroke 3 The technique exploits the fact that surface tension the tendency of atoms or molecules to resist separating becomes more important at small scales. Surface tension is the same thing that allows some insects to walk on water. 4 Although the amount of energy produced is small 20 microwatts it is quite impressive in relation to the tiny scale of the motor. The whole setup 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 engine, it would be 100 million times more powerful than a Toyota Camrys 225 horsepower V6 engine. 5 In 1988, Professor Richard Muller and colleagues made the first operating micromotor, which was 100 microns across, or about the thickness of a human hair. In 2003, Zettls 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. 練習: 1Paragraph 2 E The Working Principle of the Nanomotor2Paragraph 4 B A Description of the Nanomotor in Terms of Power and Size3Paragraph 5 D Previous Inventions of Nanoscale Products4Paragraph 6 F Possible Fields of Application in the Future5Doctors envision that the nanomotor would travel through human bodies to A remove disease6Surface tension means the tendency of atoms or molecules to B resist separating7Nanoconveyors could be used to F transport nanoscale objects8Applying a small electric current causes atoms to C shuffle between two molten metal droplets世界上最小的電動機最近科學家公布了現(xiàn)有的最小的電動機。就是在這句話的句號里,你也能塞進幾百個這樣的電動機。將來有一天,類似的發(fā)動機也許能夠為一個微型機械醫(yī)生提供動力,在人的身體里自由移動,治療疾病。 發(fā)動機通過碳納米管中的原子在兩小滴金屬溶液間來回運動進行工作。其中一個小滴甚至比另一個還要小。當微弱的電流通過時,大一點的小滴金屬溶液中的原子就會緩慢逸出,進入小一點的小滴。這樣,后者體積不斷增大但絕不會大到和前者一樣最后,與大一點的小滴金屬溶液相撞。當它們接觸時,大的小滴便奪回它失去的原子。能量這樣迅速地來回運動就產(chǎn)生一次動力沖程。 這項技術(shù)利用了表面張力的原理原子或分子有不愿被分開的傾向這在納米等級上更加重要。表面張力同樣也使某些昆蟲能在水上行走。 雖然這樣產(chǎn)生的能量很少只有20 微瓦,但與電動機的小等級相比,功率也是相當可現(xiàn)了。整個裝置一側(cè)的長度不到200納米,比人類一根頭發(fā)的寬度還要小幾百倍。如果納米電動機能按比例放大到汽車發(fā)動機的尺寸,它將會比豐田凱美瑞的225 馬力的V6 引擎功率還要大1 億倍。 1988 年,理查德烏勒教授和他的同事發(fā)明了第一臺微型發(fā)動機, 100 微米長,或者說有一根頭發(fā)那么粗。2003 年,澤特爾的小組制造出第一臺納米級的發(fā)動機。2006 年,他們又造出了納米傳送帶,能夠像工廠里傳送汽車那樣移動極小的粒子。 納米技術(shù)的工程師盡力去模擬自然,用一個個原子來制造物體。在這些事物當中,納米發(fā)動機能夠被用于光電路來改變光的方向,該過程被稱為光學轉(zhuǎn)換。未來主義者預想有一天,被納米發(fā)動機驅(qū)動的納米機器能在人體內(nèi)移動,發(fā)現(xiàn)疾病并修復被破壞的細胞。第十二篇A Strong Greenhouse Gas1 Methane is a colorless, odorless gas; it is also a potent greenhouse gas, and once released into the atmosphere, it absorbs heat radiating from Earths surface. Thats why methane is a major contributor to the planets increasing temperature rise or global warming. Molecule for molecule, methanes heat-trapping power in the atmosphere is 21 times stronger than carbon dioxide, the most abundant greenhouse gas. 2 With 13 billion cows belching almost constantly around the world (100 million in the U. S. alone), its 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 Earths atmosphere, which is 78 percent nitrogen and nearly 21 percent oxygen. And without greenhouse gases to trap the suns heat and warm the planet, life as we know it couldnt exist. 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 couldnt 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. Its 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 Thats why we say livestock gas is also a major factor of causing the global warming. 練習: 1. Paragraph 1 E Methane as a Strong Greenhouse Gas2. Paragraph 2 F Livestock as a Prime Factor of the Greenhouse Effect3. Paragraph 4 C Agriculture Also Contributes to Increased Concentrations of Methane in the Atmosphere4. Paragraph 5 D Why Livestock Releases Methane5. Methane is to the intensifying greenhouse effect. A one of the major contributors6. Greenhouse gases are indispensable to mankind, but the problem mankind is faced with is B the ever-increasing atmospheric concentrations of greenhouse gases7. Generally people heap criticism on for the planets temperature rise. F big industries and gas-guzzling vehicles8. Nothing has been mentioned in the passage about E how to cut down the cattle populations一種強烈的溫室氣體甲烷是一種無色無味的氣體,同時也是一種很強烈的溫室氣體,一旦釋放到空氣中,就會吸收地球表面散發(fā)的熱量。所以說甲烷是使這個星球日趨變暖(或叫全球變暖)的一個主要原因。按分子與分子對比,甲烷在大氣中吸收熱量的能力是二氧化碳最豐富的溫室氣體的21倍。 由于全世界有130億頭牛幾乎在連續(xù)不斷地打嘀(僅美國就有1億頭),難怪由牲畜釋放的甲烷成為全球甲烷的主要來源。其他主要的甲烷來源有:石油、鉆井、采煤、固體垃圾以及沼澤地。 甲烷和二氧化碳等溫室氣體只占地球大氣的一小部分,大氣中78%為氯氣,將近21%為氧氣。如果沒有溫室氣體來吸收太陽的熱量,使地球變暖,我們所知道的生命就不會存在。但在過去的200年里,通過燃燒油、天然氣和煤來獲取能量的人類活動加劇了溫室效應。在過去的兩個世紀里,甲燒在大氣中的濃度增加了一倍多,人們常常將此歸罪于大工業(yè)和汽車。但是,農(nóng)業(yè)在其中也扮演了一個重要角色。僅在過去40年里,全球牲畜數(shù)量就翻了一番。 牛吃的大部分是草,但卻長得身高體壯。原因何在?在于它們都長有瘤胃。它們的瘤胃可容納160升的食物,養(yǎng)育數(shù)十億的微生物。這些微小的細菌和原生動物可分解纖維素,形成可吸收的營養(yǎng)。沒有這些微生物,牛就無法生存。當微生物分解纖維素時,就會釋放出甲燒。所有長有瘤胃的動物(比如牛、綿羊和山羊)都會這樣,因此它們經(jīng)常釋放出氣體,這是它們的正常吸收過程的一部分。它們反魚時,就會將食物重新咀嚼,于是就釋放出氣體。一般每頭牛每天會排出600升甲烷。 因此,我們認為,牲畜釋放的氣體也是全球變暖的一個主要因素。第十三篇Face Masks May Not Protect from Super-Flu1 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 case. 2 But its 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 with preliminary guidelines. "We dont want people wearing them everywhere," said the CDC. "The overall recommendation really is to avoid exposure." 3 When thats not possible, the guidelines say to consider wearing a simple surgical mask if you are in one of the three following situations. First, youre healthy and cant avoid going to a crowded place. Second, youre sick and think you may have close contact with the healthy, such as a family member checking on you. Third, you live with someone whos sick and thus might be in the early stages of infection, but still 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 arent 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 subway instead. 6 Nor does flu only spread through the air. Say someone covers a sneeze with his or her hand, then touches a doorknob or subway pole. If you touch that spot next and then put germy hands on your nose or mouth, youve been exposed. Its 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. 練習: 1Paragraph 2 D Guidelines on Mask Use2Paragraph 3 C When to Use Face Masks3Paragraph 5 A Reasons for Excluding Masks from the Self-protection List4Paragraph 6 F Danger of Infection through Germy Hands and Masks5The scientists are trying to find out if masks may or may not E help protect people from being attacked by a flu6The CDC is afraid that the public may A overuse face masks7The public will not know the answer about masks until scientists F announce the results of their mask research8We can infer from the passage that the US authorities B deal with the mask problem seriously口罩也許無法預防感冒如果一場超級流感暴發(fā),口罩也許不能保護你。在下一次世界性的流感暴發(fā)期間,廣泛使用口罩是否有用還是個問題,科學家正認真研究該題,但至今還沒有任何結(jié)果。然而,為了以防萬一,政府建議人們在某些情況下還是應當考慮佩戴口罩。 但當政府為下一次流感流行做準備時,公眾仍心存疑問。所以美國疾病控制和預防中心提出了一些初步指導原則,"我們不希望人們到處戴著口罩,"他們說,",總體上是建議要避免到有流感病毒的場合去。" 在無法避免的情況下,指導原則提出,在以下三種情況下應考慮佩戴一個簡易的外科手術(shù)口罩:第一,你很健康但要到一個人群擁擠的地方;第二,你已經(jīng)生病了但仍要與健康的人接觸,如家庭成員要來看你的病情;第三,與你居住在一起的人已經(jīng)感冒了,也許你已經(jīng)處在傳染的早期階段,但你仍需外出。 當易變異的感冒病毒出現(xiàn)人們從未遇到過的新種類時,全國性的流行性感冒就會暴發(fā)。如果亞洲的禽流感開始輕易地在人與人之間傳播,就可能會引起一場這樣的大流行性疾病,雖然人們的憂慮不斷升級,但科學家仍無法預測這樣的大暴發(fā)什么時候會出現(xiàn)。 在流感期間,你應當學會自我保護。避免到人多的地方去,遠離流感病人,除非你必須照顧病人。為什么不把口罩放入自我保護的措施中呢?口罩能把咳嗽或是打噴囔飛出的含有病毒的飛沫攔截住。但簡易的外科手術(shù)口罩只能過濾大的飛沫。此外,美國疾病控制和預防中心擔心口罩可能會制造出一種虛假的安全感。 也許原本會待在家里的人會戴上一個不合適的口罩跑去坐地鐵。 流感不僅僅是通過空氣傳染。有些人打噴囔時會用手遮擋,帶有病毒的手會接觸到門把手或是地鐵里的扶手。如果你碰到這些東西,然后把帶有流感病毒的手接觸到嘴或者鼻子,你就有可能被傳染。戴口罩時你很難去擦鼻子,于是臉在口罩下就變得汗津津的,當你去擦汗時,病毒就直接被帶到了鼻子里。這些問題就是口罩帶給他們的使用者的。 人們是否應該使用口罩仍然是個問題。公眾還要耐心地等待科學家的研究結(jié)果。十四、The Magic Io Personal Digital Pen1Check out the io Personal Digital Pen launched by Logitech:Its a magic pen that can store everything you write and transfer it to your computer. And you dont have to lug a hand-held device along with you for it to work.12Logitechs 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 informationthe 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 pens memory. As far as you are concerned4, you are just using a normal pen.3It 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 downloaded you can view them, print them out or convert them to other formats.4The 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 dont have 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 off5.5It is a great product because it does not force you to work differentlywalking 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.6The io Personal Digital Pen also has potential elsewhere. FedEx6, for example, is introducing a version of the pen so that customers 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.練習:1.Paragraph 2 F Working Principles of the Io Personal Digital Pen.2.Paragraph 3 BWays to Download the Stored Information3.Paragraph 5 AA Friendly and Convenient Device4.Paragraph 6 CExamples of Other Potential Applications of the Io Pen5.There is no need to learn how to use the io Personal Digital Pen because Dit works like an ordinary pen.6.If you want to download what you have done with the magic pen, Eyou 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 Ayou dont have to carry your laptop along.8.No matter what you write or draw, Fthe movement of your pen is recorded digitally inside the pen神奇的io私人數(shù)字筆仔細看看由Logitech公司發(fā)明的io私人數(shù)字筆吧。這是一種神奇的筆??梢詫⒛銓懙乃袞|西儲存下來并轉(zhuǎn)換到計算機上,而你在使用這種數(shù)字筆時卻不必攜帶手持設備。Logitech技術(shù)的工作原理如下:這種筆使用一種普通的圓珠筆墨水,和平常一樣寫字。但是當你寫字時,筆內(nèi)的一個極小的攝像頭也在以每秒鐘100張的速度對你所寫的內(nèi)容進行快速拍攝,通過印在紙上的小點塊拼出你所寫的內(nèi)容。然后,無論你是記筆記還是畫復雜圖表,所以的信息基本上都是筆在紙上的移動都將以數(shù)字形式存儲于筆中。你可在筆的存儲器中存儲多達40頁的資料。而對你來說,你只不過是在使用一支普通的筆而已。只有當你將筆插入與PC機連接的筆座中時,有趣的事才真正開始。你的PC機的專用軟件會估算出你所做之事,并下載你最新寫下的所有文件。根據(jù)你是否在專用記事本的一些特定框里打?qū)μ?,這種筆還可以辨別出文檔是電子郵件、“待執(zhí)行”人物還是要插入文字處理文檔的圖表。文檔下載后,你就可以查看、打印或?qū)⑵滢D(zhuǎn)換為其他形式。io私人數(shù)字筆可妥善又簡單地解決手寫筆記的存儲、共享和檢索問題,也可處理圖表、圖片以及其他非文本資料。你不必攜帶電腦,你只需要拿出筆和專門用紙就能開始工作了。這是一種很了不起的產(chǎn)品,因為你的工作不會因之產(chǎn)生任何麻煩你不必攜帶顯示屏,也不必攜帶任何附件。它非常輕便,如果你需要的話,也可以當普通筆來用,而這種專用記事本看起來摸起來都很像普通記事本。有些人會很好奇,不明白為什么你在用雪茄寫字,這是唯一看起來令人費解的地方。io私人數(shù)字筆在其他方面也很有潛力。例如,聯(lián)邦快遞公司正引進一種數(shù)字筆,從而用戶可用手填寫表格,而無需再費力勞神地打進機器中。如果數(shù)字為數(shù)字型,幾乎所有事情都可由這種筆來完成例如將數(shù)據(jù)通過無線方式或手機傳輸?shù)街行挠嬎銠C上。醫(yī)生可將處方直接轉(zhuǎn)到藥房,減少了欺詐行為的發(fā)生。警察可將報告發(fā)回警察局,減少了文書工作。+第十五課Maglev Trains1 A few countries are using powerful electromagnets to develop high-speed trains,called maglev trains. Maglev is short for magnetic levitation,which means that these trains float over a guideway using the basic principles of magnets to replace the old steel wheel and track trains. 2 If youve ever played with magnet,you know that opposite poles attract and like poles repel each other. This is the basic principle behind electromagnetic propulsion. Electromagnets are similar to other magnets in 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 battery. 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 amaglev train rail system. There are three components to this system: A large electrical power source,metal coils lining a guideway 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 engineat least not the kind of engine used to pull typical train cars along steel tracks.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 combine to propel the train. 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 th 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 coi1s. 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 A、The Main Components of the Maglev Train System2. Paragraph 4 E、Comparison of Maglev Trains with Traditional Ones3. Paragraph 5 C、The Working Principle of the Maglev Train4. Paragraph 6 B、High-speed Maglev due to Zero Friction5. Several countries in the world are using strong electromagnets A、to develop a maglev train rail system6. You can connect a wire to the positive and negative ends of a battery D、to create a magnetic field7. A unique system of magnetic fields is created by the coils C、to pull and push the train forward8. The frictionless maglev train enables you F、to travel from Paris to Rome in about two hours磁懸浮列車一些國家正在使用強有力的電磁體發(fā)展高速列車,這種列車叫作磁懸浮列車。Maglev是磁懸浮的縮略詞,它意味著這些列車漂浮在導向槽上,導向槽是使用磁鐵的基本原理來替換原來的鋼輪子和鋼軌道的列車。 如果你曾經(jīng)玩過磁鐵,你知道異極相服,同極相斥的道理。這是電磁式推進背后的基本原理。電磁體與其他磁鐵在吸引金屬物品方面是一樣的,但是電磁力 是暫時的。你能通過銅絲連接一節(jié)5號電池的正負極很容易地自己創(chuàng)造出一個小的電磁體。這就創(chuàng)造了一個小磁場。如果你從電池分開導線的任意一個末端,磁場就消失。 這個導線和電池實驗創(chuàng)造的磁場是磁懸浮列車系統(tǒng)背后的簡單想法。這個系統(tǒng)有三個成分:一個大電能來源、金屬卷排列成導向槽或軌道和附著在列車下面的大的導電磁體。 磁懸浮列車和傳統(tǒng)列車之間的一個很大的大區(qū)別是磁懸浮列車沒有發(fā)動機至少不是沿著軌道拉動典型的火車車廂的那種發(fā)動機。磁懸浮列車的發(fā)動機相當不顯眼。代替礦物燃料的使用,由嵌入導向壁內(nèi)的電磁線圈產(chǎn)生的磁場加上軌道,一起推動火車前進。 導向槽是沿著軌道延伸的帶磁性的線圈。它排斥在列車的車盤上的大磁鐵,允許列車在導向槽之上1-10cm之間懸浮。一旦列車被懸浮,就把力量供給在導向槽墻體之內(nèi)的線卷來創(chuàng)造出一個單獨的磁場系統(tǒng),沿著導向槽推拉列車。在導向槽墻體內(nèi)供給線圈的電流不斷交替改變被磁化的線卷的極性。在極性上的變化造成了列車前面的磁場向前拉動列車,而在列車后面的磁場增加更多向前推力。 磁懸浮列車漂浮在氣墊上來減少摩擦。這種缺乏摩擦(的狀態(tài))讓這些列車超過500kph的速度,(這個速度)是地面交通工具史無前例的速度,或者是最快速的傳統(tǒng)列車兩倍的速度。500kph,你可能用剛好超過兩個小時的(時間)從巴黎旅行到羅馬。