简介:AseriesofLa2O3/MCnylonnanocompositeswerepreparedviainsitupolymerization.Theeffectsofcontentofnano-La2O3onthemechanicalpropertiesofnanocompositeswerestudied.Dispersionofnano-La2O3inMCnylonmatrixwasobservedwithSEM.ThecrystalstructureofnanocompositeswascharacterizedbymeansofXRD.SEManalysisshowsthatLa2O3nanoparticlesareuniformlydispersedinMCnylonmatrixandlittleclusteringexistswhenthecontentofnano-La2O3islowerthan1%,however,whenthecontentofnano-La2O3ismorethan1%,itbeginstocluster.XRDanalysisindicatsthatnano-La2O3doesnotchangethecrystalstructureofMCnylon.Mechanicalpropertiestestsshowthatthetensilestrength,elongationatbreak,impactstrength,flexuralstrength,andflexuralmodulusofnanocompositesfirstincreasethendecreaseasthecontentofnano-La2O3isincreased.Whenthecontentofnano-La2O3is0.5%,thetensilestrengthandelongationatbreakofnanocompositesreachmaximum,whichare17.9%and52.1%higherrespectivelythanthoseofMCnylon.Whenthecontentofnano-La2O3is1.0%,theimpactstrength,flexuralstrengthandflexuralmodulusofnanocompositesreachmaximum,whichare36.6%,12.7%and16.3%higherrespectivelythanthoseofMCnylon.
简介:Anisotropicstructures,nanoneedles,andnanospindlesofrareearthhydroxychloride(RE(OH)2Cl)andoxychloride(REOCl)(rareearth=EuandTb)weresynthesized.Therareearthhydroxychloridenanostructureswereformedviaathermallyassistedhydrolysisoftherare-earthsesquioxidenanocrystals.Themorphologicalevolutionofthenanostructureswasstudiedusinghigh-resolutiontransmissionelec-tronmicroscopyandscanningelectronmicroscopy,whilethestructuralevolutionwasinvestigatedusingX-raydiffractiontechniques.Thethermalstabilityoftherareearthhydroxychlorideswasinvestigatedusingthermogravimetricanalysis.Therareearthoxychloridenanospin-dlesweresynthesizedviaasimpleheat-treatmentofrareearthhydroxychloridenanospindles.
简介:TheAu/CeO2catalystsweresynthesizedbyco-precipitation(CP),deposition-precipitation(DP)andmetalliccolloidsdeposition(MCD)method,andtestedforoxidationofvolatileorganiccompounds(VOCs).ItwasrevealedthattheAu/CeO2catalystpreparedbyDPmethodwasthemostefficientcatalysttowardsthetotaloxidationoftoluene.TheAu/CeO2catalystshadobviouslyhighcatalyticactivity,andthebestresultswasobtainedon3wt.%Au/CeO2catalystpreparedbyDPmethod.Thesecatalystswerechara...
简介:ZnOnanotubeswerehydrothermallysynthesizedandtheZNTs/CeO2fluorescentcompositewerepreparedbyintroducingnanoCeO2particlesintoZnOnano-tubesviaachemicalsolutionadsorptionandannealingprocess.ThesampleswerecharacterizedbyX-raydiffraction,scanningelectronmicroscopy,Fouriertransformationinfraredspectroscopyandroomtemperaturephotoluminescencemeasurement.DuetotheinteractionbetweenCe4+andthesurfaceatomsofZnO2nano-tubes,aphotoluminescenceenhancementwasobser...
简介:Withcoalgasasareducingagent,thecatalyticreductionofSO2tosulfurinthefluegasproducedinmetallurgicalprocesseswasstudiedovercatalystsofrareearth-Fe/Al2O3(REFe/Al2O3).ThecatalyticactivityoftheREFe/Al2O3catalystonthereductionofSO2tosul-furwasinvestigatedbasedonkindsandthecontentsofrareearthsanddifferentpreparationmethodofthecatalyst.Additionally,themecha-nismofthiscatalyticreductionreactionwasalsoexplored.ResultsshowedthatdifferentrareearthimposeddifferenteffectontheactivityoftheFe/Al2O3catalyst.Especially,theadditionofSmandDygreatlyimprovedthecatalyticactivityofFe/Al2O3.TheyieldofsulfuroverSmFe/Al2O3wasincreasedto86.62%at360℃,whichwas40.5%higherthanthatoverFe/Al2O3atthesametemperature;andthesulfuryieldoverDyFe/Al2O3wasincreasedto91.62%at400℃,26.4%higherthanthatoverFe/Al2O3.ThecatalyticactivityofREFe/Al2O3wassomehowdependentonthecontentofrareearth.ForSmFe/Al2O3,thecontentofSmwasoptimizedtobeabout1.0wt.%.Therareearthcatalystpreparedwithdifferentmethodsalsoshowedvariedactivity.Thesulfuryieldoverrare-earthtransitionmetalcatalystsfollowstheorder:SmandironsolutionmixingimpregnationSmfirst,thenironsolutionimpregnationironfirst,thenSmsolutionimpregnation.ThereactionmechanismofSO2reductiontosulfurwithcoalgaswasproposedtobeanintermediatemechanism.
简介:TheNd3+3.2%(atomfraction):KGd(WO4)2crystalwasgrownbyKyropoulosmethod.TheabsorptionspectrumandfluorescencespectrumofNd3+:KGWcrystalweremeasured.Theabsorptioncrosssectionsat808nm(0.6799×10-20cm2)werecalculated,andtheoutputwavelengthoffluorescenceis1064and1351nm.Thediode-pumpedlaserwasoperatedbothinthefree-runningandpassivelyQ-switchedoperatingmodes.Themaximumlaseroutput(1064nm)is326mWwith62.7%slopeefficiencywheninputenergyis900mW.ThebeamqualityfactorM2≈1.1.Thegreenlightof532nmisobtainedinfrequencydoublingoperation.ThelaserispassivelyQ-switchedbyusingCr4+:LuAGassaturableabsorber.Thepulsewidthis170nsatrepetitivefrequencyof15kHZ.
简介:VariousopticalluminescencespectroscopictechniqueswereusedtocharacterizethehighTcsuperconductorYBa2Cu3Ox.TheemissionbandsrevealthatCu3+coexistwithCu2+andCu+inthismaterial.
简介:Inaflowinjectionseparationandpreconcentrationsystemincorporatingamicrocolumn,theadsorptionbehavior(effectofpH,kineticadsorptioncapacity)ofmetalionsCu^2+,Cr^3+,Mn^2+,Ni^2+,La^3+,Eu^3+,Ga^3+,Mo(Ⅵ)andW(Ⅵ)onTiO2owderwithdifferentcrystalstructureandparticlediameterwasstudiedandcompared.Inaddition,theechanismoftheadsorptionofmetalionsonTiO2owderwasexplored.TheresultsshowthatcrystaltructureandparticlediameteroftheTi02powderwillefinitelyaffecttheadsorptioncapacityofmetalsont.
简介:介绍SO2非稳定态氧化技术的工艺流程及特点,该技术在沈阳冶炼厂制酸系统的应用及改进,并取得了明显的节能效果。
简介:TheNaGd(WO_4)_2:Eu~(3+)phosphorswerepreparedbythemicroemulsionmediatedhydrothermalmethod.ThemorphologyandsizeofthesamplescouldbedependentonthepHintheinitialsolution.Thesephosphorsobtainedhadastrongabsorptionat395nmmatchingwiththepopularemissionofnear-UVLEDchips,andcouldemitintenseredlightat616nm.Thesmallellipsoid-likeparticlesorshortrodswereprovidedwithlargeparametersofoscillatorstrength?_2andasymmetryratio.Comparedtotheellipsoid-likephosphors,therod-likephosphorstookonstrongeremission,longerlifetimeandlargerquantumefficiency.Thisworkdemonstratedthattheone-dimensionNaGd(WO_4)_2:Eu~(3+)phosphorsmightbeamorefavorabledevicethanzero-dimensiononesforphotoluminescence.