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
外语
New Understanding of Natural Silk’s Mysteries Natural silk, as we all know, has a strength that manmade materials have long
New Understanding of Natural Silk’s Mysteries Natural silk, as we all know, has a strength that manmade materials have long
admin
2014-01-28
93
问题
New Understanding of Natural Silk’s Mysteries
Natural silk, as we all know, has a strength that manmade materials have long struggled to match. In a discovery that sounds more like an ancient Chinese proverh than a materials science breakthrough, MIT researchers have discovered that silk gets its strength from its weakness. Or, more specifically, its many weaknesses. Silk gets its extraordinary durability and ductility from an unusual arrangement of hydrogen bonds that are inherently very weak but that work together to create a strong, flexible structure.
Most materials—especially the ones we engineer for strength—get their toughness from brittleness. As such, natural silks like those produced by spiders have long fascinated both biologists and engineers because of their light weight, ductility and high strength(pound for pound, silk is stronger than steel and far less brittle). But on its face, it doesn’t seem that silks should be as strong as they are; molecularly, they are held together by hydrogen bonds, which are far weaker than the covalent bonds found in other molecules.
To get a better understanding of how silk manages to produce such strength through such weak bonds, the MIT team created a set of computer models that allowed them to observe the way silk behaves at the atomic level. They found that the arrangement of the tiny silk nanocrystals is such that the hydrogen bonds are able to work cooperatively, reinforcing one another against external forces and failing slowly when they do fail, so as not so allow a sudden fracture to spread across a silk structure.
The result is that natural silks can stretch and bend while retaining a high degree of strength. But while that’s all well and good for spiders, bees and the like, this understanding of silk geometry could lead to new materials that are stronger and more ductile than those we can currently manufacture. Our best and strongest materials are generally expensive and difficult to produce(requiring high temperature treatments or energy-intensive processes).
By looking to silk as a model, researchers could potentially devise new manufacturing methods that rely on inexpensive materials and weak bonds to create less rigid, more forgiving materials that are nonetheless stronger than anything currently on offer. And if you thought you were going to get out of this materials science story without hearing about carbon nanotubes, think again. The MIT team is already in the lab looking into ways of synthesizing silk-like structures out of materials that are stronger than natural silk—like carbon nanotubes. Super-silks are on the horizon.
Silk’s strength comes from its weak hydrogen bonds working together.
选项
A、Right
B、Wrong
C、Not mentioned
答案
A
解析
根据文章第一段最后一句话可知,蚕丝的异常耐久性和延展性来自一种特别的氢键结构,这些氢键本质上非常脆弱,但它们共同创造了一种强壮而富有弹性的结构,题目说蚕丝的力量来自其链接在一起的氢键结构。
转载请注明原文地址:https://kaotiyun.com/show/4sGd777K
本试题收录于:
职称英语理工类A级题库职称英语分类
0
职称英语理工类A级
职称英语
相关试题推荐
Weknowfromthepassagethatthewhalestraveled6,000milesfromtheArctictotheinletsofBaja______.Accordingtothepa
EconomicGrowthTheeconomyofanationrequires(46).Totaloutputmustgrowifthecountryistoabsorbabout1.5millionneww
Theirmarketingpolicyfortheproductinvolvesobtainingasmuchfreepublicityaspossible.
HowtoSeeFriendshipMorethanfortythousandreaderstolduswhattheylookedforinchosefriendships,whattheyexpected(51)
GenerationGapAfewyearsago,itwasfashionabletospeakofagenerationgap,adivisionbetweenyoungpeopleandtheir
HowtoStayYoungIfyouwanttostayyoung,sitdownandhaveagoodthink.ThisistheresearchfindingbyateamofJapan
ForecastingMethodsThereareseveraldifferentmethodsthatcanbeusedtocreateaforecast.Themethodaforecasterchoos
PaperorPlastic?TakeawalkalongtheChesapeakeBay,andyouarelikelytoseeplasticbagsfloatinginthewater.Theyh
VoiceYourOpinion—ChangeisNeededinYouthSports Everywhereyoulook,youseekidsbouncingabasketballorwavingatennis
WhenFearTakesControloftheMindApanicattackisasuddenfeelingofterror.Usuallyitdoesnotlastlong,butitmay
随机试题
患者男,54岁。糖尿病病史3年,坚持晨跑,血糖控制良好。长时间运动后血糖的变化
在磨光金属基底冠的过程中,如不慎使冠边缘过薄,技术员用普通瓷粉堆筑,烧烤后金瓷冠最易出现的问题是
属于投射性心理测验的是
疏散风寒,宣肺解表法可治疗用百合固金汤可治疗
甲购买了一件商品,该商品的产品说明书明示安全使用期为8年。如果因该商品存在缺陷造成损害,则要求赔偿的请求权最长可达()年。
凡属《实施安全质量许可制度的进口商品目录》内的进口商品,必须获得国家局签发的《进口商品安全质量许可证书》并具有国家局批准使用的“CCIB”安全标志,方准进口。
关于会计凭证的保管,下列说法不正确的是()。
由于SCL-90缺乏“情感高涨”和“思维飘忽”等项目,使其在()中的应用受到了一定限制。
前些年,动辄几百上千元的“高定价、低折扣”大书着实让读者唏嘘了很久。自去年底以来,网络商城又掀起图书价格战。“暑假囤书4.9折封顶”,“满99元返19元”……读者心中对书价的疑惑越来越浓,纷纷表示:“书价虚高,书业是暴利行业。”以下哪项如果为真,最能反驳读
面向对象程序设计将数据和什么放在一起,作为一个相互依存、不可分割的整体来处理?
最新回复
(
0
)