学科分类
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127 个结果
  • 简介:最小的dilaton模型(MDM)由叫的dilaton和dilaton顶夸克搭挡把t'称为的一汗衫数量扩大标准模型。在这个工作,我们调查t'-induced放射的修正到Higgs-strahlung生产过程e+在未来Higgs的eZh工厂。我们首先详细介绍分析计算并且显示出怎么处理紫外分叉。然后,我们由从精确electroweak数据考虑限制数字地计算修正。我们发现那,为罪恶L=0.2并且mt'=1200GeV,修正是0.26%和2.1%为,1TeV分别地,并且更大的价值能作为罪恶L增加。

  • 标签: 辐射修正 型号 辐射校正 数值计算 标准模型 合作伙伴
  • 简介:Numericalestimatesforelectronsandmesonsparticle–antiparticlecreationfromvacuuminthepresenceofstrongelectromagneticfieldsarederived,usingthecompleteprobabilitydensityrelationofPopov’simaginarytimemethod(Popov,JETPLett.13,185(1971);Sov.Phys.JETP34,709(1972);Sov.Phys.JETP35,659(1972);PopovandMarinov,Sov.J.Nucl.Phys.16,449(1973);JETPLett.18,255(1974);Sov.J.Nucl.Phys.19,584(1974));(Popov,Phys.Let.A298,83(2002)),andwithintheframeworkofanexperimentalsetupliketheE144(Burkeetal.,Phys.Rev.Lett.79,1626(1997)).Theexistenceofcrossingpointamongpaircreationefficiencycurvesofdifferentphotonenergiesandtheroleofodd/evenmultiphotonordersintheproductionratesarediscussed.Finallyakindoftunabilityprocessbetweenthetwocreationprocessesisdiscussed.

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  • 简介:研究了不同风速下激光辐照C/C复合材料的氧化速率,利用温度场计算结果,结合氧气在空气中的传质速率,计算了激光辐照下C/C复合材料氧化放热.结果表明,在亚音速的风速下,氧化对C/C复合材料烧蚀的贡献很小,因此,作为激光防护材料,可以忽略C/C复合材料在激光辐照期间的氧化烧蚀.

  • 标签: 氧化烧蚀 氧化放热 C/C复合材料 风速 激光辐照
  • 简介:Anenvironmentallyfriendlyprecursor,adenosine,hasbeenusedasadualsourceofCandNtosynthesizenitrogen-dopedcarboncatalystwith/withoutFe.Ahydrothermalcarbonizationmethodhasbeenusedandwateristhecarbonizationmedia.Themorphologyofsampleswith/withoutFecomponenthasbeencomparedbyHRTEM,andtheresultshowsthatFecanpromotethegraphitizationofcarbon.Furtherelectro-chemicaltestshowsthattheoxygenreductionreaction(ORR)catalyticactivityofFe-containingsample(C–FeN)ismuchhigherthanthatoftheFe-freesample(C–N).Additionally,theintermediatesofC–FeNformedduringeachsyntheticprocedurehavebeenthoroughlycharacterizedbymultiplemethods,andthefunctionofeachprocedurehasbeendiscussed.TheC–FeNsampleexhibitshighelectro-catalyticstabilityandsuperiorelectro-catalyticactivitytowardORRinalkalinemedia,withitshalf-wavepotential20mVlowerthanthatofcommercialPt/C(40wt%).Itisfurtherincorporatedintoalkalinepolymerelectrolytefuelcell(APEFC)asthecathodematerialandledtoapowerdensityof100mW/cm~2.

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  • 简介:Itisidentifiedthatbarelypassingelectronsarethedriveofthee-Gshbones,ratherthanthebarelytrappedelectronsatlowfrequency.Thefrequencyjumpine-Bshboneexperimentsisreproducedandanalyzed.Itisfoundthatthee-Bshbonefrequencyincreaseswiththehotelectronenergy,whichisconsistentwiththeexperiments.Thegrowthrateofthemode(m=2,n=2)isgreaterthanthatofthemode(m=1,n=1).

  • 标签: 实验 鱼刺 频率 跃变 捕获电子 电子能量
  • 简介:Afusionbreedermightbeanessentialintermediateapplicationoffusionenergyatearlierterm,sinceithasthepotentialtoprovideplentyofcommercialfissilefuel.Basedonfusionphysicsandtechnologiesavailableatpresentandinthenearfuture,therealisticfusionexperimentalbreeder,FEB-Ewasdesigned.

  • 标签: 放射化计算 核聚变实验 增殖堆 FEB-E 中子通量
  • 简介:Inthecontextofthetop-color-assistedtechnicolor(TC2)model,theflavor-changingneutral-current(FCNC)interactioninducedbythetop-higgs(h_t~0)arepredictedattreelevel.Westudytherelevantprocessesofe~+e~-(γγ)→th_t~0attheInternationalLinearCollider(ILC).ItisfoundthattheserareprocessesproductionratescanbeenhancedsignificantlyintheTC2model.Especiallyfortheprocessγγ→th_t~0,thetotalcrosssectionwillreachafewfbinthereasonableparameterspace.Wealsocalculatethedistributionsoftransversemomenta,pseudo-rapidandinvariantmassofthetop-higgs.Inviewofthemaindecaymodesoftop-higgsform_(h_t~0)<2m_t,weEndthattherewillbeseveralhundredsFCNCeventsproducedattheILCwithannuallyintegralluminosityof500fb~(-1).Duetothecleanbackground,suchFCNCsignalscanpossiblybedetectedattheILC.

  • 标签: TC2模型 电流信号 电子邮件 中性 国际直线对撞机 风味
  • 简介:Variousagriculturalcropresiduesincludingcornstover,corncob,andsorghumstalkwithamoisturecontentof75wt%weresubjectedtoalongpretreatment(12-60h)withsupercriticalCO2(scCO2),atlowtemperature(50-80℃)andapressureof17.5-25.0Mpa.Thesugaryieldsfromtheenzymatichydrolysis(EH)ofthepretreatedsampleswereasmuchasthree-tofourfoldgreaterthanthoseaffordedbytherawmaterials.However,whenpretreatmentwasconductedwithinashorttime(e.g.0.5h),aspreviouslyreportedintheliterature,onlyaslightincreaseintheEHsugaryieldswasobserved.TheproposedscCO2pretreatmentmechanismdemonstratedtheroleofmoistureinthesystem.Wetting,softening,andswellingwereobservedtomainlyaffectthelignocellulosewhenasuitableamountofwaterwasadded.Finally,thesampleswereanalysedbyX-raydiffractionandscanningelectronmicroscopy,beforeandafterpretreatment,toinvestigatethechangesinthemicroscopicstructureofthebiomass.

  • 标签: LIGNOCELLULOSE scCO2 PRETREATMENT ENZYMATIC HYDROLYSIS SUGAR
  • 简介:分子的动态模拟被执行在交流上调查事件精力的效果:从C和H的H电影生长原子流动。我们的模拟证明在低事件精力(1eV)的电影生长被H和C原子的吸附统治。在中等事件精力(10和20eV),有在表面吸附的H原子的事件H原子的抽象反应变得重要。在高事件精力(30和40eV),交流:H电影生长是一个二拍子的圆舞过程:一个人是吸附和C原子的浅培植,并且其它是H原子的深培植。[从作者抽象]

  • 标签: 分子动力学模拟 薄膜生长 入射能量 H原子 交流 流量
  • 简介:Anovelgas-phaseelectrocatalyticcellcontainingalow-temperatureprotonexchangemembrane(PEM)wasdevelopedtoelectrochemicallyconvertCO2intoorganiccompounds.TwodifferentCu-basedcathodecatalysts(CuandCu-C)werepreparedbyphysicalvapordepositionmethod(sputtering)andsubsequentlyemployedforthegas-phaseelectroreductionofCO2atdifferenttemperatures(70-90℃).ThepreparedelectrodesCuandCu-CwerecharacterizedbyX-raydiffraction(XRD),X-rayphotoemissionspectroscopy(XPS)andscanningelectronmicroscopy(SEM).Asrevealed,CuispartiallyoxidizedonthesurfaceofthesamplesandtheCuandCu-Ccathodiccatalystswerecomprisedofaporous,continuous,andhomogeneousfilmwithnanocrystallineCuwithagrainsizeof16and8nm,respectively.Theinfluenceoftheappliedcurrentandtemperatureontheelectro-catalyticactivityandselectivityofthesematerialswasinvestigated.Amongthetwoinvestigatedelectrodes,thepureCucatalystfilmshowedthehighestCO2specificelectrocatalyticreductionratesandhigherselectivitytomethanolformationcomparedtotheCu-Celectrode,whichwasattributedtothehigherparticlesizeoftheformerandlowerCuO/Curatio.Theobtainedresultsshowpotentialinterestforthepossibleuseofelectrical「enewableenergyforthetransformationofCO2intovaluableproductsusinglowmetalloadingCubasedelectrodes(0.5mgCucm2)preparedbysputtering.

  • 标签: C02 VALORIZATION ELECTRO-REDUCTION CU catalyst PEM
  • 简介:Inthepresentstudy,astatisticalinvestigationiscarriedouttoexplorewhetherthereisarelationshipbetweenthecriticalfrequency(foEs)ofthesporadic-ElayerthatisoccasionallyseenontheEregionoftheionosphereandthequasibiennialoscillation(QBO)thatflowsintheeast–westdirectionintheequatorialstratosphere.Multipleregressionmodelasastatisticaltoolwasusedtodeterminetherelationshipbetweenvariables.Inthismodel,thestationarityofthevariables(foEsandQBO)wasfirstlyanalyzedforeachstation(CocosIsland,Gibilmanna,NiueIsland,andTahiti).Then,acointegrationtestwasmadetodeterminetheexistenceofalong-termrelationshipbetweenQBOandfoEs.Afterverifyingthepresenceofalong-termrelationshipbetweenthevariables,themagnitudeoftherelationshipbetweenvariableswasfurtherdeterminedusingthemultipleregressionmodel.Asaresult,itisconcludedthatthevariationsinfoEswereexplainablewithQBOmeasuredat10hPaaltitudeattherateof69%,94%,79%,and58%forCocosIsland,Gibilmanna,NiueIsland,andTahitistations,respectively.ItisobservedthatthevariationsinfoEswereexplainablewithQBOmeasuredat70hPaaltitudeattherateof66%,69%,53%,and47%forCocosIsland,Gibilmanna,NiueIsland,andTahitistations,respectively.

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  • 简介:Carbon-supportedPdnanoparticleswerepreparedbymicrowaveheating-glycolreductionmethod,andcharacterizedbyawidearrayofexperimentaltechniquesincludingX-raydiffractionspectroscopy(XRD)andtransmissionelectronmicroscopy(TEM).TheelectrooxidationbehaviorsofethanolonthePd/Celectrodeinalkalinemediawereinvestigatedusingcyclicvoltammetry(CV),chronoamperometry(CA),electrochemicalimpedancespectroscopy(EIS)andsinglecellperformancemethods.Pd/Celectrodeforethanoloxidationshowedhighelectro-catalyticactivityandlongtermstability.However,itisobservedthatthecurrentdensitydecreaseswiththeincreasingofthepotentialandnegativeimpedancepresentsinthepotentialfrom-0.1to0.1V.Thedecreasingcurrentdensityandthenegativeimpedancecouldbeduetotheadsorbedintermediatesspeciesthatinhibitedthefurtheroxidationofethanol.BasedonthechemicalreactionanalysisandEISspectra,equivalentcircuitsrelatingtovariouspotentialzoneshavebeenobtained.TheseresultsrevealthedynamicadsorptionofintermediatesspeciesonPdsurfaces.Significantly,itisclarifiedthattheadsorptionbehaviorbeginsfromthemaximumcatalysisofelectro-catalysisandendsintheformationofthepalladium(II)oxidelayerontheelectrodesurface.

  • 标签: 纳米颗粒 碱性介质 氧化钯 乙醇 X射线衍射谱 电化学阻抗谱
  • 简介:TheCprogramminglanguageisexpressiveandflexible,butnotsafe;asitsexpressivepowerandflexibilityareobtainedthroughunsafelanguagefeatures,andimproperuseofthesefeaturescanleadtoprogrambugswhosecausesarehardtoidentify.SinceCiswidelyused,anditisimpracticaltorewriteallexistingCprogramsinsafelanguages,sowaysmustbefoundtomakeCprogramssafe.ThispaperdealswiththeunsafefeaturesofCandpresentsasurveyonexistingsolutionstomakeCprogramssafe.Wehavestudiedbinary-levelinstrumentationtools,sourcecheckers,source-levelinstrumentationtoolsandsafedialectsofC,andpresentacomparisonofdifferentsolutions,summarizedthestrengthsandweaknessesofdifferentclassesofsolutions,andshowmeasuresthatcouldpossiblyimprovetheaccuracyoralleviatetheoverheadofexistingsolutions.

  • 标签: C语言 程序设计语言 信息安全 编译工具
  • 简介:ThefirststarsintheearlyUniversewereformedabout400millionyearsafterthebigbang.VerificationoftheexistenceofthesestarsisimportantforourunderstandingoftheevolutionoftheUniverse[1].IthasbeenpredictedthatforPopulation-IIIstellarproductionyields,theabundancesofodd-Zelementsareremarkablydeficientcomparedtotheiradjacenteven-Zelements[2].Astronomersaresearchingforlong-lived,lowmassstarswiththeuniquenucleosyntheticpatternmatchingthepredictedyields[3].

  • 标签: FIRST DIRECT MEASUREMENT