学科分类
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12 个结果
  • 简介:Non-lineardevelopmentofdoubletearingmodesinducedbyelectronviscosityisnumericallysimulated.MHDflowlayersaredemonstratedtomergeinthedevelopmentofthemodes.Theshearedflowsareshowntoliejustattheboundariesofthemagneticislands,andtohavesuffcientlevelsrequiredforinternaltransportbarrier(ITB)formation.PossiblecorrelationbetweenthelayerformationandtriggeringofexperimentallyobservedITBs,preferentiallyformedinproximitiesofrationalfluxsurfacesoflowsafetyfactors,isdiscussed.

  • 标签: MHD流层 边界 托卡马克等离子体 传送屏障 电子粘性
  • 简介:AdustsedimentlayerwasfoundontheoutertubewallwhentheESCP(electrostaticcentrifugalprecipitator)trappeddieselparticulatesorganistersand.TheComptonbackscattermethodwasusedtomeasurethesedimentthicknessduringtheexperiment.Theeffectoftheinletgasvelocityonthedustsedimentlayerwasinvestigated.PIV(ParticleImageVelocimetry)wasusedtomeasurethevelocityfieldbetweentheinnerbarbtubewallandtheoutertubewall.Experimentsshowedthatthethicknessofthesedimentincreasedwithtime,andthesedimentlayeratthelowerendwasmuchthickerthanthatattheupperend.Theagglomerationontheoutertubewallcouldberemovedwhentheinletgasvelocitywasincreasedtoacertainvalue.

  • 标签: 电晕等离子体 旋风收尘器 康普顿反向散射法 气体速度 灰尘沉积层
  • 简介:Synchrontronradiationx-rayreflectivitymeasurementisusedtostudytheconcentrationprofileofaδ-dopedErlayerinSiepitaxialfilmgrownbymolecular-beamepitaxy.Theoscillationofthereflectivityamplitudeasafunctionofreflectionangleisobservedintheexperiment.Bydoingatheoreticalsimulation.theconcentrationprofileofEratomscouldbederied.Itisshownthattheoriginallygrownδ-dopedErlayerchangesintoanexpionentiallydecayedfunctionduetotheErsegregation.Thetemperaturedependenceofthe1/edecaylengthindicatesthatthesegregationisakineticallylimitedprocess.Theactivationenergyisdeterminedtobe0.044±0.005eV.

  • 标签: 硅外延薄膜 铒掺杂 同步辐照 X射线反射率
  • 简介:Amulti-objectivehybridgeneticbasedoptimizationalgorithmisproposedaccordingtothemulti-objectivePropertyofinverseplanning.Itisbasedonhybridadaptivegeneticalgorithmwhichcombinesthesimulatedannealing,usesadaptivecrossoverandmutation,andadoptsnichedtournamentselection.Theresultoftheteatcalculatationdemonstratesthatanexcellentconvergingspeedcanbeachievedusingthisapproach.

  • 标签: 反转计划 多目标优化 遗传算法 等离子物理
  • 简介:Itisaverydifficulttasktodevelopamethodofreducingturbulentboundarylayerdrag.However,inrecentyears,plasmaflowcontroltechnologyhasdemonstratedhugepotentialinfrictiondragreduction.Tofurtherinvestigatethisissue,asmoothplatemodelwasdesignedasatestingobjectarrangedwithabidirectionaldielectric-barrier-discharge(DBD)plasmaactuator.Inaddition,measurementofskinfrictiondragwasachievedbyapplyinghotwireanemometrytoobtainthevelocitydistributionoftheturbulentboundarylayer.AmethodofquantifyingthefrictiondrageffectwasadoptedbasedontheSpaldingformulafittedwiththeexperimentdata.Whenplasmaactuationwasconducted,avelocitydefectoccurredatthetwomeasuringpositions,comparedwiththenoplasmacontrolcondition;thismeansthattheDBDplasmaactuationcouldreducethedragsuccessfullyinthedownstreamoftheactuator.Moreover,dragreductioncausedbybackwardactuationwasslightlymoreefficientthanthatcausedbyforwardactuation.Withanincreasingdistancefromplasmaactuation,thedrag-reductioneffectcouldbecomeweaker.Experimentalresultsalsoshowthattheimprovementofdrag-reductionefficiencyusingaDBDplasmaactuatorcanachieveabout8.78%inthelocalregionoftheexperimentalflatmodel.

  • 标签: DBD plasma ACTUATOR flow control Spalding
  • 简介:Magneticspectrumoftheelectromagneticioncyclotronwavesintheterrestrialplasmadepletionlayer(PDL)aresometimesobservedtohaveaBIF(bifurcated)signature,whereadiminutionaround0.5ΩpwithΩptheprotongyrofrequency,occursbetweentwoactivitypeaksinthespectrum.Byone-dimensionalhybridsimulations,theeffectofrelativedriftvelocitiesbetweenprotonsandHe2+onthemagneticspectralsignaturesinthePDLisstudied.Theresultsshowthattherelativedriftvelocityenhancesthedevelopmentofprotoncyclotronwavesanddeclinesthedevelopmentofheliumcyclotronwaves.Theprotoncyclotronwavesarefirstlyexcited,andfollowedbytheexcitationofheliumcyclotronwavesduetotheincreaseintherelativedriftvelocity.Moreover,theboundarybetweentwoactivitypeaksgetsobscure.

  • 标签: 质子回旋加速器 漂移速度 光谱特征 耗尽层 等离子 离子回旋波
  • 简介:A1-Dfluidmodelforhomogeneousdielectricbarrierdischarge(DBD)inheliumispresented,aimedatunravelingthespatial-temporalcharacteristicsoftwobasicdischargeregimes:single-breakdownandmulti-breakdowndischarges.Dischargecurrents,gapvoltages,chargedensities,electrontemperatureandelectricfieldprofilesofthetworegimesmakeitclearthatthesetworegimesarequalitativelydifferent.Itisfoundthatthemulti-breakdowndischargehasamorehomogeneousfluxondielectricscomparedtothesingle-breakdowndischarge.

  • 标签: 故障放电 DBD 数值研究 氦气 大气压 介质阻挡放电
  • 简介:Removalofsinglecomponentandbinarymixturesofbenzeneandm-xyleneusingamulti-pin-meshreactorwasstudiedtofindthedecompositioncharacteristics,carbonbalanceandCO_2selectivity.Thedecompositionrateofbenzeneinmixturewasapproximately16%lowerthanthatofsinglecomponentbenzene.However,thedecompositionrateofm-xyleneinmixturewasslightlyhigherthanthatofsinglecomponentm-xylene.Carbonbalanceofthemixturedecompositionprocessachievedalowerlevelthanthatofsinglecomponentbenzene/m-xylene.IncreaseinthespecificinputenergywashelpfultoimproveCO_2selectivityinthesinglecomponentdecompositionprocess,whilethespecificinputenergyhadanegligibleeffectonCO_2selectivityinthemixturedecompositionprocess.Bychangingtheoxygencontentinbackgroundgas,wefoundthatdifferenttypesofradicalsshoweddifferentreactionactivitiestowardbenzeneandm-xylene.Benzenewasmorelikelytoreactwithnitrogen-containingradicals,whilem-xylenewasmorelikelytoreactwithoxygen-containingradicals.

  • 标签: 二元混合物 挥发性有机化合物 脉冲高电压 VOCS 电晕放电 间二甲苯
  • 简介:Interactionbetweenhigh-intensitypulsedionbeam(HIPIB)andadouble-layertargetwithtitaniumfilmontopofaluminumsubstratewassimulated.Thetwo-dimensionalnonlinearthermalconductionequations,withthedepositedenergyinthetargettakenassourceterm,werederivedandsolvedbyfinitedifferentialmethod.Asaresult,thetwo-dimensionalspatialandtemporalevolutionprofilesoftemperaturewereobtainedforatitanium/aluminumdouble-layertargetirradiatedbyapulseofHIPIB.Theeffectsofionbeamcurrentdensityonthephasestateofthetargetmaterialsnearthefilmandsubstrateinterfacewereanalyzed.BothtitaniumandaluminumweremeltedneartheinterfaceaRerashotwhentheionbeamcurrentdensityfellintherangeof100A/cm~2to200A/cm~2.

  • 标签: 脉冲离子束 高强度 数值研究 温度 辐照场 非线性热传导方程