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FirstImage-recognitionSoftware1.DartmouthresearchersandtheircolleagueshavecreatedanartificialintelligencesoftwarethatusesphotostolocatedocumentsontheInternetwithfargreateraccuracythaneverbefore.2.Thenewsystemwhichwastestedonphotosandisnowbeingappliedtovideosshowsforthefirsttimethatamachinelearningalgorithm运算法则forimagerecognitionandretrievalisaccurateandefficientenoughtoimprovelarge-scaledocumentsearchesonline.Thesystemusespixel像素datainimagesandpotentiallyvideo—ratherthanjusttext—tolocatedocuments.Itlearnstorecognizethepixelsassociatedwithasearchphrasebystudyingtheresultsfromtext-basedimagesearchengines.Theknowledgegleaned收集fromthoseresultscanthenbeappliedtootherphotoswithouttagsorcaptions图片说明makingformoreaccuratedocumentsearchresults.3."Overthelast30years"saysAssociateProfessorLorenzoTorresaniaco-authorofthestudy"theWebhasevolvedfromasmallcollectionofmostlytextdocumentstoamodernmassivefast-growingmultimediadatasetwherenearlyeverypageincludesmultiplepicturesorvideos.WhenapersonlooksataWebpageheimmediatelygetsthegist主旨ofitbylookingatthepicturesinit.YetsurprisinglyallexistingpopularsearchenginessuchasGoogleorBingstripawaytheinformationcontainedinthephotosanduseexclusivelythetextofWebpagestoperformthedocumentretrieval.Ourstudyisthefirsttoshowthatmodernmachinevisionsystemsareaccurateandefficientenoughtomakeeffectiveuseoftheinformationcontainedinimagepixelstoimprovedocumentsearch."4.Theresearchersdesignedandtestedamachinevisionsystem—atypeofartificialintelligencethatallowscomputerstolearnwithoutbeingexplicitlyprogrammed—thatextractssemantic语义的informationfromthepixelsofphotosinWebpages.ThisinformationisusedtoenrichthedescriptionoftheHTMLpageusedbysearchenginesfordocumentretrieval.Theresearcherstestedtheirapproachusingmorethan600searchqueries查询onadatabaseof50millionWebpages.Theyselectedthetext-retrievalsearchenginewiththebestperformanceandmodifiedittomakeuseoftheadditionalsemanticinformationextractedbytheirmethodfromthepicturesoftheWebpages.Theyfoundthatthisproduceda30percentimprovementinprecisionovertheoriginalsearchenginepurelybasedontext. Whenperformingdocumentretrievaltheexistingsearchenginesignore
What’skillingtheBats Firstitwasbees.Nowitisbats.BiologistsinAmericaareworkinghardtodiscoverthecauseofthemysteriousdeathsoftensofthousandsofbatsinthenortheasternpartofthecountry.MostofthebatsaffectedarethecommonlittlebrownbatsMyotislucifugusbutotherspeciessuchasthelong-earedbatthesmall-footedhattheeasternpipistrelleandtheIndianabathavealsobeenaffected.Insomecavesmorethan90percentofthebatpopulationshavedied. Onepossibilityisdisease.Awhitefungus真菌knownasfusariumhasbeenfoundonthenosesofbothlivinganddeadbats.Howeverscientistsdon’tknowIfthefungusistheprimarycauseofdeathasecondarycauseofdeathornotacauseatallbuttheresultofsomeotherconditions. Anotherpossiblecauseisalackoffood.Forexamplebatstypicallyeatalargenumberofmoths蛾andinsomestatessuchasNewYorkthenumberofmothshasbeendeclininginrecentyears.Ifbatscan’teatenoughfoodtheystarvetodeath. Stillotherscientistsbelievethatglobalwarmingistoblame.Warmertemperaturesinrecentyearshavebeenwakinguphibernating冬眠batsearlierthanusual.Ifbatsbreaktheirhibernationatthewrongtimetheymightnotfindtheirexpectedfoodsources.Theweathermightalsoturncoldagainandweakenorkillthebats. Scientistsmightnotagreeonthecausesofthebatdie-offbuttheydoagreeontheconsequences.Batsareanimportantpredatorofmosquitoes;asinglebrownbatcaneat1000ormoreinsectsinanhour.Theyalsoeatbeetlesandotherinsectsthatdamageplantcrops.Iftherearen’tenoughbatsdamagewillbegreatfromtheinsectstheyeatWhilebatslivealongtimefortheirsize－thelittlebrownbatcanliveformorethan30years－afemalebathasonlyonebabyperyearsobatpopulationsgrowslowly.ManybatspeciesintheUnitedStatesarealreadyprotectedorendangered. Howcanyouhelp?Donotdisturbsleepingornestingbats.IfyoudiscoverbatethatseemtobesickorthataredeadcontactyourlocalFish＆WildlifeDepartmentwiththedetails.Howeverbecarefulnottotouchtheanimals. WhatdoesthefirstsentenceinParagraph1mean?
Thestarvingchildrenwerea{{U}}pathetic{{/U}}sight.
FaceMasksMayNotProtectfromSuper-Flu Ifasuper-flustrikesfacemasksmaynotprotectyou.Whetherwidespreaduseofmaskswillhelporharmduringthenextworldwidefluoutbreakisaquestionthatresearchersarestudyingfuriously.Noresultshavecomefromtheirmaskresearchyet. Howeverthegovernmentsayspeopleshouldconsiderwearingthemcertainstationsanywayjustincase. Butit’saquestionthepublickeepsaskingwhilethegovernmentismakingpreparationsforthenextflupandemic大流行.SotheCentersforDiseaseControlandPreventionCDCcameupwithpreliminaryguidelines.Wedon’twantPeoplewearingthemeverywheresaidtheCDC.Theoverallrecommendationreallyistoavoidexposure. Whenthatisnotpossibletheguidelinessayyoushouldconsiderwearingasimplesurgicalmaskifyouareinoneofthethreefollowingsituations.Firstyou’rehealthyandcan’tavoidgoingtoacrowdedplace.Secondyou’resickandthinkyoumayhaveclosecontactwiththehealthysuchasafamilymembercheckingonyou.Thirdyoulivewithsomeonewho’ssickandthusmightbeintheearlystagesofinfectionbutstillneedtogoout. Influenzapandemicscanstrikewhentheeasy-to-mutate变异fluvirusshiftstoastrain菌株thatpeopleneverhaveexperienced.ScientistscannotpredictwhenthenextpandemicwillarrivealthoughconcernisrisingthattheAsianbirdflumighttriggeroneifitstartsspreadingeasilyfrompersontoperson. Duringtheflupandemicyoushouldprotectyourself.Avoidcrowdsandavoidclosecontactwiththesickunlessyoumustcareforsomeone.Whyaren’tmasksaddedtothisself-protectionlist?Becausetheycanhelptrapvirus-ladendropletsflyingthroughtheairwithacoughorsneeze.Simplesurgicalmasksonlyfilterthelargerdroplets飞沫.BesidestheCDCisafraidmasksmaycreateafalsesenseofsecurity.Perhapssomeonewhoshouldhavestayedhomewoulddon戴anill-fittingmaskandhoponthesubwayinstead. Nordoesfluonlyspreadthroughtheair.Saysomeonecoversasneezewithhisorherhandthentouchesadoorknoborsubwaypole.Ifyoutouchthatspotnextandthenputgermyhandsonyournoseormouthyou’vebeenexposed.It’shardertorubyournosewhilewearingamasksoyourfacemaygetprettysweatyundermasks.Youreachundertowipethatsweatandmaytransfergermscaughtontheoutsideofthemaskstraighttothenose.Thesearetheproblemsfacemasksmaycreatefortheirusers. Whetherpeopleshouldorshouldnotusefacemasksstillremainsaquestion.Thegeneralpublichastowaitpatientlyfortheresultsofthemaskresearchscientistsarestilldoing. Whatisthepassagemainlyabout?
BetterSolarEnergySystems:MoreHeatMoreLight Solarphotovoltaic光伏的thermalenergysystemsorPVTsgeneratebothheatandelectricitybutuntilnowtheyhaven’tbeenverygoodattheheat-generatingpartcomparedtoastand-alonesolarthermalcollector.That’sbecausetheyoperateatlowtemperaturestocoolcrystalline晶体的siliconsolarcellswhichletsthesilicongeneratemoreelectricitybutisn’taveryefficientwaytogatherheat. That’saproblemofeconomics.Goodsolarhot-watersystemscanharvestmuchmoreenergythanasolar-electricsystematasubstantiallylowercost.Andit’salsoaspaceproblem:photovoltaiccellscantakeupallthespaceontheroofleavinglittleroomforthermalapplications. InapairofstudiesJoshuaPearceanassociateprofessorofmaterialsscienceandengineeringhasdevisedasolutionintheformofabetterPVTmadewithadifferentkindofsilicon.HisresearchcollaboratorsareKunalGirotrafromThinSiliconinCaliforniaandMichaelPathakandStephenHarrisonfromQueen’sUniversityCanada. Mostsolarpanelsaremadewithcrystallinesiliconbutyoucanalsomakesolarcellsoutofamorphous非晶体的siliconcommonlyknownasthin-filmsilicon.Theydon’tcreateasmuchelectricitybuttheyarelighterflexibleandcheaper.Andbecausetheyrequiremuchlesssilicontheyhaveagreenerfootprint.Unfortunatelythin-filmsiliconsolarcellsarevulnerabletosomebad-newsphysicsintheformoftheStaebler-Wronskieffect. Thatmeansthattheirefficiencydropswhenyouexposethemtolight—prettymuchtheworstpossibleeffectforasolarcellPearceexplainswhichisoneofthereasonsthin-filmsolarpanelsmakeuponlyasmallfractionofthemarket. HoweverPearceandhisteamfoundawaytoengineeraroundtheStaebler-Wronskieffectbyincorporatingthin-filmsiliconinanewtypeofPVT.Youdon’thavetocooldownthin-filmsilicontomakeitwork.InfactPearce’sgroupdiscoveredthatbyheatingittosolar-thermaloperatingtemperaturesneartheboilingpointofwatertheycouldmakethickercellsthatlargelyovercametheStaebler-Wronskieffect.Whentheyappliedthethin-filmsilicondirectlytoasolarthermalenergycollectortheyalsofoundthatbybakingthecellonceadaytheyboostedthesolarcell’selectricalefficiencybyover10percent. WhichofthefollowingisNOTmentionedasanadvantageofthin-filmsiliconsolarcells?
FirstImage-recognitionSoftware1.DartmouthresearchersandtheircolleagueshavecreatedanartificialintelligencesoftwarethatusesphotostolocatedocumentsontheInternetwithfargreateraccuracythaneverbefore.2.Thenewsystemwhichwastestedonphotosandisnowbeingappliedtovideosshowsforthefirsttimethatamachinelearningalgorithm运算法则forimagerecognitionandretrievalisaccurateandefficientenoughtoimprovelarge-scaledocumentsearchesonline.Thesystemusespixel像素datainimagesandpotentiallyvideo—ratherthanjusttext—tolocatedocuments.Itlearnstorecognizethepixelsassociatedwithasearchphrasebystudyingtheresultsfromtext-basedimagesearchengines.Theknowledgegleaned收集fromthoseresultscanthenbeappliedtootherphotoswithouttagsorcaptions图片说明makingformoreaccuratedocumentsearchresults.3."Overthelast30years"saysAssociateProfessorLorenzoTorresaniaco-authorofthestudy"theWebhasevolvedfromasmallcollectionofmostlytextdocumentstoamodernmassivefast-growingmultimediadatasetwherenearlyeverypageincludesmultiplepicturesorvideos.WhenapersonlooksataWebpageheimmediatelygetsthegist主旨ofitbylookingatthepicturesinit.YetsurprisinglyallexistingpopularsearchenginessuchasGoogleorBingstripawaytheinformationcontainedinthephotosanduseexclusivelythetextofWebpagestoperformthedocumentretrieval.Ourstudyisthefirsttoshowthatmodernmachinevisionsystemsareaccurateandefficientenoughtomakeeffectiveuseoftheinformationcontainedinimagepixelstoimprovedocumentsearch."4.Theresearchersdesignedandtestedamachinevisionsystem—atypeofartificialintelligencethatallowscomputerstolearnwithoutbeingexplicitlyprogrammed—thatextractssemantic语义的informationfromthepixelsofphotosinWebpages.ThisinformationisusedtoenrichthedescriptionoftheHTMLpageusedbysearchenginesfordocumentretrieval.Theresearcherstestedtheirapproachusingmorethan600searchqueries查询onadatabaseof50millionWebpages.Theyselectedthetext-retrievalsearchenginewiththebestperformanceandmodifiedittomakeuseoftheadditionalsemanticinformationextractedbytheirmethodfromthepicturesoftheWebpages.Theyfoundthatthisproduceda30percentimprovementinprecisionovertheoriginalsearchenginepurelybasedontext. Paragraph1
LackofOxygenDelayedtheRiseofAnimalsonEarth Scientistshavelongspeculatedastowhyanimalspeciesdidn’tflourishsooneroncesufficientoxygencoveredtheEarth’ssurface.AnimalsbegantoprosperattheendoftheProterozoicperiodabout800millionyearsago—butwhataboutthebillion-yearstretchbeforethatwhenmostresearchersthinktherealsowasplentyofoxygen? Wellitseemstheairwasn’tsogreatthenafterall. InastudypublishedOct.31inScienceYaleresearcherNoahPlanavskyandhiscolleaguesfoundthatoxygenlevelsduringtheboringbillionperiodwereonly0.1%ofwhattheyaretoday.InotherwordsEarth’satmospherecouldn’thavesupportedadiversityofcreaturesnomatterwhatgeneticadvancementswerepoisedtooccur. ThereisnoquestionthatgeneticandecologicalinnovationmustultimatelybebehindtheriseofanimalsbutitisequallyunavoidablethatanimalsneedacertainlevelofoxygensaidPlanavskyco-leadauthoroftheresearchalongwithChristopherReinhardoftheGeorgiaInstituteofTechnology.We’reprovidingthefirstevidencethatoxygenlevelswerelowenoughduringthisperiodtopotentiallypreventtheriseofanimals. ThescientistsfoundtheirevidencebyanalyzingchromiumCrisotopesinancientsedimentsfromChinaAustraliaCanadaandtheUnitedStates.ChromiumisfoundintheEarth’scontinentalcrustandchromiumoxidationisdirectlylinkedtothepresenceoffreeoxygenintheatmosphere. Specificallytheteamstudiedsamplesdepositedinshallowiron-richoceanareasneartheshore.Theycomparedtheirdatawithothersamplestakenfromyoungerlocalesknowntohavehigherlevelsofoxygen. Oxygen’sroleincontrollingthefirstappearanceofanimalshaslongvexedscientists.WeweremissingtherightapproachuntilnowPlanavskysaid.Chromiumgaveustheproxy.Previousestimatesputtheoxygenlevelat40%oftoday’sconditionsduringpre-animaltimesleavingopenthepossibilitythatoxygenwasalreadyplentifulenoughtosupportanimallife. Inthenewstudytheresearchersacknowledgedthatoxygenlevelswerehighlydynamicintheearlyatmospherewiththepotentialforoccasionalspikes.HowevertheysaidItseemsclearthatthereisafirst-orderdifferenceinthenatureofEarthsurfaceCrcyclingbeforeandaftertheriseofanimals. Ifwearerightourresultswillreallychangehowpeopleviewtheoriginsofanimalsandothercomplexlifeandtheirrelationshipstotheco-evolvingenvironmentsaidco-authorTimLyonsoftheUniversityofCalifornia-Riverside.Thiscouldbeagamechanger. There’salotofinterestrightnowinabroaderdiscussionsurroundingtherolethatenvironmentalstabilityplayedintheevolutionofcomplexlifeandwethinkourresultsareasignificantcontributiontothatReinhardsaid.Geneticadvancementstriggeredtheriseofanimals.
What’skillingtheBats Firstitwasbees.Nowitisbats.BiologistsinAmericaareworkinghardtodiscoverthecauseofthemysteriousdeathsoftensofthousandsofbatsinthenortheasternpartofthecountry.MostofthebatsaffectedarethecommonlittlebrownbatsMyotislucifugusbutotherspeciessuchasthelong-earedbatthesmall-footedhattheeasternpipistrelleandtheIndianabathavealsobeenaffected.Insomecavesmorethan90percentofthebatpopulationshavedied. Onepossibilityisdisease.Awhitefungus真菌knownasfusariumhasbeenfoundonthenosesofbothlivinganddeadbats.Howeverscientistsdon’tknowIfthefungusistheprimarycauseofdeathasecondarycauseofdeathornotacauseatallbuttheresultofsomeotherconditions. Anotherpossiblecauseisalackoffood.Forexamplebatstypicallyeatalargenumberofmoths蛾andinsomestatessuchasNewYorkthenumberofmothshasbeendeclininginrecentyears.Ifbatscan’teatenoughfoodtheystarvetodeath. Stillotherscientistsbelievethatglobalwarmingistoblame.Warmertemperaturesinrecentyearshavebeenwakinguphibernating冬眠batsearlierthanusual.Ifbatsbreaktheirhibernationatthewrongtimetheymightnotfindtheirexpectedfoodsources.Theweathermightalsoturncoldagainandweakenorkillthebats. Scientistsmightnotagreeonthecausesofthebatdie-offbuttheydoagreeontheconsequences.Batsareanimportantpredatorofmosquitoes;asinglebrownbatcaneat1000ormoreinsectsinanhour.Theyalsoeatbeetlesandotherinsectsthatdamageplantcrops.Iftherearen’tenoughbatsdamagewillbegreatfromtheinsectstheyeatWhilebatslivealongtimefortheirsize－thelittlebrownbatcanliveformorethan30years－afemalebathasonlyonebabyperyearsobatpopulationsgrowslowly.ManybatspeciesintheUnitedStatesarealreadyprotectedorendangered. Howcanyouhelp?Donotdisturbsleepingornestingbats.IfyoudiscoverbatethatseemtobesickorthataredeadcontactyourlocalFish＆WildlifeDepartmentwiththedetails.Howeverbecarefulnottotouchtheanimals. ThemothsinParagraph3aretakenasanexampleof
FaceMasksMayNotProtectfromSuper-Flu Ifasuper-flustrikesfacemasksmaynotprotectyou.Whetherwidespreaduseofmaskswillhelporharmduringthenextworldwidefluoutbreakisaquestionthatresearchersarestudyingfuriously.Noresultshavecomefromtheirmaskresearchyet. Howeverthegovernmentsayspeopleshouldconsiderwearingthemcertainstationsanywayjustincase. Butit’saquestionthepublickeepsaskingwhilethegovernmentismakingpreparationsforthenextflupandemic大流行.SotheCentersforDiseaseControlandPreventionCDCcameupwithpreliminaryguidelines.Wedon’twantPeoplewearingthemeverywheresaidtheCDC.Theoverallrecommendationreallyistoavoidexposure. Whenthatisnotpossibletheguidelinessayyoushouldconsiderwearingasimplesurgicalmaskifyouareinoneofthethreefollowingsituations.Firstyou’rehealthyandcan’tavoidgoingtoacrowdedplace.Secondyou’resickandthinkyoumayhaveclosecontactwiththehealthysuchasafamilymembercheckingonyou.Thirdyoulivewithsomeonewho’ssickandthusmightbeintheearlystagesofinfectionbutstillneedtogoout. Influenzapandemicscanstrikewhentheeasy-to-mutate变异fluvirusshiftstoastrain菌株thatpeopleneverhaveexperienced.ScientistscannotpredictwhenthenextpandemicwillarrivealthoughconcernisrisingthattheAsianbirdflumighttriggeroneifitstartsspreadingeasilyfrompersontoperson. Duringtheflupandemicyoushouldprotectyourself.Avoidcrowdsandavoidclosecontactwiththesickunlessyoumustcareforsomeone.Whyaren’tmasksaddedtothisself-protectionlist?Becausetheycanhelptrapvirus-ladendropletsflyingthroughtheairwithacoughorsneeze.Simplesurgicalmasksonlyfilterthelargerdroplets飞沫.BesidestheCDCisafraidmasksmaycreateafalsesenseofsecurity.Perhapssomeonewhoshouldhavestayedhomewoulddon戴anill-fittingmaskandhoponthesubwayinstead. Nordoesfluonlyspreadthroughtheair.Saysomeonecoversasneezewithhisorherhandthentouchesadoorknoborsubwaypole.Ifyoutouchthatspotnextandthenputgermyhandsonyournoseormouthyou’vebeenexposed.It’shardertorubyournosewhilewearingamasksoyourfacemaygetprettysweatyundermasks.Youreachundertowipethatsweatandmaytransfergermscaughtontheoutsideofthemaskstraighttothenose.Thesearetheproblemsfacemasksmaycreatefortheirusers. Whetherpeopleshouldorshouldnotusefacemasksstillremainsaquestion.Thegeneralpublichastowaitpatientlyfortheresultsofthemaskresearchscientistsarestilldoing. OneoftheconcernstheCDChasisthat
Iwillnot{{U}}tolerate{{/U}}thatsortofbehaviorinmyclass.
FirstImage-recognitionSoftware1.DartmouthresearchersandtheircolleagueshavecreatedanartificialintelligencesoftwarethatusesphotostolocatedocumentsontheInternetwithfargreateraccuracythaneverbefore.2.Thenewsystemwhichwastestedonphotosandisnowbeingappliedtovideosshowsforthefirsttimethatamachinelearningalgorithm运算法则forimagerecognitionandretrievalisaccurateandefficientenoughtoimprovelarge-scaledocumentsearchesonline.Thesystemusespixel像素datainimagesandpotentiallyvideo—ratherthanjusttext—tolocatedocuments.Itlearnstorecognizethepixelsassociatedwithasearchphrasebystudyingtheresultsfromtext-basedimagesearchengines.Theknowledgegleaned收集fromthoseresultscanthenbeappliedtootherphotoswithouttagsorcaptions图片说明makingformoreaccuratedocumentsearchresults.3."Overthelast30years"saysAssociateProfessorLorenzoTorresaniaco-authorofthestudy"theWebhasevolvedfromasmallcollectionofmostlytextdocumentstoamodernmassivefast-growingmultimediadatasetwherenearlyeverypageincludesmultiplepicturesorvideos.WhenapersonlooksataWebpageheimmediatelygetsthegist主旨ofitbylookingatthepicturesinit.YetsurprisinglyallexistingpopularsearchenginessuchasGoogleorBingstripawaytheinformationcontainedinthephotosanduseexclusivelythetextofWebpagestoperformthedocumentretrieval.Ourstudyisthefirsttoshowthatmodernmachinevisionsystemsareaccurateandefficientenoughtomakeeffectiveuseoftheinformationcontainedinimagepixelstoimprovedocumentsearch."4.Theresearchersdesignedandtestedamachinevisionsystem—atypeofartificialintelligencethatallowscomputerstolearnwithoutbeingexplicitlyprogrammed—thatextractssemantic语义的informationfromthepixelsofphotosinWebpages.ThisinformationisusedtoenrichthedescriptionoftheHTMLpageusedbysearchenginesfordocumentretrieval.Theresearcherstestedtheirapproachusingmorethan600searchqueries查询onadatabaseof50millionWebpages.Theyselectedthetext-retrievalsearchenginewiththebestperformanceandmodifiedittomakeuseoftheadditionalsemanticinformationextractedbytheirmethodfromthepicturesoftheWebpages.Theyfoundthatthisproduceda30percentimprovementinprecisionovertheoriginalsearchenginepurelybasedontext. Thenewsystemdoesdocumentretrievalby
BetterSolarEnergySystems:MoreHeatMoreLight Solarphotovoltaic光伏的thermalenergysystemsorPVTsgeneratebothheatandelectricitybutuntilnowtheyhaven’tbeenverygoodattheheat-generatingpartcomparedtoastand-alonesolarthermalcollector.That’sbecausetheyoperateatlowtemperaturestocoolcrystalline晶体的siliconsolarcellswhichletsthesilicongeneratemoreelectricitybutisn’taveryefficientwaytogatherheat. That’saproblemofeconomics.Goodsolarhot-watersystemscanharvestmuchmoreenergythanasolar-electricsystematasubstantiallylowercost.Andit’salsoaspaceproblem:photovoltaiccellscantakeupallthespaceontheroofleavinglittleroomforthermalapplications. InapairofstudiesJoshuaPearceanassociateprofessorofmaterialsscienceandengineeringhasdevisedasolutionintheformofabetterPVTmadewithadifferentkindofsilicon.HisresearchcollaboratorsareKunalGirotrafromThinSiliconinCaliforniaandMichaelPathakandStephenHarrisonfromQueen’sUniversityCanada. Mostsolarpanelsaremadewithcrystallinesiliconbutyoucanalsomakesolarcellsoutofamorphous非晶体的siliconcommonlyknownasthin-filmsilicon.Theydon’tcreateasmuchelectricitybuttheyarelighterflexibleandcheaper.Andbecausetheyrequiremuchlesssilicontheyhaveagreenerfootprint.Unfortunatelythin-filmsiliconsolarcellsarevulnerabletosomebad-newsphysicsintheformoftheStaebler-Wronskieffect. Thatmeansthattheirefficiencydropswhenyouexposethemtolight—prettymuchtheworstpossibleeffectforasolarcellPearceexplainswhichisoneofthereasonsthin-filmsolarpanelsmakeuponlyasmallfractionofthemarket. HoweverPearceandhisteamfoundawaytoengineeraroundtheStaebler-Wronskieffectbyincorporatingthin-filmsiliconinanewtypeofPVT.Youdon’thavetocooldownthin-filmsilicontomakeitwork.InfactPearce’sgroupdiscoveredthatbyheatingittosolar-thermaloperatingtemperaturesneartheboilingpointofwatertheycouldmakethickercellsthatlargelyovercametheStaebler-Wronskieffect.Whentheyappliedthethin-filmsilicondirectlytoasolarthermalenergycollectortheyalsofoundthatbybakingthecellonceadaytheyboostedthesolarcell’selectricalefficiencybyover10percent. PVTsarenotefficientin
LackofOxygenDelayedtheRiseofAnimalsonEarth Scientistshavelongspeculatedastowhyanimalspeciesdidn’tflourishsooneroncesufficientoxygencoveredtheEarth’ssurface.AnimalsbegantoprosperattheendoftheProterozoicperiodabout800millionyearsago—butwhataboutthebillion-yearstretchbeforethatwhenmostresearchersthinktherealsowasplentyofoxygen? Wellitseemstheairwasn’tsogreatthenafterall. InastudypublishedOct.31inScienceYaleresearcherNoahPlanavskyandhiscolleaguesfoundthatoxygenlevelsduringtheboringbillionperiodwereonly0.1%ofwhattheyaretoday.InotherwordsEarth’satmospherecouldn’thavesupportedadiversityofcreaturesnomatterwhatgeneticadvancementswerepoisedtooccur. ThereisnoquestionthatgeneticandecologicalinnovationmustultimatelybebehindtheriseofanimalsbutitisequallyunavoidablethatanimalsneedacertainlevelofoxygensaidPlanavskyco-leadauthoroftheresearchalongwithChristopherReinhardoftheGeorgiaInstituteofTechnology.We’reprovidingthefirstevidencethatoxygenlevelswerelowenoughduringthisperiodtopotentiallypreventtheriseofanimals. ThescientistsfoundtheirevidencebyanalyzingchromiumCrisotopesinancientsedimentsfromChinaAustraliaCanadaandtheUnitedStates.ChromiumisfoundintheEarth’scontinentalcrustandchromiumoxidationisdirectlylinkedtothepresenceoffreeoxygenintheatmosphere. Specificallytheteamstudiedsamplesdepositedinshallowiron-richoceanareasneartheshore.Theycomparedtheirdatawithothersamplestakenfromyoungerlocalesknowntohavehigherlevelsofoxygen. Oxygen’sroleincontrollingthefirstappearanceofanimalshaslongvexedscientists.WeweremissingtherightapproachuntilnowPlanavskysaid.Chromiumgaveustheproxy.Previousestimatesputtheoxygenlevelat40%oftoday’sconditionsduringpre-animaltimesleavingopenthepossibilitythatoxygenwasalreadyplentifulenoughtosupportanimallife. Inthenewstudytheresearchersacknowledgedthatoxygenlevelswerehighlydynamicintheearlyatmospherewiththepotentialforoccasionalspikes.HowevertheysaidItseemsclearthatthereisafirst-orderdifferenceinthenatureofEarthsurfaceCrcyclingbeforeandaftertheriseofanimals. Ifwearerightourresultswillreallychangehowpeopleviewtheoriginsofanimalsandothercomplexlifeandtheirrelationshipstotheco-evolvingenvironmentsaidco-authorTimLyonsoftheUniversityofCalifornia-Riverside.Thiscouldbeagamechanger. There’salotofinterestrightnowinabroaderdiscussionsurroundingtherolethatenvironmentalstabilityplayedintheevolutionofcomplexlifeandwethinkourresultsareasignificantcontributiontothatReinhardsaid.Manyresearchersbelievetheoxygenlevelwashighduringpre-animaltimes.
GorillashaveawordforitKokoisthefirstgorillatohavebeentaughtsignlanguageawayofcommunicatingbyusinghandsandfingersratherthanspeech.Withavocabularyofmorethan1000wordssheisthefirsttoproveweshareaworldwithotherintelligentbeingswhofeelemotionslookforwardtocelebrationsandalsohaveasenseofhumour.The30-yearstudyofKokohasredefinedscience’sconceptofgorillaintelligence._____46.Butwhathadnotbeenrecognisedbythescientificcommunitywasthatgorillashavetheabilitytolearnalanguageandhavecomplexemotions.KokolivesintheSantaCruzmountainsinNorthAmericainawoodedspotoverlookingavalley._____47.Shehasabarrelonwhichshelikestositwhen’talking’tohumans-gorillasfeelmoresecurewhentheycanlookdownonothers-whilehertoysarespreadeverywhere.Inadditionshehasanoutsideenclosurewhereshespendsherdayswhenitisnotraining.ItisherconversationswithherteacherDrPennyPattersonthatareinspiring.Pennyexplains:‘Therealityofmydiscoveryisthatourabilitiesashumansourskillssensibilitiesandemotionsareverysimilartothegreatapes._____48.WhenshebeganteachingKokosignlanguageplacingthelittlefingersoftheone-year-oldgorillaintothecorrectpositionsfor’drink’’eat’’more’andrewardingherwithfoodDrPattersonhadnoideahowquicklyKokowouldlearn."AtfirstitseemedKokowasusingsignlanguageasatooltogetsomething"saysPatterson.’Itbecamethekindofrewardsystemthatyoucouldexpectofacatoradog.Butearlyinhertrainingshebegantocombinesignsthatmademethinkshewascapableofmore.’_____49.Forexampleshedidn’tknowthewordfor’ring’soshecombinedthesignsfor’finger’and’bracelet’toexpressit.DrPattersoncontinues:’Kokolovesbabiesandyoungpeople.Andwhensheisaskedwhatgorillaslikebestshealwayssays"Gorillaloveeatgood".OneofPatterson’sfavouritestoriesdemonstratesKoko’ssenseofhumour._____50.FromtheageofthreeKokosharedheraccommodationwithMichaelwhowasintendedasamate.HoweverMichaeldiedsuddenlytwoyearsagoofaheartattack.’KokowentintoadepressionfollowingMichael’sdeath’saysPatterson."Shewouldsitforhourswithherheadhunglowlookingupset."DrPattersonaskedherifshewaslookingforwardtomovingtoHawaiiwherePattersonisraisingmoneytobuildagorillarefuge.Kokosigned"Yes"providedshecouldhavecurtainsinhernewhome! 49
FaceMasksMayNotProtectfromSuper-Flu Ifasuper-flustrikesfacemasksmaynotprotectyou.Whetherwidespreaduseofmaskswillhelporharmduringthenextworldwidefluoutbreakisaquestionthatresearchersarestudyingfuriously.Noresultshavecomefromtheirmaskresearchyet. Howeverthegovernmentsayspeopleshouldconsiderwearingthemcertainstationsanywayjustincase. Butit’saquestionthepublickeepsaskingwhilethegovernmentismakingpreparationsforthenextflupandemic大流行.SotheCentersforDiseaseControlandPreventionCDCcameupwithpreliminaryguidelines.Wedon’twantPeoplewearingthemeverywheresaidtheCDC.Theoverallrecommendationreallyistoavoidexposure. Whenthatisnotpossibletheguidelinessayyoushouldconsiderwearingasimplesurgicalmaskifyouareinoneofthethreefollowingsituations.Firstyou’rehealthyandcan’tavoidgoingtoacrowdedplace.Secondyou’resickandthinkyoumayhaveclosecontactwiththehealthysuchasafamilymembercheckingonyou.Thirdyoulivewithsomeonewho’ssickandthusmightbeintheearlystagesofinfectionbutstillneedtogoout. Influenzapandemicscanstrikewhentheeasy-to-mutate变异fluvirusshiftstoastrain菌株thatpeopleneverhaveexperienced.ScientistscannotpredictwhenthenextpandemicwillarrivealthoughconcernisrisingthattheAsianbirdflumighttriggeroneifitstartsspreadingeasilyfrompersontoperson. Duringtheflupandemicyoushouldprotectyourself.Avoidcrowdsandavoidclosecontactwiththesickunlessyoumustcareforsomeone.Whyaren’tmasksaddedtothisself-protectionlist?Becausetheycanhelptrapvirus-ladendropletsflyingthroughtheairwithacoughorsneeze.Simplesurgicalmasksonlyfilterthelargerdroplets飞沫.BesidestheCDCisafraidmasksmaycreateafalsesenseofsecurity.Perhapssomeonewhoshouldhavestayedhomewoulddon戴anill-fittingmaskandhoponthesubwayinstead. Nordoesfluonlyspreadthroughtheair.Saysomeonecoversasneezewithhisorherhandthentouchesadoorknoborsubwaypole.Ifyoutouchthatspotnextandthenputgermyhandsonyournoseormouthyou’vebeenexposed.It’shardertorubyournosewhilewearingamasksoyourfacemaygetprettysweatyundermasks.Youreachundertowipethatsweatandmaytransfergermscaughtontheoutsideofthemaskstraighttothenose.Thesearetheproblemsfacemasksmaycreatefortheirusers. Whetherpeopleshouldorshouldnotusefacemasksstillremainsaquestion.Thegeneralpublichastowaitpatientlyfortheresultsofthemaskresearchscientistsarestilldoing. ThewordthatinParagraph3refersto
Theywerelockedin{{U}}mortal{{/U}}combat.
RoboticHighwayCones AUniversityofNebraskaprofessorhasdevelopedroboticconesandbarrels.Theseroboticconesandbarrelscanmoveoutofthewayorinto51_____fromcomputercommandsmademilesaway.TheycanevenbeprogrammedtomoveontheirownatanyparticularpartofthedaysaidShaneFarritoranassistantprofessorofmechanicalengineeringatNebraska. Forexampleifworkersarrivedat6amtheconescouldmovefromthesideofthehighwayto52_____offthelaneatthattime.Andtheycanreturntothe53_____placeattheendoftheday.Itjustseemslikeaverygoodapplicationforrobots.Farritorsaid.Theroboticconeswouldalsohelp54_____peoplefromhazardousjobsonthehighwayputtingbarrelsandconesintoplaceFarritorsaidinareportonhiscreation. Workontheideabeganin2002usingaNationalAcademyofSciencesgrant.The55_____allowedFarritortoworkontheprojectwithgraduatestudentsatNebraskaandhisassistantSteveGoddard. Therobotsareplacedatthebottomoftheconesandbarrelsandare56_____enoughnottogreatlychangetheappearanceoftheconstructionaides.ItwouldlookexactlythesameFarritorsaid.57_____there’sakindofrubberyblackbasetothem.Wereplacethat58_____arobot. FarritorhastalkedwithofficialsfromtheNebraskaDepartmentofRoadsabouthowtherobotswouldbemost59_____towhattheymightneed. Therobotscouldcomeinhandyfollowingaslow-movingmaintenanceoperationlikepaintingastripeonaroadormovingasphalt60_____nowthebarrelshavetobepickedupandmovedastheoperation61_____.Thatwayyoudon’thavetoblockoffa10-milestripfortheoperationFarritorsaid. 62_____prototypeshavebeenmadetheyarenotinuseanywhere.Farritorsaidhehas63_____forapatentandisconsideringwhattodonext.Heisthinkingaboutstartingasmallbusiness.Heisalsothinkingabout64_____therobotstoroadsdepartmentsandothersacrossthecountrywhomay65_____fromthem.
FirstImage-recognitionSoftware1.DartmouthresearchersandtheircolleagueshavecreatedanartificialintelligencesoftwarethatusesphotostolocatedocumentsontheInternetwithfargreateraccuracythaneverbefore.2.Thenewsystemwhichwastestedonphotosandisnowbeingappliedtovideosshowsforthefirsttimethatamachinelearningalgorithm运算法则forimagerecognitionandretrievalisaccurateandefficientenoughtoimprovelarge-scaledocumentsearchesonline.Thesystemusespixel像素datainimagesandpotentiallyvideo—ratherthanjusttext—tolocatedocuments.Itlearnstorecognizethepixelsassociatedwithasearchphrasebystudyingtheresultsfromtext-basedimagesearchengines.Theknowledgegleaned收集fromthoseresultscanthenbeappliedtootherphotoswithouttagsorcaptions图片说明makingformoreaccuratedocumentsearchresults.3."Overthelast30years"saysAssociateProfessorLorenzoTorresaniaco-authorofthestudy"theWebhasevolvedfromasmallcollectionofmostlytextdocumentstoamodernmassivefast-growingmultimediadatasetwherenearlyeverypageincludesmultiplepicturesorvideos.WhenapersonlooksataWebpageheimmediatelygetsthegist主旨ofitbylookingatthepicturesinit.YetsurprisinglyallexistingpopularsearchenginessuchasGoogleorBingstripawaytheinformationcontainedinthephotosanduseexclusivelythetextofWebpagestoperformthedocumentretrieval.Ourstudyisthefirsttoshowthatmodernmachinevisionsystemsareaccurateandefficientenoughtomakeeffectiveuseoftheinformationcontainedinimagepixelstoimprovedocumentsearch."4.Theresearchersdesignedandtestedamachinevisionsystem—atypeofartificialintelligencethatallowscomputerstolearnwithoutbeingexplicitlyprogrammed—thatextractssemantic语义的informationfromthepixelsofphotosinWebpages.ThisinformationisusedtoenrichthedescriptionoftheHTMLpageusedbysearchenginesfordocumentretrieval.Theresearcherstestedtheirapproachusingmorethan600searchqueries查询onadatabaseof50millionWebpages.Theyselectedthetext-retrievalsearchenginewiththebestperformanceandmodifiedittomakeuseoftheadditionalsemanticinformationextractedbytheirmethodfromthepicturesoftheWebpages.Theyfoundthatthisproduceda30percentimprovementinprecisionovertheoriginalsearchenginepurelybasedontext. Paragraph3
RoboticHighwayCones AUniversityofNebraskaprofessorhasdevelopedroboticconesandbarrels.Theseroboticconesandbarrelscanmoveoutofthewayorinto51_____fromcomputercommandsmademilesaway.TheycanevenbeprogrammedtomoveontheirownatanyparticularpartofthedaysaidShaneFarritoranassistantprofessorofmechanicalengineeringatNebraska. Forexampleifworkersarrivedat6amtheconescouldmovefromthesideofthehighwayto52_____offthelaneatthattime.Andtheycanreturntothe53_____placeattheendoftheday.Itjustseemslikeaverygoodapplicationforrobots.Farritorsaid.Theroboticconeswouldalsohelp54_____peoplefromhazardousjobsonthehighwayputtingbarrelsandconesintoplaceFarritorsaidinareportonhiscreation. Workontheideabeganin2002usingaNationalAcademyofSciencesgrant.The55_____allowedFarritortoworkontheprojectwithgraduatestudentsatNebraskaandhisassistantSteveGoddard. Therobotsareplacedatthebottomoftheconesandbarrelsandare56_____enoughnottogreatlychangetheappearanceoftheconstructionaides.ItwouldlookexactlythesameFarritorsaid.57_____there’sakindofrubberyblackbasetothem.Wereplacethat58_____arobot. FarritorhastalkedwithofficialsfromtheNebraskaDepartmentofRoadsabouthowtherobotswouldbemost59_____towhattheymightneed. Therobotscouldcomeinhandyfollowingaslow-movingmaintenanceoperationlikepaintingastripeonaroadormovingasphalt60_____nowthebarrelshavetobepickedupandmovedastheoperation61_____.Thatwayyoudon’thavetoblockoffa10-milestripfortheoperationFarritorsaid. 62_____prototypeshavebeenmadetheyarenotinuseanywhere.Farritorsaidhehas63_____forapatentandisconsideringwhattodonext.Heisthinkingaboutstartingasmallbusiness.Heisalsothinkingabout64_____therobotstoroadsdepartmentsandothersacrossthecountrywhomay65_____fromthem.
HebelievesthatEuropemustchangeoritwill{{U}}perish{{/U}}.
LackofOxygenDelayedtheRiseofAnimalsonEarth Scientistshavelongspeculatedastowhyanimalspeciesdidn’tflourishsooneroncesufficientoxygencoveredtheEarth’ssurface.AnimalsbegantoprosperattheendoftheProterozoicperiodabout800millionyearsago—butwhataboutthebillion-yearstretchbeforethatwhenmostresearchersthinktherealsowasplentyofoxygen? Wellitseemstheairwasn’tsogreatthenafterall. InastudypublishedOct.31inScienceYaleresearcherNoahPlanavskyandhiscolleaguesfoundthatoxygenlevelsduringtheboringbillionperiodwereonly0.1%ofwhattheyaretoday.InotherwordsEarth’satmospherecouldn’thavesupportedadiversityofcreaturesnomatterwhatgeneticadvancementswerepoisedtooccur. ThereisnoquestionthatgeneticandecologicalinnovationmustultimatelybebehindtheriseofanimalsbutitisequallyunavoidablethatanimalsneedacertainlevelofoxygensaidPlanavskyco-leadauthoroftheresearchalongwithChristopherReinhardoftheGeorgiaInstituteofTechnology.We’reprovidingthefirstevidencethatoxygenlevelswerelowenoughduringthisperiodtopotentiallypreventtheriseofanimals. ThescientistsfoundtheirevidencebyanalyzingchromiumCrisotopesinancientsedimentsfromChinaAustraliaCanadaandtheUnitedStates.ChromiumisfoundintheEarth’scontinentalcrustandchromiumoxidationisdirectlylinkedtothepresenceoffreeoxygenintheatmosphere. Specificallytheteamstudiedsamplesdepositedinshallowiron-richoceanareasneartheshore.Theycomparedtheirdatawithothersamplestakenfromyoungerlocalesknowntohavehigherlevelsofoxygen. Oxygen’sroleincontrollingthefirstappearanceofanimalshaslongvexedscientists.WeweremissingtherightapproachuntilnowPlanavskysaid.Chromiumgaveustheproxy.Previousestimatesputtheoxygenlevelat40%oftoday’sconditionsduringpre-animaltimesleavingopenthepossibilitythatoxygenwasalreadyplentifulenoughtosupportanimallife. Inthenewstudytheresearchersacknowledgedthatoxygenlevelswerehighlydynamicintheearlyatmospherewiththepotentialforoccasionalspikes.HowevertheysaidItseemsclearthatthereisafirst-orderdifferenceinthenatureofEarthsurfaceCrcyclingbeforeandaftertheriseofanimals. Ifwearerightourresultswillreallychangehowpeopleviewtheoriginsofanimalsandothercomplexlifeandtheirrelationshipstotheco-evolvingenvironmentsaidco-authorTimLyonsoftheUniversityofCalifornia-Riverside.Thiscouldbeagamechanger. There’salotofinterestrightnowinabroaderdiscussionsurroundingtherolethatenvironmentalstabilityplayedintheevolutionofcomplexlifeandwethinkourresultsareasignificantcontributiontothatReinhardsaid.ThestudyrevealedthatchromiumfoundinEarth’scontinentalcrustremainedstablebeforeandaftertheriseofanimals.
RoboticHighwayCones AUniversityofNebraskaprofessorhasdevelopedroboticconesandbarrels.Theseroboticconesandbarrelscanmoveoutofthewayorinto51_____fromcomputercommandsmademilesaway.TheycanevenbeprogrammedtomoveontheirownatanyparticularpartofthedaysaidShaneFarritoranassistantprofessorofmechanicalengineeringatNebraska. Forexampleifworkersarrivedat6amtheconescouldmovefromthesideofthehighwayto52_____offthelaneatthattime.Andtheycanreturntothe53_____placeattheendoftheday.Itjustseemslikeaverygoodapplicationforrobots.Farritorsaid.Theroboticconeswouldalsohelp54_____peoplefromhazardousjobsonthehighwayputtingbarrelsandconesintoplaceFarritorsaidinareportonhiscreation. Workontheideabeganin2002usingaNationalAcademyofSciencesgrant.The55_____allowedFarritortoworkontheprojectwithgraduatestudentsatNebraskaandhisassistantSteveGoddard. Therobotsareplacedatthebottomoftheconesandbarrelsandare56_____enoughnottogreatlychangetheappearanceoftheconstructionaides.ItwouldlookexactlythesameFarritorsaid.57_____there’sakindofrubberyblackbasetothem.Wereplacethat58_____arobot. FarritorhastalkedwithofficialsfromtheNebraskaDepartmentofRoadsabouthowtherobotswouldbemost59_____towhattheymightneed. Therobotscouldcomeinhandyfollowingaslow-movingmaintenanceoperationlikepaintingastripeonaroadormovingasphalt60_____nowthebarrelshavetobepickedupandmovedastheoperation61_____.Thatwayyoudon’thavetoblockoffa10-milestripfortheoperationFarritorsaid. 62_____prototypeshavebeenmadetheyarenotinuseanywhere.Farritorsaidhehas63_____forapatentandisconsideringwhattodonext.Heisthinkingaboutstartingasmallbusiness.Heisalsothinkingabout64_____therobotstoroadsdepartmentsandothersacrossthecountrywhomay65_____fromthem.
GorillashaveawordforitKokoisthefirstgorillatohavebeentaughtsignlanguageawayofcommunicatingbyusinghandsandfingersratherthanspeech.Withavocabularyofmorethan1000wordssheisthefirsttoproveweshareaworldwithotherintelligentbeingswhofeelemotionslookforwardtocelebrationsandalsohaveasenseofhumour.The30-yearstudyofKokohasredefinedscience’sconceptofgorillaintelligence._____46.Butwhathadnotbeenrecognisedbythescientificcommunitywasthatgorillashavetheabilitytolearnalanguageandhavecomplexemotions.KokolivesintheSantaCruzmountainsinNorthAmericainawoodedspotoverlookingavalley._____47.Shehasabarrelonwhichshelikestositwhen’talking’tohumans-gorillasfeelmoresecurewhentheycanlookdownonothers-whilehertoysarespreadeverywhere.Inadditionshehasanoutsideenclosurewhereshespendsherdayswhenitisnotraining.ItisherconversationswithherteacherDrPennyPattersonthatareinspiring.Pennyexplains:‘Therealityofmydiscoveryisthatourabilitiesashumansourskillssensibilitiesandemotionsareverysimilartothegreatapes._____48.WhenshebeganteachingKokosignlanguageplacingthelittlefingersoftheone-year-oldgorillaintothecorrectpositionsfor’drink’’eat’’more’andrewardingherwithfoodDrPattersonhadnoideahowquicklyKokowouldlearn."AtfirstitseemedKokowasusingsignlanguageasatooltogetsomething"saysPatterson.’Itbecamethekindofrewardsystemthatyoucouldexpectofacatoradog.Butearlyinhertrainingshebegantocombinesignsthatmademethinkshewascapableofmore.’_____49.Forexampleshedidn’tknowthewordfor’ring’soshecombinedthesignsfor’finger’and’bracelet’toexpressit.DrPattersoncontinues:’Kokolovesbabiesandyoungpeople.Andwhensheisaskedwhatgorillaslikebestshealwayssays"Gorillaloveeatgood".OneofPatterson’sfavouritestoriesdemonstratesKoko’ssenseofhumour._____50.FromtheageofthreeKokosharedheraccommodationwithMichaelwhowasintendedasamate.HoweverMichaeldiedsuddenlytwoyearsagoofaheartattack.’KokowentintoadepressionfollowingMichael’sdeath’saysPatterson."Shewouldsitforhourswithherheadhunglowlookingupset."DrPattersonaskedherifshewaslookingforwardtomovingtoHawaiiwherePattersonisraisingmoneytobuildagorillarefuge.Kokosigned"Yes"providedshecouldhavecurtainsinhernewhome! 47
BetterSolarEnergySystems:MoreHeatMoreLight Solarphotovoltaic光伏的thermalenergysystemsorPVTsgeneratebothheatandelectricitybutuntilnowtheyhaven’tbeenverygoodattheheat-generatingpartcomparedtoastand-alonesolarthermalcollector.That’sbecausetheyoperateatlowtemperaturestocoolcrystalline晶体的siliconsolarcellswhichletsthesilicongeneratemoreelectricitybutisn’taveryefficientwaytogatherheat. That’saproblemofeconomics.Goodsolarhot-watersystemscanharvestmuchmoreenergythanasolar-electricsystematasubstantiallylowercost.Andit’salsoaspaceproblem:photovoltaiccellscantakeupallthespaceontheroofleavinglittleroomforthermalapplications. InapairofstudiesJoshuaPearceanassociateprofessorofmaterialsscienceandengineeringhasdevisedasolutionintheformofabetterPVTmadewithadifferentkindofsilicon.HisresearchcollaboratorsareKunalGirotrafromThinSiliconinCaliforniaandMichaelPathakandStephenHarrisonfromQueen’sUniversityCanada. Mostsolarpanelsaremadewithcrystallinesiliconbutyoucanalsomakesolarcellsoutofamorphous非晶体的siliconcommonlyknownasthin-filmsilicon.Theydon’tcreateasmuchelectricitybuttheyarelighterflexibleandcheaper.Andbecausetheyrequiremuchlesssilicontheyhaveagreenerfootprint.Unfortunatelythin-filmsiliconsolarcellsarevulnerabletosomebad-newsphysicsintheformoftheStaebler-Wronskieffect. Thatmeansthattheirefficiencydropswhenyouexposethemtolight—prettymuchtheworstpossibleeffectforasolarcellPearceexplainswhichisoneofthereasonsthin-filmsolarpanelsmakeuponlyasmallfractionofthemarket. HoweverPearceandhisteamfoundawaytoengineeraroundtheStaebler-Wronskieffectbyincorporatingthin-filmsiliconinanewtypeofPVT.Youdon’thavetocooldownthin-filmsilicontomakeitwork.InfactPearce’sgroupdiscoveredthatbyheatingittosolar-thermaloperatingtemperaturesneartheboilingpointofwatertheycouldmakethickercellsthatlargelyovercametheStaebler-Wronskieffect.Whentheyappliedthethin-filmsilicondirectlytoasolarthermalenergycollectortheyalsofoundthatbybakingthecellonceadaytheyboostedthesolarcell’selectricalefficiencybyover10percent. Whichofthefollowingstatementsistrue?
Mostpeoplefind{{U}}rejection{{/U}}hardtoaccept.
Theypromote{{U}}assimilation{{/U}}ofethnicgroupsintothemain-streamculture.
I’llBeBach ComposerDavidCopeistheinventorofacomputerprogramthatwritesoriginalworksofclassicalmusic.IttookCope30yearstodevelopthesoftware.Nowmostpeoplecan’t_____51thedifferencebetweenmusicbythefamousGermancomposerJ.S.Bach1685-1750andtheBach-likecompositionsfromCope’scomputer. Itallstartedin1980intheUnitedStateswhenCopewastryingtowriteanopera.Hewashaving_____52thinkingofnewmelodiessohewroteacomputerprogramtocreatethemelodies.Atfirstthismusicwasnot_____53tolistento.WhatdidCopedo?Hebegantorethinkhowhumanbeingscomposemusic.Herealizedthatcomposersbrains_____54likebigdatabases.Firsttheytakeinallthemusicthattheyhaveeverheard.Thentheytake_____55themusicthattheydislike.Finallytheymakenewmusicfromwhatis_____56.AccordingtoCopeonlythegreatcomposersareabletocreatethedatabaseaccuratelyrememberitandformnewmusicalpatternsfromit. Copebuilta_____57databaseofexistingmusic.HebeganwithhundredsofworksbyBach.Thesoftwareanalyzedthedataa_____58itdownintosmallerpiecesandlookedforpatterns.Itthencombinedthe_____59intonewpatterns.BeforelongtheprogramcouldcomposeshortBach-likeworks.Theyweren’tgoodbutitwasastart. Copeknewhehadmoreworktodo-hehadawholeoperatowrite.Hecontinuedtoimprovethesoftware.Soonitcould_____60morecomplexmusic.Healsoaddedmanyothercomposersincludinghisownworktothedatabase. AfewyearslaterCope’scomputerprogramcalledEmmywasreadytohelphimwithhisopera.The_____61requiredalotofcollaborationbetweenthecomposerandEmmy.Copelistenedtothecomputer’smusicalideasandusedthe_____62thatheliked.WithEmmytheoperatookonlytwoweekstofinish.ItwascalledCradleFallinganditwasagreat_____63!Copereceivedsomeofthebestreviewsofhiscareerbutnooneknewexactly_____64hehadcomposedthework. SincethatfirstoperaEmmyhaswrittenthousandsofcompositions.CopestillgivesEmmyfeedbackonwhathelikesanddoesn’tlikeofhermusic_____65sheisdoingmostofthehardworkofcomposingthesedays!
Imust{{U}}compliment{{/U}}youonyourhandlingofaverydifficultsituation
RoboticHighwayCones AUniversityofNebraskaprofessorhasdevelopedroboticconesandbarrels.Theseroboticconesandbarrelscanmoveoutofthewayorinto51_____fromcomputercommandsmademilesaway.TheycanevenbeprogrammedtomoveontheirownatanyparticularpartofthedaysaidShaneFarritoranassistantprofessorofmechanicalengineeringatNebraska. Forexampleifworkersarrivedat6amtheconescouldmovefromthesideofthehighwayto52_____offthelaneatthattime.Andtheycanreturntothe53_____placeattheendoftheday.Itjustseemslikeaverygoodapplicationforrobots.Farritorsaid.Theroboticconeswouldalsohelp54_____peoplefromhazardousjobsonthehighwayputtingbarrelsandconesintoplaceFarritorsaidinareportonhiscreation. Workontheideabeganin2002usingaNationalAcademyofSciencesgrant.The55_____allowedFarritortoworkontheprojectwithgraduatestudentsatNebraskaandhisassistantSteveGoddard. Therobotsareplacedatthebottomoftheconesandbarrelsandare56_____enoughnottogreatlychangetheappearanceoftheconstructionaides.ItwouldlookexactlythesameFarritorsaid.57_____there’sakindofrubberyblackbasetothem.Wereplacethat58_____arobot. FarritorhastalkedwithofficialsfromtheNebraskaDepartmentofRoadsabouthowtherobotswouldbemost59_____towhattheymightneed. Therobotscouldcomeinhandyfollowingaslow-movingmaintenanceoperationlikepaintingastripeonaroadormovingasphalt60_____nowthebarrelshavetobepickedupandmovedastheoperation61_____.Thatwayyoudon’thavetoblockoffa10-milestripfortheoperationFarritorsaid. 62_____prototypeshavebeenmadetheyarenotinuseanywhere.Farritorsaidhehas63_____forapatentandisconsideringwhattodonext.Heisthinkingaboutstartingasmallbusiness.Heisalsothinkingabout64_____therobotstoroadsdepartmentsandothersacrossthecountrywhomay65_____fromthem.
Theprocedureswereperceivedascomplexandless{{U}}transparent{{/U}}.
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