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456 个结果
  • 简介:Inthispaper,wepresentanovelSupportVectorMachineactivelearningalgorithmforeffective3Dmodelretrievalusingtheconceptofrelevancefeedback.Theproposedmethodlearnsfromthemostinformativeobjectswhicharemarkedbytheuser,andthencreatesaboundaryseparatingtherelevantmodelsfromirrelevantones.Whatitneedsisonlyasmallnumberof3Dmodelslabelledbytheuser.Itcangrasptheuser'ssemanticknowledgerapidlyandaccurately.Experimentalresultsshowedthattheproposedalgorithmsignificantlyimprovestheretrievaleffectiveness.Comparedwithfourstate-of-the-artqueryrefinementschemesfor3Dmodelretrieval,itprovidessuperiorretrievalperformanceafternomorethantworoundsofrelevance

  • 标签: 多媒体技术 计算机软件 3D技术 检索方法
  • 简介:在这研究,为波浪精力变换与固定指南翼推进一台推动汽轮机的表演的改进以便完成,表演上的指南翼形状的效果被实验调查。调查被模型在稳定的流动状况下面测试执行。作为结果,因为转矩的增加,有3D指南翼的汽轮机的效率比有2D指南翼的汽轮机的稍微优异,这被发现指南翼,尽管越过为3D案例的汽轮机的压力落下为2D案例比那稍微高。关键词液体机械-推动汽轮机-指南翼-波浪精力变换CLC数字TK735

  • 标签: 流体机械 冲量涡轮 风向导向标 波能量转化率 水轮机
  • 简介:9to12,April,2018Suzhou,ChinaInternationalSymposiumseriesonHighPowerLaserScienceandEngineering,aimingatbringingtogetherworldwidescientistsandengineersworkingonhighpowerlaserandphysics,isheldeverytwoyearssince2014.Onbehalfofthe3rdInternationalSymposiumonHighPowerLaserScienceandEngineering(HPLSE2018),

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  • 简介:TheNd2O3nanoparticleswhichmodifiedbyAOTwaspreparedusingmicrioemulsionmethodinthesystemofwater/xylene.L3edgeXAFSwasusedtodeterminethedifferenceofthelocalstructurearundNd^3+ionandtheelectricalstructurebetweenthenanocystallineNd2O3andthecoarsebulkmicrocrystallineNd2O3.ItwasfoundthatNd-Odistanceincreasedwiththeformofnanocrystalliteandtheintensityofabsorptionedgealsoenhancedatthesametime.

  • 标签: EXAFS研究 ND2O3 毫微米粒子
  • 简介:TheCasimireffecthasbeenstudiedforvariousquantumfieldsinbothfiatandcurvedspacetimes.Asafurtherstepalongthisline,weprovideanexplicitderivationofCasimireffectformasslessspin-3/2fieldwithperiodicboundaryconditionimposedinfour-dimensionalMinkowskispacetime.ThecorrespondingresultswithDirichletandNeurnannboundaryconditionsarealsodiscussed.

  • 标签: CASIMIR效应 无质量自旋 MINKOWSKI空间 边界条件
  • 简介:Atopologymethodispresentedinthispapertorevealflowtructureoccurringinsieturbomachinery,inwhichnearwallflowstructureisrevealedbyusingwalllimitingstreamilinesandspaceflowfeatureisrevealedbyusingspacestreamilinesandcross-sectionstreamlines,Asanexample,acomputationalthree-dimensionalviscousflowfieldinsideatransonicturbinecascadeisstudied.Throughtheanalysis,theformandevolutionofvortexsystemandthewholeprocessofseparationoccurringwithinthiscascadearerevealed.Theapplicationoftopologymethodforanalyzeflowstructureinsideturbomachinmeryisveryimportantforunderstandingflowfeaturesandmechanismofflowlossevenforimprovingthedesignofturbomachineryandincreasingitsefficiency.

  • 标签: 超声速透平机 粘滞流体 拓扑结构
  • 简介:Arabidopsisthalianaisacommonresearchplantofmolecularandcellbiologicalresearchwhichhasshortlifecycleandhugeamountofseeds[1].Gammarayisoneoftheimportantphysicalmutagenswhichiswidelyusedinplantgeneticsandbreedingresearch[2].Thepurposeofthisstudyistoinvestigatethedose-effectofrayradiationsontherootdevelopmentofArabidopsis.Dryseedswereirradiatedbyrayswiththedoserangefrom100to1600Gy.

  • 标签: EFFECT IRRADIATION GROWTH
  • 简介:MalignanttumorsorcancershavebecomeoneofthemostfrequentcausesofdeathinChina;cancertherapiesareattractingmuchattention.Becauseofthenoninvasivenatureofradiationtherapy,lesserphysiologicalandpsychologicalburdenisplacedonpatientsthancomparedtothatresultingfromsurgicalorpharmaceuticaltreatments.Hadrontherapy(heavyiontherapyandprotontherapy)isconsideredsuperiorapproachforthetreatmentoftumorslocatedinhighlysensitivetissues(brain,neck,eyes),pediatriccancers,andalsotumorsthatareresistanttoradiotherapy.

  • 标签: NANOPARTICLES HADRON THERAPY
  • 简介:用微波高温固相法合成了Er^3+单掺Lu2O3,Li^+与Er^3+共掺Lu2O3及Li^+,Zn^2+,Mg^2+掺杂Lu2O3∶Er^3+的荧光粉。实验表明金属离子Li^+、Zn^2+、Mg^2+、Er^3+掺杂Lu2O3,不影响Lu2O3的立方晶相。扫描电子显微镜测量表明,Li^+掺杂可以有效改善粉体的分散性和形貌,Li^+,Zn^2+,Mg^2+共掺杂获得的粉体颗粒分布更加均匀,粒径范围为80~100nm。379nm激发下,Li^+与Er^3+共掺样品发光较单掺Er^3+样品在565nm处的发光增强了4.5倍,而Li^+、Zn^2+、Mg^2+与Er^3+共掺样品较其发光增强5.3倍。980nm激发下,Li^+与Er^3+共掺样品,Li^+、Zn^2+、Mg^2+与Er^3+共掺样品的发光分别比单掺Er^3+样品在565nm处发光增强23倍与39倍,在662nm处发光强度分别增强20倍与43倍。379nm激发下,较单掺Er3+的样品,掺杂Li^+的样品和Li^+,Zn^2+,Mg^2+和Er^3+共掺的样品荧光寿命均有所增加,而Zn^2+、Er^3+共掺及Mg^2+、Er^3+共掺样品的荧光寿命则有所缩短。

  • 标签: 微波高温固相法 Li^+ Zn^2+ Mg^2+掺杂Lu2O3∶Er^3+荧光粉 发光强度 上转换发光 荧光寿命
  • 简介:Theground-stateandthermodynamicpropertiesofquantummixed-spinchainsof1/2-1/2-1-1and3/2-3/2-1-1areinvestigatedbyaquantumMonteCarlosimulationwiththeloop-clusteralgorithm.For1/2-1/2-1-1chain,wefindithastwophasesseparatedbyanenergy-gapvanishingpointintheground-state.For3/2-3/2-1-1chain,thenumericalresultsshowtwoenergy-gapvanishingpointsisolatedbydifferentphasesinitsground-state.Ourcalculationsindicatethatallthesegroundstatephasescanbeunderstoodbymeansofvalence-bond-solidpicture,andthethermodynamicbehavioratfinitetemperaturesiscontinuousasafunctionofparameterα=J2/J1.

  • 标签: 蒙特卡罗模拟 混合自旋链 铁磁性 基态 热力学性质 能隙