学科分类
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10 个结果
  • 简介:包括的联合计划概括了选择联合的二种选择(GSC)和联合的概括顺序选择(GOSC)被调查。在GSC计划,从R差异分支的一个总数的L最强壮的差异分支被最大的比率联合选择并且协调地联合了。GOSC意味着从R差异分支的Lth最强壮的差异分支为接收被选择。为有GSC和GOSC的最大的比率传播的平均signal-to-noise比率的靠近形式的表情在使隧道褪色的瑞利被导出。

  • 标签: 传输率 信噪比 平均 瑞利衰落信道 广义结合 最大比合并
  • 简介:Theobjectiveofthisworkistoprovidedecision-makingprocesseswithanupdated/realpictureofthemobileresourcesinindustrialenvironmentsthroughaconstantfeedbackofinformation.Thecombinationofidentificationtechnologiesandwirelesssensornetworks(WSN)isproposedasakeydevelopmenttoguaranteeanaccurateandtimelysupplyofonlineinformationregardingthelocalizationandtrackingofthemobilewirelessdevices.Thisapproachusesacooperativeanddistributedlocalizationsystem,calledZigID,whichisaWSNbasedonaZigbeenetworkwithradiofrequencyidentification(RFID)activetagsasendnodes.TheWSNcanrecovernotonlytheIDinformationstoredatthetagsattachedtomobileresources,butalsoanyotherusefuldatacapturedbyspecificsensorsforacceleration,temperature,humidityandfuelstatus.ThispaperalsoshowsthedevelopmentofZigID,includingdevicesandinformationflows,aswellasitsimplementationingroundhandlingoperationsattheCiudadRealCentralAirport,Spain.

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  • 简介:在医药超声成像地里,由织物的速度不同类导致了以便获得高分辨率并且改正阶段错误,联合最小的变化beamforming的一个高分辨率的医药超声成像方法和一般连贯因素被介绍。首先,从元素的数据为集中被推迟;然后,多信道的数据被用于最小的变化beamforming;同时,数据从数组空格被转变到横梁空格计算一般连贯因素;最后,一般连贯因素习惯于重量最小的变化beamforming的结果。医药图象被成像系统得到。实验基于点目标和无回声的包囊目标被用来验证建议方法。结果证明在分辨率,对比和坚韧性的方面的建议方法比最小的变化beamforming和常规beamforming好。

  • 标签: 波束形成 最小方差 医学影像 超声成像 连贯性 高分辨率
  • 简介:TheuseofX-raymicrotomographic(XMT)methodsinanalysingparticulatesystemshasexpandedrapidlyinrecentyearswiththeavailabilityofaffordabledesk-topapparatus.ThisreviewpresentsasummaryofthemajorapplicationsinwhichcomputersimulationsareexplicitlycoupledwithXMTintheareaofgranularandporousmaterials.Weenvisagetwomainwaysofestablishingthecouplingbetweenbothtechniques,basedonthetransferenceorexchangeofinformationbyusingphysicalorgeometricalparameters(i.e.aparametriclinkthroughfittingtoaprocessmodel)orthroughthedirectuseof3DXMTdigitalimages(i.e.comparingimagepixelsandfeaturesdirectly).Examplesofcoupledapplicationsareshownforthestudyoftransportpropertiesofrocks,particlepacking,mechanicalloadingandsintering.Often,thelinkbetweenXMTandcomputersimulationsisbasedonvisualcomparisonsandweconcludethattheuseofquantitativeparameterssuchasthenumberofinterparticlecontacts,forcenetworksorgranuleshapetolinkbothtechniquesisstillunderrepresentedintheliterature.Strategiestoprovideamorerobustandquantitativeapproachtooptimisetheinformationobtainedfromsuchtomographyanalysesareproposed.

  • 标签: 计算机模拟 颗粒系统 多孔材料 X射线 材料分析 中国科学院
  • 简介:Theapplicationoflaserpulseswithpsecorshorterdurationenablesnonthermalefficientultrahighaccelerationofplasmablockswithhomogeneoushighionenergiesexceedingioncurrentdensitiesof1012Acm-2.Theeffectsofultrahighaccelerationofplasmablockswithhighenergyprotonbeamsareproposedformuonproductioninacompactmagneticfusiondevice.Theproposednewschemeconsistsofanignitionfusionsparkbymuoncatalyzedfusion(μCF)inasmallmirror-likeconfigurationwherelowtemperatureD–Tplasmaistrappedforadurationof1μs.Thisinitialfusionsparkproducessufficientalphaheatinginordertoinitiatethefusionprocessinthemaindevice.Theuseofamulti-fluidglobalparticleandenergybalancecodeallowsustofollowthetemporalevolutionofthereactionrateofthefusionprocessinthedevice.RecentprogressontheICANandIZESTprojectsforhighefficienthighpowerandhighrepetitionratelasersystemsallowsdevelopmentoftheproposeddeviceforcleanenergyproduction.Withtheproposedapproaches,experimentsonfusionnuclearreactionsandμCFprocesscanbeperformedinmagnetizedplasmasinexistingkJ/PWlaserfacilitiesastheGEKKO-LFEX,thePETALandtheORIONorinthenearfuturelaserfacilitiesastheELI-NPRomanianpillar.

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  • 简介:Anonlinearparabolicsystemisderivedtodescribeincompressiblenuclearwaste-disposalcontaminationinporousmedia.Asequentialimplicittirne-steppingisdefined,inwhichthepressureandDarcyvelocityofthemixtureareapproximatedsimultaneouslybyamixedfiniteelementmethodandthebrine,radionuclidandheataretreatedbyacombinationofaGalerkinfiniteelementmethodandthemethodofcharacteristics.Optimal-orderconvergenceinL2isproved.Time-truncationerrorsofstandardproceduresarereducedbytimesteppingalongthecharacteristicsofthehyperbolicpartofthebrine,radionuclideandhealequalios,temporalandspatialerrorarelossenedbydirectcompulationofthevelocityinthemixedmethod,asopposedtodifferentiationofthepressure.

  • 标签: NONLINEAR PARABOLIC system mixed finite element
  • 简介:我们在场一个样品栅栏的整体的集成散布了布拉格有由联合的一个量井electroabsorption调节的人(QW电动会计记帐机)的反射镜(SG-DBR)激光极端低压(55mbar)selective-area-growth(下垂)金属器官的化学蒸汽免职(MOCVD)和使混合的量井(QWI)第一次。QW电动会计记帐机和获得节能被使用同时种下垂MOCVD技术。同时,QWI技术提供在二功能的节之间的一个突然的乐队差距变化,它减少内部吸收损失。试验性的结果证明阀值电流Ith=62妈,和产量功率到达3.6mW。调节范围封面30nm的波长,和所有相应方面模式抑制比率是超过30dB。在可得到的波长隧道的扑灭比率能与-5V的偏爱到达超过14dB。[从作者抽象]

  • 标签: 单块集成电路 分布布喇格反射器 金属-有机物化学气相沉积 电子吸收调节器 量子阱
  • 简介:水晶的Au5Si2/Si异质接面nanowires(Au5Si2/SiNWs)被热蒸发的SiO粉末在一个低真空系统在厚黄金涂的硅底层上获得。生产Au5Si2/Si异质接面的结构分析被采用一台传播电子显微镜(TEM)和一个选择区域执行电的衍射计。化学作文被纳入TEM的一个精力散的X光分光镜学习。一个二拍子的圆舞生长模型被建议描述Au5Si2/SiNWs的形成。在第一步期间,水晶的SiNWs经由在相对高的温度把帮助氧化物的生长过程与vapour-liquid-solid模型相结合的生长机制被形成。在第二步,preformedSiNWs的温度减少和减少片断与残余Au反应由一个solid-liquid-solid过程形成单个水晶的Au5Si2nanowires。现在的工作应该基于nanowires为未来合成和高质量的金silicidenanowires和微电子设备的研究是有用的。

  • 标签: 异质结 纳米导体 氧化硅 蒸汽液化固态理论
  • 简介:Acouplednumericalmethodforthedirectnumericalsimulationofparticle-fluidsystemsisformulatedandimplemented,resolvinganorderofmagnitudesmallerthanparticlesize.Theparticlemotionisdescribedbythetime-drivenhard-spheremodel,whilethehydrodynamicequationsgoverningfluidflowaresolvedbythelatticeBoltzmannmethod(LBM).Particle-fluidcouplingisrealizedbyanimmersedboundarymethod(IBM),whichconsiderstheeffectofboundaryonsurroundingfluidasarestoringforceaddedtothegoverningequationsofthefluid.Theproposedschemeisvalidatedintheclassicalflow-around-cylindersimulations,andpreliminaryapplicationofthisschemetofluidizationisreported,demonstratingittobeapromisingcomputationalstrategyforbetterunderstandingcomplexbehaviorinparticle-fluidsystems.

  • 标签: 格子玻尔兹曼方法 颗粒流体系统 直接数值模拟 硬球模型 时间驱动 数值模拟计算