学科分类
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4 个结果
  • 简介:Fromtheperspectiveoftourismcompetitiveness,thepapertakes12islandcountiesofChinaastheresearchobject,andappliesthemethodoffactoranalysistostudytheircompetitiveness.TheresultshowsthatPutuoandDinghaiaremorecompetitivewhilePingtanandNan’aoarelesscompetitive.Finally,the12islandcountiesaredividedintofourstyles:first-classcompetitivecounty(Putuo),seond-classcompetitivecounties(Dinghai,Yuhuan),third-classcompetitivecounties(Chongming,Daishan,Changdao,ChanghaiandShengsi),fourth-classcompetitivecounties(Dongshan,Dongtou,PingtanandNan’ao)byclusteranalysis.Theclassificationofislandcountiesistocleartheirrelativeposition,thentopromotetheirdevelopment.

  • 标签: 因子分析法 聚类分析 竞争力 海岛 旅游 中国
  • 简介:Theresultsfromahybridapproachthatcombinesamesoscalemeteorologicalmodelwithadiagnosticmodeltoproducehigh-resolutionwindfieldsincomplexcoastaltopographyareevaluated.Thediagnosticwindmodel(CaliforniaMeteorologicalModel,CALMET)with100-mhorizontalspacingwasdrivenwithoutputsfromtheWeatherResearchandForecasting(WRF)modeltoobtainnear-surfacewindsforthe1-yearperiodfrom12September2003to11September2004.Resultswerecomparedwithwindobservationsatfoursites.Traditionalstatisticalscores,includingcorrelationcoefficients,standarddeviations(SDs)andmeanabsoluteerrors(MAEs),indicatethatthewindestimatesfromtheWRF/CALMETmodelingsystemareproducedreasonablywell.Thecorrelationcoefficientsarerelativelylarge,rangingfrom0.5to0.7forthezonalwindcomponentandfrom0.75to0.85forthemeridionalwindcomponent.MAEsforwindspeedrangefrom1.5to2.0ms-1at10metersabovegroundlevel(AGL)andfrom2.0to2.5ms-1at60mAGL.MAEsforwinddirectionrangefrom30to40degreesatbothlevels.AspectraldecompositionofthetimeseriesofwindspeedshowspositiveimpactsofCALMETinimprovingthemesoscalewinds.Moreover,combiningtheCALMETmodelwithWRFsignificantlyimprovesthespatialvariabilityofthesimulatedwindfields.ItcanbeconcludedthattheWRF/CALMETmodelingsystemiscapableofprovidingadetailednear-surfacewindfield,butthephysicsinthediagnosticCALMETmodelneedstobefurtherimproved.

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  • 简介:EarlyPaleozoicgranodioritehasbeenidentifiedonthenorthernmarginoftheNorthChinacratonintheeastsectionofthecentral-Asianorogenicbelt,whichwaspreviouslyknownasearlyIndosinianinage.ByusingtheLA-ICP-MSmethod,theobtainedzirconU-Pbageis445.62.7Ma,whichrepresentsthecrystallizationageofthegranodiorite.Thegranodioriteneartheeastofthelarge-sizedBilihegolddepositisofthetholeiiteserieswithlowpotassium.Itisquasi-aluminousI-typegranite,enrichedinsodium(Na2O/K2O=7.299.77)andmagnesium(Mg#=0.510.67).TheΣREEvalueisrelativelylow,obviousdifferentiationisshownbetweenLREEandHREEandwithinLREE,andtheEuanomalyislowandnegative(δEu=0.740.91).Intheprimitive-mantlenormalizedspiderdiagramsoftraceelements,thegranodioriteisrelativelyrichinLREEandLILE(Ba,Sr,Th),andstronglydepletedinHFSE(Nb,Ta,TiandP),whichshowsfeaturesofsubductionzonecomponents(SZC).InthediscriminationdiagramsoftectonicsettingsofgraniteforRbvs.(Nb+Y),Rbvs.(Ya+Ta),La/Nbvs.Ba/NbandTh/Nbvs.Ba/Nb,thegranodioriteexhibitstypicalfeaturesofislandarcgranite.ThenormalizedvaluesofKandRbareextremelylow,whilethevaluesofSrandEuareveryhigh,whicharesimilartothoseofislandarcmagmathathasundergonemetasomatismoffluidfromtheoceaniccrust.ThegranodioriteisrelativelydepletedinεHf(t)(5.17.1)andlowinεHf(t)modelages(1089921Ma).IntheεHf(t)vs.age(T)diagram,thedistributionareaofthegranodioriteisaccordantwiththefieldoftheXing'anling-Mongoliaorogenicbelt,whichindicatesthatthemagmaticsourcesaremainlythemixtureofpartialmeltingofwedgedmantlesubjectedtometasomatismoffluidfromtheoceaniccrustandyoungsubstancefromthecrust.ThegranodioriteissimilartothefelsicarcmagmaintheDamaoBanner,BateObon,BoinSumandOrdorSumregions,andtheyaltogetherconstituteanearlyPaleozoicaccretionaryislandarcma

  • 标签: 早古生代 内蒙古高原 古亚洲洋 金矿石 岛弧 锆石U-Pb年龄