简介：AnewcombinedFermi,betatron,andturbulentelectronaccelerationmechanismisproposedininteractionofmagneticislandsduringturbulentmagneticreconnectionevolutioninexplosiveastrophysicalphenomenaatlargetemporal-spatialscale(LTSTMR),theratioofobservedcurrentsheetsthicknesstoelectroncharacteristiclength,electronLarmorradiusforlow-βandelectroninertiallengthforhigh-β,isontheorderof10^10–10^11;theratioofobservedevolutiontimetoelectrongyroperiodisontheorderof10^7–10^9).Theoriginalcombinedaccelerationmodelisknowntobeoneofgreatestimportanceintheinteractionofmagneticislands;itassumesthatthecontinuouskinetic-dynamictemporal-spatialscaleevolutionoccursastwoseparateindependentprocesses.Inthispaper,wereconsiderthecombinedaccelerationmechanismbyintroducingakinetic-dynamic-hydrofull-coupledmodelinsteadoftheoriginalmicro-kineticormacro-dynamicmodel.Weinvestigatedifferentaccelerationmechanismsinthevicinityofneutralpointsinmagneticislandsevolution,fromthestageofshrinkandbreakupintosmallerislands(kineticscale),tothestageofcoalescenceandgrowthintolargerislands(dynamicscale),tothestagesofconstantandquasi-constant(contracting-expanding)islands(hydroscale).Asaresult,wegiveforthefirsttimetheaccelerationefficienciesofdifferenttypesofaccelerationmechanismsinmagneticislands’interactionsinsolaratmosphereLTSTMRactivities(pico-,10^–2–10^5m;nano-,10^5–10^6m;micro-,10^6–10^7m;macro-,10^7–10^8m;large-,10^8–10^9m).

简介：TheEmeishanlargeigneousprovince(hereafternamedbyitsacronymELIP)isthefirstacceptedlargeigneousregioninChina.Thecurrentstudytriestoreconstructthedensitystructureofthecrustinthisregion.Forthispurpose,weconductedthegravitysurveyalongan800-km-longprofile,whichstretchedlaterallyalongthelatitude27°NfromLijiang(Yunnanprovince)toGuiyang(Guizhouprovince).Thefieldworkincluded338gravitymeasurementsdistributedfromtheinnerzonetotheouterzoneofthemantleplumehead.Afteraseriesofgravityreductions,wecalculatedtheBouguergravityanomalyandthenconstructedthedensitymodelforELIPbyiterativeforwardmodelingfromaninitialdensitymodeltightlyconstrainedbywide-angleseismicreflectiondata.ThetopographyoftheMoho,herephysicallyinterpretedasadensitydiscontinuityof~0.4g·cm–3,graduallyrisesfromtheinnerzone(~50kmdeep)totheouterzone(~40km),describesathickercrustintheinnerzonethaninanyothersegmentoftheprofileandlargelyreproducestheshapeoftheBouguergravityanomalycurve.BoththeBouguergravityandthedensitystructureshowsignificantdifferenceswithrespecttotheinnerzoneandtheothertwozonesofELIPaccordingtothecommonlyacceptedpartitionoftheEmeishanarea.Athickeranddensermiddle-lowercrustseemstobethemainfeatureofthewesternsectionoftheprofile,whichislikelyrelatedtoitsmaficmagmaticcompositionduetomagmaticunderplatingofthePermianmantleplume.