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简介：Becausetheypossessexcellentvisiblelightabsorptionproperties,lead-freecolloidalcopper-basedchalcogenidequantumdots(QDs)haveemergedinphotoelectronicfields.Bymeansoflocalizedsurfaceplasmonicresonance(LSPR),theabsorptionpropertiesofQDscanbeenhanced.Inthispaper,wefabricatealead-freeCuInSe2QDfieldeffectphototransistor(FEpT)byutilizingtheLSPRenhancementofAunanoparticles(NPs).TheplasmonicFEpTdemonstratesresponsivityupto2.7μA·W-1andaspecificdetectivityof7×103Jonesatzerobiasunderilluminationbya532nmlaser,valuesthatareenhancedbyapproximately200%morethandeviceswithoutAuNPs.Particularly,theFEpTexhibitsamulti-wavelengthresponse,whichisphotoresponsiveto405,532,and808nmirradiations,andpresentsstabilityandreproducibilityintheprogressofON–OFFcycles.Furthermore,theenhancementinducedbyAuNPLSPRcanbeinterpretedbyfinite-differencetimedomainsimulations.Thelow-costsolution-basedprocessandexcellentdeviceperformancestronglyunderscoreleadfreeCuInSe2QDsasapromisingmaterialforself-poweredphotoelectronicapplications,whichcanbefurtherenhancedbyAuNPLSPR.

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简介：Ba0.85Ca0.15Ti0.9Zr0.1O3(BCTZ)lead-freepiezoelectricceramicsco-dopedwithCeO2(x=0.1wt.%,0.2wt.%,0.3wt.%,0.4wt.%,0.5wt.%)andLi2CO3(0.6wt.%)werepreparedbyconventionalsolid-statereactionmethod.InfluenceofCeO2dopingamountonthepiezoelectricproperties,dielectricproperties,phasecompositionandmicrostructureofpreparedBCTZlead-freepiezoelectricceramicsdopedwithLi2CO3wereinvestigatedbyX-raydiffraction(XRD)andscanningelectronmicroscopy(SEM)andotheranalyticalmethods.TheresultsshowedthatthesinteredtemperatureofBCTZlead-freepiezoelectricceramicsdopedwithCeO2decreasedgreatlywhenLi2CO3dopingamountwas0.6wt.%;apureperovskitestructureofBCTZlead-freepiezoelectricceramicsco-dopedwithLi2CO3andCeO2andsinteredat1050°Ccouldalsobeobtained.Thepiezoelectricconstant(d33),therelativepermittivity(εr)andtheplanarelectromechanicalcouplingfactor(kp)ofBCTZceramicsdopedwithLi2CO3increasedfirstlyandthendecreased,thedielectricloss(tanδ)decreasedfirstlyandthenincreasedanddecreasedatlastwhenCeO2dopingamountincreased.TheinfluenceofCeO2dopingonthepropertiesofBCTZlead-freepiezoelectricceramicsdopedwithLi2CO3werecausedby'softeffect'and'hardeffect'piezoelectricadditiveandcausinglatticedistortion.WhenCeO2dopingamount(x)was0.2wt.%,theBCTZceramicsdopedwithLi2CO3(0.6wt.%)andsinteredat1050°Cpossessedthebestpiezoelectricpropertyanddielectricpropertywithd33of436pC/N,kpof48.3%,εrof3650,tanδof1.5%.

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简介：Leadisoneofthepoisonoustraceelementforhumanbody.Itisimportanttofindawayformeasuringcontentoflead.Deterninationofleadbyelectrochemistryisoneofamethod[1].Inthispaper,leadisdeterminedbysingle-sweeppolarography.Theabsorptionbehaviorofmeso-tetra(4-sulfonylphenyl)porphyrin(H2TPPS4)complexwithleadionhasalsobeenstudied.InNa2B4O7-NaOHsolutionwithpH=l0.5,thereductionpeaksoftheligandareP1(Ep1=-0.38V),P2(Ep2=-1.04V),whichpotentialsareobtainedvs.S.C.E.Whenleadionhasbeenaddedintoabovesolution.ThepeakcurrentofP1andP2decrease,andanewreductionpeakP3(Ep3=-1.10V)appears.ItshowsthattheTPPS4-Pb(Ⅱ)complexforms,andthismethodcanbeappliedtostudythecomplex.

简介：迈克尔·戴尔是全球知名IT产品及服务供应商——戴尔公司的首席执行官(ChiefExeeutiveOfficer)。他是IT精英，于19岁时创立了戴尔公司。下面是他的一篇报告《让兴趣引导你》。

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简介：Powermeansdifferentthingstodifferentpeople.Somesaythatpoweristheabilitytoexert(施加)influencebeyondthoseoneactuallycontrols.Othersmaintainthatpowerboilsdown(压缩，简化)totheabilitytogetwhatonewants.Consideringthatweneedincometoobtainthethingsthatweneedorwant,

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简介：IntroductionLead-inmeanstointroducestudentsgentlytotopicstheyaregoingtodealwith,settlethemdownatthebeginningofalessonandgenerallypreparethemforthetopic.Usinglead-insinlanguageteachingisnotanewidea.Someofthemorerecenttextbooks,notably‘StepbyStep’,andotherteachers’books,havewarming-upexercisesandculturalbackgroundinformationwhichteacherscanuseaslead-in.However,formanyyears,becauseofalackofsuitabletraininginteachingmethodology,manyEnglishteacherstendedtoneglectlead-in,thefirststepinpresentingatext,andwentdirectlyintothetextitself.Thestudentswereconfrontedwithsomethingtheyknewnothingabout,andhadnoparticulardesiretoknowabout.Theywereexpectedtoadjustthemselvestotheteachingcontext.

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