简介:研究了YBaCu3O6~7超导催化剂上CO2的加氢制醇反应。考察了温度、压力和空速等条件对催化剂反应性能的影响。反应的主要产物是甲醇、CO和少量甲醚。利用XPS、XRD和AFM等技术对催化剂的结构、铜的存在状态和反应活性位进行表征发现,在反应过程中,YBa2Cu3O6~7由orthombic相转变为tetragonal相。反应活性位可能是Cu(I)物种。反应后催化剂颗粒的分散程度明显提高
简介:Amolybdenumdisulfide(MoS2)saturableabsorberwasfabricatedbythermallydecomposingtheammoniumthiomolybdate.ByusingtheMoS2absorber,acompactdiode-pumpedpassivelyQ-switchedTm:GdVO4laserhasbeendemonstrated.AstableQ-switchedlaserwithrepetitionratesfrom25.58to48.09kHzwasachieved.Maximumaverageoutputpowerwas100mWwiththeshortestpulsedurationof0.8μs.Maximumpulseenergyis2.08μJatcenterof1902nm.
简介:Theroleofpulseparametersonnanoparticlepropertyisinvestigatedself-consistentlybasedonacoupleoffluidmodelandaerosoldynamicsmodelinacapacitivelycoupledparallel-plateacetylene(C2H2)discharge.Inthismodel,themasscontinuityequation,momentumbalanceequation,andenergybalanceequationforneutralgasaretakenintoaccount.Thus,thethermophoreticforceariseswhenagastemperaturegradientexists.Thetypicalresultsofthismodelarepositiveandnegativeiondensities,electronimpactcollisionsrates,nanoparticledensity,andchargedistributions.Thesimulationisperformedfordutyratio0.4/0.7/1.0,aswellaspulsemodulationfrequencyfrom40kHzto2.7MHzforpureC2H2dischargesatapressureof500mTorr.Wefindthatthepulseparameters,especiallythedutyratio,haveagreataffectonthedissociativeattachmentcoefficientandthenegativedensity.Moreimportantly,bydecreasingthedutyratio,nanoparticlesstarttodiffusetothewall.Undertheactionofgasflow,nanoparticledensitypeakiscreatedinfrontofthepulseelectrode,wherethegastemperatureissmaller.
简介:TheternaryCu(Ⅱ)complexwith2,2′-bipyridyl(bipy)andL-methioninte(L-Met)hasbeensynthesizedandcharacterizedbyelementalanalysis,molarconductivity,UV-Visspectra,IRspectraandpH-potentiometrictitrationmethods.Thestructureofthecomplex[Cu(L-Met)(bipy)(H2O)]ClO4·3/8H2OwascharacterizedbytheX-raydiffractionanalysis.Itcrystallizesinthetriclinicsystem,spacegroupP1withfourmoleculesinaunitcellofdimensions,a=0.7656(2)nm,b=1.3142(3)nm,c=2.0596(4)nm,α=97.70(3)°,β=97.96(3)°,γ=94.33(3)°,V=2.0244(8)nm^3,R1=0.0441andwR2=0.0678,Thecrystalcontainsfourcrystallographicallyindependent[Cu(L-Met)(bipy)(H2O)]^+complexes(Cu1-Cu4),havingadistortedsquare-pyramidalgeometrywiththesamecoordinatedatomsaroundeachcoppercenter.Thebaseplaneisoccupiedbytwonitrogenatomsofonebipy,theaminonitrogenatomandonecarboxylateoxygenatomfromeachindependentL-Metmoiety,andonewateroxygenatanaxialposition.CulandCu3areessentiallyenantiomersofCu2andCu4.Thefourmoleculesarepackedwitheachotherbyintermolecularhydrogen-bondingandaromatic-ringstackinginteractions.
简介:Variousenolsof2-acylmethyl-4,4-dimethyl-2-oxazolineswerepreparedinmoderateyieldsviaultrasonicallycatalyzedreactionsof2,4,4-trimethyl-2-oxazolinewitharenecarboxylicestersinthepresenceofUDP-t-BuCl-i-Pr2NHsystem.
简介:Thepaperdealswiththeinfluenceofanodematerialontheefficiencyofdegradationfororganicpollutantsinwatersystem.Theelectrochemicalperformanceoffluorineiondopedleaddioxide(F--PbO2)electrodeforthedegradationofanilinewascomparedwiththatofundopedleaddioxide(PbO2)electrodebyultraviolet-visible(UV-Vis)spectroscopy,linearvoltammetryandotheranalyticalmethods,suchasthemeasurementbychemicaloxygendemandanalyzer,highperformanceliquidchromatographyandscanningelectronmicrography.ItwasshownthatbothPbO2electrodeandF--PbO2electrodecouldmakeanilinebemineralizedcompletelyandhavethesamedegradationcourse,butF--PbO2electrodehasmuchhigherelectrocatalyticactivitythanundopedPbO2electrodefortheelectrochemicaldegradationofaniline.TheexperimentalresultsconfirmthatF--PbO2electrodehasmuchhigherpotentialforoxygenevolutionthanundopedPbO2electrode.
简介:Thenotionofmultibandsuperconductivitywithdominanttwo-gapfeatureshasbeenrecentlyappliedtotheunconventionalsuperconductorCeCu2Si2forchallengingthepreviouslyacceptedconceptofnodald-wavepairing.Intheproposedstudy,therealisticmultibandFermisurfacetopologyofCeCu2Si2wasobtainedthroughfirst-principlescalculations,andanalysiswasconductedwithaneffectivetwo-bandhybridizationmodelincludingdetailedbandstructure.WithintheT-matrixapproximation,theobtainedcalculationresultsshowthatdifferentpairingcandidates,includingfullygappeds-wave,loop-nodals-wave,andd-wavepairings,couldyieldqualitativelydistinctfeaturescharacterizedbyimpurity-inducedboundstates.Thesefeaturescanbeverifiedthroughhigh-resolutionscanningtunnelingmicroscopyorspectroscopyandprovidecorroborativejustificationthatwouldbebeneficialfortheongoingresearchregardingthesuperconductinggapsymmetryofCeCu2Si2atambientpressure.
简介:Lifetimemeasurementsoflow-lyingexcitedstatesin^87Zrhavebeenperformedviaβ-γcoincidences.The127MeV^32SbeamwasdeliveredfromtheSector-FocusingCyclotron(SFC)oftheHeavyIonResearchFacilityinLanzhou(HIRFL).Theparentnuclei^87Nbwereproducedbythereaction58Ni(32S,2p1n),atabeamenergy127MeVthrougha8umAldegrader.A200ug/cm^2layerof58Nievaporatedontoa200ug/cm^2thickcarbonfoilwasemployedasthetarget.Afterevaporationresidueswereseparatedfromtheprojectilebeamsbythegas-filledrecoilseparatorSHANS[1],thenucleiofinterest87Zrcanbeobtainedwithahigherpurityandthenwereimplantedintoa300umsilicondetector.
简介:Theneworganic-inorganiccompound,[C_6H_7N_2O_2]_3TeCl_5·2Clwassynthesizedanditsstructurewasdeterminedatroomtemperatureinthetriclinicsystem(P~-1)withthefollowingparameters:a=10.5330(11)?,b=10.6663(11)?,c=15.9751(16)?,α=82.090(2)°,β=71.193(2)°,γ=68.284(2)°andZ=2.ThefinalcycleofrefinementledtoR=0.057andRw=0.149.ThecrystalstructurewasstabilizedbyanextensivenetworkofN--H···Clandnon-classicalC--H···Clhydrogenbondsbetweenthecationandtheanionicgroup.Severalthermalanalysistechniquessuchasthermogravimetricanalysis,differentialscanningcalorimetricanalysisandevolvedgasanalysiswereused.Weusedisoconversionalkineticsmethodstodeterminethekineticsparameters.Weobservethatthedecompositionof[C_6H_7N_2O_2]_3TeCl_5·2Clentailstheformationhydrochloricacidofnitroanilineasvolatiles.Theinfraredspectrawererecordedinthe4000–400cm~(-1)frequencyregion.TheRamanspectrawererecordedintheexternalregionoftheanionicsublatticevibration50–1500cm~(-1).TheopticalbandgapwascalculatedfromtheUV-VisabsorbancespectrausingclassicalTaucrelationwhichwasfoundtobe3.12and3.67eV.
简介:Anovelsupportedliquidphasefilmcatalyst:SupportedPdCl2-(n-C4H9)4N+Cl-moltensaltswasfoundtobeaneffectivecatalystwithgoodstabilityforselectivehydrodechlorinationofCCl2F2(CFC-12)toitsalternativesCH2F2andCHClF2.AdditionofCoCl2,GaCl3andCuCl2toPdCl2-(n-C4H9)4N+Cl-modifiesthecatalyticperformanceofsupportedmoltensalts.
简介:HL-2AisanewdivertortokamakunderconstructionatSouthwesternInstituteofPhysics(SWIP),Chengdu,China,basedontheexperiencefromHL-1andHL-1M.HListheshorttermofaChinesewordthatmeans"ToroidalCurrentDevice".ThemainobjectivesofHL-2Aaretoproducemoreadaptabledivertorconfigurationstostudyenergyexhaustandimpuritycontrol(thefirstdivertortokamakplasmainChina),andtostudyenhancedplasmaconfinementbyprofilecontrolandmoderateplasmashaping.