简介：

简介：SawtoothactivityonHT-7tokamakhasbeeninvestigatedexperimentallymainlybyusingsoftx-raydiodearrayandmagneticprobes.Theirbehaviorsandoccurrencesarecorrelatedcloselytothedischargeconditions:theelectrondensityNe,theelectrontemperatureTe,thesafetyfactorqaonplasmaboundaryandwallconditionetc.Whencentralline-averagedelectrondensityNe(0)isover2.0×1013cm-3,majorsawtoothactivityemergeswithaperiodofupto6.5msandafluctuationamplitudeofupto2～30%ofSXRradiationsignal.Insomecasessuchasthesafetyfactorbetween4.2～4.7andZeff=3.0～6.0,amonstersawtoothactivityoftenemergeswithoutapparentdeteriorationofplasmaconfinementandwithoutmajordisruption.Duringtheseevents,abundantMHDphenomenaareobservedincludingpartialsawtoothoscillations.Inthispaper,theobservedsawtoothbehaviorsandtheirdependenceontheandtheirdependencedensityNeandwallconditioninohmicallyheatedplasmaareintroduced,theresultsarediscussedandpresented.

简介：

简介：Implementationofaweb-basedlogbooksystemonEASTisintroduced,whichcanstorethecommentsfortheexperimentsintoadatabaseandaccessthedocumentsviavariouswebbrowsers.Thethree-tiersoftwarearchitectureandasynchronousaccesstechnologyareadoptedtoimprovethesystemeffectively.Authorizeduserscanviewtheinformationofreal-timedischarge,commentsfromothersandsignalplots;add,delete,orrevisetheirowncomments;searchsignaldataorcommentsundercomplicatedsearchconditions;andcollectrelevantinformationandoutputittoanexcelfile.Thewebpagescanbeautomaticallyupdatedafteranewdischargeiscompletedandwithoutrefreshment.

简介：AseriesofoxideizedCO-K-Mo/γ-Al2O3catalystsamples,preparedbyimpregnatingoxidizedK-Mo/γ-Al2O3sampleswithanaqueoussolutionofcalculatedCo(NO3)2andthencalcininginairattemperaturesof350℃，500℃65℃and800℃respectively,weresulfidedandtheninvestigatedfortheactivityinthesynthesisofmixedalcoholsfromCOhydrogenationunderconditionsofp=5.0MPa,T=350℃andGHSV=4800h^-1.TheresultsdemonstratethattheadditionofcobaltpromoterisfavorabletotheformationofhigheralcoholsandtheopimumcalcinationtemperaturesafterimpregnatingwithCo^2+areabout500-650℃.ThestructureofCoandMospeciesontheoxidizedandsulfidedsampleswasdeterminedbyX-raydiffraction(XRD),laserRamanspectrum(LRS)andextendedX-rayabsorptionfinestructure(EXAFS).Foroxidizedsamplecalcinedat350℃,cobaltexistsasCo3O4spectiesandcoversthesurfaceofK-Mo-Ospecies,thestructureofK-Mo-OspeciesisthesameasthatinK-Mo/Al2O3sample.TheinteractionbetweencobaltandK-Mo-Ospeciesisrelativelyweak.Aftersulfidation.Cobaltexistsassulfidecrystalliteswithanoctahedralcoordinatedstructure,andmolybdenumasMoS2crystallites.Foroxidizedsamplescalcinedat500-650℃,CocomponentinteractswiththeK-Mo-Ospeciesanddestroysthelong-rangeorderoftheK-Mo-Ospectesgradually,Aftersulfidation.CotendstoexistasasulfidewithtetrahedralcoordinatedstructureandMostillasMoS2crystallites.Foroxidizedsamplecalcinedat800℃,CocomponentexistsmainlyasCoAl2O4species,mostofwhichcannotbesultidedduringsulfidation.

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.

简介：

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：

简介：

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：

简介：

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.