学科分类
/ 2
23 个结果
  • 简介:InthispaperweusedMOF-5andCu3(BTC)2toseparateCO2/CH4andCH4/N2mixturesunderdynamicconditions.Bothmaterialsweresynthesizedandpelletized,thusallowingforameaningfulcharacterizationinviewofprocessscale-up.ThematerialswerecharacterizedbyX-raydiffraction(XRD)andscanningelectronmicroscopy(SEM).Byperformingbreakthroughexperiments,wefoundthatCu3(BTC)2separatedCO2/CH4slightlybetterthanMOF-5.BecausethecrystalstructureofCu3(BTC)2includesunsaturatedaccessiblemetalsitesformedviadehydration,itpredominantlyinteractedwithCO2moleculesandmoreeasilycapturedthem.Conversely,MOF-5withasuitableporesizeseparatedCH4/N2moreefficientlyinourbreakthroughtest.

  • 标签: BTC CO2 混合物 分离 扫描电子显微镜 X射线衍射
  • 简介:Inthisreport,wepresentasimulatedresultontheion-massindependenceoftheguidedtransmission,whichisinagreementwiththepreviousexperimentalresults[1].Inordertosearchtheinuenceoftheionmassonguidedtransmission,variousspeciesofionsusedasprojectilesinsimulations.Fig.1showsthetransmissionfractionsforNe7+,Ar7+,Kr7+,andXe7+ions.Thesedatawereacquiredfortiltangleof2inenergyof7keV.Itisseenthatallofionfractionsgraduallyrisesafteratimedelay,andnallyreachstable.

  • 标签: INDEPENDENCE GUIDING Insulating
  • 简介:Morelocalizedenergydepositionisabletobeproducedinantiproton-nucleuscollisionsincomparisonwithheavy-ioncollisionsduetoannihilationreactions.Searchingforthecoldquark-gluonplasma(QGP)withantiprotonbeamshasbeenconsideredasahottopicbothinexperimentsandinthereticalcalculationsoverthepastseveraldecades.Strangenessproductionandhypernucleusformationinantiproton-inducednuclearreactionsareimportanceinexploringthehyperon(antihyperon)-nucleon(HN)potentialandtheantinucleon-nucleoninteraction,whichhavebeenhottopicsintheforthcomingexperimentsatPANDAinGermany.

  • 标签: STRANGENESS PRODUCTION ANTIPROTON
  • 简介:MoleculardynamicssimulationsareperformedtostudythegrowthmechanismofCH4-CO2mixedhydrateinxCO2=75%,xCO2=50%,andxCO2=25%systemsatT=250K,255Kand260K,respectively.OursimulationresultsshowthatthegrowthrateofCH4-CO2mixedhydrateincreasesastheCO2concentrationintheinitialsolutionphaseincreasesandthetemperaturedecreases.Viahydrateformation,thecompositionofCO2inhydratephaseishigherthanthatininitialsolutionphaseandtheencagingcapacityofCO2inhydratesincreaseswiththedecreaseintemperature.ByanalysisofthecageoccupancyratioofCH4moleculesandCO2moleculesinlargecagestosmallcages,wefindthatCO2moleculesarepreferablyencagedintothelargecagesofthehydratecrystalascomparedwithCH4molecules.Interestingly,CH4moleculesandCO2moleculesfrequentlyreplacewitheachotherinsomeparticularcagesitesadjacenttohydrate/solutioninterfaceduringthecrystalgrowthprocess.Thesetwospeciesofguestmoleculeseventuallyacttostabilizethenewlyformedhydrates,withCO2moleculesoccupyinglargecagesandCH4moleculesoccupyingsmallcagesinhydrate.

  • 标签: 分子动力学模拟 水合物 CO2 CH4 混合 二氧化碳浓度
  • 简介:Highenergyprotonbeamhasthelongpenetrationlengthinsolidmatteranditcouldproducetheradiographsandindicatethetomographyandmaterialpropertiesinsideofthespecimen.Consideringtheexpensivecoststoconstructahighenergyprotonaccelerator,theothercandidateofhighenergyelectronbeambecomesmoreacceptable[1??3].Duetothehighspatialandtemperalresolutionofhighenergyelectronbeam.Itisapowertooltodiagnosetheinnerstructurechangeduringthehighenergydensitymatterproductionandtheinertialconfinementfusionprocess.Inordertostudythedensityresolutionofthehighenergyelectronbeamradiography,astep-targetwasdesignedandproduced.ThestructureandthetargetpicturesareshowninFig.1andtheSitargetswithdifferentslot-widthwereproducedbyusingthemicroetchtechnics.

  • 标签: DESIGN ENERGY ELECTRON
  • 简介:TemperatureisoneofthekeythermodynamicparametersofHEDmatter.Asapopulartechnique,thepyrometerofnarrow-bandlterstogetherwithphotodiodes(namelymulti-channelpyrometer)hasbeenapplied.However,thepyrometercanonlymeasureone-positiontemperatureinsingleshot[1;2].Actually,itisveryimportanttoknowtemperatureevolutionofmultiplepositionsinsingleshot,especiallyforthetargetinducedbyheavyionbeam,wherealargevolumeofHEDmattercanbegenerated.Consequently,afastnew-typepyrometerhasbeendesigned.

  • 标签: MEASUREMENT SPATIAL TEMPORAL
  • 简介:Grapheneistwodimensionalmaterialswhichismadeofhoneycombedcarbonatoms.Itattractsextensiveinterestsforitswonderfulcharacteristicsthatmakethegrapheneapotentialcandidateinfieldsofmicroelectronicsproduction,moleculedetection,desalinationandDNAsequencing.Highlychargedion(HCI)hashugepotentialenergyforpeelingoffelectrons.Wheninteractingwithsolidsurface,theHCIdistortedthesolidlatticeviapotentialdepositionandthenthenanostructureswereformedonthesolidsurface.TheHCIwasexpectedasatoolforsurfacemodification.Inthiswork,HOPGandgraphemewereirradiatedwithXeq+andArq+ions.ThetypicalRamanspectraofgrapheneandHOPGirradiatedwithhighlychargedionswereshowninFig.1.TheDpeakappearedat1335cm??1onthespectraofgrapheneirradiatedwithhighlychargedions.TheintensityofDpeakincreasedwithfluence.TheratioofintensityofDpeaktothatofGpeakvariedwithfluenceinFig.2.Theratioroselinearlywiththesquarerootoffluencewhenfluencewaslow.Theratiosaturatedwhentheirradiationfluencewashigh.Thecriticalfluencedependedonthechargestateofion.Thehigherchargestateitwas,thelowercriticalfluenceitwouldbe.

  • 标签: CHARGE SPECTRA GRAPHENE
  • 简介:Duetolowactivationcharacteristics,desirablehigh-temperaturestrength,goodresistancetoradiationdamageandusablefabricationproperties,vanadium(V)alloysareattractivecandidatestructuralmaterialsforfusionreactors[1].Irradiationinducedhardening/embrittlementatlowtemperatureisamajorproblemforthematerialsapplicationinfusionreactor[2].Inthisstudy,H/Heionswithvariousenergieswereusedtoirradiateapurevanadium(V)andaValloy(V-4Ti)toobtainadamageplateaufromsamplesurfacetothedepthof1.5m,asshowninFig.1[3].Thedetailsofirradiationparameters(energies,fluences)forHandHeionsareshowninTable1.NanoindentationwasperformedtoinvestigatethehardeningbehaviorofV-4TialloyandpureVunderirradiation.

  • 标签: NANOINDENTATION ALLOY IRRADIATED
  • 简介:Highlychargedions(HCIs)carryingamountofpotentialenergywillproducesomenewphysicalphenomenabecausethepotentialenergywillbedepositedintoaverysmallvolumewithinaveryshorttime.WewouldapplythecalorimetricmethodtostudytheenergydepositionofHCIs[1;2].Hereinweintroducethenewsetupforcalorimetricmeasurementforthepotentialenergydepositionofhighlychargedionsat320kVHighlyChargedIonsPhysicsExperimentalPlatform.Thesetupwasconstructedby3parts:theDewar,theelectricaltemperaturecontrollerandthemainpart.ThediamondtargetwasconnectedtotheLN2cooledheatsinkby4copperwiresandaPlatinumtemperaturesensorwasgluedtotherearsideofthetarget.AsshowninFig.1.

  • 标签: Calorimetric Measurement DEPOSITED
  • 简介:Two-dimensional(2-D)BiVO4nanosheets-graphene(GR)compositeswithdifferentweightadditionratiosofGRhavebeenpreparedviaafacilewetchemistryprocess.X-raydiffraction(XRD),Ramanspectra,X-rayphotoelectronspectra(XPS),UV-visdiffusereflectancespectra(DRS),field-emissionscanningelectronmicroscopy(FE-SEM),transmissionelectronmicroscopy(TEM),nitrogenadsorption-desorption,transientphotocurrentresponseandphotoluminescence(PL)spectrawereemployedtodeterminethepropertiesofthesamples.ItisfoundthatBiVO4nanosheetscouldpavewellonthesurfaceofgraphenesheets.BiVO4nanosheets-GRcompositeswithaproperadditionamountofGRexhibitedhigherphotocatalyticactivitythanbareBiVO4nanosheetstowardliquid-phasedegradationofrhodamineB(RhB)andmethylorange(MO)undervisiblelightirradiation.TheenhancementofphotocatalyticactivitiesofBiVO4nanosheets-GRcompositescanbeattributedtotheeffectiveseparationofphotoexcitedelectron-holepairs.Thisworknotonlyprovidesasimplestrategyforfabricatingspecific2-Dsemiconductor-2-DGRcomposites,butalsoopensanewwindowofsuch2-Dsemiconductor-2-DGRcompositesasvisiblelightphotocatalyststowardanimprovedvisiblelightphotoactivityinpurifyingpollutedwaterresources.

  • 标签: 可见光照射 光催化活性 复合材料 纳米 石墨 X-射线光电子能谱
  • 简介:Thegreenlong-after-glowluminescencefromTb3+-dopedSr2SiO4phosphors,whicharesynthesizedbythehightemperaturesolidstatereactioninareductiveatmosphere,isobservedinthispaper.Theresultsshowthatunderultravioletexcitation,theobtainedphosphorsproduceanintensegreen-lighting-emissionfromtheTb3+,andthegreen-lightinglongafter-glowluminescencerelatedtoTb3+canlasthalfanhouraftertheirradiationsourcehasbeenremoved.Moreover,theeffectsofco-dopingLi+,Dy3+,Er3+,Gd3+,andYb3+withTb3+onthedecaypropertiesandthermoluminescencepropertiesareinvestigatedtoconfirmthelong-after-glowmechanism.

  • 标签: 长余辉发光 铽掺杂 固相反应合成 绿色照明 还原性气氛 衰变性质
  • 简介:TheinteractionprocessofionsandplasmasisanimportanttopicinIon-Beam-DrivenHighEnergyDensityPhysicsandInertialConfinementFusionresearch.Duetothestrongnon-lineareffectsandthespecialimportanceinICFresearch,moreandmoreemphasishasbeengiventotheinvestigationsforionbeaminlowenergyrangeand/orforplasmawithhighintensity[1;2].Here,weaddressthenewlymeasuredresultsoftheenergylossbyslowionspenetratingthefullyionizedhydrogenplasmatarget.

  • 标签: ENERGY MEASUREMENT IonsPenetrating
  • 简介:CuFe2O4network,preparedviatheelectrostaticspraydepositiontechnique,withhighreversiblecapacityandlongcyclelifetimeforlithiumionbatteryanodematerialhasbeenreported.Thereversiblecapacitycanbefurtherenhancedbycoatinghighelectronicconductivepolypyrrole(PPy).Atthecurrentdensityof100mA·g-1.Li/CuFe2O4electrodedeliversareversiblecapacityof842.9mAh·g-1whilethereversiblecapacityofLi/PPy-coatedCuFe2O4electrodeincreasesupto1106.7mAh-g’.Ahighcapacityof640.7mAhg"1fortheLi/PPy-coatedCuFe2O4electrodeismaintainedincontrastof398.9mAh·g-1forCuFe2O4electrodeafter60cycles,whichdemonstratesgoodelectrochemicalperformanceofthecompositeduetotheincreaseofelectronicconductivity.Theelectrochemicalimpedancespectroscopy(EIS)furtherrevealsthattheLi/PPy-coatedCuFe2O4electrodehasalowerchargetransferresistancethantheLi/CuFe2C>4electrode.

  • 标签: 锂离子电池 电化学性能 聚吡咯 被覆 制备 可逆容量
  • 简介:Rhodium-andironphosphate-basedcatalystsarebyfarthemostpromisingcatalystsforoxy-brominationofmethane(OBM)reaction.However,mostliteraturereportedeitherRh-orFePO4-basedcatalysts,andtheresultswererarelystudiedinauniformenvironmentalcondition.Inthisreport,comparativestudywasconductedonsilica-andsiliconcarbide-supportedrhodiumandironphosphatecatalystswiththemainfocusesonstabilityperformanceandcokedeposition.ThecatalyticresultsdemonstratedthatthestabilityofbothRh-andFePO4-basedcatalystswasgreatlyinfluencedbythesupportsused,andsiliconcarbide-supportedcatalystsshowedmuchbetteranti-cokingabilityascomparedwithsilica-supportedones.Temperature-programmedoxidationovertheusedcatalystsfurtherindicatedthatthecokeformationmechanismswerecompletelydifferentbetweensilica-supportedrhodiumandironphosphatecatalysts.WhilecokesmightbecausedbycondensationofCH2Br2oversupportedironphosphate,methanedecompositionmightbethereasonforcokeformationoversilica-supportedrhodiumcatalyst.ThesefindingsmightpavethewayfordesigninghighlyefficientandstablecatalystsoftheOBMreaction.

  • 标签: METHANE RH FePO4 oxy-bromination STABILITY coke
  • 简介:Siliconcarbidefiber/siliconcarbidematrix(SiCf/SiC)compositesareofinterestasafuelcladdingandstructuralmaterialindesignsofadvancednuclearreactorduetotheirsuperiorthermo-mechanicalpropertiesandstabilitiesandlowcross-sectionforneutroncaptureunderthesevereserviceenvironmentincludinghightemperatureandhighenergyneutronbombardment.SiCf/SiCcompositionsconsistsofSiCfiberandSiCmatrixwhichexistinwellover100polymorphsdependentonthevariedstackingofSi-Cclose-packedatomicplanes,2H-SiC,4H-SiC,6H-SiC,3C-SiC,15R-SiC,etc.EnergeticHeatomscanbecreatedandaccumulatedvianuclearreactions.HeatomsagglomerateandcoarsenintoHebubblesandcandeterioratestructuralpropertiesbyinducingcrackandcreep.Inthisexperiment,thedamageofn-type4H-SiCwafers(researchstandard,suppliedbytheCreeResearchInc.)withathicknessof0.38mmimplantedwith100keVHe+toafluenceof31016He+/cm2andpost-implantation-annealedbehavioratdifferenttemperaturewerestudiedusingRamanscatteringspectroscopy.

  • 标签: INVESTIGATION Spectra RAMAN
  • 简介:采用燃烧法合成了La1.6(MoO_4)_3:Eu_0.4^3+纳米晶末,研究了其声子一掺杂-晶格相互作用和发光性质。x射线粉末衍射(XRD)分析表明,在500~900℃退火后,La1.6(MoO_4)_3:Eu_0.4^3+样品为单一晶相。对样品进行了光致发光(PL)测量,激发Mo^6+-O^2-电荷迁移带,观察到Eu^3+的系列发光,表明Mo^6+-O^2-带和Eu^3+间存在能量传递,中心波长分别在λ1=469nm和λ2=426nm处的两个one-phonon边带,相应的声子能量分别为767和1202cm^-1,分别对应于Mo=0和Mo-0-Mo伸缩振动。同时,计算了两个局域模电子一声子耦合强度的黄昆因子分别为S1=0.055和S2=0.037,为揭示其三价离子高传导特性及其负热膨胀物理特性提供了实验基础。

  • 标签: 发光特性 燃烧法 La1.6(MoO_4)_3:Eu_0.4^3+纳米晶 局域模 one-phonon边带
  • 简介:H+-restackednanosheetsandnanoscrollspeeledfromK4Nb6O17displaydifferentstructuresandsurfacecharacters.Thetworestackedsampleswithincreasedsurfaceareashaveanamazingvisible-lightresponseforthephotodegradationofdyes,whichissuperiortocommercialTiO2(P25)andNb2O5.Bycomparison,H+/nanosheetshavearelativelyfasterphotodegradationrateoriginatedfromlargeandsmoothbasalplane.Theworkrevealsthatdyeadsorbedontheunfoldednanosheetscaneffectivelyharvestsunlight.Duetofacilepreparation,low-costandhighphotocatalyticefficiency,H+/nanosheetsandH+/nanoscrollsmightbeusedforthevisiblelight-drivendegradationoforganicdyesasasubstituteforTiO2inindustry.

  • 标签: 可见光降解 染料吸附 纳米 堆栈 压入 可见光响应
  • 简介:Wereportanovelapproachtoobtainingaclassicalblue-greenexcitableCaS:Eu2+phosphorwithdesiredredemissionbymicrowave(MW)firingprocedureintheabsenceofaddingelementalsulphur.ThedisturbingeffectofMWelectromagneticfieldondecompositionofCaSO4intoCaSactivatedbyeuropiumisdistinctlyobservedtogivepurehostphasewithoutaddinganyelementalsulphurandcarbon.ThehostphaseevolutionisobservedtobehighlydependentonthevariationofappliedMWpowerfromX-raydiffraction(XRD)patternsandthecorrespondingphotoluminescence(PL),andamaximumPLintensityat1100WofMWpowerisacquiredfortheobtainedpurerhostphase.Thenon-thermalandnon-equilibriumeffectsbyMWarerevealedtocorrelatewiththeinteractionbetweenpolarstructureofthehostandappliedelectromagneticfield.Theresultsdemonstrateanoptionalproceduretopreparethisred-emittingphosphorinaneffective,environment-friendlyandscalableapproachforphosphorproductionintheapplicationofbio-illuminationforplantcultivationandartificialphotosynthesis.

  • 标签: 光致发光性质 红光发射 微波促进 荧光粉 硫酸钙 CAS