学科分类
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299 个结果
  • 简介:Pd-containingionicliquid(IL)1-hexyl-3-methylimidazoliumtetrafluoroborate(C6MIMBF4)immobilizedon7-Al2O3(Pd-IL/γ-Al2O3)waspreparedandcharacterizedbyFouriertransforminfraredspectroscopy(FTIR),scanningelectronmicroscopy(SEM)andBrunauer-Emmett-Teller(BET)analysis.TheinfluencesofC6MIMBF4loadingandPdonmethaneconversiontoC2hydrocarbonsundercoldplasmawereinvestigated.FTIRandSEManalysesindicatedthatC6MIMBF4hadbeensuccessfullyimmobilizedon7-Al2O3andtheC6MIMBF4showedexcellentstabilityundercoldplasma.TheresultsofBETandmethaneconversionshowedthatwiththeincreaseinimmobilizationamountofC6MIMBF4ontoγ-Al2O3,thespecificsurfaceareaandporevolumeofIL/γ-Al2O3decreased,whiletheselectivityandyieldofC2hydrocarbonsincreased.TheselectivityofC2hydrocarbonswas94.6%whentheloadingofC6MIMBF4was40%,andthepercentageofC2H4inC2hydrocarbonswasashighas64%whenusingPd-IL/γ-Al2O3asacatalystwithnoconventionalthermalreductiontreatment.Opticalemissionspectra(OES)fromthecoldplasmareactorduringmethaneconversionwerealsostudied.TheresultsindicatedthattheintensityoftheC2,CH,H,andCactivespeciesfrommethaneandhydrogendecompositionincreasedwhenIL/γ-Al2O3orPd-IL/γ-Al2O3wasintroducedintotheplasmasystem.BasedontheanalysesofthegasproductandOESspectra,itcanbeconcludedthatthesurfacecatalyzedreactionsbetweenplasmaandionicliquidwereveryimportantforthereductionofPd2+andtheformationofC2H4.

  • 标签: 冷等离子体 甲烷转化 离子液体 傅里叶变换红外光谱 扫描电子显微镜 等离子体反应器
  • 简介:ActivationMeasurementsofNeutronDoseEquivalentRatesin50MeV/u ̄(18)O-ionTargetArea¥LiGuisheng;ZhangTianmei;LiZongweiandSuYouwuNe...

  • 标签: TARGET
  • 简介:Inthecurrentpaper,dry(CO2)-reformingofglycerol,anewreformingroute,wascarriedoutoveralumina(Al2O3)-supported,non-promotedandlanthanum-promotednickel(Ni)catalysts.Bothsetsofcatalystsweresynthesizedviaawetco-impregnationprocedure.Physicochemicalcharacterizationofthecatalystsshowedthatthepromotedcatalystpossessedsmallermetalcrystallitesize,hencehighermetaldispersioncomparedtothevirginNi/Al2O3catalyst.ThiswasalsocorroboratedbythesurfaceimagescapturedbytheFESEManalysis.Fromtemperature-programmedcalcinationanalysis,thederivativeweightprofilesrevealedtwopeaks,whichrepresentawatereliminationpeakatatemperaturerangeof373to473Kfollowedbynickelnitratedecompositionfrom473to573K.Inaddition,BETsurfaceareameasurementsgave85.0m2g-1forthenon-promotedNicatalyst,whilstthepromotedcatalystsshowedanaverageof1%to6%improvementdependingontheLaloadings.Significantly,reactionstudiesat873KshowedthatglyceroldryreformingsuccessfullyproducedH2.The2%La-Ni/Al2O3catalyst,whichpossessedthelargestBETsurfacearea,gaveanoptimumH2generation(9.70%)ataglycerolconversionof24.5%.

  • 标签: Ni CATALYSTS dry REFORMING LANTHANIDE promotion
  • 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:OptimalexploitationofhadronicfinalstatesplayedakeyroleinsuccessesofallrecenthadroncolliderexperimentinHEP,andtheabilitytousehadronicfinalstateswillcontinuetobeoneofthedecisiveissuesduringtheanalysisphaseoftheLHCexperinentsMonteCarloimplementationsofhadronicshowermodelsprovidedwithGEANT4facilitatetheuseofhadronicfinalstates,andhavebeendevelopedformanyyears.Wewillgiveanoverviewonthephysicsunderlyinghadronicshowersimulation,discussingthethreebasictypesofmodelling;datadriven,parametrisationdriven,andtheorydrivenmodelling,andtheirrespectiveimplementationstatusinGEANT4.Wewillconfrontthedifferenttypesofmodellingwithavalidationsuiteforhadronicgeneratorsbasedoncross-sectionsmeasurementsfromthintargetexperiments,andexposethestrengthandweaknessesoftheindividualapproaches.

  • 标签: 高能物理学 强子碰撞实验 强子末态
  • 简介:Themainworkoftheirradiationtechniquegroupfocusesonthefollowingtwoaspectsin2016:1.TechniquesupportWehavehadabout772.5hbeamtimefor39roundsofsingleeventeffect(SEE)tests,whichiscooperatingwithvariousinstitutes,universities,andcompanies.Thetestsarethebasicsafeguardforthespacecraftandsatellite.InordertoguaranteethetestefficiencyoftheTerminal5,themaintenanceandimprovementforthevacuum,thesampletransferandbeammonitorsystemhavebeenachieved.

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

  • 标签: STRANGENESS PRODUCTION ANTIPROTON
  • 简介:β-glucanisoneofthemostimportantsourcesofcellwallinyeaststrains(Saccharomycescerevisiae).Itisnowknownthatβ-glucannotonlyexhibitsabroadspectrumofbiologicalactivitiesincludingimmune-modulating,anti-inflammatory,anti-cancer,andanti-agingproperties,butalsocanbeusedinfoodproductionasmoisturizer,dietaryfibers(DF)[1].Therefore,itisimperativetobreedyeaststrainswithhigherbiomassproductionandoptimizethefermentationprocess.Saccharomycescerevisiaeneedscarbonsourcesinbiomassaccumulation,butglucoseisexpensiveinindustrialfermentation[2].TheaimofthisstudyistoevaluatethedifferentcarbonsourcesonthegrowthofSaccharomycescerevisiae.

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  • 简介:Hf的加速器质谱分析要求必须提供纯度极高的HfF4样品,以便获得足够多的HfF5^-离子流来进行测量。氧同位素等杂质会导致产生HfF3O^-,HfFO2^-等无测量价值的离子流,造成HfF5^-束流强度降低,使测量能力下降。“干法”制备技术有助于获得纯度高、无氧和水等杂质的HfF4样品,从而改善加速器质谱的测量效果。

  • 标签: 干法制备 样品 加速器质谱 测量能力 质谱分析 氧同位素
  • 简介:1.ThemutationbreedingofplantsIn2016,themutationmechanismofvariousplantmutantsincludingArabidopsisthaliana,Geranium,Trades-cantiauminensis,TaraxacumkoksaghyzRodinandalgaeobtainedbyheavyionbeammutationbreedingtechniqueswereinvestigated.Thegenome-wideprofilingofanArabidopsismutantnamedcivar(CarbonionbeamsInducedVariegated)wasrevealedbyusingre-sequencingandtheroughmap-basedcloningtechniques.AphenotypescreeningofArabidopsisthalianairradiatedbycarbonionbeamsbasedonhigh-throughputimagingtechniquecombiningtheprincipalcomponentanalysisandscattermatrixclusteringanalysiswasbuiltandoptimizedwhichcanscreenthevariationofplantmutantpopulations.Thepigmentcomponentsandquantitiesandexpressionprofilesofkeygenesinvolvedinanthocyaninbiosynthesisofflower-colormutantofGeraniumandleaf-colormutantofTrades-cantiauminensiswereinvestigated.MutationbreedingofTaraxacumkoksaghyzRodininducedbycarbonionbeamirradiationswhichisnotableforitsproductionofhighqualityrubberandinulinwasstarted.Inaddition,thephotosyntheticresponseofthemutantsofScenedesmusquadricaudawithalteredpigmentfeatureswereanalyzed.

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  • 简介:TheannealingbehaviorofAgnanoparticlesinsilicawithandwithoutdefectswasinvestigatedinthisstudy.SilicasampleswithandwithoutArionpre-irradiationwereimplantedwithAgionsandthenannealedattemperaturefrom300to850℃.UV-VISspectroscopyandTEMwereusedtocharacterizetheopticalabsorbancepropertyandsizedistributionofAgnanoparticles,respectively.OpticalabsorbanceresultsshowthattheabsorbanceintensityofSPR(SurfacePlasmonResonance,SPR)peakfromAgnanoparticlesinthesamplewithpre-irradiationisstrongerthaninthesamplewithoutpre-irradiation,whichindicatesthatthedefectsproducedbypre-irradiationpromptthenucleationofAgnanoparticles.Duringannealing,theSPRpeakshiftstoshortwavelengthdirection,asshowninFig.1.

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  • 简介:Solidstatenanoporesornanochannelspreparedinpolymer[1;2]andsemiconductorfilms[3]haveshowninterestingtransportphenomena,becauseoftheirdiametersatthenanoscaleandpositiveornegativechargesontheirwalls.Grapheneisanidealmaterialfordevelopingsolidstatenanoporesnotonlyduetoitsatomicscalethickness,highmechanicalstrengthandchemicalstabilitiesbutalsobecauseoftheimpermeabilityofthepristinesinglelayergraphenetoallatomsandmoleculesexceptprotons[4].AsthesingleGraphene/PET(G/PET)nanoporeistheelementarybuildingblockfornanoporousmembrane,theunderstandingandcontrolofitsindividualionictransportpropertiesarealsocrucialinproteinseparation,waterdesalination,andbio-moleculedetectionusingarraysofidenticalnanopores.Here,thesingleG/PETnanoporewassuccessfullypreparedbyusingionirradiationtechnologyandasymmetricetchingmethod[5]andthecorrespondingionictransportpropertieswereinvestigatedindetail.

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  • 简介:AnewSnO_2-Fe_2O_3/SWCNTs(single-walledcarbonnanotubes)ternarynanocompositewasfirstsynthesizedbyafacilehydrothermalapproach.SnO_2andFe_2O_3nanoparticles(NPs)werehomogeneouslylocatedonthesurfaceofSWCNTs,asconfirmedbyX-raydiffraction(XRD),transmissionelectronmicroscope(TEM)andenergydispersiveX-rayspectroscopy(EDX).Duetothesynergisticeffectofdifferentcomponents,theassynthesizedSnO_2-Fe_2O_3/SWCNTscompositeasananodematerialforlithium-ionbatteriesexhibitedexcellentelectrochemicalperformancewithahighcapacityof692mAh·g~(-1)whichcouldbemaintainedafter50cyclesat200mA·g~(-1).Evenatahighrateof2000mA·g~(-1),thecapacitywasstillremainedat656mAh·g~(-1).

  • 标签: 纳米Fe2O3 单壁碳纳米管 纳米复合材料 锂离子电池 电化学性能 SNO2
  • 简介:Thispaperreportsonthelongevityofglycerol-dry(CO2)reformingoverthelanthanum(La)promotedNi/Al2O3catalysts.TheXRDresultsshowedthattheNiparticlewaswell-dispersedinthepresenceofLapromoter.Inaddition,viatheNH3-TPDanalysis,itwasfoundthattheLapromoterhasreducedtheacidityofNicatalystwhichmayhaveexplainedthemitigationofcarbonlaydown.Itwasdeterminedthatthe3.0wt%La-promotedNi/Al2O3catalystpossessedthelargestBETspecificsurfaceareaof97m2g-1.Consequently,ityieldedthebestcatalyticlongevityperformancewithconversionattainedmorethan90%,evenafter72hofreactionduration.Significantly,itcanbeconfirmedthatthepresenceofCO2duringtheglyceroldryreformingwasessentialinreducingcarbondeposition,mostlikelyviagasificationpathway.Thishasensuredastabilityofcatalyticactivityforalongreactionperiod(72h).

  • 标签: 镍催化剂 Al2O3 CO2 甘油 重整 长寿
  • 简介:Thenatureofresistivetransitionofhigh-qualitycrystallinethinfilmsofYBa2Cu3O7-δhasbeenstudiedundermagneticfields(H)appliedalongthecdirectionoverawiderangeofdopedholes,p,intheCuO2planes.Thefield-andtemperature-dependentin-planeresistivity,ρab(T,H),hasbeenanalyzedwithinthethermallyassistedflux-flow(TAFF)formalism.Thefluxactivationenergy,U(T,H),hasbeenextractedfromthisanalysis.Thelow-Tpartoftheρab(T,H)datacanbedescribedbyanactivationenergyhavingthefunctionalformofU(T,H)=(1-t)m(H-0/H)β,wheret=T/Tc(reducedtemperature),andH0isafieldscalethatprimarilydeterminesthemagnitudeofU(T,H).Thetemperatureexponent,m,showsasystematicvariationwithp,whereasthefieldexponent,β,isinsensitivetothepvaluesandisclosetounity.TheH0,ontheotherhand,changesrapidlyaspisvaried.U(T,H)islinkedtothepinningpotentialandconsequentlyonthesuperconductingcondensationenergy.Sincethenormalstatepseudogapdirectlyaffectssuperconductingcondensationenergy,aclearcorrespondencebetweenH0andthePGenergyscale,εg,isfound.Possibleimplicationsoftheseresultsarediscussed.

  • 标签: 电阻转变 涡动力学 薄膜 赝能隙 YBA2CU3O7 跃迁
  • 简介:Thispaperreportsthattheetchingmorphologyofdislocationsin8°off-axis4H-SiCepilayerisobservedbyusingascanningelectronicmicroscope.Itisfoundthatdifferenttypesofdislocationscorrespondwithdifferentdensitiesandbasalplanedislcation(BPD)arrayandthreadingedgedislocation(TED)pileupgroupliealongsomecertaincrystaldirectionsintheepilayer.Itisconcludedthattheelasticenergyofthreadingscrewdislocations(TSDs)ishighestandTEDsislowestamongthesedislocations,sothedensityofTSDsislowerthanTEDs.TheBPDscanconverttoTEDsbutTSDscanonlypropagateintotheepilyerinspiteofthehigherelasticenergythanTEDs.ThereasonoftheformofBPDsarrayinepilayeristhatthebigstepalongthebasalplanecausedbyfacedefectsblockedtheupstreamatoms,andTEDspileupgroupisthatthedislocationsslideisblockedbydislocationgroupsinepilayer.

  • 标签: 刃型位错 外延层 SiC 离轴 扫描电子显微镜 逃生装置
  • 简介:Asamemberof1Dnanostructuredmaterials,theferromagneticandnonmagneticmultilayernanowiresexhibittremendouspotentialapplicationsinmanyfieldsduetotheiruniquemagneticandelectricalproperties.Thebasicpropertyofmultilayernanowirearrays,suchascoercivity,iscrucialimportantforthefutureapplication.Inordertoobtainthecoercivityinformation,besidesdirectlymeasuringitthroughexperiment,theoreticalcalculationalsoprovidesausefulandfastwaytoevaluatethemultilayer’scoervicity.Fig.1(a)and(b)demonstrateasinglemultilayernanowireandnanowirearraysembodiedinamatrix,respectively.Inthiswork,byimprovingPant’smodel,wedevelopedthenewmodelandsuccessfullypredictedtherelationshipbetweenthecoercivitychangingofCu/Nimultilayernanowirearraysandstructualparameters.Fig.

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  • 简介:Zn2SnO4(ZTO)nanowireswithauniquedendriticnanostructureweresynthesizedviaasimpleone-stepthermalevaporationandcondensationprocess.ThemorphologyandmicrostructureoftheZTOnanodendritehavebeeninvestigatedbymeansoffieldemissionscanningelectronmicroscopy(SEM),x-raydiffraction(XRD)andhigh-resolutiontransmissionelectronmicroscopy(HRTEM).SEMobservationrevealedtheformationofbranchednanostructuresandshowedthateachbranchexhibitedauniqueperiodicstructureformedbyarowofoverlaidrhombohedraofZTOnanocrystalsalongtheaxisofthenanobranch.HRTEMstudiesdisplayedthatthebranchesgrewhomoepitaxiallyassingle-crystallinenanowiresfromtheZTOnanowirebackbone.ApossiblegrowthmodelofthebranchedZTOnanowiresisdiscussed.Tosuccessfullypreparebranchedstructureswouldprovideanopportunityforbothfundamentalresearchandpracticalapplications,suchasthree-dimensionalnanoelectronics,andopto-electronicnanodevices.

  • 标签: Zn2SnO4 晶体生长 树突 光致发光