简介:AhypereutecticAl-Sialloypowderwaspreparedbyultrasonicgasatomizationprocess.Themorphologies,microstructureandphaseconstituentofthealloypowderwerestudied.TheresultsshowedthatpowderofthealloywasveryfineanditsrnicrostructurewasmainlyconsistedofSicrystalsplusintermetalliccompoundAl9FeSi3,whichwere.veryfineanduniformlydistributed.
简介:Thispaperpresentstheresultsofourinvestigationsofbreakdownmechanisms,aswellasadescriptionoftheirinfluenceonthedistributionsoftimedelaydistributions,foragastubefilledwithnitrogenat4mbar.Thevaluesofthetimedelayaremeasuredfordifferentvoltages,andthevaluesoftherelaxationtimesandtheirdistributionsandprobabilityplotsareanalyzed.TheobtaineddensitydistributionshaveGaussiandistributionsandexponentialdistributionsfordifferentvaluesofrelaxationtimes(Gaussianforsmallvaluesandexponentialforlargevaluesofrelaxationtime).ItisshownthatformiddlevaluesofrelaxationtimethedelaydistributionshaveashapebetweenGaussianandexponentialdistributions,whichisaresultofthedifferentinfluencesofelectricalbreakdown.
简介:Withanalloycontentashighas80%ormore,Ni-basedOCTGisastrategicproductsrelatedtothestateenergysecurity,mainlyappliedintheexploitationanddevelopmentofsourgasfieldswithcomplicategeologicalformation,hightemperature,highpressureandseverecorrosivewellconditions.Ni-basedOCTGisregardedasthepipeproductwithmosthightechnologiesduetothecomplexityandgreatdifficultyinmanufacturingandrigorousrequirementsinqualitycontrol.Inthispaper,thetechnicalfeaturesandqualityrequirementsofNi-basedOCTGaresummarized,andthequalityandpropertiesoftheNi-basedOCTGproductsofBaosteelareintroducedindetail.WiththehelpofSEM,XPSandTEM,thecorrosionmechanismofNickle-basedOCTGintheenvironmentscontainingH2S,CO2,Cl-andelementarysuifurarealsoanalyzed.
简介:Turbulentreactingflowsinagenericswirlgasturbinecombustormodelareinvestigatedbothnumericallyandexperimentally.Intheinvestigation,anemphasisisplacedupontheexternalfluegasrecirculation,whichisapromisingtechnologyforincreasingtheefficiencyofthecarboncaptureandstorageprocess,which,however,canchangethecombustionbehavioursignificantly.Afurtheremphasisisplacedupontheinvestigationofalternativefuelssuchasbiogasandsyngasincomparisontotheconventionalnaturalgas.FlamesarealsoinvestigatednumericallyusingtheopensourceCFDsoftwareOpenFOAM.Inthenumericalsimulations,alaminarflameletmodelbasedonmixturefractionandreactionprogressvariableisadopted.Asturbulencemodel,theSSTmodelisusedwithinaURANSconcept.Computationalresultsarecomparedwiththeexperimentaldata,whereafairagreementisobserved.
简介:IntroductionTheelectrochemicalreductionofO2wasinvestigatedwidelyduringthepasttwodecades.O2-canreactwithvariousorganiccompounds.O2-asanewsynthesisreagenthasbeenbeingexplored.
简介:Numericalsimulationofgas-solidflowinatwo-dimensionalfluidizedbedwithaninclinedjetwasperformed.Thenumericalmodelisbasedonthetwo-fluidmodelofgasandsolidsphaseinwhichthesolidsconstitutiveequationsarebasedonthekinetictheoryofgranularflow.TheimprovedICEalgorithm,whichcanbeusedforbothlowandhigh-velocityfluidflow,wereusedtosolvethemodelequations.Themechanismofjetformationwasanalyzedusingbothnumericalsimulationsandexperiments.Theemergenceandmovementofgasbubbleswerecapturednumericallyandexperimentally.Theinfluencesofjetvelocity,nozzlediameter,nozzleinclinationandjetpositiononjetpenetrationlengthwereobtained.Asemi-empiricalexpressionwasderivedandtheparameterswerecorrelatedfromexperimentaldata.Thecorrelationequation,whichcanbeeasilyusedtoobtaintheinclinedjetpenetrationlength,wascomparedwithourexperimentaldataandpublishedcorrelationequations.
简介:Wavelengthmodulationtechnique(WMT)andactiveintracavitytechnique(ACIT)arefirstintroducedinthispaper,whichareusedtorealizetheconcentrationdetectionofmethaneandacetylenerespectively.WhenACITiscombinedwithwavelengthsweeptechnique(WST),thedetectionsensitivityofacetylenecanbeenhancedsharply.WhenACITiscombinedwithWSTandWMT,thedetectionsensitivityofacetylenecanbeenhancedfurther.
简介:Gas-liquidcouplingoscillationisanovelapproachtoreducingtheresonantfrequencyandtoelevatingthepressureamplitudeofathermoacousticengine.Ifathermoacousticengineisusedtodrivelow-frequencypulsetuberefrigerators,thefrequencymatchingbetweenthethermoacousticengineandtherefrigeratorplaysanimportantrole.Basedonanacoustic-electricanalogy,alumpedparametermodelisproposedtoestimatetheresonantfrequencyofastanding-wavethermoacousticenginewithgas-liquidcouplingoscillation.Furthermore,asimplifiedlumpedparametermodelisalsodevelopedtoreducethecomputationcomplexity.Theresonantfrequencydependenceonthemeanpressure,thegasspacevolume,andthewatercolumnlengthiscomputedandanalyzed.Theimpactofdifferentworkinggasesontheresonantfrequencyisalsodiscussed.Theeffectivenessofthemodelsisvalidatedbycomparingthecomputedresultswiththeexperimentaldataofthegas-liquidcouplingoscillationsystem.Anincreaseinthemeanworkingpressurecanleadtoariseintheresonantfrequency,andalowerresonantfrequencycanbeachievedbyelongatingtheliquidcolumn.Incomparisonwithnitrogenandargon,carbondioxidecanrealizealowerfrequencyduetoasmallerspecificheatratio.
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简介:Asecond-ordermomenttwo-phaseturbulencemodelforsimulatingdensegas-particleflows(USM-Θmodel),combiningtheunifiedsecond-ordermomenttwophaseturbulencemodelfordilutegas-particleflowswiththekinetictheoryofparticlecollision,isproposed.Theinteractionbetweengasandparticleturbulenceissimulatedusingthetransportequationoftwo-phasevelocitycorrelationwithatwo-time-scaledissipationclosure.Theproposedmodelisappliedtosimulatedensegas-particleflowsinahorizontalchannelandadowner.Simulationresultsandtheircomparisonwithexperimentalresultsshowthatthemodelaccountingforbothanisotropicparticleturbulenceandparticle-particlecollisionisobviouslybetterthanmodelsaccountingforonlyparticleturbulenceoronlyparticle-particlecollision.TheUSM-Θmodelisalsobetterthanthek-ε-kp-Θmodelandthek-ε-kp-εp-ΘmodelinthatthefirstmodelcansimulatetheredistributionofanisotropicparticleReynoldsstresscomponentsduetointer-particlecollision,whereasthesecondandthirdmodelscannot.
简介:Inthispaper,weconsiderthemulti-dimensionalasymptoticpreservingunifiedgaskineticschemeforgrayradiativetransferequationsondistortedquadrilateralmeshes.Differentfromtheformerscheme[J.Comput.Phys.285(2015),265-279]onuniformmeshes,inthispaper,inordertoobtaintheboundaryfluxesbasedontheframeworkofunifiedgaskineticscheme(UGKS),weusetherealmulti-dimensionalreconstructionfortheinitialdataandthemacro-termsintheequationofthegraytransferequations.Wecanprovethattheschemeisasymptoticpreserving,andespeciallyforthedistortedquadrilateralmeshes,anine-pointscheme[SIAMJ.SCI.COMPUT.30(2008),1341-1361]forthediffusionlimitequationsisobtained,whichisnaturallyreducedtostandardfive-pointschemefortheorthogonalmeshes.Thenumericalexamplesondistortedmeshesareincludedtovalidatethecurrentapproach.
简介:ThispaperistodiscussthesensingcharacteristicsofSnO2semiconductorcomponentsinwhichPr6O11isadded.Whenexperimentingunder11gasesofCH3COCH3,C2H5OH.C6H5CH3,H2,NH3,CO,CO2CH4,C4H10,n—C6H14andn—C7H16,wefindthatthecomponentshaveselectivitytoCH3COCH3,C2H5OHandthattheidealamountofPr6O11inthecomponentsisaboutI.Owt%.TheexperimentsalsoshowthatwiththeincreaseoftheamountofPr6O11,theidealworkingtemperature,theresponseandrestorationtimedecrease.
简介:克莱在在抵抗力索引之间的关系上有重要影响我和水浸透Sw(即,I-Sw关系)水库岩石因为它复杂化这些岩石的当前的路径。因为在岩石内的泥土的毛孔结构,微分发和内容不能在实验期间被观察并且控制,由物理实验室大小在各种各样的岩石的传导性上揭示这些泥土效果的物理机制是困难的。我们在场在水库的电的运输性质上学习这些泥土效果的一条数字岩石途径用格子气体在毛孔规模摇自动化(LGA)方法。数字岩石样品从水库岩石的SEM图象与谷物尺寸分发的信息被构造。LGA然后充分在这些数字岩石上被使用与液体浸透了为在I-Sw关系的非高射炮行为上揭示体积的效果和泥土的分发模式模仿电的运输性质。在模仿的结果和实验室大小之间的好协议清楚地在岩石物理的数字研究表明LGA的有效性。把研究基于这些,一个新模型为描述在浸透代表和泥土的体积之间的关系的份量上被开发了(V嘘)。这开发可以在水库岩石中为液体浸透改进评估。
简介:MicrodosimetricSpectrumandRadialDoseDistributionof239PnorRayinCH4Gas¥ZhuLianfang;LiXuekan;ChenXuebing;HeYusheng;SuYouwuand...