简介：

简介：Thispaperstudiedthespotweldingstructureofultra-highstrengthsteel22MnB5.ANSYSsoftwarewasadoptedtosimulateitsstaticstrength;BS5400algorithmwasusedtocalculatethefatiguelife;andthegroupingmethodwasusedtotestthefatigueperformanceoftensileshearspotweldspecimens.Thesimulationresultswereingoodagreementwiththeexperimentalvalues.Basedonthevalidationofthesimulationmethod,influencesofdifferentstructuralparametersonstaticstrengthandfatiguelifewereexploredbyadoptingsinglefactor.Theresultsshowedthatwithintheselectedstructureparameterrange,increaseofthesheetthickness,nuggetdiameter,sheetwidthandoverlappinglengthcanleadtolongerfatiguelife.Besides,thefatiguelifeofspotweldtookonalinearrelationshipwiththeoverlappinglength,aDoseResprelationshipwiththesheetthickness,andasingleexponentialdecayrelationshipwiththesheetwidthandthenuggetdiameter.Moreover,inordertoestimatetheimpactfromvariousparametersonthefatiguelifeofthespecimens,theTaguchiorthogonaldesignmethodwasappliedinthesimulationdesign.Thesimulatingresultindicatedthatinfluenceofthesheetthicknessonfatiguelifewasthemostsignificant.Inaddition,theeffectsofnuggetdiameter,sheetwidthandoverlappinglengthonfatiguelifewerereducedinturn.

简介：Inthisstudy，theweldingthermalcyclecurveexhibitedtwotemperaturepeaksinhighheat-inputtwin-wireseparate-poolsubmerged-arcweldingandcoarse-grainedheataffectedzoneexistedintheweldedjoint.Theinclusionsofprimaryweldmetalandcoarse-grainedheataffectedzoneofCe-addedSAWshouldbeAl203,MnO,Si02,TiO,Ce2S3,CeS,Ce202SandCe203.Undertheeffectofweldingthermalcycle,oxy-sulfidesinclusionsofCe,thediameterofwhichwaslessthan2.0|Jim,slightlygrewlarger,butthecompositionandtypeoftheinclusionsdidn，tchange.ThemicrostructureofthelargeheatinputweldmetalhadacicularferritethatCeoxidesulphideparticlesinducednucleationandproeutectoidferrite.Inthecoarse-grainedheataffectedzoneofweldmetal,home-positionprecipitationofacicularferriteandsympatheticacicularferritewerebothobserved.Itwassupposedthatpreviouscrystalcellsofacicularferriteinaustenitegrainpromotedhome-positionprecipitationofacicularferrite.Meanwhile,sympatheticacicularferritetendedtonucleateattheprimaryacicularferritegrainboundaries,wherehighdislocationdensitywaslocated,andgrewinsidetheneighboringcarbon-depletedausteniticregions.Thegranularbainitenucleatedintheausteniticzonewithhighcarboncontentclosetoacicularferriteandsympatheticacicularferrite.

简介：电子结构和在不同压力(260，320，400和600GPa)的新奇Na-hP4高压力阶段的光性质被密度调查有为交换和关联精力的概括坡度近似(GGA)的功能的理论(DFT)。沿着在Brillouin地区，状态(DOS)的密度和状态(PDOS)的部分密度的更高的对称斧子的乐队结构被介绍。乐队差距增加，精力乐队膨胀到某程度，压力增加。绝缘的功能，反射率，精力损失功能，光吸收系数，光传导性，折射索引和扑灭系数为在不同压力讨论Na-hP4高压力阶段的光性质被计算。

简介：

简介：Usingorganicaquaregia,arecentlydiscoveredpowerfulorganicleachingagent,aneffectiveprocessofrecoveringPtdirectlyfromPt-Aubimetallicnanoparticleswasdemonstrated.ThepuritiesofthePtrecoveredfromamixtureofAuandPtnanoparticlesandfromPt-Aucore-shellnanoparticlecatalystareashighas(99.49±0.22)％,and(95.02±0.08)％,respectively.Thenovelrecoveryprocesspromisesapplicationsincatalysisindustry.

简介：nano石墨表/氧化铝composites被一个灵巧的受精减小过程在situ准备。composites的微观结构被X光检查衍射(XRD)分析，并且在减小以后的最后的阶段作文是艾尔2O3,金属Fe和石墨水晶。扫描电子显微镜学(SEM)图象证明Fe的粒子尺寸是大约20?nm，和石墨的lamellae厚度是大约30?nm。然后，绝缘的性质和composites的传导性的机制在0.01-1.00的频率范围试验性地被调查?由阻抗分析器的GHz。composites的介电常数的真实部分与Fe3+集中增加的结果表演，由于在Fe和艾尔23和薄片状的石墨形成的三维的网络。因此，悦耳的microtopography和nano石墨表/氧化铝composites的电的参数能被改变Fe3+集中认识到。

简介：β-phase上的超声的处理的效果(Mg17Mg-9.0wt.%Al合金的艾尔12)形态学被学习。结果证明与在Mg-9.0wt.%Al团结期间采用的高紧张的超声的颤动，在营舍的全部生气的节的β-phase显著地被精制并且也变化了从对不连续的形态学连续。球形的β-phase在与高紧张的超声的颤动对待的营舍的团结期间被形成。

简介：Inthispaperanewmethodforpreventingweldinghotcracking—theinversestrainmethod(ISM)isdevelopedontheprincipleofweldingmechan-ics.EffectivenessandfeasiblityofmethodinpreventingweldinghotcrackingofhighstrengthaluminumalloyLY12CZbysynchronousrollingduringwelding(SRDW)alongbothsidesoftheweldatasuitabledistancebehindtheweldingarcareexamined.ExperimentalresulteindicatethatweldinghotcrackingofLY12CYcanbeeffectivelypreventedandthemechanicalpropertiesofweldedjointcanalsobeimprovedbythemethod.Itisanimportantnewsolutionforpreventinghotcrackinginweldingofsheetmetal.