简介:A60%Fe/Al2O3catalystwaspreparedbytheco-precipitationmethod.ItwasreducedbyH2toproducemetallicFe,whichwasthensulfidedbyCS2toFe0.96SandFe3S4orphosphidedbytriphenylphosphine(PPh3)inliquidphasestoFe2PandFeP.Itwasfoundthattheironsulfides(Fe0.96SandFe3S4)exhibitedthelowactivityforthehydrodesulfurization(HDS)reactions.TheHDSactivitywasalsolowontheFe(metal)/Al2O3andFe2P/Al2O3catalystssincetheywereconvertedintoFe0.96SandFe3S4duringtheHDSreactions.Incontrast,theFeP/Al2O3wasfoundtobestableandactivefortheHDSreactions.Inparticular,FeP/Al2O3possessedsignificantlysmallerFePparticlesthanFeP/C,leadingtothesignificanthigherHDSactivityofFeP/Al2O3thanFeP/C.
简介:Liquid-phase-exfoliationtechnologywasutilizedtopreparelayeredMoS2,WS2,andMoSe2nanosheetsincyclohexylpyrrolidone.Thenonlinearopticalresponseofthesenanosheetsindispersionswasinvestigatedbyobservingspatialself-phasemodulation(SSPM)usinga488nmcontinuouswavelaserbeam.ThediffractionringpatternsofSSPMwerefoundtobedistortedalongtheverticaldirectionrightafterthelasertraversingthenanosheetdispersions.Thenonlinearrefractiveindexofthethreetransitionmetaldichalcogenidesdispersionsn2wasmeasuredtobe10-7cm2W-1,andthethird-ordernonlinearsusceptibilityχ(3)10-9esu.TherelativechangeofeffectivenonlinearrefractiveindexΔn2e∕n(2e)oftheMoS2,WS2,andMoSe2dispersionscanbemodulated0.012–0.240,0.029–0.154,and0.091–0.304,respectively,bychangingtheincidentintensities.Ourexperimentalresultsimplynovelpotentialapplicationoftwo-dimensionaltransitionmetaldichalcogenidesinnonlinearphasemodulationdevices.
简介:In[1],ShenGuangyuconstructedseveralclassesofnewsimpleLiealgebrasofcharacteristic2,whicharecalledthevariationsofG2.Inthispaper,theauthorsinvestigatetheirderivationalgebras.ItisshownthatG2anditsvariationsallpossessuniquenondegenerateassociativeforms.TheauthorsalsofindsomenonsingularderivationsofViGfori=3,4,5,6,andtherebyconstructsomeleft-symmetricstructuresonViGfori=3,4,5,6.Someerrorsaboutthevariationsofsi(3,F)in[1]arecorrected.
简介:Theobjectinthispaperistoconsidertheproblemofexistence,uniqueness,explicilrepresentationof(0,2)-interpolationonthezerosof(1-x2)Pn-1(x)/xwhennisodd,wherePn-1denotesLegendrepolynomialofdegreen-1,andtheproblemofconvergenceofinterpolatorypolynomials.
简介:ThispaperstudiestheelectronicstructureandnativedefectsintransparentconductingoxidesCuScO2andCuYO2usingthefirst-principlecalculations.Sometypicalnativecopper-relatedandoxygen-relateddefects,suchasvacancy,interstitials,andantisitesintheirrelevantchargestateareconsidered.Theresultsofcalculationshowthat,CuMO2(M=Sc,Y)isimpossibletoshown-typeconductivityability.ItfindsthatcoppervacancyandoxygeninterstitialhaverelativelylowformationenergyandtheyaretherelevantdefectsinCuScO2andCuYO2.Coppervacancyisthemostefficientacceptor,andunderO-richconditionoxygenantisitealsobecomesimportantacceptorandplaysanimportantroleinp-typeconductivity.
简介:ConsideringthatKBe2BO3F2(KBBF)isanoutstandingdeepultravioletcrystalwhichcangeneratetheshortestwavelengthsinsecondharmonicgenerationandsum-frequencygeneration,wereportthedeterminationofthenonlinearopticalcoefficientsoftheKBBFcrystal.Thed11coefficientwasdeterminedtobe0.49pm/VbytheMakerfringesmethodatthewavelength1064nm,whichisinagreementwellwiththetheoreticalvalue.
简介:Theeffectofbismuth(Bi)forbothVO2+/VO2+andV3+/V2+redoxcouplesinvanadiumflowbatteries(VFBs)hasbeeninvestigatedbydirectlyintroducingBionthesurfaceofcarbonfelt(CF).TheresultsshowthatBihasnocatalyticeffectforVO2+/VO2+redoxcouple.Duringthefirstchargeprocess,BiisoxidizedtoBi3+(neverreturnbacktoBimetalinthesubsequentcycles)duetothelowstandardredoxpotentialof0.308V(vs.SHE)forBi3+/BiredoxcouplecomparedwithVO2+/VO2+redoxcoupleandBi3+exhibitno(orneglectable)electro-catalyticactivity.Additionally,therelationshipbetweenBiloadingandelectrochemicalactivityforV3+/V2+redoxcouplewasstudiedindetail.2wt%Bi-modifiedcarbonfelt(2%-BiCF)exhibitsthehighestelectrochemicalactivity.Usingitasnegativeelectrode,ahighenergyefficiency(EE)of79.0%canbeachievedatahighcurrentdensityof160mA/cm2,whichis5.5%higherthanthepristineone.Moreover,theelectrolyteutilizationratioisalsoincreasedbymorethan30%.Eventhecelloperatedat140mA/cm2forover300cycles,theEEcanreach80.9%withoutobviousfluctuationandattenuation,suggestingexcellentcatalyticactivityandelectrochemicalstabilityinVFBs.
简介:运用水热法合成了1个新的配合物[Ni(Phtpy)2](CH3COO)2(化合物1),(Phtpy=4′-苯基-2,2′∶6′,2″-三联吡啶),并通过X-射线单晶衍射方法确定了该化合物的晶体结构.结构分析表明化合物1属于三斜晶系,P-1空间群,晶胞参数a=0.90560(8)nm,b=1.10307(9)nm,c=2.02014(15)nm,α=94.3830(10)°,β=100.9830(10)°,γ=106.3120(10)°,V=1.8831(3)nm3,Z=2,R1=0.0872,wR2=0.1831.配合物中存在3种氢键和多种π-π相互作用,使其成为一个3D配合物.
简介:Inthiswork,theinfluenceofCO2onthestructuralvariationandcatalyticperformanceofNa2WO4/Mn/SiO2foroxidativecouplingofmethanetoethylenewasinvestigated.ThecatalystwaspreparedbyimpregnationmethodandcharacterizedbyXRD,RamanandXPStechniques.AppropriateamountofCO2inthereactantgasesenhancedtheformationofsurfacetetrahedralNa2WO4speciesandpromotedthemigrationofOinMOx,Na,Wfromthecatalystbulktosurface,whichwerefavorableforoxidativecouplingofmethane.WhenthemolarratioofCH4/O2/CO2was3/1/2,enrichedsurfacetetrahedralNa2WO4speciesandhighsurfaceconcentrationofOinMOx,Na,Wweredetected,andthenhighCH4conversionof33.1%andhighC2H4selectivityof56.2%wereobtained.WithfurtherincreaseofCO2inthereagentgases,thecontentofactivesurfacetetrahedralNa2WO4speciesandsurfaceconcentrationofOinMOx,Na,Wdecreased,whilethatofinactivespecies(MnWO4andMn2O3)increaseddramatically,leadingtolowCH4conversionandlowC2H4selectivity.ItcouldbespeculatedthatNa2WO4crystalwastransformedintoMnWO4crystalwithexcessiveCO2addedunderthereactionconditions.PretreatmentofNa2WO4/Mn/SiO2catalystbymoderateamountofCO2beforeOCMalsopromotedtheformationofNa2WO4species.
简介:Thetitlecomplex,[La(baec)1/2(H2btec)1/2(H2O)]n(H4btec=1,2,4,5-benzenetetracarboxylicacid)(1)wassynthesizedbythehydrothermalreactionof1,2,4,5-benzenetetracarboxylicdianhydridewithLa(NO3)3·6H2OinH2O,andcrystallizesinthetriclinicsystem,spacegroupP-1withα=0.64403(3)nm,b=0.94500(4)nm,c=0.96380(5)nm,α=88.535(2)°,β=100.314(2)°,γ=76.6470(10)°,V=1.69968(10)nm^3,Z=2,andfinalR=0.0274,Rw=0.0735.In1,eachLa(Ⅲ)ioniscoordinatedbyeightoxygenatomsfromsixcarboxylategroupsandonecoordinatedwatermolecule.TwodifferentcoordinstionmodesofH4btecwerePresentinthestructure,oneofwhichcontainstwoprotonatedcarboxylategrougpstobalancethecharge.