完型填空
Solar Power without Solar Cells
A dramatic and surprising magnetic effect of light discovered by University of Michigan1researchers 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 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 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, lights 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 lights 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 centimeter8. Sunlight isnt 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 light9 like sunlight is theoretically almost 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. Thats equivalent to todays 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 .Its already made in bulk, and it doesnt require as much processing. Transparent ceramics might be even better.
51. A. disc B. fiber C. instrument D. battery
答案:D
52. A. applications B. components C. resources D. differences
答案:B
53. A. concerned B. ignored C. expected D. noticed
答案:B
54. A. conduct B. produce C. use D. consume
答案:A
55. A. reactive B. preferable C. due D. equivalent
答案:D
56. A. light B. electricity C. chemical D. gas
答案:A
57. A. plant B. source C. equipment D. line
答案:B
58. A. up B. down C. apart D. together
答案:C
59. A. this B. those C. that D. these
答案:C
60. A. material B. device C. detector D. meter
答案:A
61. A. bright B. faint C. visible D. intense
答案:D
62. A. more B. as C. much D. such
答案:B
63. A. skill B. technology C. miracle D. prototype
答案:B
64. A. extensive B. interactive C. selective D. intensive
答案:A
65. A. all B. some C. others D. both
答案:D
北京市朝阳区2004英语
2001福州市英语试题
北京市初中英语毕业
2006年北京市海淀区初中毕业考试英语试卷答案
中考英语阅读理解:电视与收音机对儿童的影响
2007中考英语总复习:单项选择200道
2006年中考英语最后测验模拟试题(三)
中考英语阅读测试(二)
中考英语阅读理解:本杰明·富兰克林
中考英语阅读理解:带着房车旅行
历年初中英语补全对话点拨
2006年中考英语最后测验模拟试题(二)
2003年北京西城区中考英语试题
2007年中考英语单选预测题集锦(一)
2001年北京市东城区初中升学统一考试试题
北京朝阳区2004英语中考试卷
2006年中考英语最后测验模拟试题(四)
2000年北京丰台区中考英语试题
2001年哈尔滨市初中升学英语试题
提高英语阅读速度克服指读和声读不良习惯
中考英语阅读测试(三)
中考英语阅读理解:读者与作者
中考英语阅读测试(一)
中考英语词汇训练4(上)
2005英语中考试卷答案
2002年北京市海淀区中考英语试题
2006年北京市海淀区初中毕业考试英语试卷
中考英语阅读理解:欧洲的天气
中考英语阅读理解汇总
中考英语阅读理解:垃圾收集工
| 不限 |
| 英语教案 |
| 英语课件 |
| 英语试题 |
| 不限 |
| 不限 |
| 上册 |
| 下册 |
| 不限 |