学科分类
/ 1
5 个结果
  • 简介:TherestorationofforestlandscapehasdrawnmuchattentionsincethecatastrophicfiretookplaceonthenorthernslopeofGreatXing'anMountainsin1987.Forestcanopydensity,whichhascloserelationtoforestproductivity,wasselectedasakeyfactortofindhowmuchtheforestqualitywaschanged13yearsafterfire,andhowfireseverity,regenerationwayandterrainfactorsinfluencedtherestorationofforestcanopydensity,basedonforestinventorydatainChina,andusingKendallBivariateCorrelationAnalysis,andDistancesCorrelationAnalysis.Theresultsshowedthatfireseveritywhichwasinverselycorrelatedwithforestcanopydensitygradewasaninitialfactoramongallthatselected.Regenerationwaywhichdidnotremarkablyaffectforestcanopydensityrestorationinshortperiod,mayshortenthecycleofforestsuccessionandpromotetheforestproductivityofconophoriuminthefuture,Amongthethreeterrainfactors,theeffectofslopewasthestrongest,thepositiononslopewasthesecondandtheaspectwasthelast.

  • 标签: 大兴安岭北坡 火烧迹地 森林郁闭度 森林景观 影响因子
  • 简介:BlueschistaccompaniedbypeliticschistexposealongtheXinlin-XiguitufaultintheToudaoqiaoarea,northeasternChina.Inthispaper,theblueschistissystematicallystudiedonthepetrographyandmineralchemistry.Theamphibolesintheblueschistarezonedfromwinchitecoretomagnesioriebeckite/glaucophanerimtowinchiteoutermostrim.Thepeakmetamorphicconditionsaredefinedbythemineralassemblageofmagnesioriebeckite/glaucophane,epidote,high-Siphengite(Si<7.1),chlorite,albite,hematiteandquartz,indicatinganepidote-blueschistfaciesmetamorphism.TheP-TconditionsareestimatedasT=350–400℃andP=10-12kbar.TheoccurrenceoftheblueschistalongtheXinlin-XiguitufaultstronglysuggeststhefaultisthesuturebetweentheErgunandtheXing'anblockssituatedintheeasternportionsoftheCentralAsiaOrogenicBelt(CAOB).

  • 标签:
  • 简介:Basedonthesurveyresearchofpovertycontrollingmodelof'ThreeDrives,FourJoints'inZhen’anCounty,itsformingmotives,implementingmechanism,andconstraintfactorshavebeenexploredtotestifyitsenlightenmentandapplicability,establishingapromotable,applicable,andeffectivepovertyalleviationmodel.'ThreeDrives,FourJoints'modelislinkedtothepoorwholacksabilityofself-development.Relyingonthedrivesfromkeyleadingcompanies,thecapableandtherich,acommunitywithsharedinterestsbythepoorandthesubjectsofthe'threedrives'couldbeformedthrough'JointProduction,JointResources,JointCommunityofStock,andJointOperation'.Thelinkedpovertyalleviationdevelopmentmodelof'theinfluentialandtherichbringalongthepoor'and'Arichhouseholdwouldhelptheothers'comeintobeing.Itisfoundoutthatthemodelof'ThreeDrives,FourJoints'isinessenceapovertyalleviationmethodfocusingontheincreaseoftheincomeanddiversifiedwaysofincreasingtheearnings.Problemsofpovertyalleviationcarrierandjointmechanismhavebeensolvedinthepovertyalleviationprocess.Themodelisinnovativeinactivatingtheresourceelements,helpingtomovethepooroutofpoverty.Areferential,copyable,andapplicablemodelisofferedtoadvancethepovertyalleviationinmountainousareasinChina.

  • 标签:
  • 简介:Basedondetailedgeologicstudy,theimportantroleofstructuringintheformationofgolddepositsintheareaisdiscussedwithspecialreferencetostructuralevolution,Syngeneticfaultingcontemporaneouswithtectonic-volcaniceventsisthoughttoberesponsibleforprovidingtheore-formingmaterialatdepth.ThelithofaciesformedbyhighlyalternatingdepositionofterrestrialandcarbonatedetritusischemicallycharacterizedbytheassemblageofAu-Sb-As,constituteingafavorablesourcebedfortheactivationandenrichmentofgold.Thisgoldsourcebedhasundergonefourmajorstagesofstructuraldeformation,accompaniedbymulti-stagedalterationandmineralization.

  • 标签: 金矿床 陕西 延展性 脆性 地质构造 成矿作用