首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
考研
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
admin
2015-03-25
33
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.
About Aerographite, which of the following is TRUE?
选项
A、Air in this material is its own weight.
B、It is light because it’s airy.
C、It is as light as helium balloon.
D、Air makes it heavier than other materials.
答案
A
解析
推理判断题。根据选项提示词airy,helium balloon.定位至最后一段。该段最后两句指出:阿罗石墨中的空气就是其自身的重量。如果把空气抽干,这种物质就会像氦气球一样从桌面上升起来,由此可以推出[A]正确。
转载请注明原文地址:https://jikaoti.com/ti/jxFRFFFM
0
考研英语一
相关试题推荐
"Hightech"and"stateoftheart"aretwoexpressionsthatdescribeverymoderntechnology.Hightechisjustashorterwayof
ItisgenerallybelievedthatthedigitaldivideissomethingAccordingtotheauthor,thenotionthatcomputersaretoblamef
Inthesetimeswhenmarketforcesappearincreasinglycomplicatedandmorevolatile,itisallthemoreimportanttounderstand
EthicswasgenerallyconsideredtobeInwhatwayisethicscomparabletolanguageusage?
Spain’sgovernmentisnowchampioningacausecalled"righttobeforgotten".IthasorderedGoogletostopindexinginformation
EveryyearLesWexner,theownerofVictoria’sSecret,alingerie(女士内衣)retailer,takesamonthofftotraveltheworldlooking
Weareonthevergeofdestroyingourozonelayer.Weareclosetodestroyinghundredsofexquisiteanimalspecies.Moreover,we
Languageswillcontinuetodiverge.EvenifEnglishweretobecometheuniversallanguage,itwouldstilltakemanydifferentfo
Success,itisoftensaid,hasmanyfathers—andoneofthemanyfathersofcomputing,thatmostsuccessfulofindustries,wasCh
Parenthoodisn’tacareer-killer.Infact,economistswithtwoormorekidstendtoproducemoreresearch,notless,thantheir
随机试题
指出下列哪项不对?()
大叶性肺炎合并金黄色葡萄球菌感染可引起
血胸病人行胸腔闭式引流,考虑拔管时,24小时引流量应()
体格检查最可能的发现是(假设信息)如果单纯饮食控制治疗效果不佳时,应选择哪种治疗方法
A.唇痈B.鼻疖C.丹毒D.急性淋巴结炎E.口底、颌下急性蜂窝织炎需接触隔离的浅部软组织化脓性感染是
关于肩关节的描述,正确的是
根据合同法律制度的规定,下列关于合同变更对保证责任的影响的表述不符合法律规定的是()。
某公司进口卷烟100箱,每箱成交价50000元,每箱购货佣金42元,入境前的运保费每箱31元。卷烟的关税税率为25%,则进口卷烟应缴纳的消费税为()万元。
根据契税法律制度的规定,下列各项中,以成交价格作为契税计税依据的有()。
Now,morethanever,itdoesn’tmatterwhoyouarebutwhatyoulooklike.Janetwasjusttwenty-fiveyearsold.Shehada
最新回复
(
0
)