首页
登录
职称英语
Noses have their advantages. They’re cute, they’re versatile, and they’re sm
Noses have their advantages. They’re cute, they’re versatile, and they’re sm
游客
2024-02-16
56
管理
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?" [br] 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://tihaiku.com/zcyy/3455142.html
相关试题推荐
Noseshavetheiradvantages.They’recute,they’reversatile,andthey’resm
Noseshavetheiradvantages.They’recute,they’reversatile,andthey’resm
Noseshavetheiradvantages.They’recute,they’reversatile,andthey’resm
Noseshavetheiradvantages.They’recute,they’reversatile,andthey’resm
Noseshavetheiradvantages.They’recute,they’reversatile,andthey’resm
Obviouslytelevisionhasbothadvantagesanddisadvantages.Inthefist
随机试题
Lookatthefollowingstatements(Questions36-40)andthelistofpeoplebelow.M
Whatsurprisedmewasnotwhathesaidbut______hesaidit.A、thewayB、inthewa
Acommonassumptionabouttheprivatesectorofeducationisthatitcaters
Fewpeopleknewthesuccessfulbusinessmanwhoisalsoacountry’scelebritywas
男性,50岁,上腹不适,食欲不振三个月。一个月来出现黄疸进行性加重,有体重减轻,
A.心肺脾肝 B.心肺脾肾 C.心肝脾肾 D.肺脾肝肾 E.心肺肝肾与津
把下面的六个图形分为两类,使每一类图形都有各自的共同特征或规律,分类正确的一项是
在一元线性回归分析中,根据数据(xi,yi),已知:Lxx=10,Lxy=8,
洋地黄制剂的适应证是()A.心房颤动伴快速心室率 B.预激综合征并发心房颤
根据《招标投标法实施条例》,招标人可以采用两阶段招标的项目是( )。A.建设规模
最新回复
(
0
)