2012 理工A英语新增.doc

Solar Power without Solar CellsA dramatic and surprising magnetic effect of light discovered by University of Michigan1 researchers could lead to solar power without traditional semiconductor-based solar cells.The researchers found a way to make an opticalbattery, said Stephen Rand, a professor in the departments of Electrical Engineering and Computer Science, Physics and Applied Physics. Light has electric and magnetic components. Until now, scientists thought theeffectsof the magnetic field were so weak that they could be ignored. What Rand and his colleagues found is that at the right intensity, when light is traveling through a material that does not conduct electricity, the light field can generate magnetic effects that are 100 million times stronger thanpreviouslyexpected. Underthese circumstances, the magnetic effects develop strength equivalent to a strong electric effect.This could lead to a new kind of solar cell without semiconductors and without absorption to produce charge separation, Rand said. In solar cells, the lightgoes into a material, gets absorbed and creates heat. Here, we expect to have a very low heat load2. Instead of the light being absorbed, energy is stored in the magnetic moment3. Intense magnetization can be induced by intense light and then it is ultimately capable of providing a capacitive power source.What makes this possible is a previously undetected brand of optical rectification4, says William Fisher, a doctoral student5 in applied physics. In traditional optical rectification, lights electric field causes a charge separation, or a pullingapartof the positive and negative charges6 in a material. This sets up a voltage, similar tothatin a battery.Rand and Fisher found that under the right circumstances and in right types of materials, the lights magnetic field can also create optical rectification. The light must be shone through7 amaterialthat does notconductelectricity, such as glass. And it must be focused to an intensity of 10 million watts per square centimeter8. Sunlight isnt this intense on its own, but new materials are being sought that would work at lower intensities, Fisher said.In our most recent paper, we show that incoherent light9 like sunlight is theoretically almost as.effectivein producing charge separation as laser light is, Fisher said.This newtechniquecould make solar power cheaper, the researchers say. They predict that with improved materials they could achieve 10 percent efficiency inconvertingsolar power to useable energy. Thats equivalent to todays commercial-grade solar cells.To manufacturemodernsolar cells, you have to do extensive semiconductor processing, Fisher said. All we would need are lenses to focus the light and a fiber to guide it. Glass works forboth. Its already made in bulk10, and it doesnt require as much processing. Transparent ceramics might be even better.Sharks Perform a Service for Earths WatersIt is hard to get people to think of sharks as anything but a deadly enemy. They are thought toattackpeople frequently. But these fish perform a valuableservice for earths waters and for human beings. Yet business and sport fishing3 are threatening theirexistenceSome sharks are at risk of disappearing from EarthWarm weather may influence both fish and shark activity. Many fish swim near coastal areasbecause oftheir warm waters. Experts say sharks may follow the fish into the same areas, wherepeople also swim. In fact, most sharks do not purposely charge at or bite humans. They are thought to mistake a personfora sea animal, such as a seal or sea lion. That is why people should not swim in the ocean when the sun goes down or comes up. Those are thetimeswhen sharks are looking for food. Experts also say that bright colors and shiny jewelry may cause sharks to attack.A shark has an extremely good sense of smell. It can find small amounts of substances in water, such as blood, body liquids andchemicalsproduced by animals. These powerfulsenseshelp sharks find their food. Sharks eat fish, anyother sharks, and plants that live in the ocean.Medical researchers want to learn more about the sharks body defense, and immunethoseagainst disease. Researchers know that sharksrecoverquickly from injuries. Theystudy the shark in hopes of finding a way to fight human disease.harks are important for the worlds oceansThey eat injured and diseased fish. Their hunting activities mean that the numbers of other fish in ocean waters do not become toogreatThis protects the plants and other forms of life that exist in the oceans. 小而聪明12月14日，美国国家航空航天局发射了一个体积小而威力大的望远镜，它的名字叫“WISE”（聪明），大约只有一个垃圾盒子那么宽。你可千万不要轻视这个小东西，WISE可是一款商强数码相机，它将在人类已知的宇宙里拍摄任何你所能想到的天体，包括小行星、那些只能看到微弱的光和因燃烧而无法观察的天体，以及自行星和恒星诞生以来的巨大尘埃云。Ned Wright是主持WISE项目的科学家，他说：“我十分兴奋，因为我们就要看到以前从未看到过的那部分宇宙”。到达宇宙空间后，WISE由于受极地轨道重力作用，一直在围绕地球旋转。（这意味着，每转一圈，它就离南极和北极靠近）。它的镜头是向外的，远离地球。每11分钟WISE就会抓拍天空一个不同的部分。六个月之后，它将把整个天空拍摄完毕。然而，WISE拍摄的相片不会像我们日常的数码相片。WISE是Wide-field Infrared Survey Explorer （广域红外勘测探测器）的缩写。正如名字所示，WISE能拍到发出红外线辐射物体的相片。辐射是波浪状行进的一种能量。人能看到的光，包括大家熟悉的、在彩虹里看到的光谱就是射线的一个例子。当普通的数码相机给一棵树照相时，它能接收到树反射回来的、可见的光波。光波通过镜头进入到相机里，相机对它进行加工，然后把图像合成。红外线的波长比可见光长，所以，普通的数码相机捕捉不到他们，人眼也看不到这种射线。尽管人们看不到，人的皮肤能感受到较长红外线带来的温暖。这就是为什么WISE能捕捉到其他望远镜看不到的物体的主要原因。宇宙中，不是所有的东西都以可见光的方式呈现出来。例如，小行星是在太空中漂浮的大岩石，但是小行星吸收射到他们表面的大部分光。他们不能反射光，所以要看到他们很困难。但他们却释放出红外线，所以，像WISE这样的红外线望远镜才能够捕捉到它们的图像。WISE的任务就是拍摄成千上万的小行星图像。WISE的另一任务是为另外一种太空深处的天体一褐矮星拍照。这种天体是“失败的”恒星，它们是一些不够大，不能像太阳的能量那样启动相同的反应。褐矮星只能缩小和冷却。他们发出的光如此之微弱，人们根本看不到，但是在线外频谱中，它们是发光的。1 .What is so special about WISE?AIt is small in size but carries a large camera.BIt is as small as a trashcan.CIts digital camera can help astronomers to see the unknown space.DNever before has a telescope carried a digital camera in space.2. Which is NOT the synonym for the word snap in the third paragraph?Amake. Bshoot Ctake. Dphotograph.3. The camera on WISEAis no different from an ordinary camera.Bdoes not see infrared radiation while the ordinary camera does.Ccatches the infrared radiation while the ordinary camera does not.Dreflects light that human eyes can see.4. Which of the following is NOT correct about asteroids according to paragraph 7?AAsteroids float through space giving off visible light.BAsteroids do not reflect light that reaches them.CIt is difficult to take asteroids pictures by ordinary cameras,DThe WISE telescope can take pictures of asteroids5.What is implied in the last paragraph?ABrown dwarfs give off visible light.BBrown dwarfs give off infrared radiation.CBrown dwarfs are power stars like the sun.DBrown dwarfs are impossible to see with the WISE telescope.蚂蚁作为“生态系统工程师”对环境影响巨大埃克斯特大学所做的研究表明，蚂蚁作为“生态系统工程师”和食肉动物的行为对当地的环境影响巨大。该研究发表在动物生态杂志上，它表明蚂蚁对当地的环境有两大显著的影响。第一，通过筑巢而挪动土壤或采集食物，蚂蚁影响土壤的营养水平。这可间接影响当地从腐生物到食物链高层的许多动物种群的数量。第二，它们捕食的动物种类很多，包括那些被大量工蚁攻击的大猎物。Dirk Sanders是该大学生态和保护中心所做的此项研究的作者，他说：“蚂蚁是高效的食肉动物，而且能大量繁殖。它们具有很强的领地意识，并且会竭尽全力对抗其他的食肉动物来保卫自己的领地。所有这些都意味着蚂蚁对周围环境影响巨大。”“在该研究中，我们第一次对蚂蚁带来的影响程度及微妙程度进行研究。所得到的发现是：尽管是食肉动物，蚂蚁的出现能促使其他动物族群在数量和品种上的增长。并对当地的环境起到切实重要的作用，对大草原的食物链影响巨大。”Sanders说。该研究在德国进行，它对花园黑蚂蚁和一般的红蚂蚁在不同混合程度和不同密度下的影响力进行研究。黑蚂蚁和红蚂蚁在整个欧洲包括英国都能找到。研究发现，一个地区的蚂蚁密度小，而其他动物尤其是食草动物和腐生物的数量和种类会增多。如果蚂蚁的密度大，就不可能产生同样的影响，或者产生相反的影响，这表明，蚂蚁的掠食活动会抵消蚂蚁给环境带来的积极影响。Dr Frank van Veen是本研究的另一作者，他说：“我们的发现是：如果蚂蚁的数量少，其对土壤的营养水平的影响会对动物族群产生积极的效果。如果蚂蚁的数量增加，其捕食的影响会达到最大化，因此会抵消蚂蚁通过生态工程给环境带来的积极影响。”蚂蚁是生态系统的重要组成部分，不仅因为它占有很大部分的生物量，而且因为其作为生态系统工程师的角色。蚂蚁具有难以想象的多样性，但极易受人类的影响，这就使它的多样性有显著的减少。然而，科学家还不消楚人类对蚂蚁这种干扰如何破坏蚂蚁对生态系统的维护作用。蚂蚁通过变动物理的和化学的环境，通过对植物、微生物和其他土壤生物的影响而对生态环境起至关重要的作用。1 .Why are ants compared to ecosystem engineers?ABecause they build their own nests.BBecause they collect food.CBecause their activity affects the environment.DBecause they are predators.2. As predators, antsAprey on small as well as large animals.Bcollect nutritious food from the soilCcollect food as decomposers.Dprey on species much higher up the food chain.3. Dir Sanders stud