简介:Carbazole-basedbi-functionalphotorefractivepolyacrylateswerepreparedviafreeradicalpolymerizationandpost-azo-couplingreaction.ThestructureofpolymerswascharacterizedbyFouriertransforminfraredspectroscopy(FTIR)andprotonnuclearmagneticresonance(1H-NMR)spectroscopy.Thedifferentialscanningcalorimetry(DSC)andthethermalgravimetricanalysis(TGA)wereusedtocharacterizethethermalpropertyofpolymers.Theresultsindicatethatthoughtheglasstransitiontemperature(Tg)ofpolymersincreaseswithincreasingtheratioofNLOgroups,thepolymerswithdifferentratiosofNLOgroupsstillallshowlowglasstransitiontemperaturesaround60°C,andgoodthermalstability,whicharefavorabletothepracticalapplicationofthesepolymers.Thegelpermeationchromatographic(GPC)resultindicatesthatthesepolymersallhavehigh-molecular-weightwhichisfavorabletothelongtermstabilityofthematerial.Further,thesepolymershavegoodsolubilityinchloroformsolvent,andthesolutionscaneasilybefabricatedintoopticallytransparentfilms.Gaincoefficientsof75cm-1,185cm-1and66cm-1canbeobservedatzeroexternalelectricfieldwithoutanyadditionagentorpre-polingforpolymersP-2,P-3andP-4respectively.ThedifferentcontentsofNLOgroupsresultinthedifferentpropertiesofpolymersP-2,P-3andP-4.
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%.
简介:Chalcopyrite-typeCuInSe2nanoparticlesaresuccessfullypreparedbyusingIn2Se3nanoparticlesasaprecursorreactedwithcopperchloride(CuCl)solutionviaaphasetransformationprocessinlowtemperature.Thereactiontimeisakeyparameter.Afterthereactiontimeincreasingfrom0.5hto8h,In2Se3andCuClreactwitheachothergraduallyviaphasetransformationintoCuInSe2withoutanyintermediatephase.ThecrystallinestructureandmorphologyoftheCuInSe2nanoparticlesarecharacterizedbyX-raydiffraction(XRD)andfieldemissionscanningelectronmicroscopy(FESEM).ThediameterofCuInSe2nanoparticleswithgooddispersibilityrangesfrom10nmto20nm.ThebandgapoftheCuInSe2nanoparticlesis1.04eVcalculatedfromtheultraviolet-visible(UV-VIS)spectrum.
简介:Weproposeageneralmethodologytodefinetheoptimumdopingionvolumedistributionrequiredforanefficientsolid-statelaseramplifier.ThisapproachisillustratedinthecontextoftwoexperimentaldiodepumpedYb:YAGamplifiersoperatingat300and160K.Processingofsuchtailoredgainmediaisnowpossiblethroughhorizontaldirectcrystallization.
简介:Oxygenisotopefractionationbetweencoexistingmineralsinslowlycooledrocksconveysinformationabouttheircoolinghistory.Byusingthefastgrainboundary(FGB)modeltosimulateclosed-systemdiffusiveexchangeofoxygenisotopesbetweencoexistingminerals,Ishowthattheapparentequilibriumtemperatures(Tae)bythemineralpairwiththelargestisotopicfractionation(PLIF)alwaysliesbetweentheclosuretemperatures(Tc)ofthosetwominerals.Therefore,whentherateofoxygendiffusionandhenceTcforthePLIFchancetobecomparable(suchasinthecaseofquartzandmagnetite),TaewillserveasagoodapproximationofTcregardlessofvariationinmineralproportions.ThespecialtyofthePLIFinconstrainingTaewithintheirTcrangecanbegeneralizedtootherstableisotopesystemsandelementpartitioning.ByapproximatingTcwithTaeandinvertingDodson'sequation,thecoolingrateofplutonicormetamorphicrockscanbeinferred.
简介:<正>Polyhalite(K2SO4·MgSO4·2CaSO4·2H2O)isoneoftheinsolublepotassiummineralwhichiswidelydistributedinsulfate-typepotassium-bearingdeposit,andthetheoreticalconcentrationofK2SO4is28%.Itcanbedirectlyusedasa
简介:Strainageinginsteelwasfirstobservedduringthe19thcenturywhenthemaximumloadcarryingcapacityofatestpiecewasincreasedafterithadbeenretestedfollowingapreviousseriesoftestinginaplasticrange.Overthelastdecades,agreatdealofresearchhasbeenperformedtogaindeeperinsightsintothephenomenonofstrainageing.Thesynergisticdevelopmentoftheoreticalhypothesisandnewexperimentalevidenceshaspromotedtheunderstandingofthemechanismsunderlyingstrainageing.Thecontentofthispaperisorganizedintofourcomponents.First,wehavecomparedthemaintheoriesdevelopedinrecentyears.Second,wehavesummarizedthemetallurgicaleffectsonthestrainageingbehaviorobservedinexperiments.Moreover,wehavemadeanattempttocorrelatetheexperimentalresultsandtheabove-mentionedtheories.Third,wehaveproposedafeasiblesolutiontocontrolstrainageinginlowcarbonsteels.Finally,wehaveelaboratedthepotentialityoftheatomprobetechniqueinfacilitatingdirectcharacterizationofthedistributionofsoluteatoms.
简介:ForthereliabilityandpowerconsumptionissuesofEthernetdatatransmissionbasedonthefieldprogrammablegatearray(FPGA),alow-powerconsumptiondesignmethodisproposed,whichissuitableforFPGAimplementation.Toreducethedynamicpowerconsumptionofintegratedcircuit(IC)design,theproposedmethodadoptsthedynamiccontroloftheclockfrequency.Formostofthetime,whentheportisintheidlestateorlower-ratestate,userscanreduceoreventurnoffthereadingclockfrequencyandreducetheclockflipfrequencyinordertoreducethedynamicpowerconsumption.Whenthereceivingrateishigh,thereadingclockfrequencywillbeimprovedtimelytoensurethatnodatawilllost.SimulatedandverifiedbyModelsim,theproposedmethodcandynamicallycontroltheclockfrequency,includingthedynamicswitchingofhigh-speedandlow-speedclockfliprates,orstopoftheclockflip.
简介:Thispaperinvestigatestheinfluenceoflow-carbonpoliciesonchannelcoordinationforatwo-echelonsupplychainconsistingofonesupplierandoneretailer.Fourdifferentmodelsareconsidered:thebasicmodel,thecarbonemissionmodel,thecarbonemissiontradingmodelandthecarbontaxmodel.Wefindthatthegovernmentpolicyonallcarbonemissionmodelsisnotuniversalamongthefirmsaswellasthecustomers.Thecarbonemissiontradingpolicyisalwaysbetterthanthecarbonemissionpolicyandthecarbontaxpolicywhentheallocatedcarbonemissionquotasaregreaterthanthecarbonemissions.Thecarbonemissiontradingpolicyisprovedtobeaneffectivemechanismwhichcanmotivatethesupplychaintoreducecarbonemissions.Undercertainconditions,thesupplychainprefersthecarbonemissiontradingpolicywithhighercarbonpricetootherpolicies.IntheframeworkofStackelberggamewiththesupplierastheleader,foreachcarbonpolicy,thepaperpresentscoordinationmechanismwiththeall-unitwholesalequantitydiscountcontract(AWQD).Weanalyzeandcomparetheinfluenceoflow-carbonpoliciesonchannelcoordinationforthefourlow-carbonpolicies.Numericalexperimentsareconductedtoexamineourfindings.
简介:影响司烧混合的层温度变化上的飘移被考虑Stokes飘移在混合的层温度并且用的方程导致的一个移流的热运输学期估计海洋并且从一个全球海洋发行量模型(HYCOM)和一个波浪的波浪参数当模特儿(波浪手表III)。维的分析和量的评价方法被进行估计Stokes飘移导致的效果的重要性并且分析它的空间分发和季节的变化特征。到在mid-to-high纬度的混合的层温度变化的Stokes飘移的贡献与吝啬的水流的是可比较的结果表演,和混合的层温度变化的实质的部分被考虑Stokes飘移效果导致。尽管Stokes飘移导致的移流热运输不是为混合的层温度方程的领先的术语,它不能被忽视并且甚至为upperocean温度的模拟在一些区域变得批评。
简介:Inthisstudy,weexaminedtheeffectofelevatedtemperatureontheexpressionpatternsofgenes,i.e.,nacrein,irr,n16,n19,andhsp70inthepearloysterPinctadafucata.Theexperimentwascarriedoutat4temperatures,i.e.,20℃(ambient,control),24,28℃,and32℃.TheexpressionlevelsoftargetgenesinP.fucatawereassayedat0,6,24,48,and96hviareal-timepolymerasechainreaction.Resultsshowedthattheexpressionlevelsofnacreinandirrhadnosignificantvariationsamongdifferenttimepointsbelow28℃,butsignificantlyincreasedovertimeat32℃.Theexpressionlevelsofn16andn19didnotchangemarkedlyat20℃.Theformerincreasedsignificantlyat6hand24hwhilethelattersubstantiallydecreasedduring6–96hat24,28and32℃.Amongdifferenttemperatures,thelevelofn16wassignificantlylowerat20℃thanatothertemperaturesduring6–96h,andthelevelofn19significantlyvariedamongdifferenttemperaturesat48hand96h.Theexpressionlevelofhsp70wassignificantlyhigherat32℃thanat20,24and28℃at24h.TheseresultsdemonstratedthatelevatedtemperatureimpactedthephysiologicalprocessesofP.fucataandpotentiallyinfluenceditsadaptabilitytothermalstress.
简介:Basedontheanalysisontheglobalwarmingandenvironmentaldeterioration,low-carbonconcepthasreceivedmoreandmoreattentionfromgovernments,expertsandscholarsathomeandabroad.TheBritishgovernmentfirstputforwardtheconceptoflow-carboneconomy,andafterthattheJapanesegovernmentproposedtheconstructionoflow-carbonsociety.Inourcountry,expertsandscholarsbegantoresearchonlow-carboncityfrom2007.Thispaperlooksthroughthepracticalandtheoreticalstudiesonlow-carboncityconstructionofthedomesticexpertsandscholars.Thecurrentbackgroundoflowcarboncityconstructionisfirstintroduced.Toclarifyfundamentalconnotation,characteristicsandtargetofChina’slow-carboncityisveryimportant.Therefore,thispapersummarizestheresearchprogressofthelow-carboncityconstructionfromthenecessity,theconnotationandcharacteristicsoftarget.Then,weshouldpayattentiontochoosingtherightindex,combiningtheregioncharacteristicswiththecurrentdevelopmentmodelandevaluationindexessystem,toreflectandimprovecarbonemissions.Finally,thepapergivesanoverviewofsuggestionsbyexpertsandscholarsontheconstructionoflowcarboncity.