学科分类
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5 个结果
  • 简介:Aleafinclinationangledistributionmodel,whichisapplicabletosimulateleafinclinationangledistributioninsixheightsoflayeredcanopyatdifferentgrowthstages,wasestablishedbycomponentfactorsaffectingplanttypeinrice.Theaccuracyofthesimulationresultswasvalidatedbymeasuredvaluesfromafieldexperiment.Thecoefficientofdetermination(R2)andtherootmeansquareerror(RMSE)betweenthesimulatedandmeasuredvalueswere0.9472and3.93%,respectively.Thesimulationresultsshowedthatthedistributionofleafinclinationanglesdifferedamongthethreeplanttypes.TheleafinclinationangleswerelargerinthecompactvarietyLiangyoupeijiuwitherectleavesthanintheloosevarietyShanyou63withdroopyleavesandtheintermediatevarietyLiangyouY06.TheleafinclinationanglesweredistributedinthelowerrangeinShanyou63,whichmatchedupwithfieldmeasurements.Thedistributionofleafinclinationanglesinthesamevarietychangedthroughoutthesevengrowthstages.Theleafinclinationanglesenlargedgraduallyfromtransplantingtobooting.Duringthepost-bootingperiod,theleafinclinationangleincreasedinShanyou63andLiangyouY06,butchangedlittleinLiangyoupeijiu.Ateverygrowthstageofeachvariety,canopyleafinclinationangledistributiononthesixheightsofcanopylayerswasvariable.Ascanopyheightincreased,thelayeredleafareaindex(LAI)decreasedinallthethreeplanttypes.However,whiletheleafinclinationanglesshowedlittlechangeinLiangyoupeijiu,theybecamelargerinShanyou63butsmallerinLiangyouY06.Thesimulationresultsusedintheconstructedmodelwereverysimilartotheactualmeasurementvalues.Themodelprovidesamethodforestimatingcanopyleafinclinationangledistributioninriceproduction.

  • 标签: 叶片倾角 水稻产量 冠层叶 模拟 紧凑型品种 分布模型
  • 简介:Birthdefectsaffectthequalityofthenewbornpopulation,andhavebecameamajorpublichealthprobleminChina.Geneticfactors,environmentalfactors,andtheinteractionofthetwoisthedirectcauseoftheincidenceofbirthdefects.Thisreview,basedontheneuraltubedefectsasanexample,giveinsightintothepathogenesisofbirthdefectsfromthegenomics,epigenetics,metabonomicsandenvironmentfactorsandexplorenewstrategyofbirthdefectpreventioninChina.

  • 标签: 出生缺陷 中国 生物学 公共卫生问题 环境因素 发病机制
  • 简介:AIM:Todescribetheresultsof5consecutivecasesofclearlensextractioninangleclosurepatientsforthetreatmentofelevatedintraocularpressure(IOP).·METHODS:Retrospectiveobservationalcaseseries.Allangleclosurepatientswereontwoormoretopicalglaucomamedicationsandhadpriorlaseriridotomy.Eyesunderwentclearlensextractionbyphacoemu-lsificationwithintraocularlensimplantation.·RESULTS:Allfivepatientsinthiscaseseriescarriedthediagnosisofangle-closureglaucomaandhaduncontrolledIOPpriortosurgerydespitetopicalmedications.AfterclearlensextractionthreeofthecaseshadgoodIOPcontrol(IOP<22mmHg)withouttheneedfortopicalmedications.InonecasetheIOPwasbettercontrolledaftersurgery,however,topicalmedicationswererequired.ThedesiredIOPwasnotmetinonecasedespiterestartingmaximumtopicaltherapy.·CONCLUSION:Thiscaseseriessuggeststhattheremaybearolefortherapeuticclearlensextractioninselectcasesofangle-closureglaucoma.

  • 标签: clearlens GLAUCOMA CATARACT angleclosure
  • 简介:Thispaperdiscussestheproblemofdirectionofdeparture(DOD)anddirectionofarrival(DOA)estimationforabistaticmultipleinputmultipleoutput(MIMO)radar,andproposesanimprovedreduced-dimensionCaponalgorithmtherein.Comparedwiththereduced-dimensionCaponalgorithmwhichrequirespairmatchingbetweenthetwo-dimensionalangleestimation,theproposedalgorithmcanobtainautomaticallypairedDODandDOAestimationwithoutdebasingtheperformanceofangleestimationinbistaticMIMOradar.Furthermore,theproposedalgorithmhasalowercomplexitythanthereduced-dimensionCaponalgorithm,anditissuitablefornon-uniformlineararrays.ThecomplexityoftheproposedalgorithmisanalyzedandtheCramer-Raobound(CRB)isalsoderived.Simulationresultsverifytheusefulnessoftheproposedalgorithm.

  • 标签: 降维算法 角度估计 MIMO 双基地 雷达 阉鸡