2013年职称英语考试 理工类 A级 完形填空 押题 【必考】.doc

2013年理工新书(红色标题为2013年新增文章)
注: +表示A级文章;*表示B即文章;其他为C级文章;
二、2013年(理工A)
完形填空 A级
+第十三篇:Better Solar Energy Systems: More Heat, More Light(A级)
+第十四篇:Sharks Perform a Service for Earth’s Waters(A级)
+第十五篇:"Liquefaction" Key to Much of Japanese Earthquake Damage(A级)
第十三篇 Better Solar Energy Systems:More Heat,More Light
  Solar photovoltaic thermal energy systems or PVTs, generate both heat and electricity, but until now they haven't been very good at the heat-generating pared to a stand-alone solar thermal collector. That's because they operate at low temperatures to cool crystalline silicon solar cells, which 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 cost. And it's also a space problem: photovoltaic cells can take up all the space on the roof, leaving little rooms for thermal applications.
  In a pair of studies, Joshua Pearce, an associate professor of materials science and engineering, has devised a solution in the form of a better PVT made with a different kind of silicon. His research collaborators are Kunal Girotra from ThinSilicon in California and Michael Pathak and Stephen Harrison from Queen's University, Canada.
  Most solar panels are made with crystalline silicon, but you can also make solar cells out of amorphous silicon, commonly known as thin-film silicon, They don't create as much electricity, but they are lighter, flexible , and cheaper:. And, because they require much less silicon, they have a greener footprint. Unfortunately, thin-film silicon solar cells are vulnerable as some bad-newsphysics in the form of the Staebler-Wronski effect.
  "That means that their efficiency drops when you expose them to light - pretty much the worst possible effect for a solar cell," Pearce explains, which is one of the reasons thin-film solar panels make up only small fra