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[共享题干题]【2012年真题】（一） Solar Power without Solar       Cell A dramatic and surprising magnetic effect of light discovered by University of Michigan researchers could lead to solar power without traditional semiconductor-based solar cells. The researchers found a way to make an “optical_________51 ,” said Stephen Rand, a professor in the departments of Electrical Engineering and Computer Science, Physics and Applied Physics. Light has electric and magnetic_________52. Until now, scientists thought the effect of the magnetic field were so weak that they could be_________53. What Rand and his colleagues found is that at the right intensity, when light is traveling through a material that does not_________54 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_________55 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 _________56  goes into a material, gets absorbed and creates heat. Here, we expect to have a very low heat load. Instead of the light being absorbed, energy is stored in the magnetic moment. Intense magnetization can be induced by intense light and then it is ultimately capable of providing a capacitive power _________57 What makes this possible is a previously undetected brand of “optical rectification,” says William Fisher, a doctoral student in applied physics. In traditional optical rectification, light's electric field causes a charge separation, or a pulling _________58 of the positive and negative charges in a material. This sets up a voltage, similar to _________59 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 through a _________60 that does not conduct electricity, such as glass. And it must be focused to an intensity of 10 million watts per square centimeter. Sunlight isn't this _________61 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 lightg like sunlight is theoretically almost as_________62 effective in producing charge separation as laser light is,” Fisher said. This new _________63 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 modem solar cells, you have to do _________64 semiconductor processing,” Fisher said. “All we would need are lenses to focus the light and a fiber to guide it. Glass works for _________65 .It's already made in bulk, and it doesn't require as much processing. Transparent ceramics might be even better. ”
单选题第1题_____.
A.thi
B.those
C.that
D.these

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