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+第十三篇 Solar Power without Solar Cells（A 级）A 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 "optical battery," 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 the effects of 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 than previously expected. Under these 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 light goes 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, light's electric field causes a charge separation, or a pulling apart of the positive and negative charges6 in a material. This sets up a voltage, similar to that in a battery. Rand and Fisher found that under the right circumstances and in right types of materials, the light's magnetic field can also create optical rectification. The light must be shone through7 a material that does not conduct electricity, such as glass. And it must be focused to an intensity of 10 million watts per square centimeter8. Sunlight isn't 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 effective in producing charge separation as laser light is," Fisher said.This new technique could make solar power cheaper, the researchers say. They predict that with improved materials they could achieve 10 percent efficiency in converting solar power to useable energy. That's equivalent to today's commercial-grade solar cells."To manufacture modern solar 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 for both. It's already made in bulk10, and it doesn't require as much processing. Transparent ceramics might be even better."第十四篇： Sharks Perform a Service for Earth’s Waters (A级)It is hard to get people to think of sharks as anything but enemy. They are thought to attack people frequently. But these fish perform a valuable service for earth’s waters and for human beings. Yet business and sport fishing are threatening their existence. Some sharks are at risk of disappearing from Earth.Warm weather may influence both fish and shark activity. Many fish swim near coastal areas because of their warm waters. Experts say sharks may follow the fish into the same areas, where people also swim. In fact, most sharks do not purposely charge at or bite humans. They are thought to mistake a person for a 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 the times when 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 and chemicals produced by animals. These powerful senses help sharks find their food. Sharks eat fish, any other sharks, and plants that live in the ocean.Medical researchers want to learn more about the shark’s body defense and immune systems against disease. Researchers know that sharks recover quickly from injuries. They study the shark in hopes of finding a way to fight human disease.Sharks are important for the world’s oceans. They eat injured and diseased fish. Their hunting activities mean that the numbers of other fish in ocean waters do not become too great . This protects the plants and other forms of life that exist in the oceans.+第十五篇“Liquefaction” Key to Much of Japanese Earthquake Damage（A级）The massive subduction zone1 earthquake in Japan caused a significant level of soil "liquefaction"2 that has surprised researchers with its widespread severity, a new analysis shows."We've seen localized3 examples of soil liquefaction as extreme as this before, but the distance and extent of damage in Japan were unusually severe," said Scott Ashford, a professor of geotechnical engineering4 at Oregon State University5. "Entire structures were tilted and sinking into the sediments," Ashford said. "The shifts in soil destroyed water, drain and gas pipelines6, crippling the utilities and infrastructure these communities need to function. We saw some places that sank as much as four feet."Some degree of soil liquefaction7 is common in almost any major earthquake. It's a phenomenon in which soils soaked with water, particularly recent sediments or sand, can lose much of their strength and flow during an earthquake. This can allow structures to shift or sink or collapse.But most earthquakes are much shorter than the recent event in Japan, Ashford said. The length of the Japanese earthquake, as much as five minutes, may force researchers to reconsider the extent of liquefaction damage possibly occurring in situations such as this8."With such a long-lasting earthquake, we saw how structures that might have been okay after 30 seconds just continued to sink and tilt as the shaking continued for several more minutes," he said. "And it was clear that younger sediments, and especially areasbuilt on recently filled ground, are much more vulnerable."The data provided by analyzing the Japanese earthquake, researchers said, should make it possible to improve the understanding of this soil phenomenon and better prepare for it in the future. Ashford said it was critical for the team to collect the information quickly, before damage was removed in the recovery efforts9."There's no doubt that we'll learn things from what happened in Japan10 that11 will help us to reduce risks in other similar events," Ashford said. "Future construction in some places may make more use of techniques known to reduce liquefaction, such as better compaction to make soils dense, or use of reinforcing stone columns." Ashford pointed out that northern California have younger soils vulnerable to liquefaction ---on the coast, near river deposits or in areas with filled ground. The "young" sediments, in geologic terms, may be those deposited within the past 10,000 years or more. In Oregon, for instance, that describes much of downtown Portland, the Portland International Airport and other cities.Anything near a river and old flood plains is a suspect12, and the Oregon Department of Transportation has already concluded that 1,100 bridges in the state are at risk from an earthquake. Fewer than 15 percent of them have been reinforced to prevent collapse. Japan has suffered tremendous losses in the March 11 earthquake, but Japanese construction standards helped prevent many buildings from collapse ---even as they tilted and sank into the ground.第四＋五篇阅读 Small But Wise 理工（A级）On December 14, NASA1 blasted 特别 a small but mighty telescope into space. The telescope is called WISE and is about as wide around as a trashcan. Don't let its small size fool you: WISE has a powerful digital camera, and it will be taking pictures of some the wildest objects2 in the known universe, including asteroids, faint stars, blazing galaxies3 and giant clouds of dust where planets and stars are born. stars, blazing galaxies3 and giant clouds of dust where planets and stars are born. "I'm very excited because we're going to be seeing parts of the universe that we haven't seen before," said Ned Wright, a scientist who directs the WISE project. 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。