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
Is that Folgers coffee in your cup or Maxwell House? Now you no longer have to rely on your nose to tell. Researchers have devel
Is that Folgers coffee in your cup or Maxwell House? Now you no longer have to rely on your nose to tell. Researchers have devel
admin
2013-09-07
41
问题
Is that Folgers coffee in your cup or Maxwell House? Now you no longer have to rely on your nose to tell. Researchers have developed an analyzer that can distinguish between 10 commercial brands of coffee and can even tell apart coffee beans roasted at various temperatures for different times. The advance could help growers determine within minutes whether a particular batch of coffee is just as good as the previous one or whether it’s undrinkable.
Researchers have been trying for years to come up with a simple way to analyze coffee. But it’s no easy task. The challenge is that the pleasant smell of roasted coffee beans consists of more than 1,000 compounds that change with roasting temperatures and time. Traditional methods of chemical analysis generally have difficulty distinguishing between compounds that are very similar to one another. And "electronic noses," an array of dyes, and other devices that change color or chemical properties when they react with certain molecules suffer from the same drawback.
Over the past decade, chemist Kenneth Suslick and colleagues at the University of Illinois, Urbana-Champaign, have refined the electronic nose approach. In the new study, they used dyes that interact strongly with other chemicals, making them more specific. They then put drops of 36 dyes on a polymer(聚合物)film the size of a nickel. The colors in the dyes belonged to a range of chemical classes, including pH indicators and molecules that change color with certain chemical vapors.
The device produced a pattern of colors as each coffee’s mixture of volatile(易蒸发的)compounds interacted with the dyes. When the investigators pumped vapors from various coffees including Starbucks, Sumatra Roast and Folgers Grande Supreme Decaf-over the arrays, all generated unique color patterns, like a molecular "fingerprint," they report this month in Analytical Chemistry.
The array doesn’t give any information about the individual compounds in the smell. "The important thing is that we can easily tell the difference between different roastings and coffees," notes Suslick. And that should help growers quickly and cheaply analyze problems with coffee, such as burnt flavors, during their initial screening process, says food scientist Felix Escher at the Swiss Federal Institute of Technology Zurich.
The applications for the kind of device created by Suslick’s team go beyond coffee, says chemist Pavel Anzenbacher at Bowling Green State University in Ohio. Similar arrays, he notes, could be used in everything from detecting explosives to spotting contaminants(污染物)in water.
The electronic nose approach refined by Kenneth Suslick and colleagues can now _____.
选项
A、tell the difference between similar compounds
B、use fewer dyes but produce more distinct colors
C、reduce the impacts of chemical reactions on dyes
D、distinguish between different brands of coffee
答案
D
解析
原文这两句都表明改良后的电子鼻测试法可轻易区分不同品牌的咖啡和使用不同方法烘焙的咖啡,D与前一个功能的内容相同,故为本题答案。
转载请注明原文地址:https://kaotiyun.com/show/Qq97777K
0
大学英语六级
相关试题推荐
AscivilwarseruptedthroughouttheRomanRepublicinthe1stcenturyB.C.,countrydwellersmayhavefledtocities.Beforet
A、TeachDon’sclasswhilehe’sabsent.B、GiveProfessorWebsterthekeytoDon’soffice.C、LeaveamessageontheboardinDon’s
A、Planningatrip.B、Reading.C、Sleeping.D、Doingresearch.C
AutomationThetermautomationwascoinedaround1946bytheautomobileindustrytodescribetheincreaseduseofautomatic
A、Itdependsontheirage.B、Itdependsonwheretheylive.C、It’samatterofpersonalchoice.D、It’samatterofsocialcustom
Acontroversyeruptedinthescientificcommunityinearly1998overtheuseofDNA(deoxyribonucleicacid)fingerprintingincr
A、Themanshouldworkwithsomebodyelse.B、Themanshouldmeethispartner’sneeds.C、Theyshouldcometoacompromise.D、They
A、Chineseancienthistory.B、Europeanhistory.C、Americannativecivilization.D、Americanhistory.D本题测试对话的话题,要求听者根据全文进行归纳的能力。
Mannersaredifferentineverycountry;buttruepolitenessiseverywherethesame.Mannersareonly【C1】______helpswhichignor
Anorganization’sreputation,profitability,andevenitscontinuedexistencecandependonthedegreetowhichitstargetedpub
随机试题
A.心房扑动B.房颤C.阵发性室上性心动过速D.阵发性室性心动过速E.窦性心动过缓以上心室率可快可慢可规则也可不规则的是
普通袋制备手工分离浓缩血小板保存期()小时
生脉散的证治要点是四君子汤的证治要点是
关于受精与着床,以下哪项恰当
价值工程的核心是对产品进行()分析。
在下列组合机床部件中,()不属于通用部件。
根据《关于加强证券经纪业务管理的规定》的规定,证券公司应当建立健全绩效考核制度,下列表述中,错误的有()。Ⅰ.绩效考核和激励不应仅与客户开户数挂钩Ⅱ.绩效考核和激励不应仅与客户交易量挂钩Ⅲ.客户投诉的情况不作为绩效考核的重要内容
通常使用实际利率计算资本成本的情况有()。
______howtodo,thelittleboycried.
A、First.B、Second.C、Third.D、Fourth.C选项为序数词,推断本题为排序题。听音时要注意排序的相关信息。题目问PodemosParty党在大选中的排名。新闻中提到,第二名是SocialistParty(工社党),紧随其
最新回复
(
0
)