简介:Themercurycontentin158fishesand28musselsintheSecondSonghuariverweredetected.Therangeofmercuryconcentrationsinfishesandmusselswas0.02-0.66mg/kgand0.002-0.056mg/kg,respectively.Thehistorychangeofmercurycontentinfisheswasanalyzedinthispaper.Fromupstreamtodownstream,theaveragemercuryconcentrationsinfishesincreasedwiththeincreaseofthedistancetotheheadstream,thendecreasedinthedownstreamofWujiazhantown(samplingsite).Thefactilluminatedthatthesourceofmercurycontaminationwasmercuryinsediment.Inthedifferentspeciesoffishes,themercuryconcentrationinParasiburusasvtuswasthehighestandtheorderofmercurydistributioninfisheswas:themercuryvalueinfishesintheriverbottom>thatinfishesinthesurfaceandthatinpredaciousfishes>thatinherbivorousfishes.Intheinvestigation,therewereamountoffisheswhosemercuryvalueexceededthecriterionforthatinfishesthatsuggestedthatthemercurycontaminationintheSecondSonghuaRiverhavenotcompletelybeeneliminateduntilnow.
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简介:Accordingtotheideasandconceptsofsystemsdynamicofcontinentstructure,usingpreviousinformationrelatedtothestudyarea,combininganalysesonorogenicbelt,basinandmagmaticrock,thepresentpapersynthesizesthetectono-sedimentarydevelopmentofsoutheasterncoastregion,China,withspecialemphasisonthemountainmaking,basiningandmagmafcactivity.ThetectonicevolutionafterLateCaledonianorogenywasdominatedbyalternatingriftingandconverging,subsidinganduplifting,mountainmakingandbasiningincentralandsouthernpartsofsoutheasternChinaandtheadjacentregionstotheeastandwest.Seventeengeologicevents,nineeventsofplateorterrainconvergence,andcontinentalcrustaccretion,aswellaseighteventsofintracontinentalriftingandbasinfaulting,arecloselyrelatedtothetectonicandsedimentaryevolutionofthestudyarea.Theaccompaniedintenseandfrequentsedimentation,folding,faulting,magmatismandore-formingprocessallowedhugecoal
简介:Adistinctivepatternofovipositionlesionsoccursonaginkgoaleanseed,Yimaiacapituliformis,whichlikelywasinflictedbyakalligrammatidlacewingwithalong,sword-like,plant-piercingovipositor.Thisnewlyrecordedovipositiontype,DT272,occursinthe165million-year-oldJiulongshanFormation,ofMiddleJurassicage,inNortheasternChina.DT272consistsfromthreetoseven,approximatelyequallyspacedlesionswithsurroundingcallustissue,thefabricatorofwhichtargetedfleshyouterandinnertissuesofaginkgophytefruit.Thisdistinctivedamagealsoisknownfromthefleshyattachmentpadsurfacesofbasalbennettitaleanbracts.Examinationofthelifehistoryofthisprobableginkgoalean-kalligrammatidovipositioninteractionindicatesthatthespacingoftheeggsinsubstratetissuesdisfavoredinter-larvalcontact,butlittlecartbesaidofdefenseandcounterdefensestrategiesbetweentheplanthostandthenewlyhatchedimrnatures.
简介:Anacademic"SeminaronTibetanHistory",hostedbyChinaTibetologyResearchCenter,washeldinBeijingfromSeptemberItoSeptember3,2002.ProfessorsandExperts.inTibetanhistoryfromseveralTaiwanuniversities,suchasTaiwanPoliticsUniversity,CultureUniversity,ZhongzhengUniversity,SouthChinaUniversityandMingchuanUniversitytookpartintheseminar,andmorethan3omainlandscholarsfromTibet,Beijing,NanjingandChengdualsoparticipatedintheseminar.