职称英语理工类新增问题完形填空.doc

完形填空 第十三篇 Solar Power without Solar Cells 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 1 , 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 2 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 3 expected. 4 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 5 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 6.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 pulling 7 of the positive and negative charges6 in a material. This sets up a voltage, similar to 8 in 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 a 9 that does not 10 electricity, such as glass. And it must be focused to an intensity of 10 m