简介:Inthepresentpaper,thegraphicalmethoddeterminationofoptimalweldingparametersofGMAWisdescribed.Somequalitycomplexcriteriathataretheratioofweldsizeshavebeenproposed.Thesecriteriaallowoptimizingtheshapeoftheweldmetalzone,reducingthelikelihoodofhotcracksformation,andreducingthestressconcentrationoftheweldatthetoe.Intheproposedmethodology,theearlierdescribedequationsconnectingtheweldingparametersandthewelddimensionsofmildandlow-alloysteelsareexplored.Determinationoftheoptimalweldingparametersiscarriedoutgraphicallytakingintoaccountthevarianceoftheweldingparameters.Anexampleofusingtheproposedmethoddestinedtodeterminetheoptimumweldingparametersisprovided.Itisshownthatitsaccuracyissufficientlygoodforapracticalapplication.
简介:MoS_2,MoSe_2andWSe_2thinflakeswerefabricatedbythestandardmicromechanicalcleavageprocedures.ThethicknessandtheopticalcontrastoftheatomicthindichalcogenideflakesonSiO_2/Sisubstratesweremeasuredbyatomicforcemicroscopy(AFM)andspectroscopicellipsometer.Arapidandnondestructivemethodbyusingreflectionspectrawasproposedtoidentifythelayernumberof2DlayeredtransitionmetaldichalcogenidesonSiO_2(275nm)/Sisubstrates.Thecontrastspectraof2DnanosheetswithdifferentlayernumbersareinagreementwiththeoreticalcalculationsbasedonFresnel'slaw,indicatingthatthismethodprovidesanunambiguousandnondestructivecontrastspectrafingerprintforidentifyingsingle-andfew-layeredtransitionmetaldichalcogenides.Theresultswillgreatlyhelpinfundamentalresearchandapplication.