简介:Implementationofaweb-basedlogbooksystemonEASTisintroduced,whichcanstorethecommentsfortheexperimentsintoadatabaseandaccessthedocumentsviavariouswebbrowsers.Thethree-tiersoftwarearchitectureandasynchronousaccesstechnologyareadoptedtoimprovethesystemeffectively.Authorizeduserscanviewtheinformationofreal-timedischarge,commentsfromothersandsignalplots;add,delete,orrevisetheirowncomments;searchsignaldataorcommentsundercomplicatedsearchconditions;andcollectrelevantinformationandoutputittoanexcelfile.Thewebpagescanbeautomaticallyupdatedafteranewdischargeiscompletedandwithoutrefreshment.
简介:Neutrondiagnostics,includingfluxandenergyspectrummeasurements,havebeenappliedontheexperimentaladvancedsuperconductingtokamak(EAST).TheabsolutecalibrationofneutronyieldshasbeenachievedbyacalculationmethodusingtheMonteCarloautomaticmodeling(MCAM)systemandtheMonteCarloN-Particles(MCNP)code.Sincetheneutronyieldiscloselyrelatedwiththeiondensityandtemperature,itisagoodmeasureofplasmaperformance,especiallythewaveheatingeffect.Inioncyclotronrangeoffrequencies(ICRF)experiments,theincreaseintheiontemperaturederivedbytheneutronyieldindicatesaneffectiveplasmaheating.Minorityprotonsdampalargefractionofthetotalwavepower,andthentransferpartoftheenergytodeuteriumbycollisions.NeutronspectrummeasurementsalsoindicatethatnotailiscreatedbyhighenergydeuteronsduringICRFheating.However,theiontemperaturederivedbytheneutronyieldisconsistentwiththeresultbyusingapoloidalX-rayimagingcrystalspectrometer(PXCS),showingareliabletransportcalculation.
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简介:Atriggerdeviceandatriggeredpseudosparkswitch(TPSS)weredesignedbasedonsurfaceflashovertechnology,inordertomeettherequirementsfrompresentpulsepowertechnol-ogyandpulsecurrenttesttechnologysuchasalonglifetime,reliabilityinawidevoltagerange,ashortdelaytime,aswellassmalldelayjitters.Thetriggerdevicesweremadefromdifferentdielectricmaterials,withtheirpermittivitiesfromtenstothousands.ThetriggercharacteristicsofTPSSwereinvestigated.Theresultsindicatethatthehigh-dielectrictriggerdeviceshowsbetterperformanceandhigheremittedchargeoftheelectronemissionwithinalladjustedparametersincludingthegaspressureandappliedvoltage.Forthedielectricmaterialwithrelativepermittiv-ityε_rof3460,whenthegaspressureis7Pa,thehold-offvoltageofTPSSis28kV,theminimumtriggerswitchvoltagedropsto128V,theminimumdischargingdelaytimeanddelayjitterarelessthan35nsand6ns,respectively,andthereliableoperationcanbereachedwithinaverylargerangeofchargingvoltage,between0.46%and99%ofitsself-breakdownvoltage.
简介:Breakdowncharacteristicsofagapbreakdownloadwasinvestigatedinthispaper,andareverselyswitcheddynistor(RSD)dischargecircuitwasdesignedbasedontheload.Basedonthecharacteristicsoftheload,theRSDdischargecircuitwasimprovedandoptimized.Thevolumeofthemagneticswitchwasreduced.ToprotectthethyristorandRSD,adiodewasantiparallelyconnectedwiththethyristor,whichreducedthetimerequirementwhenapowervoltagewasappliedtoRSD.Experimentalresultsshowthecircuitdesignedinthispapercanswitchahighvoltageandhighcurrentsmoothly,andallowsthepowervoltagetochangeinawiderrange.
简介:Amulti-objectivehybridgeneticbasedoptimizationalgorithmisproposedaccordingtothemulti-objectivePropertyofinverseplanning.Itisbasedonhybridadaptivegeneticalgorithmwhichcombinesthesimulatedannealing,usesadaptivecrossoverandmutation,andadoptsnichedtournamentselection.Theresultoftheteatcalculatationdemonstratesthatanexcellentconvergingspeedcanbeachievedusingthisapproach.
简介:AfewCT-basedvoxelphantomswereproducedtoinvestigatethesensitivityofMonteCarlosimulationsofX-raybeamandelectronbeamtotheproportionsofelementsandthemassdensitiesofthematerialsusedtoexpressthepatient'sanatomicalstructure.Thehumanbodycanbewelloutlinedbyair,lung,adipose,muscle,softboneandhardbonetocalculatethedosedistributionwithMonteCarlomethod.TheeffectsofthecalibrationcurvesestablishedbyusingvariousCTscannersarenotclinicallysignificantbasedonourinvestigation.ThedeviationfromthevaluesofcumulativedosevolumehistogramderivedfromCT-basedvoxelphantomsislessthan1%forthegiventarget.
简介:Laser-inducedbreakdownspectroscopy(LIBS)wasdevelopedtodetectaluminuminnickel-basedsuperalloys(K417,GH4033,DZ125L,(?)742y)usinganon-intensified,non-gated,low-costdetectionsystem.TheprecisionofLIBSdependsstronglyontheexperimentalconditions.ThecalibrationcurvesofA1(I)394.4nmandA1(I)396.2nmundertheoptimumexperimentalparametersarepresented.Finallythelimitofdetection(LOD)foraluminumiscalculatedfromtheexperimentaldata,whichisintherangeof0.09%to0.1%byweight.
简介:Thegeometryofaninductivelycoupledplasma(ICP)etcherisusuallyconsideredtobeanimportantfactorfordeterminingbothplasmaandprocessuniformityoveralargewafer.Duringthepastfewdecades,theseparametersweredeterminedbythe'trialanderror'method,resultinginwastesoftimeandfunds.Inthispaper,anewapproachofregressionorthogonaldesignwithplasmasimulationexperimentsisproposedtoinvestigatethesensitivityofthestructuralparametersontheuniformityofplasmacharacteristics.ThetoolforsimulatingplasmaisCFD-ACE+,whichiscommercialmulti-physicalmodelingsoftwarethathasbeenproventobeaccurateforplasmasimulation.Thesimulatedexperimentalresultsareanalyzedtogetaregressionequationonthreestructuralparameters.Throughthisequation,engineerscancomputetheuni-formityoftheelectronnumberdensityrapidlywithoutmodelingbyCFD-ACE+.Anoptimizationperformedattheendproducesgoodresults.
简介:Asanimportantnon-ferrousmetalstructuralmaterialmostusedinindustryandproduction,aluminum(Al)alloyshowsitsgreatvalueinthenationaleconomyandindustrialmanufacturing.HowtoclassifyAlalloyrapidlyandaccuratelyisasignificant,popularandmeaningfultask.Classificationmethodsbasedonlaser-inducedbreakdownspectroscopy(LIBS)havebeenreportedinrecentyears.AlthoughLIBSisanadvanceddetectiontechnology,itisnecessarytocombineitwithsomealgorithmtoreachthegoalofrapidandaccurateclassification.Asanimportantmachinelearningmethod,therandomforest(RF)algorithmplaysagreatroleinpatternrecognitionandmaterialclassification.ThispaperintroducesarapidclassificationmethodofAlalloybasedonLIBSandtheRFalgorithm.TheresultsshowthatthebestaccuracythatcanbereachedusingthismethodtoclassifyAlalloysamplesis98.59%,theaverageofwhichis98.45%.ItalsorevealsthroughtherelationshiplawsthattheaccuracyvarieswiththenumberoftreesintheRFandthesizeofthetrainingsamplesetintheRF.Accordingtothelaws,researcherscanfindouttheoptimizedparametersintheRFalgorithminordertoachieve,asexpected,agoodresult.TheseresultsprovethatLIBSwiththeRFalgorithmcanexactlyclassifyAlalloyeffectively,preciselyandrapidlywithhighaccuracy,whichobviouslyhassignificantpracticalvalue.
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.
简介:Oneofthetechnicalbottlenecksoftraditionallaser-inducedbreakdownspectroscopy(LIBS)isthedifficultyinquantitativedetectioncausedbythematrixeffect.Totroubleshootthisproblem,thispaperinvestigatedacombinationoftime-resolvedLIBSandconvolutionalneuralnetworks(CNNs)toimproveKdeterminationinsoil.Thetime-resolvedLIBScontainedtheinformationofbothwavelengthandtimedimension.Thespectraofwavelengthdimensionshowedthecharacteristicemissionlinesofelements,andthoseoftimedimensionpresentedtheplasmadecaytrend.Theone-dimensionaldataofLIBSintensityfromtheemissionlineat766.49nmwereextractedandcorrelatedwiththeKconcentration,showingapoorcorrelationofR^2c=0.0967,whichiscausedbythematrixeffectofheterogeneoussoil.Forthewavelengthdimension,thetwo-dimensionaldataoftraditionalintegratedLIBSwereextractedandanalyzedbyanartificialneuralnetwork(ANN),showingR^2v=0.6318andtherootmeansquareerrorofvalidation(RMSEV)=0.6234.Forthetimedimension,thetwo-dimensionaldataoftime-decayLIBSwereextractedandanalyzedbyANN,showingR^2v=0.7366andRMSEV=0.7855.Thesehigherdeterminationcoefficientsrevealthatboththenon-KemissionlinesofwavelengthdimensionandthespectraldecayoftimedimensioncouldassistinquantitativedetectionofK.However,duetolimitedcalibrationsamples,thetwo-dimensionalmodelspresentedover-fitting.Thethree-dimensionaldataoftime-resolvedLIBSwereanalyzedbyCNNs,whichextractedandintegratedtheinformationofboththewavelengthandtimedimension,showingtheR^2v=0.9968andRMSEV=0.0785.CNNanalysisoftime-resolvedLIBSiscapableofimprovingthedeterminationofKinsoil.
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:Co-basedcatalystswerepreparedbyusingdielectric-barrierdischarge(DBD)plasmaasanalternativemethodtoconventionalthermalcalcination.ThecharacterizationresultsofN2-physisorption,temperatureprogrammedreduction(TPR),transmissionelectronmicroscope(TEM),andX-raydiffraction(XRD)indicatedthatthecatalystspreparedbyDBDplasmahadahigherspecificsurfacearea,lowerreductiontemperature,smallerparticlesizeandhighercobaltdispersionascomparedtocalcinedcatalysts.TheDBDplasmamethodcanpreventthesinteringandaggregationofactiveparticlesonthesupportduetothedecreasedtreatmenttime(0.5h)atlowertemperaturecomparedtothelongerthermalcalcinationathighertemperature(at500℃for5h).Asaresult,thecatalyticperformanceoftheFischer-TropschsynthesisonDBDplasmatreatedCo/SiO2catalystshowedanenhancedactivity,C5+selectivityandcatalyticstabilityascomparedtotheconventionalthermalcalcinedCo/SiO2catalyst.
简介:Anexperimentalsetuphasbeendesignedandrealizedinordertooptimizethecharacteristicsoflaser-inducedbreakdownspectroscopysystemworkinginvariouspressureenvironments.Anapproachcombinedthenormalizationmethodswiththepartialleastsquares(PLS)methodaredevelopedforquantitativeanalysisofmolybdenum(Mo)elementinthemulti-componentalloy,whichisthefirstwallmaterialintheExperimentalAdvancedSuperconductingTokamak.Inthisstudy,thedifferentspectralnormalizationmethods(totalspectralareanormalization,backgroundnormalization,andreferencelinenormalization)areinvestigatedforreducingtheuncertaintyandimprovingtheaccuracyofspectralmeasurement.TheresultsindicatesthattheapproachofPLSbasedoninter-elementinterferenceissignificantlybetterthantheconventionalPLSmethodsaswellastheunivariatelinearmethodsinthevariouspressureformolybdenumelementanalysis.