Better Solar Energy Systems: More Heat, More Light Solar photovoltaic (光电的)...

作者: tihaiku 人气: - 评论: 0
问题 Better Solar Energy Systems: More Heat, More Light Solar photovoltaic (光电的)thermal energy systems,or PVTs,generate both heat and electricity,but _______ (51) now they haven’t been very good at the heatgenerating part compared with a stand-alone solar thermal collector. That’s because they operate at low temperatures to cool crystalline silicon (晶体桂)solar cells, ________(52) lets the silicon generate more electricity but isn’t a very efficient way to gather heat. That’s a problem of economics. Good solar hot-water systems can harvest much more energy than a solar-electric system at a substantially lower ____________ (53) _ And it’salso a space problem: photovoltaic cells can_____________ (54) up all the space on the roof,leaving little room for thermal applications. In a pair of studies,Joshua Pearce, an associate professor of materials science and engineering,has devised a _______ (55) in the form of a better PVT made with a different kind of silicon. Most solar panels are made with crystalline silicon,but you can also make solar cells out of amorphous (非晶形的)silicon,commonly known _____________ (56) thin-film silicon. They don’t create as much electricity, but they are lighter, flexible, and cheaper. And, because they __________ (57) much less silicon, they have a greener footprint. ______ (58),thin-film silicon solar cells are vulnerable to some bad-news physics in the form of the Staebler-Wronski effect. “That means that their efficiency drops when you (59) them to light — pretty much the worst possible effect for a solar cell,” Pearce explains,which is one of the _________ (60) thin-film solar panels make up only a small fraction of the market. However, Pearce and his team found a________ (61) to engineer around the Staebler-Wronski effect by incorporating thin-film silicon in a new____________ (62) of PVT. You don’t have to cool down thin-film silicon to make it work. In fact, Pearce’s group discovered that by heating it to solar-thermal operating temperatures,near the boiling _____ (63) of water,they could make thicker cells that largely _______ (64) the Staebler-Wronski effect. When they applied the thin-film silicon directly to a solar thermal energy cell ector,they also found that by baking the cell once a day, they _____(65) the solar cell’s electrigal eff行iciency by over 10 percent.
选项 A cover B relate C face D expose
答案 D
解析 本题考查动词词义。A是“覆盖”,B是“涉及,与……有某种关系”,C是“面对”,D是“使暴露在(空气、阳光等中)”。本句的意思是当你把它们暴露在阳光下,它们的效率就会降低。所以答案是D。

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