简介:AseriesofCeB6-dopedandCeO2-dopedCa1-xSiAlN3:xCe3+(denotedasCASN:Ce3+@CeB6andCASN:Ce3+@CeO2,respectively)weresynthesizedbyalloy-nitridationmethodunderhigh-puritynitrogenatmosphere.Themorphologies,crystalphases,andluminescencepropertieswereinvestigatedindetail.WithanincreaseintheconcentrationofCeB6,theunitcellvolumeofCASN:Ce3+@CeB6slightlyincreasesduetothesubstitutionbetweenions,whichleadstoachangeofmicrostructurearoundCe3+.CASN:Ce3+@CeB6efficientlyemitsyellow-orangelightwithamaximumemissionintensityataround550nmforthecontentxof0.01(beingincomparablesituation,CASN:Ce3+@CeO2isx=0.04)whenexcitedat460nm.ComparedwithCASN:Ce3+@CeO2,theredemissioncomponentofCe3+inCASN:Ce3+@CeB6ismuchstronger.Thisisascribedtoenergytransferofintra-Ce3+(withinoneCe3+ion)andinter-Ce3+(betweenCe3+andCe3+ions).Inaddition,thereplacementsofN3-(0.132nmforCN=4)andO2-(0.124nmforCN=4)byB2-(0.140nmforCN=4),whichcanleadtoamarkedexpansionofthehostlatticeandadecreaseoftheoxidationofsamples,arealsoresponsiblefortheincreaseofredemissioncomponent.Furthermore,CASN:Ce3+@CeB6phosphorhasanexcellentthermalstabilitybecauseofthepartialsubstitutionofCe-O(Ce-N)bondsbymorecovalentCe-B.Asaresult,theoutstandingluminescentpropertiesofCASN:Ce3+@CeB6phosphormakeitpracticaltouseinthesinglephosphor-coatedhigh-color-renderingpowerwhiteLED.
简介:Pt-freecounterelectrode(CE)composedofLa2MoO6(La2O3-MoO3)wassuccessfullysynthesizedbysimplepyrolysisoflanthanumacetate(C6H9O6La·xH2O)andhexaammoniumheptamolybdatetetrahydrate((NH4)6Mo7O24·4H2O).Furthermore,threeproportionscompositescatalystsofLa2MoO6@MWCNTsbasedonLa2MoO6andmultiwallcarbonnanotubes(MWCNTs)werepreparedandcharacterizedasPtfreecatalystforCEindye-sensitizedsolarcells(DSSCs).ThemorphologyandstructureofLa2MoO6@MWCNTscompositesweredeterminedbyscanningelectronmicroscopy,transmissionelectronmicroscopeandX-raydiffraction.TheelectrochemicalperformanceofLa2MoO6@MWCNTscompositecatalystsforCEswasdeterminedbyphotocurrent-voltagemeasurements,cyclicvoltammetry,electrochemicalimpedancespectroscopy,andTafelpolarization.Thepowerconversionefficienciesof4.68%,4.87%and5.06%areobtainedforLa2MoO6:MWCNTswiththemassratiosof5:1,3:1and1:1towardsthereductionofI3-toI-underthesameconditions,respectively,whicharesuperiortothoseofMWCNTs(3,94%)andLa2MoO6(1.71%)electrodes.TheexperimentalresultsrevealthatthepresenceofMWCNTsresultsinanaugmentedactivecatalyticsurfaceareaandenhancedchargetransferfromCEtotheelectrolyte.
简介:EnvironmentalfriendlyrecyclingprocessforNd-Fe-Bsinteredmagnetsludgesgeneratedinthemanufacturingprocess,whichcontainlargeamountofrareearth,includingNd,PrandDy,isbadlyneededsofar.Inpresentstudy,wehavedevelopedaneffectiveroutetoobtainrecycledsinteredmagnetsfromNd-Fe-Bsinteredmagnetsludgesbycalciumreduction-diffusion(RD)process.Comparedtoconventionalrecyclingprocess,ourresearchisfocusedonrecoveringmostoftheusefulelements,includingNd,Pr,Dy,Co,andFetogetherinsteadofjustrareearthelements.Toimprovetherecyclingefficiencyandreducepollution,theco-precipitatingparametersweresimulatedandcalculatedusingMATLABsoftware.Mostofusefulelementswererecoveredbyaco-precipitationmethod,andtheobtainedcompositepowderswerethendirectlyfabricatedasrecycledNd-Fe-Bpowdersbyacalciumreduction-diffusion(RD)method.Therecoveryratesare98%,99%,99%,93%,and99%,forNd,Pr,Dy,Co,andFe,respectively.Theamountofusefulelementscontainedintherecoveredcompositepowdersisgreaterthan99.71wt%.TheprocessofRDforsynthesizingNd2Fe14BandsubsequentlyremovingCaOwasthoroughlyinvestigated.Furthermore,therecycledNd-Fe-Bmagnetexhibitsaremanenceof1.1T,acoercivityof1053kA/m,andanenergyproductof235.6kJ/m3,respectively,indicatingthatrecycledNd-Fe-Bsinteredmagnetwassuccessfullyrecoveredfromtheseverelycontaminatedsludgesviaaneffectiverecyclingroute.
简介:采用金相组织观察、力学性能测试和统计分析等手段,研究了成品退火工艺对Φ5mmTP2内螺纹铜管微观组织和力学性能影响规律。结果表明:Φ5mmTP2内螺纹铜管退火温度为470~480℃时,铜管组织细小、均匀,同时能获得较高塑性和较高强度;490~500℃时,铜管晶粒尺寸、力学性能波动大;510~520℃时,铜管组织易粗大。Φ5mmTP2内螺纹铜管在470℃退火时,晶粒尺寸随退火时间的规律变化为d=0.0008t3-0.062t^2+1.7t-1.3,保温21min时,铜管再结晶基本完成,保温时间为28~31min时,铜管组织状态和综合力学性能最佳。