简介：Adigitalarcweldingpowersupplywasdesignedwiththeadvancedreducedinstructionsetcomputermachine(ARM)andembeddedreal-timemulti-taskoperatingsystemmicroC/OS-Ⅱ.TheARM,withitspowerfulcalculatingspeedandcompleteperipheralequipments,isverysuitabletoworkasthecontrollerofthedigitalpowersupply.ThemicroC/OS-ⅡtransplantedinARM,helpstoimprovetherespondentspeedagainstvariousweldingsignals,aswellasthereliabilityofthecontrollingsoftware.Theweldingprocessconsistsofninetasks.Thetasksofgreatsignificanceonreliabilityofthewelder,forexample,theA/Dconversionofcurrentandvoltage,enjoytoppriority.Toavoidsimultaneous-sharingonA/DconverterandLCDmodule,twosemaphoresareintroducedintoensurethesmoothperformanceoftheweldingpowersupply.Provenbyexperiments,theARMandthemicroC/OS-Ⅱcangreatlyimproveboththerespondentspeedandthereliabilityofthedigitalwelder.

简介：OnthebasisOftheYoung-LaplaceEquationthatdescribesthepressuredifferencebetweeneachsideofacurvedliquidsurface,astaticequilibriummodelisestablishedtodescribethesurfaceshapeoftheweldbead.Thegeo-metricalmodelforthemoltenpoolisincluded,whichisessentialtoexplaintheundercutphenomenonduringhighspeedbead-on-platewelding.Theresultsgotfromaniterationalgorithmshowthatitistheforcebalanceontheliquidmixtureofthedepositedmetalandthedepositedmetalandthemoltenbasemetalandthemoltenbasemetalthatcausestheundercut.Somefactorsandtheireffectsarealsoana-lyzed.

简介：由使用焊接电线的镍，焊接弧的以铁酸盐为主要成的可锻的铁的部分熔化地区(PFZ)和焊接金属的机械性质的寒心的趋势上的alloying的效果系统地被学习了。在这个基础上，为以铁酸盐为主要成的可锻的铁(QT400-17)的弧焊的一个新镍电极第一次被开发。它的焊接金属的机械性质能以铁酸盐为主要成的可锻的铁匹配那些。在PFZ的碳化物层(WCL)的宽度显著地被减少，焊接关节有优秀马赫无能，焊接金属有高热的抗碎裂性。(编辑作者摘要)3个裁判员。

简介：本文提出用交流弧原子发射光谱全能量法,以高倍数光谱纯石墨粉稀释样品,将少量被稀释后样品,装于特制电极中,在60秒钟内烧完,激发光谱,测定粉末样品中的主体元素。通过实验,选定了最佳测定条件,其RSD为4.1—9.0％。在岩石(GSR)、土壤(GSS)和水系沉积物(GSD)三个系列组成变化较大的样品的测定中得到初步应用。对标准参考物分析结果与推荐值基本一致。

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简介：IntheautomaticCO2arcwelding,thealterationoftheverticaldistancebetweentheweldingtorchandtheworkpiecehasastrongeffectontheweldingparameterssuchasweldingcurrentandvoltage,withtheresultthattheappearanceandqualityofweldarenotsteady.Toweakentheinfluenceofthedistancealteration,amethodisputforwardinthepaper.Themethodisthatthealternatewire-feedcontrolisusedforcompensatingtheweldingcurrent.Onthebasisoftheoreticalanalysis,astaticnumericalmodelforalternatewire-feedcontrolisestablished.Theexperimentsshowthatthemodel-basedregulationofthewirefeedratecancompensatetheweldingcurrentandensuretheappearanceofweld.Whenthealterationofverticaldistancebetweenthetorchandtheworkpieceisgreater,notonlyisthewirefeedrateregulated,buttheoutputvoltageofthepowersourceisadjustedtoensuretheappearanceandqualityofweld.

简介：Asensingsystemisdevelopedtomeasuretheweldpoolboundaryandpoolsurfacedeformationingastungstenarcwelding.LaserStrobetechniqueisusedtoeliminatethestrongarclightinterference,andspecularreflectionfromthepoolsurfaceissensedtodescribetherelationbetweenthedeformedstripesandpoolsurfacedepression.Clearimagesofboththepoolboundaryandthedeformedstripesedgesareobtainedduringgastungstenarcweldingprocess,whichlaysfoundationforreal-timemonitoringthepoolsurfacedepressionandweldpenetration.

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简介：ThispaperpresentsabriefoverviewofCO2reformingofCH4（CRM）byvariousformsof'arc'plasma,whichismoresuitabletoCRM,andtheenergyefficiencyisusedtoevaluatedifferentplasmaprocessesspecifically.Accordingtothereportedresults,thearcthermalplasmawithbinodeexhibitedbetterperformance.Moreover,theplasmaCRMprocesswascomparedwiththereportedplasmasteamreformingofCH4（SRM）process,andtheresultsshowedthattheformerprocesshasadvantagesonenergyefficiencyandCH4consumption.Additionally,itisbelievedthattheplasmaCRMprocesswouldbecompetitivewiththeconventionalSRMprocessinbothenergyefficiencyandCO2emissiononcetheheatmanagementisemphasizedandtherenewablepowerisused.Finally,aconceptofplasmareactorforindustrialapplicationisproposed.

简介：ThefrictionandwearbehaviorofFe-Alintermetallicsbasedcoatingproducedbyhighvelocityarcsprayingtechniqueunderdryslidingatroomtemperaturewereinvestigatedusingaball-on-disctribotester.Theeffectofslidingspeedonfrictioncoefficientandwearofthecoatingwasstudied.Thewornsurfaceofthecoatingwasanalyzedbyscanningelectronmicroscope(SEM)toexploreslidingfrictionandwearmechanism.Theresultsshowthatthevariationsoffrictioncoefficientcanbedividedintothreedistinctstepsduringthetrail.Boththefrictioncoefficientandthewearofthecoatingincreasewithincreasedslidingspeedduetoacceleratedcrackpropagationrateandlamellarstructurewithpoorductilityofthecoating.Thecoatingsurfaceissubjectedtoalternatelytensilestressandcompressionstressduringslidingwearprocess,andthepredominantwearmechanismofthecoatingsappearstobebrittlefractureanddelamination.

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简介：ThepreparationofcrystallineC_3N_4filmswasinvestigatedusingpulsedarcdischargefrommixedmethanolandammoniawateratatmosphericpressure.TheX-raydiffraction(XRD)patternsofthefilmspreparedatasubstratetemperatureof450℃suggestedthatthefilmwascomposedofα-C_3N_4andβ-C_3N_4crystallites.RamanspectraexhibiteddistinctpeakswhichareingoodagreementwiththosepredictedtheoreticallyforC_3N_4crystallites.

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简介：InspiteofthecurrentprevalenceoftheCVD-basedprocesses,theelectricarcremainsaninterestingprocessforthesynthesisofcarbonnanoforms,thankstoitsversatility,robustnessandeasiness.Italsoallowsperformingin-situsubstitutionofcarbonatomsbyhetero-elementsinthegraphenelattice.Ourworkaimstoestablishacorrelationbetweentheplasmaproperties,typeandchemicalcomposition(andthesubstitutionrate)oftheobtainedsingle-wallcarbonnanotubes.TheplasmawascharacterizedbyopticalemissionspectroscopyandtheproductswereanalyzedbyhighresolutiontransmissionelectronmicroscopyandcorelevelElectronEnergy-LossSpectroscopy(EELS).Resultsshowthatahighboroncontentleadstoaplasmatemperaturedecreaseandhinderstheformationofnanotubes.Thiseffectcanbecompensatedbyincreasingthearccurrentand/oryttriumcontent.Theoptimalconditionsforthesynthesisofboron-and/ornitrogen-substitutednanotubescorrespondtoahighaxialplasmatemperatureassociatedtoastrongradialgradient.EELSanalysisconfirmedthattheboronincorporatesintothegraphemelattice.

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简介：Non-contactmagneticmeasurementmethodisaneffectivewaytostudytheairarcbehaviorexperimentally.Oneofthecrucialtechniquesistosolveaninverseproblemfortheelectromagneticfield.Thisstudyisdevotedtoinvestigatingdifferentalgorithmsforthiskindofinverseproblempreliminarily,includingthepreconditionedconjugategradientmethod,penaltyfunctionmethodandgeneticalgorithm.Thefeasibilityofeachalgorithmisanalyzed.Itisshownthatthepreconditionedconjugategradientmethodisvalidonlyforfewarcsegments,theestimationaccuracyofthepenaltyfunctionmethodisdependentontheinitialconditions,andtheconvergenceofgeneticalgorithmshouldbestudiedfurtherformoresegmentsinanarccurrent.

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简介：AfterRodiniasupercontinentwasdisintegratedinLateProterozoic,anocean,namely,TethysOcean,occurredbetweenGondwanacontinentalgroupandPan-CathaysiancontinentalgroupfromLateProterozoictoMesozoic.FromEarlyPaleozoictoMesozoic,TethysOceanwassubductedtowardPan-Cathaysianblockgroup,whichresultsinbackarcexpansion,arc-landcollisionandforearcaccretion.Whenthebackarcbasinexpandsandreachesthesmalloceanicbasin,ophiolitemelangewillbegenerated.Asaccretionhadalreadyoccurredinthesouthofthecontinentalmarginintheearlierstage,thesucceedingbackarcexpansionandthefrontalarcpositionweremigratedtowardsouthcorrespondingly.Therefore,multipleophiolitebeltsandmagmaticrockbeltsoccurred,andshowatrendofdecreasingagefromnorthtowardsouth.Asthecontinentalmarginwassplitandmigratedtowardsouthandreachedahighlatitudeposition,i.e.,withtheshorteningandsubductionofoceaniccrust,thesedimentarybodiesathighlatitudewasaccretedcontinuouslytowardlowlatitudeareatogetherwiththeformationofoceanicisland,mixingofcold-typeandwarm-typeorganismwasgenerated.Moreover,blockssplitandseparatedfromPan-CathaysianorGondwanacontinentalgroupcannottraversetheoceanicmedianridgeandjoinswithanothercontinentalblock.Asaresult,theKunlunbeltontheSWmarginofthePan-Cathaysianlandwasresultedfromthemulti-arcorogenesissuchasthebackarcseabedexpansion,arc-arccollision,arc-landcollisionoceanicbed,andthecontinuoussouthwardaccretionprocess.

简介：TiBCNnanocompositecoatingsweredepositedoncementedcarbideandSi（100）byacathodearcplasmasystem,inwhichTiB2cathodeswereusedinmixturegasesofN2andC2H2.X-raydiffractionshowsthatTiB2andTi2B5peaksenhanceatlowflowratesofC2H2,buttheyshrinkwhentheflowrateisover200seem.AnincreaseofdepositionratewasobtainedfromdifferentTiBCNthicknessesforthesamedepositiontimemeasuredbyscanningelectronmicroscopy.Atomicforcemicroscopyshowsthatthesurfaceroughnessesare10nmand20nmatC2H2flowratesof0-100sccmandof150-300sccm,respectively.HighresolutiontransmissionelectronmicroscopyandX-rayphotoelectronspectroscopyshowthatthecoatingsconsistofnanocrystalphasesTi2B5,TiB2andTiN,andamorphousphasecarbonandBN.Theaveragecrystalsizesembeddedintheamorphousmatricesare200nmand10nmatC2H2flowratesof200sccmand300sccm,respectively.InRamanspectra,theD-andG-bandsincreasewithC2H2flowsatlowflowrates,butweakenathighflowrates.Themicrohardnessofthecoatingsdecreasesfrom28.6GPato20GPaastheC2H2increasesfrom0sccmto300sccm,andtheball-on-diskmeasurementshowsadramaticdecreaseofthefrictioncoefficientfrom0.84to0.13.ThereasonforthereducedhardnessandfrictioncoefficientwiththechangeofC2H2flowratesisdiscussed.