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

简介：Adistributedcontrolsystemisdesignedforplasmasprayingequipmentandtheconfigurationsofsystemsoftwareandhardwareisdiscussed.Throughfoundinganexpertdatabase,thesprayingprocessparametersareworkedoutandtheinitializationandcontrolofsprayingprocessarerealized.Theplasmasprayingsystemwiththiscontrolconfigurationcansimplifythesprayingoperation,improveautomationlevelofsprayprocess,andapproachtheexperiencecriterionassoonaspossible.

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

简介：Athree-dimensionalsimulationmodelfortheplasma-MIGweldingprocess,whichtakestheinteractionbetweentheplasmaarcandMIGarcintoaccount,ispresentedandthequasi-steadytemperaturefieldsontheworkpiecearecalculatedwiththemodel.The10mm-5A06aluminumalloyisweldedandthetemperaturefieldsaremeasuredwiththethermoelectriccouple.Thesimulationresultsandmeasuredresultsshowthatthebiggestdeviationofpeaktemperaturebetweenthemisbelow20℃,whichindicatesgoodcoincidencebetweenthesimulationandmeasurement.

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简介：Thecombinedquadraticorthogonalregressionmethodofexperimentdesignwasemployedtoexploretheeffectsofprocessparametersofplasmanitridingoftantalumsuchastotalpressure,temperatureandoriginalhydrogenmolarfractiononthehardness,roughnessandstructureofnitridingsurfaces.Theregressionequationsofhardness,roughnessandstructureweregivenaccordingtotheresultsofregressionandstatisticanalysis.Andthediffusionactivationenergyofnitrogenintantalumonplasmanitridingconditionswascalculatedaccordingtotheexperimentaldataofhardnessofplasma-nitridingoftantalumvstimeandtemperature.Thediffusionactivationenergycalculatedbelongsto(155.49+10.51)kJ/mol(783-983K).

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简介：Thenon-isothermalleachingkineticsofprimarytitanium-richmaterialbymicrowaveheatingwasinvestigated,andthetemperature-pressurecurvesofleachingsystemandmicrowaveabsorptioncharacteristicsofmixturesolutionsbeforeandafterleachingweremeasured.Theresearchofnon-isothermalkineticswasevaluatedbytheleachingrateofFeandthetotalapparentvelocityequationofthenon-isothermalkineticsofleachingforprimarytitanium-richmaterialbymicrowaveheatingwasobtained.Itisshownfromthetemperature-pressurecurvesthatthehightemperatureandhighpressureofclosedleachingsystemarefavorabletotheenhancementoftheleachingrateofFe.Microwaveabsorptioncharacteristicsofmixturesolutionsbeforeandafterleachingshowthatthereareabruptchangesofmicrowaveabsorptioncharacteristicsfor15%HClsolutionandthemixturesolutionafterleachingby20%HCl.

简介：二酸矿排水(AMD)样品TS和WK，从在Guangxi省的Dachang充满金属的矿，中国，用基于PCR的克隆被学习途径。44个运作的分类单位(OTU)的一个总数从二件AMD样品被获得。然而，仅仅三OTU(GXDC-9，GXDC-19和GXDC-50)在样品TS检测了能也在样品WK被观察。种系发生的分析表明在二件样品的细菌掉进四个通常认为的部门，它是Nitrospira，Alphaproteobacteria，Gamaproteobacteria，和Acidobacteria。类Acidithiobacillus和Leptospirillum的有机体，在gamaproteobacteria班和Nitrospira家庭上，分别地在二件样品是主导的。在样品TS，它被低pH描绘，高硫酸盐，高铁，和高砷化物，二种(Acidithiobacillusferrooxidans和Leptospirillumferrooxidans)组成了98.22%全部微生物引起的社区。与样品TS相比，在样品WK的微生物引起的社区根据观察是更多样化的。抱持兴趣地，Legionella种类，很少在low-pH环境被观察，在样品WK被检测。这个工作帮助我们进一步理解微生物引起的社区与唯一的地球化学和acidophiles的忍耐能力在极端酸矿排水住在一起到重金属的差异。

简介：MechanicallyactivatedW-Cupowdersweresinteredbyasparkplasmasinteringsystem(SPS)inordertodevelopanewprocessandimprovethepropertiesofthealloy.Propertiessuchasdensityandhardnessweremeasured.ThemicrostructuresofthesinteredW-CualloysampleswereobservedbySEM(scanningelectronmicroscope).Theresultsshowthatsparkplasmasinteringcanobviouslylowerthesinteringtemperatureandincreasethedensityofthealloy.Thisprocesscanalsoimprovethehardnessofthealloy.SPSisaneffectivemethodtoobtainW-Cupowderswithhighdensityandsuperiorphysicalproperties.

简介：Inthispaper,laserinducedplasmasignalswereanalyzedduringkeyholeweldingthroughthreemethods.Accordingtotheresults,therelativitybetweenopticalandacousticsignalsofplasmaisshownwhenweldsareinfull-penetration,orpartial-penetrationandnon-penetration.

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简介：Keyholeplasmaarcweldingexperimentsareconductedtomeasuretheweldgeometryandpenetrationatdifferentmomentsduringtheinitialphasefromignitingarctoquasi-steadystate.Indirectinformationonkeyholeformationandevolutioninplasmaarcweldingcanbeextractedbasedontheweldmacrophotographatcrosssection.Ithaslaidfoundationtoverifythemathematicalmodelsofkeyholeplasmaarcwelding.

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简介：Anewkindofcontrolsystemforkeyholeplasmaarcwelding(K-PAW)wasdevelopedbasedonthecomputerandtheGraphicsLanguage-LabVIEW.Itcansetandoutputtherequiredcurrentwaveformswithdesireddecreasingslopessothatthecorresponding'openingandclosing'ofkeyholecanoccurperiodically.Withthiscontrolstrategyofweldingcurrentwaveforms,theworkpieceisfullypenetratedwhilenoburn-throughoccurs.Keyholeplasmaarcweldingexperimentswereconductedtoverifythestabilityandreliabilityofthedevelopedsystem.

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简介：Sinceamorphousalloyshavewiderapplication,theycannotbefabricatedusingtheconventionalcoolingvelocity.ThebarmaterialplasmasprayingisadoptedtofabricateFebaseamorphousalloyinthisinvestigation.Thecrystallizationdegree,microstructure,micro-hardness,composition,crystallizationtemperatureoftheamorphousalloyandtheflyingrulesoftheatomizedparticlesintheprocessoftheplasmasprayaretested.Theresultsshowthatthealloypreparedhasthehighamorphousdegreeandhomogeneousmicrostructure,micro-hardnessandthecrystallizationtemperaturecanreach1187HVand531℃respectively.Theatomizationisverywellduringtheprocessofplasmaspraying;andthereishighthermalgradient,thecoolingvelocityreaches6.07×107K/s.

简介：有五个分支的像花瓣的icosahedralquasicrystal，被认为是icosahedralquasicrystal的代表性的形态学，在Y富有的Mg-Zn-Y第三的合金被观察了。而且，像多角形的形态学，icosahedralquasicrystal的另一个模式，也在Y富有的Mg-Zn-Y第三的合金被发现了。后者形态学源于以前的进化。icosahedralquasicrystal的像花瓣的形态学的生长机制也被讨论。Alloying作文，即，Y元素内容，是导致icosahedralquasicrystal的形态学进化的一个主要因素。