简介：Metalgrainsinstonymeteoritesarerelativelymovableduringthermalnetamorphism(Wood,1967;XieandWang,1979;Xie,1986).InviewofthefactthattheJilinmeteoriteisthelargestintheworldknownuptonow,itsmainbodyweighing1770kganditstotalvolumeamountingto117×93×84cm^3,ade-tailedinvestigationintosuchahugemeteoritebodywouldundoubtedlyprovideuswithalotofcluesandinformationvaluableinthestudyofthebehaviorofFe-Nimetalduringthermalmetamorphismofmeteorites.OurrecentinvestigationhasrevealedthatduringthermalmetamorphismoftheJilinchondirtefineFe-Nimetalparticlesmigratedeasilybydiffusioninsolidstate,andsubsequentlyaggregatedintometalnodulesabout5-10mminlength,andthelargestnodulewefoundis30mminsize(Photo1).Inthispaperwepresentsomenewresultsofourstudyconcerningthemigra-tionandconcentrationofFe-NimetalintheJilinchondriteonthebasisofop-tical,SEMobservationsandhigh-temperature-highpressureaswellasshockloadingexperiments.

简介：Understandingtheeffectsoforganicacids（OA）onthetransformationofFeandMntosurfacewaterfromtheweatheringcoalgangueisofgreatbene?ttoriskassessmentandremediationstrategiesforcontaminatedwaterandsoil.BasedontheinvestigationonsurfacewaterinthecentralcoaldistrictsoftheGuizhouProvince,18watersampleswerecollectedforheavymetalanalysis.TheresultsindicatedthatthepHvalueofsurfacewaterislow（3.11–4.92）,andFeconcentration(1.31–5.55mgL-1)andMnconcentration(1.90–5.71mgL-1)were,onaverage,10.86and34.33timesthelimitofSurfaceWaterQualityStandards,respectively.InordertoevaluatetheeffectsoftheOAonthedissolutionofFeandMnfromtheweatheringcoalgangue,columnelutionandbatchleachingexperimentswereconducted.Theresultsshowthatthelowmolecularweightoforganicacids（LMWOAs,i.e.,oxalic,tartaric,malicandcitricacids）andfulvicacidssigni?-cantlyacceleratedthedissolutionofFeandMn;inaddition,whentheconcentrationofOAreached25mmolL-1,theconcentrationsofFe,andMnwere1.14–67.08and1.11–2.32timesashighasthosein0.5mmolL-1OA,respectively.Furthermore,themigrationofFeandMnwassigni?cantlyin?uencedbythepHandEh,especiallyforFe;theionMnwasdissolvedfromtheganguemoreeasilythantheionFeinthecolumnleaching,whichwascontrarytotheresultsofbatchleaching.

简介：ThestrongadaptabilityofBroussonetiapapyrifera(L.)Vent.tolowphosphorus(P)conditionscanbeattributedtothelargeamountofroot-exudedorganicacidsandthehighef?ciencyofPextraction.However,microelementcontentsarein?uencedbylow-Pstress,andtheireffectsonthephotosyntheticcapabilityofB.papyriferaremainunknown.Inthisstudy,weinvestigatedtheeffectsoflow-Ptreatmentonnetphotosyntheticrate(P_N);chlorophylla?uorescence(ChlF)characteristics;andFe,Mn,Cu,andZncontentsofB.papyriferaandMorusalbaL.seedlings.ResultsshowthatB.papyriferaexhibitedbetterphotosyntheticcapabilityundermoderatePde?-ciency(0.125,0.063,and0.031mmol/LPtreatments),whereasthephotosyntheticcapabilityofM.albadecreasedundermoderateandseverePde?ciency(0.016and0mmol/LPtreatments).UndermoderatePde?ciency,thedecreaseinCuandZncontentsinB.papyriferawaslowerthanthatinM.alba.UnderseverePde?ciency,aconsiderabledecreaseofphotosyntheticcapabilityinB.papyriferaandM.albawasassociatedwithlowCuandZncontents.ThePNofthetwoMoraceaespeciesexhibitedabettercorrelationwithCuandZncontentsthanwithFeorMncontent.Pde?ciencycouldnotonlydecreasecyclicphotophorylationandphotosyntheticef?ciency,butcouldalsoaffectthestabilityofthylakoidmembranestructureandelectrontransportef?ciencybyin?uencingthecontentsofCuorZn,therebyaffectingphotosynthesis.