简介:Thecrackingandaromatizationofn-hexaneoverH-ZSM-5modifiedbyvariousrareearthswereinvestigatedbymeansofcontinuousflowmicro-reactor.ThesurfacepropertiesofmodifiedH-ZSM-5catalystswereobtainedfromIR,XRDandXPS.Theresultsshowthattherareearthsenhancethearomatizingpropertiesofthecatalystswhicharepreparedbymechanicalmixturemethod.Theresultsofn-hexanecrackingandaromatizationarecorrelatedwiththeacidity.TheBrnstedacidicsitesaretheactivesitesofn-hexanearomatization,whileLewisacidsiteplaysanimportantroleinn-hexanecracking.
简介:ThemeasurementsoftemperaturedependenceofthemagneticsusceptibilityofLa1-xSrxCoO3perovskiteoxidesatdifferentSrdoping(0≤x≤0.5)andannealingtemperaturewerepresented.Forthesamplewithx=0.1,ashoulderwasobservedaround150K,andapeakwhichisonefeatureofspinglassappearedaround50Kinthecurveofsusceptibilityversustemperature.Thehigh-temperature(250~420K)susceptibilityfitswellwithCurie-Weisslawforallsamples.WeissconstantandeffectivemagneticmomentweredeterminedandtheirvariationswithSrdopingandoxygenannealingconditionwereobtained.TheWeissconstantincreasesmonotonouslywithSrcontentforx>0.2.Thevaluesofeffectivemomentswereinterpretedwiththespinstateofcobaltions.Studiesonthesusceptibilitiesofthesampleswithx=0.2underdifferentpreparationtemperaturesandannealingtemperaturesshowthattherisingofsinteringtemperatureandannealingtemperaturewillincreasethepara-ferromagnetictransitiontemperature,andreducetheeffectivemomenttonormalvalue.OurresultshowsthatbothCo3+andCo4+ionsshouldbeinISstateafterannealingandtheoxygenannealingcausesthetransitionofCo3+spinstatefromHStoIS.
简介:探讨了在大生产条件下4Cr5MoSiV1钢的脱碳层测定原则。结果表明,金相法测定结果较准确且操作简便
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简介:Thesinglecrystalofthecomplex[Sc(NO3)3(H2O)2]·(15C5)hasbeenpreparedinacetonitrile.Thenewcomplexhasbeencharacterizedbyelementalanalysis,IRspectra,solubilityandmolarconductancemeasurements.ThestructureofthecomplexisdeterminedbysinglecrystalX-raydiffractionanalysis.
简介:TheextractionofCe(Ⅳ)inH2SO4/H3PO4systemwasinvestigatedsystematicallyusingbifunctionalionicliquidextractants(Bif-ILES)[A336][P507],[A336][P204]and[A336][C272]inn-heptane.TheeffectsofH2SO4concentration,extractantconcentrationandsalting-outagentconcentrationwereobservedindetail.TheextractionmechanismofCe(Ⅳ)inH2SO4/H3PO4systemwasobtained.ThecomparisonwithotherextractantssuchasCyanex923,TBPwasalsostudied.Thermodynamicfunctionsoftheextractionreactionwerecalculated,showingthattheextractionwasanexothermicprocess.TheseparationofCe(Ⅳ)fromRE(Ⅲ)andTh(Ⅳ)wasalsoinvestigated.TheresultindicatedthatCe(Ⅳ)couldbeselectivelyextractedinthissystem.CePO4nanoparticleswereobtainedintheprocessofstrippingusingH2O2inH2SO4/H3PO4system.X-raydiffraction(XRD),scanningelectronmicroscopy(SEM)andspectroscopywereadoptedforthecharacterizationofthesample.
简介:Reactionof(MeC5H4)3LnwithHOCH2CH2NMe2intetrahydrofuran(THF)givesthenewcomplexes[(MeC5H4)2Ln(μ-OCH2CH2NMe2)]2(Ln=Sm,Y,Nd)withnitrogenfunctionalizedμ-alkoxideligand.ThecomplexeswerecharacterizedbyelementalanalysisandIR,and[(MeC5H4)2Sm(μ-OCH2CH2NMe2)]2wasstructurallycharacterizedbytheX-raydiffractiontobeadimerformedbytwounsymmetricoxygenbridges.ThecomplexhasatricyclicskeletonwiththeadditionaltwoSm-NbondsviaintramolecularcoordinationofOCH2CH2NMe2.ThecoordinationnumberofthecentralmetalSmisnine.Thetitlecomplexesshowgoodcatalyticactivityforring-openingpolymerizationofε-caprolactone.
简介:Silicawasused,asacatalystcarrier,toloadceroussulfateforcatalyzingthesynthesisofn-butylacetate.Themainpurposeofthisresearchwastoexplorethefeasibilityofsilicainimprovingthedecentralityandactivityofthecatalyst.Theeffectsofmolarratioofbutylalcoholtoaceticacid,theceroussulfateloadingsandthereactiontimeontheconversionofaceticacidwerestudiedbysinglefactorexperimentmethodandorthogonalexperimentmethodrespectively.Therefractiveindex(n20D)andmolecularstructureofthepreparedn-butylacetateweremeasuredbyAbbeRaefractometerandFourierTransformInfraredspectroscope,respectively.Thecomparisonsofthesilicaloadedandunloadedcatalystsforcatalyzingthesynthesisofn-butylacetateweremade.Theresultsshowedthatthesuitableconditionsforsynthesizingn-butylacetatewere:molarratioofbutylalcoholtoaceticacidof1.4∶1,uselevelofloadedceroussulfateof0.30gandreactiontimeof50min,respectively.Themaximumconversionofaceticacidforthesilicaloadedcatalystreached98.62%whichwas12.32%and16.43%higherthanthosefortheunloadedcatalystsreportedinliteratures,buttheuselevelofceroussulfatefortheformerwasmuchlessthanthoseforthelattersundersimilaroptimaltechnicalconditions.Thesilicawasprovedtobeagoodcatalystcarrierforenhancingdecentralityandactivityofthecatalystandincreasingtheconversionofaceticacid.Therepentanceofthesilicaloadedceroussulfatewasalsoinvestigatedintheexperiment.
简介:SeveralREEdatasetswerecollectedinCoreDD2andEC2005intheinnershelfofEastChinaSea,CoreY127inthenorthernOkinawaTrough,CoreNT1,C9247andC92169inthesouthYellowSeatochecktheapplicabilityoftheδEuN-ΣREEsmodelforquantita-tivelydistinguishingsedimentsfromtheYangtzeRiverandtheYellowRiver.Bycomparison,severalsedimentsincoresDD2,EC2005,Y127aregenerallyinaccordancewiththismodel.ThecoresNT1,C9247andC92169,whichhavebeeninfluencedbytheYangtzeRiverandtheYellowRivertogether,however,wereinconsistentwiththeδEuN-ΣREEsmodel.TheδEuN-ΣREEsplotanditscorrespondingregressionequation,whichcouldbeusedtodistinguishsediments"intuitivelyandquantitatively"fromtheYangtzeRiver,andtheYellowRivershouldbereconsideredorreassessed.
简介:二高度光的铕(III)和铽(III)的准备有succinimide(SI)和N-hydroxysuccinimide(NHSI)的建筑群被报导,它进一步通过元素的化学分析,热分析,英尺红外,粉末X光检查衍射,SEM和荧光光谱学被调查。通过这些分析收集的数据揭示了Eu(III)的形成,有上面的Tb(III)建筑群对ligand在金属提及ligands(M:L)1:3的臼齿的比率。光中心从photoluminescent系列调查被保留的关于通过lanthanide的协作地点的有效促进感受性的有趣的结论。当时,强壮的光排放在Eu(III)-SI和Tb(III)-NHSI建筑群的情况下被观察-SI建筑群展出了的相应Eu(III)-NHSI和Tb(III)没有相片光性质。最新获得的光lanthanide建筑群可能具有为在光电子的各种各样的应用的特别兴趣。