共用题干 Solar Power Without Solar CellsA 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 effects of the mag-netic 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 matenal,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 unde- tected brand of"optical rectification",says William Fisher,a doctoral student in applied physics.In tradi- tional 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 light 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 usable energy.That's equivalent to today's commercial-grade solar cells."To manufacture modern 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.Glassworks for _________ (65).It's already made in bulk,and it doesn't require as much processing.Transparent ceramics might be even better." _________(51)
A.disc B.fiber C.instrument D.battery正确答案D
