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
Noses have their advantages. They’re cute, they’re versatile, and they’re small enough to be carried around. Which may be why th
Noses have their advantages. They’re cute, they’re versatile, and they’re small enough to be carried around. Which may be why th
admin
2013-03-11
56
问题
Noses have their advantages. They’re cute, they’re versatile, and they’re small enough to be carried around. Which may be why the artificial odor detectors that engineers have been building since the 1950’s to try to mimic the olfactory(嗅觉的) abilities of our built-in sensors have taken so long to find their way to the market--and then, in most cases, have flopped(失败).
But things are finally looking up for the electronic nose. Thanks to advances in chip technology and pattern-recognition techniques, increasingly tiny sniffers (嗅探器) are beginning to live up to their moniker (模仿者)- Today e-noses are being tested for everything from disease detection to disaster prevention, and lower-prices models are starting to come to the market including an $ 8,000 device called the Cyranose 320 being introduced this week by Cyrano Sciences of Pasadena, Calif.
Like our proboscises(长鼻子), e-noses are only as good as their sensors, and all of them operate on oiliness(油质)--rather than to the molecule itself. Working together, the receptors can generate unique principles remarkably similar to those of a real nose. Humans detect odors with up to 650 types of receptors found on cells high up in the nasal passages, somewhere between our eyebrows. How the nose works is still something of a mystery, but it is believed that each receptor responds to a subtle characteristic of a molecule that carries odor--its peculiar shape, say, or degree of "smell prints" of a wide variety of odors, which are then parceled off to the brain and stored.
In e-noses, chemical sensors replace the body’s cellular receptors, and microprocessors substitute for the brain. "What limits these devices is how well the sensors are doing," explains Nathan Lewis, the Caltech chemist who helped invent the sensor technology licensed by Cyrano and who has since continued his research independently. He compares the power of e-noses to the resolution of computer monitors: "Are you seeing the world in eight shades of gray or in 16 million colors?"
It can be learned from the passage that ______.
选项
A、the artificial noses are even better than the human noses
B、it has not taken long for the artificial noses to be introduced to the market
C、the attempts of the artificial noses to imitate the olfactory abilities have been largely unsuccessful
D、the artificial noses have their own advantages over the human noses
答案
C
解析
细节理解题。该题问从文章中可得知什么,实际上浏览选择项,可以断定问的是关于“人工鼻子”即“the artificial odor detectors”(人造气味探测器)的问题。此题涉及到第一段第三句话中的非限制性定语从句的理解“which may be why…have flopped”(这大概是工程人员自20世纪五十年代起一直制造的人工气味探测器,力图模仿我们内嵌的感应器的嗅觉功能和花费了如此长的时间才打入市场——并且在多数情况下失败了的原因。)因此选项C是正确答案。
转载请注明原文地址:https://kaotiyun.com/show/UBr7777K
0
大学英语四级
相关试题推荐
OurrealAmericanfoodshavecomefromoursoilandhavebeenusedbymanygroups—thosewhoalreadylivedhereandthosewhohav
A、Tallbuildingsblotoutthesun.B、Peoplelosetouchwiththeland.C、Therearenotreesaroundtallbuildings.D、Peoplelive
A、Toavoidbeingrecognizedbyothers.B、Toprotecteyesbeinghurtbystrongsunlight.C、Tomakeherselflooksmarterthanbefo
ARoofoverOurHeadsManhasthreebasicneeds:food,clothing,andshelter.Ifamanlivesinawarmclimate,clothingis
Whenshouldanyvacationsfromthinkingbetaken?Inthissection,youwillhearatimes.Whenthepassageisreadforthefirst
A、Theyshouldshowboththegoodandbadsidesofthehouse.B、Themanshouldtakeasmanypicturesaspossible.C、Theyarebett
A、Herhusbandhadgotahigherposition.B、Herhusbandhadlosthisjob.C、Shewantedtohaveacleanerhouse.D、Shewantedtom
Ifyou’replanningtotraveloverseas,themostcommonformof【B1】______isbyairplane.Knowingtheentire【B2】______frombuying
Ifyou’replanningtotraveloverseas,themostcommonformof【B1】______isbyairplane.Knowingtheentire【B2】______frombuying
A、Buyatractor.B、Fixahouse.C、Seeapieceofproperty.D、Signabusinesscontract.CWhatarethespeakersgoingtodoatthe
随机试题
A.补脾益气,和胃化湿B.补脾益肾,益气和营C.补养气血,健运脾胃D.补中益气,升举清阳眩晕动则加剧,唇甲不华,心悸少寐,饮食减少,舌质淡,脉细弱者,治法宜选
根据我国法律规定,涉外不动产法定继承,适用()
2010年7月,我国A公司与法国B公司签订出口货物的CIF合同,合同约定货物装船日期为2010年12月,以信用证方式结算货款。合同签订后,A公司委托C公司运送货物至目的港法国马赛港。由于A公司未能及时组织货源,直到2011年1月15日方装船。A公司要求C公
不属于白细胞特性的是()
A.虚热证B.肝经有热C.心火上炎D.外感风热初期E.实热证舌体小,舌色鲜红而少苔,或有裂纹,或红光无苔的临床意义是
A.急性肾小球肾炎B.慢性肾小球肾炎C.肾病综合征D.急性肾盂肾炎E.慢性肾盂肾炎常见有脂肪管型,容易见细、粗颗粒管型.也可见透明管型的为
甲女委托乙公司为其拍摄一套艺术照。不久,甲女发现丙网站有其多张半裸照片,受到众人嘲讽和指责。经查,乙公司未经甲女同意将其照片上传到公司网站做宣传,丁男下载后将甲女头部移植至他人半裸照片,上传到丙网站。下列哪些说法是正确的?(2011年卷三第66题)
在质量管理的工具和方法中,直方图一般是用来( )。
电在导线里的传播速度和电磁波在空中的传播速度哪个快()。
表达式x.operator+(y.operator++(0))还可以写成【】。
最新回复
(
0
)