简介：Tounveilthecharacteristicsandavailablepropagationmechanismofcoaxial-typemicrowaveexcitedline-shapeplasma,theeffectsofparametersincludingmicrowavepower,workingpressure,dielectricconstant,andexternalmagneticfieldontheplasmadistributionwerenumericallyinvestigatedbysolvingacoupledsystemofMaxwell’sequationsandcontinuityequations.Numericalresultsindicatethathighmicrowavepower,relativelyhighworkingpressure,lowdielectricconstant,andshapedmagneticfieldprofileswillhelpproduceahigh-densityanduniformplasmasource.Excitingbothendsbymicrowavecontributedtothehigh-densityanduniformplasmasourceaswell.Possiblemechanismswereanalyzedbyusingthepolarizationmodeloflowtemperatureplasma.Thegenerationandpropagationprocessesoftheline-shapeplasmamainlydependontheinteractionofthreeaspects,i.e.thetransmittedpart,penetrationpartandabsorptivepartoftheelectromagneticfield.Thenumericalresultswerequalitativelyconsistentwithavailableexperimentalresultsfromliterature.Moreelaboratedescriptionsofthethreeaspectsandcorrespondinginteractionsamongthemneedtobeinvestigatedfurthertoimprovethepropertiesoftheline-shapeplasma.

简介：Chemicalvapordeposition-tungsten(CVD-W)coatingcoveringthesurfaceoftheplasmafacingcomponent(PFC)isaneffectivemethodtoimplementthetungstenmaterialasplasmafacingmaterial(PFM)infusiondevices.ResidualthermalstressinCVD-Wcoatingduetothermalmismatchbetweencoatingandsubstratewassuccessfullysimulatedbyusingafiniteelementmethod(ANSYS10.0code).Thedepositionparametriceffects,i.e.,coatingthicknessanddepositiontemperature,andinterlayerwereinvestigatedtogetadescriptionoftheresidualthermalstressintheCVD-Wcoating-substratesystem.AndtheinfluenceofthesubstratematerialsonthegenerationofresidualthermalstressintheCVD-WcoatingwasanalyzedwithrespecttotheCVD-WcoatingapplicationasPFM.ThisanalysisisbeneficialforthepreparationandapplicationofCVD-Wcoating.

简介：Thispaperpresentstheresultsofourinvestigationsofbreakdownmechanisms,aswellasadescriptionoftheirinfluenceonthedistributionsoftimedelaydistributions,foragastubefilledwithnitrogenat4mbar.Thevaluesofthetimedelayaremeasuredfordifferentvoltages,andthevaluesoftherelaxationtimesandtheirdistributionsandprobabilityplotsareanalyzed.TheobtaineddensitydistributionshaveGaussiandistributionsandexponentialdistributionsfordifferentvaluesofrelaxationtimes(Gaussianforsmallvaluesandexponentialforlargevaluesofrelaxationtime).ItisshownthatformiddlevaluesofrelaxationtimethedelaydistributionshaveashapebetweenGaussianandexponentialdistributions,whichisaresultofthedifferentinfluencesofelectricalbreakdown.

简介：IntheframeworkoftheITER,qualificationtests,thefirstChinaTFconductorsample（CNTFl）wastestedattheSULTANfacility.ThesamplewasmadeoftwoTFconductorsectionsmanufacturedfromidenticalinternalstannumstrandsprovidedbytheOxfordSuperconductingtechnologycompany（OST）.Inordertoevaluatetheconductorperformance,thecurrentsharingtemperature(Tcs)wasmeasuredatspecifiedelectromagneticloadcyclingsteps.BothconductorsectionsoftheCNTFlsampleshowedidenticalperformance.Tcswas7.2Kbeforecyclingloading,and6.9Kevenafter950cycles,withoutsignificantdegradation,whichsubstantiallyexceedstheITERrequirementof5.7K.ThetestsoftheCNTFlconductorsampleshowedthattheelectromagneticcyclicloadexhibitedanegligibleeffectontheconductorperformance.Thecouplingtimeconstant8forAClosswas214msand71.52msbeforeandafterthecyclingload,respectively.Thetestresultsofthesamplearecomparedwiththestrandperformanceandparametermodelanalysis.

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简介：Tomakethelarge-scaleheliumcryogenicsystemoffusiondeviceEAST(experimentaladvancedsuper-conductingtokamak)runstably,asthecorepart,theheliumturbineexpandermustmeettherequirementofrefrigerationcapacity.However,previousdesignswerebasedononedimensionflowtodeterminetheaveragefluidparametersandgeometricparametersofimpellercross-sections,sothatitcouldnotdescriberealphysicalprocessesintheinternalflowoftheturbineexpander.Therefore,basedontheinversepropositionofstreamlinecurvaturemethodinthecontextofquasi-three-dimensionalflows,theall-over-controlledvortexconceptwasadoptedtodesigntheimpellerunderspecifiedcondition.Thewrapangleoftheimpellerbladeandthewholeflowdistributiononthemeridianplanewereobtained;meanwhiletheperformanceofthedesignedimpellerwasanalyzed.Thusanewdesignmethodisproposedherefortheinversepropositionoftheheliumturbineexpanderimpeller.

简介：Accordingtothemultipleresearchesinthelastcoupleofyears,laser-inducedbreakdownspectroscopy(LIBS)hasshownagreatpotentialforrapidanalysisinsteelindustry.Nevertheless,theaccuracyandprecisionmaybelimitedbycomplexmatrixeffectandself-absorptioneffectofLIBSseriously.Anovelmultivariatecalibrationmethodbasedongeneticalgorithm-kernelextremelearningmachine(GA-KELM)isproposedforquantitativeanalysisofmultipleelements(Si,Mn,Cr,Ni,V,Ti,Cu,Mo)inforty-sevencertifiedsteelandironsamples.First,thestandardizedpeakintensitiesofselectedspectralinesareusedastheinputofmodel.Then,thegeneticalgorithmisadoptedtooptimizethemodelparametersduetoitsobviouscapabilityinfindingtheglobaloptimumsolution.Basedonthesetwostepsabove,thekernelmethodisintroducedtocreatekernelmatrixwhichisusedtoreplacethehiddenlayer’soutputmatrix.Finally,theleastsquareisappliedtocalculatethemodel’soutputweight.InordertoverifythepredictivecapabilityoftheGA-KELMmodel,theR-squarefactor(R2),Root-mean-squareErrorsofCalibration(RMSEC),Root-mean-squareErrorsofPrediction(RMSEP)ofGA-KELMmodelarecomparedwiththetraditionalPLSalgorithm,respectively.TheresultsconfirmthatGA-KELMcanreducetheinterferencefrommatrixeffectandself-absorptioneffectandissuitableformulti-elementscalibrationofLIBS.

简介：InHL-2Atokamaks,thebehaviorofheatfluxdepositedonthedivertortargetshasbeenstudiedduringdeuteriumgasfuelling.Theheatfluxisreducedsignificantlyaftersupersonicmolecularbeaminjection(SMBI)fuellingduringOhmicandelectroncyclotronresonanceheating(ECRH)divertordischarges.TheSMBIfuellingcausesanincreaseintheplasmadensityandthischangeresultsintheexperiencedchangeoftheedgeproperties.MostofthisreductionindivertortargetheatfluxoccurstogetherwithahighplasmaradiationregionlocatedatneartheX-point.Thelargestreductioninheatfluxprofilesisobservedattheoutboarddivertorseparatrixstrikepoint,whiletheheatfluxfarfromthestrikepointremainsalmostunchanged.Inparticular,withSMBImulti-pulsesgasfuelling,apartiallydetacheddivertorregimeisobservedwithahighlyradiatingregionattheX-point.Withtheonsetofthepartiallydetacheddivertorregime,asuddendropinbothheatfluxandpowerflowonthedivertortargetisobserved.Thereductioninpowerloadonthedivertortargetsisroughlyequaltotheincreaseinplasmaradiationloss.

简介：BasedonthetransmissionlinecodeTLCODE,a1Dcircuitmodelforatransmissionlineimpedancetransformerwasdevelopedandthesimulationresultswerecomparedwiththoseintheliterature.Themodelwasusedtoquantifytheefficienciesofvoltage-transport,energytransportandpower-transportforatransmission-lineimpedancetransformerasfunctionsofΨ(theratiooftheoutputimpedancetotheinputimpedanceofthetransformer)andΓ(theratioofthepulsewidthtotheone-waytransittimeofthetransformer)underalargescaleofm(thecoefficientofthegeneralizedexponentialimpedanceprofile).SimulationresultssuggestthatwiththeincreaseinΓ,fromOto∞,thepowertransportefficiencyfirstincreasesandthendecreases.Themaximumpowertransportefficiencycanreach90%orevenhigherforanexponentialimpedanceprofile(m=1).Withaconsiderationofdissipativelossinthedielectricandelectrodesofthetransformer,tworepresentativedesignsofthewater-insulatedtransformerareinvestigatedforthenextgenerationofpetawatt-classz-pinchdrivers.Itisfoundthatthedissipativelossesintheelectrodesarenegligiblysmall,below0.1%,butthedissipativelossinthewaterdielectricisabout1%to4%.

简介：Thegeometryofaninductivelycoupledplasma(ICP)etcherisusuallyconsideredtobeanimportantfactorfordeterminingbothplasmaandprocessuniformityoveralargewafer.Duringthepastfewdecades,theseparametersweredeterminedbythe'trialanderror'method,resultinginwastesoftimeandfunds.Inthispaper,anewapproachofregressionorthogonaldesignwithplasmasimulationexperimentsisproposedtoinvestigatethesensitivityofthestructuralparametersontheuniformityofplasmacharacteristics.ThetoolforsimulatingplasmaisCFD-ACE+,whichiscommercialmulti-physicalmodelingsoftwarethathasbeenproventobeaccurateforplasmasimulation.Thesimulatedexperimentalresultsareanalyzedtogetaregressionequationonthreestructuralparameters.Throughthisequation,engineerscancomputetheuni-formityoftheelectronnumberdensityrapidlywithoutmodelingbyCFD-ACE+.Anoptimizationperformedattheendproducesgoodresults.

简介：Opticalemissionspectroscopy(OES)wasappliedforplasmacharacterizationduringtheerosionofasphaltenesubstrates.Anamountof100mgofasphaltenewascarefullyappliedtoanelectrodeandexposedtoair-plasmaglowdischargeatapressureof1.0Torr.Theplasmawasgeneratedinastainlesssteeldischargechamberbyanacgeneratoratafrequencyof60Hz,outputpowerof50Wandagasflowrateof1.8L/min.Theelectrontemperatureandiondensitywereestimatedtobe2.15±0.11eVand(1.24±0.05)×1016m-3,respectively,usingadoubleLangmuirprobe.OESwasemployedtoobservetheemissionfromtheasphalteneexposedtoairplasma.BothmolecularbandemissionfromN2,N+2,OH,CH,NH,O2aswellasCN,andatomiclightemissionfromVandHγwereobservedandusedtomonitortheevolutionofasphalteneerosion.Theasphalteneerosionwasanalyzedwiththeaidofascanningelectronmicroscope(SEM)equippedwithanenergydispersiveX-ray(EDX)detector.TheEDXanalysisshowedthatthetimeevolutionofelementsC,O,SandVweresimilar;andthechemicalcompositionoftheexposedasphaltenesremainedconstant.Particlesizeevolutionwasmeasured,showingamaximumsizeof2307μmafter60min.Thisbehaviorismostlikelyrelatedtoparticleagglomerationasafunctionoftime.

简介：Athreedimensionalsteady-statemagnetohydrodynamicmodelisdevelopedforthearcplasmainaDCsubmergedelectricarcfurnacefortheproductionoffusedMgO.Thearcisgeneratedinasmallsemi-enclosedspaceformedbythegraphiteelectrode,themoltenbathandunmeltedrawmaterials.Themodelisfirstusedtosolveasimilarprobleminasteelmakingfurnace,andthecalculatedresultsarefoundtobeingoodagreementwiththepublishedmeasurements.ThebehaviorofarcswithdifferentarclengthsisalsostudiedinthefurnaceforMgOproduction.Fromthedistributionofthearcpressureonthebathsurfaceitisshownthatthearcplasmaimpingementislargeenoughtocauseacrater-likedepressiononthesurfaceoftheMgObath.Thecirculationofthehightemperatureairundertheelectrodemayenhancethearcefficiency,especiallyforashorterarc.

简介：Theaccuracyoflaser-inducedbreakdownspectroscopy(LIBS)quantitativemethodisgreatlydependentontheamountofcertifiedstandardsamplesusedfortraining.However,inpracticalapplications,onlylimitedstandardsampleswithlabeledcertifiedconcentrationsareavailable.Anovelsemi-supervisedLIBSquantitativeanalysismethodisproposed,basedonco-trainingregressionmodelwithselectionofeffectiveunlabeledsamples.Themainideaoftheproposedmethodistoobtainbetterregressionperformancebyaddingeffectiveunlabeledsamplesinsemi-supervisedlearning.First,effectiveunlabeledsamplesareselectedaccordingtothetestingsamplesbyEuclideanmetric.Twooriginalregressionmodelsbasedonleastsquaressupportvectormachinewithdifferentparametersaretrainedbythelabeledsamplesseparately,andthentheeffectiveunlabeledsamplespredictedbythetwomodelsareusedtoenlargethetrainingdatasetbasedonlabelingconfidenceestimation.Thefinalpredictionsoftheproposedmethodonthetestingsampleswillbedeterminedbyweightedcombinationsofthepredictionsoftwoupdatedregressionmodels.Chromiumconcentrationanalysisexperimentsof23certifiedstandardhigh-alloysteelsampleswerecarriedout,inwhich5sampleswithlabeledconcentrationsand11unlabeledsampleswereusedtotraintheregressionmodelsandtheremaining7sampleswereusedfortesting.Withthenumbersofeffectiveunlabeledsamplesincreasing,therootmeansquareerroroftheproposedmethodwentdownfrom1.80%to0.84%andtherelativepredictionerrorwasreducedfrom9.15%to4.04%.

简介：Anexperimentalsetuphasbeendesignedandrealizedinordertooptimizethecharacteristicsoflaser-inducedbreakdownspectroscopysystemworkinginvariouspressureenvironments.Anapproachcombinedthenormalizationmethodswiththepartialleastsquares(PLS)methodaredevelopedforquantitativeanalysisofmolybdenum(Mo)elementinthemulti-componentalloy,whichisthefirstwallmaterialintheExperimentalAdvancedSuperconductingTokamak.Inthisstudy,thedifferentspectralnormalizationmethods(totalspectralareanormalization,backgroundnormalization,andreferencelinenormalization)areinvestigatedforreducingtheuncertaintyandimprovingtheaccuracyofspectralmeasurement.TheresultsindicatesthattheapproachofPLSbasedoninter-elementinterferenceissignificantlybetterthantheconventionalPLSmethodsaswellastheunivariatelinearmethodsinthevariouspressureformolybdenumelementanalysis.