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Roguetheoryofsmellgetsaboost
1.Acontroversialtheoryofhowwesmell,whichclaimsthatourfinesenseofodourdependsonquantummechanics,hasbeengiventhethumbsupbyateamofphysicists.
2.CalculationsbyresearchersatUniversityCollegeLondon(UCL)showthattheideathatwesmellodourmoleculesbysensingtheirmolecularvibrationsmakessenseintermsofthephysicsinvolved.
3.That'sstillsomewayfromprovingthatthetheory,proposedinthemid-1990sbybiophysicistLucaTurin,iscorrect.Butitshouldmakeotherscientiststaketheideamoreseriously.
4."Thisisabigstepforward,"saysTurin,whohasnowsetuphisownperfumecompanyFlexitralinVirginia.Hesaysthatsincehepublishedhistheory,"ithasbeenignoredratherthancriticized."
5.Mostscientistshaveassumedthatoursenseofsmelldependsonreceptorsinthenosedetectingtheshapeofincomingmolecules,whichtriggersasignaltothebrain.Thismolecular'lockandkey'processisthoughttoliebehindawiderangeofthebody'sdetectionsystems:itishowsomepartsoftheimmunesystemrecogniseinvaders,forexample,andhowthetonguerecognizessometastes.
6.ButTurinarguedthatsmelldoesn'tseemtofitthispictureverywell.Moleculesthatlookalmostidenticalcansmellverydifferent—suchasalcohols,whichsmelllikespirits,andthiols,whichsmelllikerotteneggs.Andmoleculeswithverydifferentstructurescansmellsimilar.Moststrikingly,somemoleculescansmelldifferent—toanimals,ifnotnecessarilytohumans—simplybecausetheycontaindifferentisotopes(atomsthatarechemicallyidenticalbuthaveadifferentmass).
7.Turin'sexplanationforthesesmellyfactsinvokestheideathatthesmellsignalinolfactoryreceptorproteinsistriggerednotbyanodourmolecule'sshape,butbyitsvibrations,whichcanenourageanelectrontojumpbetweentwopartsofthereceptorinaquantum-mechanicalprocesscalledtunnelling.Thiselectronmovementcouldinitiatethesmellsignalbeingsenttothebrain.
8.Thiswouldexplainwhyisotopescansmelldifferent:theirvibrationfrequenciesarechangediftheatomsareheavier.Turin'smechanism,saysMarshallStonehamoftheUCLteam,ismorelikeswipe-cardidentificationthanakeyfittingalock.
9.Vibration-assistedelectrontunnellingcanundoubtedlyoccur—itisusedinanexperimentaltechniqueformeasuringmolecularvibrations."Thequestioniswhetherthisispossibleinthenose,"saysStoneham'scolleague,AndrewHorsfield.
10.StonehamsaysthatwhenhefirstheardaboutTurin'sidea,whileTurinwashimselfbasedatUCL,"Ididn'tbelieveit".But,headds,"becauseitwasaninterestingidea,IthoughtIshouldproveitcouldn'twork.Ididsomesimplecalculations,andonlythenbegantofeelLucacouldberight."NowStonehamandhisco-workershavedonethejobmorethoroughly,inapapersoontobepublishedinPhysicalReviewLetters.
11.TheUCLteamcalculatedtheratesofelectronhoppinginanosereceptorthathasanodorantmoleculeboundtoit.Thisratedependsonvariouspropertiesofthebiomolecularsystemthatarenotknown,buttheresearcherscouldestimatetheseparametersbasedontypicalvaluesformoleculesofthissort.
12.Thekeyissueiswhetherthehoppingratewiththeodorantinplaceissignificantlygreaterthanthatwithoutit.Thecalculationsshowthatitis—whichmeansthatodouridentificationinthiswayseemstheoreticallypossible.
13.ButHorsfieldstressesthatthat'sdifferentfromaproofofTurin'sidea."Sofarthingslookplausible,butweneedproperexperimentalverification.We'rebeginningtothinkaboutwhatexperimentscouldbeperformed."
14.Meanwhile,Turinispressingaheadwithhishypothesis."AtFlexitralwehavebeendesigningodorantsexclusivelyonthebasisoftheircomputedvibrations,"hesays."Oursuccessrateatodorantdiscoveryistwoordersofmagnitudebetterthanthecompetition."Attheveryleast,heisputtinghismoneywherehisnoseis.
Questions5-9
Completethesentencesbelowwithwordsfromthepassage.UseNOMORETHANTHREEWORDSforeachanswer.
5.Thehypothesisthatwesmellbysensingthemolecularvibrationwasmadeby______.
6.Turin'scompanyisbasedin______.
7.Mostscientistsbelievedthatournoseworksinthesamewayasour______.
8.Differentisotopescansmelldifferentwhen______weighdifferently.
9.AccordingtoAudrewHorsfield,itisstilltobeprovedthat______couldreallyoccurinhumannose.
Tobeginwith,"muzak"(音乐广播网)wasintendedsimplytocreateasoothing(安慰)atmosphere.Recently,however,it'secomebigbusiness—thanksinparttorecentresearch.Dr.RonaldMilliman,anAmericanmarketingexpert,hasshownthatmusiccanboostsalesorincreasefactoryroductionbyasmuchasathird.But,ithastobelightmusic.Afastonehasnoeffectatallonsales.Slowmusiccanincreasereceiptsby38%.Thisisprobablybecauseshoppersslowdownandhavemoreopportunitytospotitemstheyliketobuy.Yet,slowmusicisn'talwaysanswer.Dr.Millimanfound,forexample,thatinrestaurantsslowmusicmeantcustomerstooklongertoeattheirmeals,whichreducedoverallsales.Sorestaurantsownersmightbewelladvisedtoplayup-tempomusictokeepthecustomersmoving—unlessofcourse,theresultingindigestionleadstocomplaints!
练习：
1.Thereasonwhybackgroundmusicissopopularisthat______.
A.itcanhaveapowerfuleffectonthosewhohearit
B.itcanhelptocreateasoothingatmosphere
C.itcanboostsalesorincreasefactoryproductionerywhere
D.itcanmakecustomerseattheirmealsquickly
2.Backgroundmusicmeans________.
A.lightmusicthatcustomersenjoymostB.fastmusicthatmakespeoplemovefast
C.slowmusicthatcanmakecustomersenjoytheirmeals
D.themusicyouarelisteningtowhileyouaredoingomething
3.Restaurantownerscomplainaboutbackgroundmusicbecause______.
A.itresultsinindigestion
B.itincreasestheirsales
C.itkeepscustomersmoving
D.itdecreasestheirsales
4.Theword"up-tempomusic"probablymeans_____.
A.slowmusic
B.fastmusic
C.lightmusic
D.classicalmusic
