2. 考研
  3. This summer, as Olympic athletes go faster, higher, and stronger in London, a record has fallen in a lab in Hamburg: Scientists

This summer, as Olympic athletes go faster, higher, and stronger in London, a record has fallen in a lab in Hamburg: Scientists

admin2015-03-25  47
问题     This summer, as Olympic athletes go faster, higher, and stronger in London, a record has fallen in a lab in Hamburg: Scientists have created the world’s lightest material. The new carbon nanomaterial, called Aerographite, weighs 0.2 milligrams per cubic centimeter. That’s less than a quarter the weight of the last record-holder, a nickel-phosphorous microlattice created by American researchers last year. And it’s six times lighter than air.
    Nanotechnology researchers have been working with carbon nanotubes for years(as the name suggests, these are very, very small tubes made of carbon atoms), building everything from superlight bicycles to medical implants. What the German team(from the University of Hamburg and the University of Kiel)figured out was how to build a network of branching nanotu-bules, thereby making the material stronger and a better conductor of electricity—two qualities that make it much more widely useful in electronics. The unprecedented lightness was an unexpected bonus.
    Aerographite was created by a clever molecular-scale version of the lost-wax process: Carbon gas was pumped into a furnace, where it coated a lattice of zinc oxide molecules(think of Dairy Queen hard-shell coating soft-serve ice cream). Then hydrogen gas was pumped into the furnace, bonding with the oxygen in the zinc oxide to form water, which evaporated, and leaving the zinc to in turn evaporate as gas. What was left was a hollow interconnected web of carbon tubes.
    Aerographite has a foam-like consistency, so it’s hard to imagine building Formula One race cars or fighter jets out of it. Because of its extraordinary lightness and strength, though, as well as its compressibility(it can be squashed down by 95 percent without any damage)and ability to conduct electricity, its creators believe it can be used to create better batteries and other electrical components like supercapacitors. Using Aerographite would remove weight, of course, but, more important for power sources, could add energy—the anodes in batteries work by storing electrons, and all of the tiny pores in Aerographite are spaces for electrons to become embedded.
    A cubic centimeter of Aerographite is 99.99 percent air, and perhaps the weirdest thing about it is that all that air actually makes the material heavier. Normally, things are light because they’re airy—as in Styrofoam or cotton candy. Not so with Aerographite, whose carbon nanotubes are actually less dense than the molecules in a cubic centimeter of air(six times less, as you’ll recall). The air in Aerographite weighs it own. Suck it out somehow, and the stuff would just lift off the table like a helium balloon.
According to the passage, Aerographite
选项 A、looks like foam.
B、is hard when builting Formula One race cars.
C、can be used to remove weight.
D、has small pores in it.
答案D
解析 事实细节题。根据选项提示词Formula One race cars，pores，foam可定位至第四段。该段最后一句话指出：阿罗石墨中所有的微小气孔都是电子可以嵌入的空间。因此[D]为正确答案。该段第一句提出：阿罗石墨的黏稠度像泡沫一样，由此可知[A]错误；该段第一句后半部分提及“很难想象用这种材料制造F1赛车或战斗机”，[B]与文意不符；[C]在文中未提及此用途，故均排除。
转载请注明原文地址:https://kaotiyun.com/show/aT74777K
0

考研英语一

相关试题推荐
随机试题
最新回复(0)