简介：Withtheenhancedwarmingandacidificationofglobalocean,whetherandtowhatextentthenaturally-weatheredfluvialsedimentintotheseacanreleaseelementsandthusinfluencethegeochemicalprocessandecosystemofglobaloceanremaintoberesolved.Inthiscontribution,anexperimentalstudywascarriedouttoexaminethereleaseratesofmajorelements(Ca,K,MgandAl)fromthesurfacesedimentsintheChangjiang(YangtzeRiver)EstuaryunderthepHvaluesof4.0,6.0and7.0.Thetwostudiedsedimentsconsistprimarilyofquartz,plagioclase,calciteandclayminerals,withtheBET(Brunauer,EmmettandTeller)surfaceareasof61.7m2g-1and23.1m2g-1.MajorelementsofCa,K,MgandAlshowdifferentreleaseratesunderdifferentsolutionpHvalues.WiththedecreasingsolutionpH,thereleaseratesofCaandKincreaseobviously,whilethereleaseratesofMgandAlincreasewiththeinitialsolutionpHvaryingfrom6.0to7.0.Thedifferentreleaseratesoftheseelementsarecloselyrelatedtotheoriginalmineralcompositionofthesedimentsandthereactionkinetics.Basedontheexperimentalobservation,quartzandclaymineralsthathavelowdissolutionratesmaydominatethemajorelementreleasetotheaqueousphase.Thisstudyrevealsthattheenhancingoceanacidificationcouldcauseconsiderablereleaseofmajorelementsfromnaturalterrigenoussedimentsintotheambientmarineenvironment,whichhastobeconsideredcarefullyinthefuturestudyonglobalchange.更多还原

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简介：Theelasto-plasticpostbucklingoffibermetallaminatedbeamswithdelaminationandtheenergyreleaseratealongthedelaminationfrontarediscussedinthispaper.Consideringgeometricalnonlinearity,thermalenvironmentandgeometricalinitialimperfection,theincrementalnonlinearequilibriumequationsofdelaminatedfibermetallaminatedbeamsareestablished,whicharesolvedusingthedifferentialquadraturemethodanditerativemethod.Basedonthese,accordingtotheJ-integraltheory,theelasto-plasticenergyreleaserateisstudied.Theeffectsofsomeimportantparametersontheelasto-plasticpostbucklingbehaviorandenergyreleaserateofthearamidreinforcedaluminumlaminatedbeamsarediscussedindetails.

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