简介：Thedielectricbarrierdischarge(DBD)intheglowregimeinneonhasbeeninvestigatedbyexperimentandtwo-dimensional(2D)fluidmodeling.ThedischargewascarriedoutinaplanarDBDsystemwithsegmented-electrodesdrivenbysquare-wavevoltage.TheresultsshowthattheglowDBDoriginatesinthecenteroftheelectrodeandexpandsoutwardtotheelectrodeedgeduringeachhalfcycleofthevoltage,formingaradialstructure.Thedischargedecaysfirstlyintheinnerareabutsustainslongerintheedgearea,showingareverseddischargearea.Thedischargecannotcompletelycovertheentireelectrodesurface,butremainsaborderofnon-orweakdischarge.Thefluidmodelingshowsasimilarresultinagreementwiththeexperiments.Thesimulationsindicatethattheelectricfieldintheedgeareaisdistortedduetotheboundaryeffectsothattheelectricfieldandchargedistributionaredifferentfromthatintheinnerpart.Thedistortedfieldreducesthelongitudinalcomponentneartheedgeandcausesthelocalfieldtobelowerthanthatinthecenter,andhencemakesthedischargebehindhand.Italsoinducesatransversefieldthatmakesthedischargeextendradiallyoutwardtotheedge.TheboundaryeffectplaysanimportantroleintheglowDBDstructure.
简介：Tocleantheexhaustemissionsasoneofthemostimportanttasksinpollutioncontrol,astudyonthetreatmentofengineemissionswithdischargeassistancewasreported.ADBDplasmasourceshapedingridandcylinderwasexaminedindifferentengineoperationalmodestoreducetheNO_xcontentofdieselengineexhaust.Thecompositionoftheexhaustgasesandchemicalreactionsinitiatedbythedischargewereanalyzed.Thedischargeh'equencyhadacrucialimpactonthedevice'sperformanceandgastreatment.Thevoltagesappliedtothedischargegapcouldalterthechemicalreactionsoccurringinthetreatedgases,whichwereindicatedbytheNOtoNO_2ratio.Theoperationofthesystemwasstudiedatfrequenciesrangingfrom400Hzto16kHz.
简介：Anatmospheric-pressureargonplasmajetwithscrewring-ringelectrodesinsurfacedielectricbarrierdischargeisgeneratedbyasinusoidalexcitationvoltageat8kHz.Thedischargecharacteristics,suchasrotationalandvibrationaltemperatureofnitrogen,electronicexcitationtemperature,oxygenatomicdensity,nitrogenmoleculardensity,andaverageelectrondensity,areestimated.Itisfoundthattherotationaltemperatureofnitrogenisintherangeof352～392KbycomparingthesimulatedspectrumwiththemeasuredspectrumattheC3Πu→B3Πg(△ν=2)bandtransition,theelectronicexcitationtemperatureisfoundtobeintherangeof3127～3230KbyusingtheBoltzmannplotmethod,theoxygenatomicandnitrogenmoleculardensityareoftheorderofmagnitudeof1016cm-3bytheactinometrymethod,andtheaverageelectrondensityisoftheorderofmagnitudeof1012cm-3bytheenergybalanceequation.Besides,theeffectivepower,conduction,anddisplacementcurrentaremeasuredduringthedischarge.
简介：Inthisstudy,micro-hollowcathodedischarge(MHCD)isinvestigatedbyafluidmodelwithdrift-diffusionapproximation.TheMHCdeviceisacathode/dielectric/anodesandwichstructurewithoneholeofadiameterD=200μm.ThegasisaNe/Xemixtureatapressurep=50～500Torr.Theevolutionsofthedischargeshowthattherearetwodifferentdischargemodes.AtlargerpDthedischargeplasmaandhighdensityexcitedspeciesexpandalongthecathodesurfaceand,aringeddischargemodeisformed.AtsmallerpD,thedischargeplasmaandtheexcitedspeciesexpandalongtheaxisofthecathodeaperturetoformacolumnardischarge.
简介：Electricaldischargemachining(EDM)process,atpresentisstillanexperienceprocess,whereinselectedparametersareoftenfarfromtheoptimum,andatthesametimeselectingoptimizationparametersiscostlyandtimeconsuming.Inthispaper,artificialneuralnetwork(ANN)andgeneticalgorithm(GA)areusedtogethertoestablishtheparameteroptimizationmodel.AnANNmodelwhichadaptsLevenberg-Marquardtalgorithmhasbeensetuptorepresenttherelationshipbetweenmaterialremovalrate(MRR)andinputparameters,andGAisusedtooptimizeparameters,sothatoptimizationresultsareobtained.Themodelisshowntobeeffective,andMRRisimprovedusingoptimizedmachiningparameters.
简介：Anoveldischargedeviceisdesignedonthebasisoftheconfigurationofmicro-hollowcathodedischarge(MHCD).ByusingmanyMHCDsinparallelconnection,amicro-dischargearraycanbeconstructed.Withthemicro-dischargearray,ahigh-pressurehigh-currentdensityglowdischargeplasmascanbeformedtomakeaplasmadisplaypanel(PDP).Anairdischargeexperimentisfinishedwiththedischargedevice.Thestabledirectcurrentglowdischargeisformedunderthepressurefrom20Torrto500Torr.Thevoltage-currentcharacteristiccurveandthedischargephotographarenoted.Thevoltage-currentcharacteristiccurvehasapositivedifferentialresistancecoefficientonthewholedischargerange.Theestimatedcurrentdensityreaches70.1A/cm3,thepowerdensityis3.6×104W/cm3,andtheelectrondensityisintheorderof1013cm-3atp=200TorrandID=10mA.TheexperimentalresultsindicatethatthedesigneddischargedeviceisappropriateforPDP.
简介：Aself-consistenthybridMonteCarloFluidmodelispresentedtodescribethenitrogendcglowdischarge.ThemovementoffastelectronsissimulatedbytheMonteCarlomethodwhilethedynamicsofslowelectronsandionsisbyfluidequations.Thespatialfeaturesofthechargedspeciesandthecorrespondingelectricfieldthroughoutthedischargehavebeencalculated,whichincludethecreationratesofionsandslowelectrons,densitiesofthechargedspecies,theelectricfieldandthepotentialdistribution.Thesecloselyrelatedresultscangiveaselfconsistentexplanationofthedischargecharacteristicsthroughoutthespaceofnitrogendcglowdischarge.Thecalculatediondensityisalsocomparedwiththecorrespondingexperimentalresult.
简介：Titaniumnitride(TIN)filmsweredepositedonAISI304stainlesssteelsubstratesusinghollowcathodeplasmaphysicalvapordeposition(HC-PVD).TitaniumwasintroducedbyerodingtheTicathodenozzleandTiNwasformedinthepresenceofanitrogenplasmaexcitedbyradiofrequency(RF).Thesubstratebiasvoltagewasvariedfrom0to-300Vandtheuniformityinfilmthickness,surfaceroughness,crystalsize,microhardnessandwearresistanceforthefilmwithadiameterof20mmwasevaluated.Althoughthecentralzoneoftheplasmahadthehighestiondensity,thefilmthicknessdidnotvaryappreciablyacrossthesample.Theresultsfromatomicforcemicroscopy(AFM)revealedalowsurfaceroughnessdominatedbyanisland-likemorphologywithasimilarcrystalsizeontheentiresurface.Highermicrohardnesswasmeasuredatthecentralzoneofthesample.Thesampletreatedat-200Vhadexcellenttribologicalpropertiesanduniformity.
简介：Experimentalresultswerecomparedwiththecomputedresultsobtainedfromtheninemostwell-knownmethodsforcomputationofdischargeinacompoundchannel.Theresultsdemonstrateahighaccuracyofthedividedchannelmethodwiththehorizontaldivisionlines,whilethelengthofdivisionlineisincludedwithinthecalculationofthewettedperimeter.Inaddition,asrelativedepthincreases,theresultsoftheallmethodsconvergetoeachotherandalsoincaseofsteeperslopesinlowerrelativedepths,moreagreementsbetweendifferentcalculatedmethodsandexperimentalresultswereobserved.Furthermore,theresultsshowtheeffectsofthemaximummomentumtransferonthehorizontalinterfacebetweenthemainchannelandfloodplains,whilefurtherangulardistancefromthehorizontalinterfacetowardtheverticalinterfacebetweenmainchannelandfloodplainscausesgradualdecreaseofmomentumtransfereffects.
简介：1.IntroductionAnobviousimprovementindesigningandmanufacturingtransformershasbeenachievedsincetheapplicationofpartialdis-charge(PD)testonpowertransformerswasaccepted.ChineseNationalStandardhasstipulatedthatPDtestisaroutineitemfortransformerswithratedvoltage220kVandabove.Manytransform-
简介：Thispaperdiscussestheconversionofnitricoxide(NO)withalow-temperatureplasmainducedbyacatalyticpacked-beddielectricbarrierdischarge(DBD)reactor.Aluminaoxide(Al_2O_3),glass(SiO_2)andzirconiumoxide(ZrO_2),threedifferentsphericalpackedmaterialsofthesamesize,wereeachpresentintheDBDreactor.TheNOconversionundervaryinginputvoltageandspecificenergydensity,andtheeffectsofcatalysts(titaniumdioxide(TiO_2)andmanganeseoxide(MnOx)coatedonAl_2O_3)onNOconversionwereinvestigated.TheexperimentalresultsshowedthatNOconversionwasgreatlyenhancedinthepresenceofpackedmaterialsinthereactor,andthecatalyticpackedbedofMnOx/Al_2O_3showedbetterperformancethanthatofTiO_2/Al_2O_3.Thesurfaceandcrystalstructuresofthematerialsandcatalystswerecharacterizedthroughscanningelectronmicroscopyanalysis.ThefinalproductswereclearlyobservedbyaFouriertransforminfraredspectrometerandprovidedabetterunderstandingofNOconversion.
简介：Ahighlyefficientflowdischargemeasuringmethodwasproposedinthisstudy.EitherthetraditionalvelocimetersortheAcousticDopplerProfiler(ADP)canbeusedtomeasurethemaximumflowvelocity,Umaxatthey-axis(verticalpassingthroughthemaximumpointvelocityinachannelcrosssection).Themeanvelocityofthecrosssection(U)wascomputedbyφUmax,whereφwasestimatedfromthefielddatacollectedwiththecup-typecurrentmeterusingthe"two-pointmethod".Theflowdischargewasthencomputedbymultiplyingtheestimatedflowareawith(U).Incontrasttothetraditionalmethod,whereflowdepthandflowvelocitymeasurementsareneededforeachvertical,theproposedmethodhastheadvantagesofshortoperationtimeandhighaccuracy.Thesefeaturesareespeciallyimportantforthemeasurementofunsteadyflow.
简介：下游的移动与暴风雨长度袭击的假设不到分水岭长度(Ls/L<1.0)放大在以前的研究由运动学波浪的模型显示了的山峰分泌物在无尺寸的山峰分泌物和无尺寸的暴风雨速度的分析被评估。在UrbanaChampaign在伊利诺大学在分水岭试验系统(WES)为一个塑造V的分水岭收集的以前未出版的试验性的数据，与一个运动学波浪的模型的模拟结果比较被使用。与L山峰与静止暴风雨相比解除到有限程度的s/L<1.0增加，和运动学波浪的模型说大话源于下游的移动的山峰流动的增加与Ls/L<1.0。为了评估回水的重要性，在试验性的分水岭完成，为源于在上游、下游的动人的暴风雨的表面流量的模拟的运动学波浪、动态波浪的模型的精确性被评估利用一样的试验性的数据。运动学波浪的模型模仿在上游的移动暴风雨相当好，即模型的NashSutcliffe系数分别地为等于、不等于分水岭长度的暴风雨长度适合等于0.948和0.831的效率。而，运动学的波浪模型实质地过高估计下游地移动暴风雨，和收益的山峰分泌物通常更差比为在上游的动人的暴风雨适合，即为有等于、不等于分水岭长度的长度的暴风雨的NSE平等者到0.867和0.674分别地。动态波浪的模型模仿下游的移动暴风雨相当好，即为有等于、不等于分水岭长度的长度的暴风雨的NSE平等者到0.843和0.879分别地，显示回水显著地为甚至这个简单试验性的分水岭影响流量。考虑到那个暴风雨运动实质地没放大山峰分泌物，在标准hydrologic设计做的静止暴风雨的假设似乎合理、足够。
简介：Theflowthroughabreastwallspillwayisgreatlyaffectedbythecentripetalforceduetoadownstreamcurvedprofile.Therefore,themeanverticalpressuredistributionattheoutletsectionisnotconsistentwiththehydrostaticpressurelaw.Thisdistributioninturnaffectsthedischargecapacityofthebreastwallspillway.Thispaperexperimentallystudiestheeffectofaconvexdownstreamprofileonthemeanpressurevariationandthedischargeofabreastwallspillwaywithoutgates.Itisindicatedthattheeffectofthecurvilinearstreamlineonthemeanverticalpressurevariationissignificant.TheregressionanalysismethodisusedtodeterminethewaterheadeffectZooftheorificeopeningthroughthemeanpressurevariation.Adischargepredictionformulaofthebreastwallspillwayisobtainedunderthelimitedconditionsofalaboratoryflume.Thepredicteddischargeiscomparedtothemeasureddischarge.Agoodagreementisevidencedforthefreeorificeflowwitherrorswithin?5%,whileabigerror(20%orevenmore)isobtainedifthehydrostaticpressurelawisusedforthedeterminationofZo.
简介：AwaterplasmawasgeneratedbyDCarcdischargewithahafniumembeddedrodtypecathodeandanozzle-typeanode.Thedischargecharacteristicswereexaminedbychangingtheoperationparameterofthearccurrent.Thedynamicbehaviorofthearcdischargeledtosignificantfluctuationsinthearcvoltageanditsfrequency.Analysesofthehighspeedimageandthearcvoltagewaveformshowedthatthearcdischargewasintherestrikemodeanditsfrequencyvariedwithinseveraltensofkilohertzaccordingtotheoperatingconditions.Thelargerthermalplasmavolumewasgeneratedbythehigherflowfromtheformingsteamwithahigherrestrikefrequencyinthehigherarccurrentconditions.Inaddition,thecharacteristicsofthewaterplasmajetwereinvestigatedbymeansofopticalemissionspectroscopytoidentifytheabundantradicalsrequiredinanefficientwastetreatmentprocess.
简介：Anexperimentalinvestigationofananosecondpulseddielectricbarrierdischargeinatmosphericairispresented.Inthesetupaquartztubewasinsertedbetweentheconeandplaneelectrodesinthedirectionparalleltotheelectricfield.Itwasshownthattheappearanceandpropertyofthedischargeweresensitivetothesizeandthepositionofthequartztube.Whenthetubewasplacedonthegroundedplaneelectrode,thedischargeintensitywasfoundtoimprovegraduallywiththeincreaseinthediameterofthequartztube.Furthermore,withanappropriatedistancebetweenthebottomedgeofthequartztubeandtheplaneelectrode,thedischargetendedtoexhibitbetterperformanceingeneratinghomogeneousdiffusiveplasma.Thepossiblemechanismisdiscussed.
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