学科分类
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39 个结果
  • 简介:Therecursivestructureandquasi-recursivestructureofAdaptiveVolterraFil-ter(AVF)areputforward,theiralgorithmsaregiven,andtheircharacteristicsandapplicationsarediscussed.TheintroductionofrecursivestructurecanremarkablyreducetheparametersandcomputationalcostofAVF.

  • 标签: Adaptive FILTERS System identification Noise elimination/volterra
  • 简介:Theelectroluminescencethinfilmsdopedwitherbium,fabricatedbythermalevaporationwithtwoboats,areanalyzedbyX-raydiffraction(XRD).Therelationshipbetweenelectroluminescencebrightnessandmicrostructureofthethinfilmsisobtained.Theresultsrevealthatthelargegrainsizeinhighindexplaneofdepositedmicrocrystallinefilmhasaneffectonelectroluminescencecharacteristicsofthefilmdevices.

  • 标签: 场致发光 ZNS薄膜 微结构 红外线衍射 XRD
  • 简介:Theγ-rayradiationwillspeedupthedischargeofthestoredchargeinnonvolatileMNOSstructure.Theradiationabsorptionmechanismtoenhancethedischargeisdiscussed.Adirectradiationemissionmodelfromtheinterfacetrapsdistributingbothinenergylevelandinspaceisgiven.Thetheoreticalresultsbasedonthismodelareingoodagreementwithexperimentalmeasurement.

  • 标签: MNOS Γ辐射 直接辐射模式 辐射吸收
  • 简介:UniversalSpectralModulationSensors:(Ⅰ)TheoryandStructure①SHIYongji(LuoyangTechnologyColege,Luoyang471003,CHN)Abstract:Auniver...

  • 标签: SPECTRAL MODULATION SENSOR Fiber OPTIC SENSOR
  • 简介:在大约431nm的蓝光在C+培植以后从取向附生的硅被获得,在顺序蚀刻的氢环境和化学药品退火。随化学蚀刻的增加,蓝山峰起初被一座红山峰最后提高,然后减少了并且代替。C=O混合物在C+培植期间被介绍并且在纳米Si的表面嵌入在退火期间形成了,并且最后被形成纳米硅与嵌入结构,它贡献蓝排放。介绍是光致发光的可能的机制。

  • 标签: C^+种植 退火 化学侵蚀 植入结构
  • 简介:Thispaperanalyzesthepossibilitytodiscriminatebetweenconvectiveprecipitationandstratiformprecipitation.Thisstudyaimstoimprovethemeasurementofrainfallfromteledetectiondataobtainedbothonthegroundandinspace.Forthis,twoparameters,fractaldimensionandfractallacunarity,areconsidered.Tocalculatethefractaldimension,weusetheapproachofbox-countingandshowthatthefractaldimensiondiffersbetweenconvectivescellsandstratiformsones.Andthenthefractallacunarityparameteriscalculatedbyusingtheslidingboxesalgorithm.Thestudyforalltheregionsshowsthatprecipitationcellscanbedescribedbydifferentlacunaritieswhateverthescaleofanalysis.Wededucethatthetwoparameters,fractaldimensionandfractallacunarity,canbeusedtoclassifyprecipitationsinconvectiveregimeandstratiformregime.

  • 标签: 分形几何 ES细胞 结构分析 分类 沉淀 层状云降水
  • 简介:Anovelmethodfordesigningabeam-switchingantennawiththeplanedipoleispresented.Theantennaiscomposedofdoubledipolesplacedatthecenterofanactivesquarestructurethatisdividedinfourequalsectorsbymetallicsheets.Metallicpatchesattheoutsideofthestructureareusedtoenhancetheradiationperformanceoftheantenna.Ineachstep,thediodesinonesectorareon,whereasotherdiodesareoff.Thesectorwithoff-statediodesdefinesthedirectionoftheradiationpattern.AnantennamodelisdesignedonthesubstrateofFR4.Theproposedantennaoperatesfrom4.8GHzto5.5GHzwithgainof6.3dBiandF/B(fronttobackratio)of13.2dBiwhentheoperatingfrequencyis5.2GHz.Theantennaradiationpatterncanbesweptintheentireazimuthplaneinfourstepswitha3dBbeamwidthof90.Theresultsrevealthattheantennacouldbeusedinthebasestationofthewirelesscommunicationsystems.

  • 标签: ANTENNA DIODES RECONFIGURABLE switch-beam.
  • 简介:聚合Mach-Zehnder肋骨波导的系统的分析基于计算和优化被介绍。模拟与有效索引方法(EIM)被执行并且二维(2-D)有限差别横梁繁殖方法(FD-BPM)。在连续聚合物层之间的大折射索引步被使用EIM减少,因此,计算的精确被保证。象Y连接角度和分离差距那样的波导的重要参数被讨论,他们与光力量繁殖和损失特征的关系在这篇论文被调查。优化结构的全部的损失是0.258dB。CLC数字TN252这个工程被基础为武器设备的进展研究节目支持,中国(资助No.02040105DZ02)。

  • 标签: 聚合物材料 Mach-Zehnder条形波导 结构优化 集成光波导器件
  • 简介:AsimplephotoelasticopticalmodulatorwithaFabry-Perotcavitybasedonthesilicon-on-insulatorsystemwasfabricated.A50%modulationdepthhasbeenobtatinedatcurrentdensityofabout1.5×10^3A/cm^2.Theinsertionlosswasabout15dB.

  • 标签: 调制器 绝缘体上外延硅 光弹性
  • 简介:Anovelmethodfordesigningabeam-switchingantennawiththeplanedipoleispresented.Theantennaiscomposedofdoubledipolesplacedatthecenterofanactivesquarestructurethatisdividedinfourequalsectorsbymetallicsheets.Metallicpatchesattheoutsideofthestructureareusedtoenhancetheradiationperformanceoftheantenna.Ineachstep,thediodesinonesectorareon,whereasotherdiodesareoff.Thesectorwithoff-statediodesdefinesthedirectionoftheradiationpattern.AnantennamodelisdesignedonthesubstrateofFR4.Theproposedantennaoperatesfrom4.8GHzto5.5GHzwithgainof6.3dBiandF/B(fronttobackratio)of13.2dBiwhentheoperatingfrequencyis5.2GHz.Theantennaradiationpatterncanbesweptintheentireazimuthplaneinfourstepswitha3dBbeamwidthof90.Theresultsrevealthattheantennacouldbeusedinthebasestationofthewirelesscommunicationsystems.

  • 标签: 波束切换 偶极子 子结构 天线 平面 无线通信系统
  • 简介:Superlatticesconsistingofalternatinglayersoforganic/polymericmaterialshavebeenfabricatedfromtris(8-hydroxyquinoline)aluminum(Alq3)andpoly(N-vinylcarbazole)(PVK)byamultisource-typehigh-vacuumorganicmoleculardeposition.ThecharacteristicsofsuperlatticestructuresaredeterminedbythesmallangleX-raydiffraction,opticaladsorptionandphotoluminescence.Theelectroluminescentdeviceswiththesuperlatticestructurehavealsobeenfabricatedandtheemissioncharacteristicsarediscussed.

  • 标签: 有机超晶格 电致发电 聚合物 半导体
  • 简介:DecentralizedVariableStructureControlofComplexGiantSingularUncertaintySystems¥WenXiangcai&LiuYongqing(DepartmentofAutomation,...

  • 标签: COMPLEX GIANT SINGULAR UNCERTAINTY systems Multiple
  • 简介:Anovelcompactelectromagneticbandgap(EBG)structureconstructedbyetchingtworeversesplitrings(RSRs)andinsertinginterleavingedge(IE)onthepatchofconventionalmushroom-likeEBG(CML-EBG)isinvestigated.SimulateddispersiondiagramsshowthattheproposedEBGstructurepresentsa13.6%sizereductioninthecenterfrequencyofthebandgap.TwocomparisonshavebeencarriedoutfortheanalysisoftheeffectoftheRSRsandIEconfiguration.Then,asampleofthisnovelEBGisfabricatedandtested,furtherexperimentaldataagreewellwiththesimulatedresults.Thus,thisEBGstructuremakesagoodcandidatetodecreasemutualcouplingincompactmicrostrippatcharray.

  • 标签: 电磁带隙结构 紧凑型 设计 IE浏览器 EBG 中心频率
  • 简介:OrderingbasedsearchmethodshaveadvantagesovergraphbasedsearchmethodsforstructurelearningofBayesiannetworksintermsontheefficiency.Withtheaimoffurtherincreasingtheaccuracyoforderingbasedsearchmethods,wefirstproposetoincreasethesearchspace,whichcanfacilitateescapingfromthelocaloptima.Wepresentoursearchoperatorswithmajorizations,whichareeasytoimplement.Experimentsshowthattheproposedalgorithmcanobtainsignificantlymoreaccurateresults.Withregardtotheproblemofthedecreaseonefficiencyduetotheincreaseofthesearchspace,wethenproposetoaddpathpriorsasconstraintsintotheswapprocess.Weanalyzethecoefficientwhichmayinfluencetheperformanceoftheproposedalgorithm,theexperimentsshowthattheconstraintscanenhancetheefficiencygreatly,whilehaslittleeffectontheaccuracy.Thefinalexperimentsshowthat,comparedtoothercompetitivemethods,theproposedalgorithmcanfindbettersolutionswhileholdinghighefficiencyatthesametimeonbothsyntheticandrealdatasets.

  • 标签: BAYESIAN network structure learning ORDERING SEARCH
  • 简介:Cr-dopedZnOthinfilmsarepreparedonglasssubstratesbythemagnetronsputteringtechnique.AnX-raydiffraction(XRD)isusedtoanalyzethestructuralpropertiesofthethinfilms.Itindicatesthatallthethinfilmshaveapreferentialc-axisorientation.Thepeakpositionofthe(002)planeshiftstothehigher2θvalue,andthepeakintensitydecreaseswiththeincreaseofCrdoping.Theresultsofthescanningelectronmicroscopy(SEM)showthatthesurfacemorphologybecomesloosewiththeincreaseofCrdoping.Besides,itisfoundfromthephotoluminescence(PL)measurementatroomtemperaturethattheultravioletemissionpeakandgreenemissionbandarelocatedat375nmand520nm,respectively,andbothintensitiesofthemdecreasewiththeincreaseoftheCrdopingconcentration,whilethebandgapoftheultravioletemissionshiftstothelowerwavelength.TheexperimentalresultsconfirmthattheoptimalCrdopingconcentrationis2at.%.

  • 标签: ZNO薄膜 结构特性 铬掺杂 光学特性 最佳掺杂浓度 扫描电子显微镜
  • 简介:Thispaperproposesalanedetectionalgorithmbasedonmulti-structureelementmodelofmorphological.Theinnovativepointofthealgorithmliesinthefactsthattheflexiblestructurehasthemulti-structureelementsthatlanemodelfeatureshave,andthatthealgorithmadoptsthemorphologicalfilteringprincipletoextractthepixelsintheimage,whichissimilartothelanemodel.Inthealgorithm,theinterestedareaisextractedbyamodeloftrapeziumfromoriginalimage,whichisdetectedbytheoperatorofCanny,andthelanesareextractedbythestructureelements,whichhavesimilarcharacteristicstothatoflanemodel.SeverallinesaredetectedbyHoughtransformation,thenthetrafficlanesarereconstructed.Experimentsshowthatthisalgorithmissimpleandrobust,andcanefficientlydetectthelanemaskaccuratelyandquickly.

  • 标签: 多结构元素 CANNY算子 Hough变换 检测模型 特征提取 测算法
  • 简介:Thedielectricpropertiesofceramicswithcompositionof(Sr1-xBix)TiO3+x/2(wherex=0.05~0.70)weremeasuredatfrequencyof1MHz.Theexperimentalresultsindicatethatthedielectricpropertiesof(Sr1-xBix)TiO3+x/2systemaregreatlyvariedwithanincreaseofthestoichiometricamountsofBi2O3.Therelativepermittivityofthesolidsolutionsishigh,andthedissipationfactorislow.Thepositronannihilationtechnique(PAT)wasadoptedtostudythedefectstructure.AnexplanationofthedielectricpropertiesofBi-dopedSrTiO3ceramicshasbeensuggestedintermsofelectron-compensationandvacancyordefect-compensationmechanismsandspace-chargepolarizationmechanism.

  • 标签: SRTIO3 绝缘陶瓷 结构缺陷 正电子消除
  • 简介:GratingAngular-movementTransducerUsingaFabry-PerotStructure①LIZhiquan(YanshanUniversity,Qinghuangdao066004,CHN)Abstract:Anove...

  • 标签: Angular-movement TRANSDUCER FABRY-PEROT INTERFEROMETER GRATING Transducers
  • 简介:Inrecentyears,thepotentialofrenewablegreenenergysourceshasbeenextensivelystudied.Theproventechnologywhichisphotovoltaicsolarcellsstrictlydependsondaylightandproduceslow-efficiently.Toovercometherestrictions,onetechnologystudiedisthroughharvestingthethermalradiationenergywhichcanprovidea24-hourenergysource.Thecontinuityofenergysourcespromisesverygoodenergyconversionespeciallyformilitaryapplications.Thisarticlepresentsanewstructurethatcanharvesttheabundantthermalradiationenergyintousableenergyatthewavelengthof10μm.Arectangularstructurewithaperturbationslitwasdesignedtointegratewitharectifiercircuitforgreenenergyconversion.Theslittunneljunctionguidedtheelectromagneticfieldintoajunctionwheretheenergycouldbecollectedandconverted.Anenhancementfactorofapproximately110.6canbeachievedbyaperturbationslitlengthof1.0μm.Theresultsextractedfromtheproposeddesignpromiseabettercandidatetoovercomethedisadvantagesofphotovoltaicsolarcellsforenergyharvestingdevices.

  • 标签: Enhancement factor green energy harvesting RENEWABLE thermal radiation