学科分类
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79 个结果
  • 简介:基于低精力QCDLagrangian质子上的理论和交叉对称关系,奇怪的介子相片生产和它的联系放射的俘获reinvestigated在[SU_(SF)(6)直接XO(3)]_(sym)。工具条的DirectXSU_C(3)夸克模型有一个仅仅一样的输入参数的那里的结构,唯一的强壮的联合常数α_M。为生气的节,γ+p→K~++Λ反应的p极化和为有Y=Λ的K~-+p→γ+Y的K~放射的俘获的分叉的比率的计算,Σ~0被执行。到数据的好协议被获得,结果证明与传统的现象学的模型相比,低energyQCDLagrangian理论提供对奇怪的mesonphoto生产和它的联系放射的俘获的成功的、统一描述。

  • 标签: 低能QCD拉格朗日量 夸克 胶子 重子
  • 简介:Self-affinemultiplicityfluctuationisinvestigatedbyusingthetwo-dimensionalfactorialmomentmethodologyandtheconceptoftheHurstexponent(H).Investigationontheexperimentaldataofcompoundparticlesandtargetfragmentsemittedin84Kr-AgBrinteractionsat1.7AGeVrevealsthatthebestpowerlawbehavioursareexhibitedatH=0.7and0.6respectively,andthedataforshowerparticlesproducedin84Kr-emulsioninteractionsat1.7AGeVindicatethatthebestpowerlawbehaviouroccursatH=0.6,allofwhichshowtheself-affinemultiplicityfluctuationpatterns.Themultifractalityandthenon-thermalphasetransitionoccurringduringproducingthecompoundparticles,thetargetfragments,andtheshowerparticlesinthe84Kr-AgBrinteractionandthe84Kr-emulsioninteractionarealsodiscussed.Themultifractalityisobservedduringproducingcompoundparticles,targetfragments,andshowerparticles.Inthetargetfragmentproduction,anevidenceofnon-thermalphasetransitionisobserved,butintheshowerparticleproductionandthecompoundparticleproduction,noevidenceofnon-thermalphasetransitionisobserved.

  • 标签: 原子核物理 高能重离子碰撞 高能光子测量 核子
  • 简介:Thetop-pairproductioninassociationwithaZ~0-bosonataphoton-photoncolliderisanimportantprocessinprobingthecouplingbetweentop-quarksandvectorbosonanddiscoveringthesignatureofpossiblenewphysics.WedescribetheimpactofthecompletesupersymmetricQCD(SQCD)next-to-leadingorder(NLO)radiativecorrectionsonthisprocessatapolarizedorunpolarizedphotoncollider,andmakeacomparisonbetweentheeffectsoftheSQCDandthestandardmodel(SM)QCD.Weinvestigatethedependenceofthelowest-order(LO)andQCDNLOcorrectedcrosssectionsinboththeSMandminimalsupersymmetricstandardmodel(MSSM)oncollidingenergys~(1/2)indifferentpolarizedphotoncollisionmodes.TheLO,SMNLO,andSQCDNLOcorrecteddistributionsoftheinvariantmassoftt-pairandthetransversemomentaoffinalZ~0-bosonarepresented.OurnumericalresultsshowthatthepureSQCDeffectsinγγ→ttZ~0processcanbemoresignificantinthe++polarizedphotoncollisionmodethaninothercollisionmodes,andtherelativeSQCDradiativecorrectioninunpolarizedphotoncollisionmodevariesfrom32.09%to-1.89%whens~(1/2)goesupfrom500GeVto1.5TeV.

  • 标签: 量子色动力学 光子对撞机 矢量玻色子 超对称 非线性光学 碰撞模式
  • 简介:Fractionalpyrolysisandone-steppyrolysisofnaturalalgaeCyanobacteriafromTaihuLakewerecomparativelystudiedfrom200to500°C.One-steppyrolysisproducedbio-oilwithcomplexcompositionandlowhighheatingvalue(HHV30.9MJ/kg).FractionalpyrolysisseparatedthedegradationofdifferentcomponentsinCyanobacteriaandimprovedtheselectivitytoproductsinbio-oil.Thatis,acidsat200°C,amidesandacidsat300°C,phenolsandnitrilesat400°C,andphenolsat500°C,weregotasmainproducts,respectively.HZSM-5couldpromotethedehydration,crackingandaromatizationofpyrolyticintermediatesinfractionalpyrolysis.AtoptimalHZSM-5catalystdosageof1.0g,theselectivitytoproductsandthequalityofbio-oilwereimprovedobviously.Themainproductsinbio-oilchangedtonitriles(47.2%)at300°C,indoles(51.3%)andphenols(36.3%)at400°C.Theoxygencontentwasreducedto7.2wt%and9.4wt%,andtheHHVwasraisedto38.1and37.3MJ/kgat300and400°C,respectively.Fractionalcatalyticpyrolysiswasproposedtobeanefficientmethodnotonlytoprovideapotentialsolutionforalleviatingenvironmentalpressurefromwaterblooms,butalsotoimprovetheselectivitytoproductsandobtainhighqualitybio-oil.

  • 标签: HZSM-5催化剂 蓝藻水华 生物油 热解 品质 小数
  • 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:Wastebiomassisalwaysgeneratedduringtheproductionprocessinindustries.Theordinarywaytogetridofthewastebiomassistosendthemtolandfillorburnitintheopenfield.Thewastemaypotentiallybeusedforco-firingwithcoaltosavefossilfuelconsumptionandalsoreducenetcarbonemissions.Inthiscasestudy,thebio-wastefromaNicotianaTabacum(NT)pre-treatmentplantisusedasthebiomasstoco-firewithcoal.ThesamplesofNTwasteswereanalysed.Itwasfoundthatthewasteswereoftherelativelyhighenergycontentwhichweresuitableforco-firingwithcoal.ToinvestigatethepotentialandbenefitsforaddingNTwastestoaFluidisedBedCombustion(FBC)boilerintheplant,detailedmodellingandsimulationarecarriedoutusingtheEuropeanCoalLiquefactionProcessSimulationandEvaluation(ECLIPSE)processsimulationpackage.ThefeedstockblendingratiosofNTwastetocoalstudiedinthisworkarevariedfrom0%to30%.TheresultsshowthattheadditionofNTwastesmaydecreasetheemissionsofCO2andSOxwithoutreducingtheboilerperformance.

  • 标签: 废弃生物质 工业生产过程 煤炭液化 蒸汽锅炉 化石燃料 燃料消耗
  • 简介:AnovelSr2CuInO3Soxysulfidep-typesemiconductorphotocatalysthasbeenpreparedbysolidstatereactionmethodanditexhibitsintriguingvisiblelightabsorptionpropertieswithabandgapof2.3eV.Thep-typesemiconductorcharacterofthesynthesizedSr2CuInO3SwasconfirmedbyHallefficientmeasurementandMott-Schottkyplotanalysis.First-principlesdensityfunctionaltheorycalculations(DFT)andelectrochemicalmeasurementswereperformedtoelucidatetheelectronicstructureandtheenergybandlocations.Itwasfoundthattheas-synthesizedSr2CuInO3Sphotocatalysthasappreciateconductionandvalencebandpositionsforhydrogenandoxygenevolution,respectively.Photocatalytichydrogenproductionexperimentsunderavisiblelightirradiation(λ>420nm)werecarriedoutbyloadingdifferentmetalandmetal-likecocatalystsonSr2CuInO3SandRhwasfoundtobethebestoneamongthetestedones.

  • 标签: 半导体光催化剂 可见光照射 Mott-Schottky图 P型 制氢 密度泛函理论
  • 简介:Forsyngasproduction,thecombustionoffossilfuelsproduceslargeamountsofCO2asagreenhousegasannuallywhichintensifiesglobalwarming.Inthisstudy,chemicalloopingcombustion(CLC)hasbeenutilizedfortheeliminationofCO2emissiontoatmosphereduringsimultaneoussyngasproductionwithdifferentH2/COratioinsteamreformingofmethane(SR)anddryreformingofmethane(DR)inaCLC-SR-DRconfiguration.InCLC-SR-DRwith184reformertubes(similartoanindustrialscalesteamreformerinZagrosPetrochemicalCompany,Assaluyeh,Iran),DRreactionoccursoverRh-basedcatalystsin31tubes.Also,SRreactionishappenedoverNi-basedcatalystsin153tubes.CLCviaemploymentofMn-basedoxygencarrierssuppliesheatforDRandSRreactionsandproducesCO2andH2Oasrawmaterialssimultaneously.AsteadystateheterogeneouscatalyticreactionmodelisappliedtoanalyzetheperformanceandapplicabilityoftheproposedCLC-SR-DRconfiguration.Simulationresultsshowthatcombustionefficiencyreached1attheoutletoffuelreactor(FR).Therefore,pureCO2andH2OcanberecycledtoDRandSRsides,respectively.Also,CH4conversionreached0.2803and0.7275attheoutletofSRandDRsides,respectively.Simulationresultsindicatethat,3223kmolh-1syngaswithaH2/COratioequalto9.826wasproducedinSRsideofCLC-SR-DR.Afterthat,1844kmolh-1syngaswithaH2/COratioequalto0.986wasachievedinDRsideofCLC-SR-DR.ResultsillustratethatbyincreasingthenumberofDRtubesto50tubesandconsidering184fixedtotaltubesinCLC-SR-DR,CH4conversionsinSRandDRsidesdecreased2.69%and3.31%,respectively.However,thissubjectcausedtotalsyngasproductioninSRandDRsides(inallof184tubes)enhanceto5427kmolh-1.Finally,thermalandmolarbehaviorsoftheproposedconfigurationdemonstratethatCLC-SR-DRisapplicableforsimultaneoussyngasproductionwithhighandlowH2/COratiosinanenvironmentalfriendlyprocess.

  • 标签: 甲烷重整 蒸汽重整 合成气 CO2 CLC 生产
  • 简介:One-potachievementofethyllevulinatefromcassavawasconductedinethanol-watersystemoverseveralsimplesulfatesaltcatalysts.Al2(SO4)3catalysthadthebestperformanceinsynthesizingethyllevulinatecomparingwiththoseofaseriesofsulfatesalts.Thehighestyieldsofethyllevulinatewasupto39.27%aswellas7.78%levulinateacidwhencassavawascatalyzedinethanolmediumbyadding10wt%water.13Cand1HNMRspectroscopicinvestigationsconfirmedthatisomerizationofglucosetofructoseoverAl2(SO4)3catalystisanimportantstepinproducingethyllevulinateandlevulinateacid.DuetoaggregationsofAl3+underhydrothermalconditions,tinyamountofAl3+weredetectedinfiltrateatthepercentageof0.32%evenifinabsolutewater.BronstedandLewisacidscouldimprovetheyieldofethyllevulinateandlevulinateacidbysynergisticeffect.AllresultssuggestedthatA12(SO4)3wasasimpleandefficientcatalystforethyllevulinateandlevulinateacidproduction.

  • 标签:
  • 简介:MetaloxidesemiconductormaterialssuchasZnOhavetremendouspotentialaslightabsorbersforphotocatalysedelectrodesintheelectrochemicalreductionofwater.PromoterssuchasrGOhavebeenaddedtoreducetherecombinationlossesofchargecarriersandimproveitsphotoelectrochemicalactivity.Inthisstudy,theeffectoflayerorderingonthechargetransferpropertiesofrGO-hybridisedZnOsandwichthinfilmsforthephoto-catalysedelectrochemicalreductionofwaterwasinvestigated.rGO-hybridisedZnOsandwichthinfilmswerepreparedviaafacileelectrodepositiontechniqueusingalayer-by-layerapproach.ThethinfilmswereanalysedusingFESEM,XRD,Raman,PL,UV–vis,EISandCVtechniquestoinvestigateitsmorphological,opticalandelectrochemicalproperties.TheFESEMimagesshowtheformationofdistinctlayersofrGOandZnOnanorods/flakesviathelayer-by-layermethod.XRDconfirmedthewurtzitestructureofZnO.PLspectroscopyrevealedareductionofphotoemissionintensityinthevisibleregion(580nm)whenrGOwasincorporatedintotheZnOthinfilm.Amongthesixthinfilmsprepared,ZnO/rGOshowedsuperiorperformancecomparedtotheotherthinfilms(0.964mA/cm)duetothepresenceofgrapheneedgeswhichparticipateasheterogenouselectrocatalystsinthephotocatalysedelectrolysisofwater.rGOalsoactsaselectronacceptor,formingann-pheterojunctionwhichimprovestheactivityofZnOtooxidisewatermoleculestoO_2.EISrevealedthattheapplicationofrGOasbackcontact(rGO/ZnO,rGO/ZnO/rGO)reducesthechargetransferresistanceofasemiconductorthinfilm.Alternatively,rGOasfrontcontact(ZnO/rGO,rGO/ZnO/rGO)improvesthephoto-catalysedelectrolysisofwaterthroughtheparticipationoftherGOedgesinthechemicalactivationofwater.Thefindingsfromthisstudyindicatethatthelayerorderingsignificantlyaffectsthethinfilm'selectrostaticpropertiesandthisunderstandingcanbefurtheradvantageousfortunableapplications.

  • 标签: ZNO薄膜 膜催化 杂交 夹心 三明治薄膜 光催化活性
  • 简介:最高的帮助颜色的彩色印片法模型(TC2)预言一个非通用的Z'计量器波色子,它与提高的力量联合到第三产生费米子。我们在LHC通过过程ggt在生气的节和最高的夸克对生产的旋转关联上学习这个非通用的计量器波色子的效果。我们发现全部的生气的节和旋转关联能被减少由?4.7%并且?1.4%分别地在允许的参数空格。

  • 标签: 非普适规范玻色子 TC2模型 夸克对产生 对撞机 审判 生产关系
  • 简介:CuO-CeO2catalystswerepreparedbyaureaprecipitationmethodfortheoxidativesteamreformingofethanolatlow-temperature.Thecatalyticperformancewasevaluatedandthecatalystswerecharacterizedbyinductivelycoupledplasmaatomicemissionspectroscopy,X-raydiffraction,temperature-programmedreduction,fieldemissionscanningelectronmicroscopyandthermo-gravimetricanalysis.OverCuOCeO2catalysts,H2withlowCOcontentwasproducedinthewholetestedtemperaturerangeof250–450C.Thenon-noblemetalcatalyst20CuCeshowedhigherH2productionratethan1%Rh/CeO2catalystat300–400Candtheadvantagewasmoreobviousafter20htestingat400C.TheseresultsfurtherconfirmedthatCuO-CeO2catalystsmaybesuitablecandidatesforlowtemperaturehydrogenproductionfromethanol.

  • 标签: CuO-CeO2 catalyst hydrogen production OXIDATIVE steam
  • 简介:HydrotalciteprecursorsofLamodifiedNi-Al2O3andNi-SiO2catalystspreparedbyco-precipitationmethodandthecatalyticactivitieswereexaminedfortheproductionofCOx-freeH2byCH4decomposition.Physico-chemicalcharacteristicsoffresh,reducedandusedcatalystswereevaluatedbyXRD,TPRandO2pulsechemisorptions,TEMandBET-SAtechniques.XRDstudiesshowedphasesduetohydrotalcite-likeprecursorsinovendriedformproduceddispersedNiOspeciesuponcalcinationinstaticairabove450C.Ramanspectraofdeactivatedsamplesrevealedthepresenceofbothorderedanddisorderedformsofcarbon.Ni-La-Al2O3catalystwithamoleratioofNi:La:Al=2:0.1:0.9exhibitedtremendouslyhighlongevitywithahydrogenproductionrateof1300molH2mol1Ni.AdirectrelationshipbetweenNimetalsurfaceareaandhydrogenyieldswasestablished.

  • 标签: CH4 decomposition Ni-La-Al HYDROTALCITE NI metal
  • 简介:Nanostructuredγ-Al2O3withhighsurfaceareaandmesoporousstructurewassynthesizedbysol-gelmethodandemployedascatalystsupportfornickelcatalystsinmethanereformingwithcarbondioxide.ThepreparedsampleswerecharacterizedbyXRD,N2adsorption-desorption,TPR,TPO,TPH,NH3-TPDandSEMtechniques.TheBETanalysisshowedahighsurfaceareaof204m2g-1andanarrowpore-sizedistributioncenteredatadiameterof5.5nmforcatalystsupport.TheBETresultsrevealedthatadditionoflanthanumoxidetoaluminumoxidedecreasedthespecificsurfacearea.Inaddition,TPRresultsshowedthatadditionoflanthanumoxideincreasedthereducibilityofnickelcatalyst.Thecatalyticevaluationresultsshowedanincreaseinmethaneconversionwithincreasinglanthanumoxideto3mol%andfurtherincreaseinlanthanumcontentdecreasedthecatalyticactivity.TPOanalysisrevealedthatthecokedepositiondecreasedwithincreasinglanthanumoxideto3mol%.SEMandTPHanalysesconfirmedtheformationofwhiskertypecarbonoverthespentcatalysts.AdditionofsteamandO2todryreformingfeedincreasedthemethaneconversionandledtocarbonfreeoperationincombinedprocesses.

  • 标签: 甲烷二氧化碳重整 镍催化剂 纳米结构 氧化镧 合成气 NH3-TPD