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 million watts per square centimeter8. Sunlight isnt 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. 11 in producing charge separation as laser light is, Fisher said.
This new 12 could make solar power cheaper， the researchers say. They predict that with improved materials they could achieve 10 percent efficiency in 13 solar power to useable energy. Thats equivalent to todays commercial-grade solar cells.
To manufacture 14 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 15 . Its already made in bulk10， and it doesnt require as much processing. Transparent ceramics might be even better.
词汇：
optical adj.光学的
incoherent adj.非相干的
capacitive adj. 电容（量）的
semiconductor n.半导体
rectification n.改正，修正
ceramics n.陶瓷
注释：
1.University of Michigan：密歇根大学。建校于1817 年，是美国名列前茅的公立大学，拥有优良的师资和顶尖的商学院、法学院、医学院和工学院。
2. heat load：热负荷
3. magnetic moment：磁矩
4. optical rectification：光学校正
5. doctoral student：博士生
6. positive and negative charges：正电荷与负电荷
7. shone through：shone是shine的过去式。shine through是（光）通过.
8. an intensity of 10 million watts per square centimeter：每平方厘米一千万瓦特的强度
9. incoherent light：非相干光
10.Its already made in bulk：它（指玻璃）已大量生产。in bulk 是大量，成批.
练习：
1.A microscope B instrument C fiber D battery
2. A modifications B effects C applications D results
3. A frequently B privately C previously D formally
4.A Under B At C On D Over
5.A light B electricity C chemical D magnetism
6.A plant B equipment C source D line
7.A down B up C together D apart
8. A this B that C those D it
9. A material B lens C meter D detector
10.A produce B convey C use D conduct
11.A remote B poor C effective D rare
12.A prototype B skill C technique D miracle
13.A converting B obtaining C delivering D transmitting
14.A compact B modern C durable D handy
15. A others B some C all D both
答案与题解：
1.D第一段说密歇根大学发现，光所产生的巨大磁效应有望用于太阳能发电，从而取代传统的半导体太阳能电池。因此本题的正确选项应该是battery.optical battery是光电池.
optical microscope （光学显微镜）、optical instrument （光学仪器）或optical fiber （光纤）与第一段的意思没有联系。
2.B 选择本题的答案的依据还是要回到第一段。第一段第一句的起始词语是A dramatic and surprising magnetic effect of light.本篇文章中心议题是用magnetic effect of light开发新型的太阳能电池。而以前的科学家认为magnetic effect of light太微弱，不值得去关注它。因此，本题选effects与上下文的意思很连贯。
3. C 本句的意思是：当光通过一种绝缘材料时，光场产生的磁效应比以前想象的要强一亿倍。previously是当然的选择。其他三个选项填入句子中，意思不合逻辑：frequently（频繁地）/privately（私下地）/formerly（正式地）expected.
4. A under these circumstances 是固定词组，意为在这种情况下.也可以说in these circumstances ，而at、on或over 都不与circumstances 连用。
5.A通篇文章谈的是光产生的磁效应，所以在太阳能电池中，当然是光进入某种材料起作用。答案是选项A.
6. C 密歇根大学的科学家发现太阳光产生强烈的磁效应，再转换为电，所以磁效应是产生电的源泉（source）。power plant （发电厂）、power equipment （电力设备）或power line （输电线）与上文的意思接不上。
7.D or 在本句的意思是即，后面的词语是解释专业术语charge separation （电荷分离）。选apart与pushing构成pushing apart.pushing apart 的意思相当于separation.所以本题的答案是D.
8. B 从上下文判断，要填人的代词是替代前面的voltage.根据英语语法，替代单数名词的代词要用that ，替代复数名词的代词要用those.voltage 是单数，所以that 是答案。
9.A从本句句末的such as glass 判断，要填入的词一定是包括glass 的概括词。因此，只有选项material 符合这个条件。而且第三、四段也都提到光磁场效应是由光通过一个不导电的材料（ material ）而产生的。
10.D 答案的根据可以在第三段中找到。原句是：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.选项conduct 是答案。
11.C 激光通过特定材料时能产生charge separation .密歇根大学科学家发现，阳光通过特定材料时也像激光一样能产生charge separation.如果charge separation 是remote、 poor 或rare，密歇根大学科学家所说的利用光磁场效应开发新型的太阳能电池就不可能成立。所以答案是effective.
12.C 说这种样机（ this prototype ）、技巧（ this skill ）或这一奇迹（ this miracle ）能降低太阳能的价格，似乎离题太远。只有用这一技术（ this technology ）概括上一段的意思才准确。因此本题答案是technology.
13.A 科学家预测，通过改进材料，可使太阳能转化成可用能源的效率达到10%.本题的答案是converting.而obtaining（得到）、delivering （输送）和transmitting（发射）与能量转换挂不上号。
14. B 通篇文章没有谈到新型太阳能电池是compact（紧凑小型的）、durable（耐用的）或handy（使用便利的），所以不会是答案。选modern是合理的，因为密歇根大学科学家研发的不用半导体的太阳能电池是先进的。
15.D 答案是both，指代的是上一句的to focus the light and a fiber to guide it这两点。