简介：

简介：Thegasdynamicandelectromagneticfactorsaffectingthepositionofarcrootsinatubulararcheaterareanalyzed.Magnitudesofthevariousfactorsareestimatedthroughnumericalmodelling,andtheoverallactiononthearcassessed.Itisfoundthattheactionsonthearcintherearelectrodecanbebalancedinastablemannerandthearcrootcanbestabilizedatacertainaxialposition.Inthefrontelectrode,thevariousfactorscannotbebalanced,andthearerootcanonlystaywithintheelectrodethroughthemechanismofrecurrentshunting.Theseconclusionsagreewithexperimentalobservations.

简介：煤气的金属弧焊(GMAW)的数字模型正在试着联合液体(VoF)的弧和体积的magnetohydrodynamics(MHD)模型的电流金属转移当模特儿。他们忽视蒸发并且为弧区域假定氩气氛，因为它是为煤气的钨弧焊的模型的普通实践。这些模型在20000K和类似于钨的温度分布上面预言温度惰性的气体(TIG)弧。然而，在GMAW弧的当前的分光镜的温度大小表明低得多的弧温度。与TIG弧相对照，他们发现了光线的温度分发的中央本地最小。纸论述考虑金属蒸汽的一个GMAW弧模型并且它在与试验性地观察的温度的一个很好的协议。而且，模型能第一次在光线的温度和光线的电流密度分布预言本地中央最小。向轴的方向焊接火炬，工作片，电线和弧(液体领域)的对称的模型象在氩的狂暴的混合和金属蒸汽的热demixing一样实现MHD。从模拟获得的铁蒸汽的集体部分在2000～5000K在弧的穗上在弧核心和另一累积显示出累积。demixing效果导致在这二个区域之间的铁的很低的集中。敏感分析证明运输的影响和金属蒸汽的放射性质喂。最后模型预言与Zieliska等的测量结果相比。

简介：我们考虑决定作为生气的节有一条开的弧的薄绝缘的无限的柱体的形状的反的散布问题。假设电场在TM模式被极化，这为在R2在一条开的弧的外表定义的Helmholtz方程导致一个混合边界价值问题。我们假定弧混合了Dirichlet阻抗边界状况，并且试着由使用因式分解方法通过远地模式恢复弧的形状。然而，我们不能使用樱桃酒介绍对待远地操作员F的基本定理，并且一些辅助操作员不得不被考虑。到我们的问题的因式分解方法的理论确认在这份报纸被给，并且一些数字结果被介绍显示出我们的方法的生存能力。[从作者抽象]

简介：Thearcsprayingprocessisdividedintotwostages:thefirststageisatomization-sprayingstream(ASS)andthesecondoneissprayingdeposition(SD).Thenstudystatusisdescribedofbothstages'physicalmodelandcorrespondingcontrolling-equation.Basedontheanalysisofstudystatus,theconclusionasfollowsisgot.TheheatandmasstransfermodelswithtwoorthreedimensionsinASSstageshouldbeestablishedtofardeeplyanalysesthedynamicalandthermalbehavioroftheoverheatdroplet.Thestatisticslawofoverheateddropletsshouldbefurtherstudiedbyconnectingsimulationwithexperiments.MorepropervalidationexperimentsshouldbedesignedforflatteningsimulationtomodifythemodelsinSDstage.

简介：AprototypeofPulsedPlasmaArcCladdingsystemwasdeveloped,inwhichsinglepowersourcesuppliesbothtransferredplasmaarc(TPA)andnon-transferredplasmaarc(N-TPA).BothplasmasworkinturninahighfrequencycontrolledbyanIGBTconnectingnozzleandworkpiece.TheworkingfrequencyofIGBTrangesfrom50～7000Hz,inwhichtheplasmascanworkinturnsmoothly.Higherthan500HzofworkingfrequencyissuggestedforpromotionofcladdingqualityandprotectionofIGBT.DragphenomenonofTPAintensifiesasthefrequencygoesup,whichtendstoincreasethecurrentproportionofTPAandsuppressN-TPA.TheoccupationratioofIGBTcanberegulatedfrom5%～95%,whichbalancesthepowersuppliesofbothplasmas.Anoccupationratiohigherthan50%givesadequateproportionofarccurrentforN-TPAtopreheatpowder.

简介：Forgivendata(ti,yi),I=0,1,…,n,0=t0＜t1＜…＜tn=1westudyconstrainedinterpolationproblemofFavardtypeinf{‖f'‖∞|f∈W2∞[0,1],f(ti)=yi,i=0,…,n,l(f;[0,1])≤l0},wherel(f';[0,1])=∫10/1+f'2(x)dxisthearclengthoffin[0,1].Weprovetheexistenceofasolutionf*oftheaboveproblem,thatisaquadraticsplinewithasecondderivativef'*,whichcoincideswithoneoftheconstants-‖f'*‖∞,0,‖f'*‖∞betweeneverytwoconsecutiveknots.Thus,weextendaresultofKarlinconcerningFavardproblem,tothecaseofrestrictedlengthinterpolation.

简介：

简介：Thispaperpresentsanewsplinecalledarcspline.Ittakestwoarcsconnectingadjacentpointsamongasampledseries,withknowntangentalofeachsampledpoint.Thecalculationfortheparallel.thecurvelengthandthesegment-ingpointcoordinatesaresimple,thusmakingmapsymbolgenerationsimplified.When'arclet'occurs,somespecialprocessingmustbetaken.

简介：Aspectraldiagnosticsofcomplexareplasmausingmultiplespectralinformationofareself-emittingispro-posed.Thismethodisabletosimultaneouslydeterminecomponentdensities,thecorrespondingtemperatureandtheirdis-tributionsbyafewlineintensitiesmeasurent.Theprincipleofthemethodandtherelevantmeasuringsystemarede-scribed.Anequationsystemisestablishedforcomputationofthestatevariablesinareplasma.Anexperimentunderweldingareconditionismadeasanapplicationofthemethod.Theeffectsofprobableerrorsourcesonthemeasurementarealsoanalysed.

简介：ＯＮＡＲＣ┐ＴＲＡＮＳＩＴＩＶＥＣＩＲＣＵＬＡＮＴＤＩＧＲＡＰＨＳＨＵＡＮＧＱＩＯＮＧＸＩＡＮＧＡｂｓｔｒａｃｔ．ＤｅｎｏｔｅｂｙＣｎ（Ｓ）ｔｈｅｃｉｒｃｕｌａｎｔｄｉｇｒａｐｈｗｉｔｈｖｅｒｔｅｘｓｅｔＺｎ＝｛０，１，２，．．．，ｎ－１｝ａｎｄｓｙ...

简介：Thevariationinarccharacteristicsandbehaviorofmetaltransferwiththechangeinpulseparametershasbeenstudiedbyhighspeedvideocameraduringpulsecurrentflux-coredarcwelddeposition.Acomparativestudyofsimilarnaturehasalsobeencarriedoutduringflux-coredarcwelddepositioninglobularandspraytransfermodes.Theeffectofpulseparametershasbeenstudiedbyconsideringtheirmeancurrentandarcvoltage.Thearccharacteristicsstudiedbyitsrootdiameter,projecteddiameterandlength,andthebehaviorofmetaltransfernotedbythemetaltransfermodelandthedropletdiameterhavebeenfoundtovarysignificantlywiththepulseparameters.TheobservationmayhelpinunderstandingthearccharacteristicswithrespecttothevariationinpulseparameterswhichmaybebeneficialinusingpulsecurrentFCAWtoproducedesiredweldquality.

简介：Manyapplicationsofultrasonic-assistedmethodswereusedduringmetalsolidification,buttheycouldnotbeintroducedintoweldpool.Inthispaper,awayofultrasonicassistedTIGweldingisintroduced.Bydirectlyimposedultrasonicvibrationonweldingarc,thevibrationinteractswitharcplasmaandpassestotheweldpool.Measurementresultsshowthatarcpressureissignificantlyincreasedwiththeultrasonicvibrationandthearcpressuredistributionmodelsarechanged.Bead-on-plateweldingtestsonSUS304confirmthatthistechnologycaninfluencethestyleofmetalmeltingandincreaseweldpenetrationdepth.

简介：<正>CENTRALCHINAARCSERIESANDITSMETALLOGENYJiangZhenya(HubeiInstituteofGeoscience,Wuhan,430022,Hubei,P.R.China)arc,metailogeny,CentralChinaThecentralChinaarcseriesliesacrossthewholecentralChina,embodyingQinghuaiarc,Esuarc,Changjiangarc,Chuzhearc,andXianggangarc.Itisagigantictecton-icarcseries.TheseriesistheresultofnorthandsouththrustingofhorizontaldiferrentialbucklingundertheuniversalnorthandsouthcompressingineasternChina.ItbeganatYingzhimovement,formedatthefirststageofYanshanmovement,andsolidifiedatthesceondstageofYanshanmovement.Theseriescontrollssedimentation,exogenicdeposits,magmatism,andendogenicdeposits.Menawhileitaffectsmordentopography,alluvialsystem,andclimate.

简介：AnexperimentalsystemofACarcdischargeinwaterwasdesignedwithpole-poleelectrodesandapeakvoltageof1500Vandatestcircuitwassetupusingvirtualinstrumenttechnology.ThemechanismofanACplasmaarcgeneratedinwaterwasanalyzed.ThevoltagecurrentcharacteristicoftheACplasmaarcwasobtainedfromthewaveform.Thetemperaturecharacteristicwastestedwithaspectrumdiagnosissystem,andtheeffectofdifferentelectrodematerialsonthestrikingvoltageandpeakcurrentwasanalyzed.Theresultsshowthatwhenapowersupplyof6kWisappliedonelectrodeswithagapof2mminwater,thestrikingvoltageisfrom900Vto1300V,thearcvoltageisfrom40Vto100V,thearccurrentisfrom2Ato7A,andthezerorestperiodisfrom1msto2ms.Inaddition,thearcvoltageandcurrentaredifferentforelectrodesinaluminum,copperandstainlesssteel.Thearcvoltageislowerandthecurrentishigherforanaluminumelectrodethanthoseforcopperandstainlesssteelones.Thehighesttemperatureofthearcis7643K.

简介：Thekeyproblemfornumericalsimulationofplasmaarcwelding(PAW)processistodevelopasuitableandadaptivevolumetricheatsourcemodewhichreflectsthephysicalcharacteristicsofkeyholePAW.Tothisend,thekeyholegeometryunderdifferentPAWprocessconditionsmustbepredicted.Inthispaper,amathematicalmodelfordeterminingthekeyholeshapeisdevelopedwithconsideringthemassandmomentumconservationofthein-keyholeplasmajetaswellasthepressureequilibriumattheplasmajet/liquidmetalboundary.AsuitableheatsourcemodelrelatedtothekeyholeshapeisappliedtothecalculationofPAWwelddimensions.Thepredictedresultsareingoodagreementwiththeexperimentalones.

简介：

简介：Throughtheinvestigationontraditionalarcstudweldingprocess,anewweldinggunanditscontrolsystemweredevelopedinthispaper.Thesteppingarcstudweldinggunwasmainlymadebyasteppingmotorasactuatingunitandascrew-drivendeviceasmovingunit.AcontrolsystemwithaMCS-51single-chipmicrocomputerasmaincontrolcomponentwasusedtorealizethenewstudweldingprocedure.Thisnewweldingprocesswithsteppingstudweldinggunisnamedassteppingarcstudwelding.Inthenewweldingprocess,thestudactioncanbelookedasconstitutedbysomemicrosteps.Thesettingandadjustingofthesteppingarcweldinggunbehaviorparametersareaccomplishedindependently.Itisindicatedfromtheresultsofprocesstestsandbendingtestthatthesteppingarcstudweldingprocessispracticable.

简介：本文介绍了应用于金属互联工艺的ARC(抗反射层或防反射层)技术.通过对抗反射层基本原理的说明,结合工艺实验,深刻地理解ARC技术.最后给出了可以用于0.5μm工艺生产的ARC结构及用于衡量ARC性能的参数.

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