学科分类
/ 2
30 个结果
  • 简介:AdoublehelixmodelofchargetransportinDNAmoleculeisgivenandthetransmissionspectraoffourDNAsequencesareobtained.ThecalculatedresultsshowthatthetransmissioncharacteristicsofDNAarenotonlyrelatedtothelongitudinaltransportbutalsotothetransversetransportofmolecule.Theperiodicsequencewiththesamecompositionhasstrongerconductionability.Withtheincreasingofbasescomposition,theconductiveabilityreduces,buttheweightofθdirectionrisesinchargetransfer.

  • 标签: 电荷运输 DNA分子 传输工具 物理
  • 简介:Influenceofpulsedpowertransmissiononradiowaveenvironmentisinvestigated.Thepowerpulsesaretransmittedintermittentlyinpulsedpowernetworkthatisalreadyproposedforanalternativeofupcomingsmartgrids.Incontrasttoconventionalpowertransmissionwithcontinuouselectriccurrentoflowfrequencysinewave,pulsedpowertransmissionmayaffectsurroundingfieldwithhighfrequencyradionoises.Inthispaper,basedontheanalysisofelectricfieldstrengtharoundapowerline,theradionoisesgeneratedbyvariousformsofpulsedpowertransmissionareevaluated.Asaresult,twopointsarederived.First,thoughthetotalofgeneratedradionoisepowerobviouslyexceedsthatofconventionalpowertransmissions,peakstrengthofelectricfieldratherfallsbehindtheconventionalone.Second,concerningtheinfluenceontheradiowaveofthelowestfrequency40kHzthatisactuallyusedforstandardtimeandfrequencysignal,thenoiseintensitypossiblyexceedstheweakradiosignaltoleranceaccordingtotheshapeofeachpowerpulsetransmitted.

  • 标签: SMART GRID power PACKET energy PACKET
  • 简介:我们建议plasmonic为提高的光传播弄皱角结构并且理论上分析。它在倾斜的发生使用单向性的宣传表面电浆子电磁声子的改进。象沟深度和宽度那样的几何参数被优化。分析证明它为沟的一个小数字比公牛的眼睛结构介绍更好的表演。

  • 标签: 等离子增强 波纹喇叭 光传输 结构 离子极化 几何参数
  • 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:Openwaveguidesarewidelyusedinmodernphotonicdevices,suchasmicrostructuredfiberfiltersandsensors.Theirabsorptionandtransmissionspectraarethemostimportantpropertiesindeterminingtheoverallperformanceofthephotonicdevices.Theimaginarypartsoftheireigenvalueshavebeencommonlyusedtocalculatetheabsorptionandconsequentlythetransmissionspectra.Hereweshowthatthisformulismisgenerallyincorrectandnotconsistentwiththesimulationresultsobtainedbythebeampropagationmethod.Werevisitthefundamentaltheoryfortheabsorptionofopenwaveguidesandpresentageneralformulism.Wefoundthatparity-time-symmetrytransitions,whichhavebeenconventionallyignored,playacriticalroleinthepropertiesofthecoupledwaveguide.Theabsorptionandtransmissionarehighlydependentonthephysicallengthofthesystem.Onthebasisofourfindings,optimizationcriteriafordesigningphotonicsensorsandfiltersarepresented.

  • 标签: the ABSORPTION and transmission PCF PT
  • 简介:Theenergytransmissionofthelongmicrowavepulseforthefrequencyof2.45GHzand5.8GHzisstudiedbyusingtheelectronfluidmodel,wheretheratecoefficientsarededucedfromtheBoltzmannequationsolvernamedBOLSIG+.Thebreakdownthresholdsfordifferentairpressuresandincidentpulseparametersarepredicted,whichshowgoodagreementwiththeexperimentaldata.Belowthebreakdownthreshold,thetransmittedpulseenergyisproportionaltothesquareoftheincidentelectricfieldamplitude.Whentheincidentelectricfieldamplitudehigherthanthebreakdownthresholdincreases,thetransmittedpulseenergydecreasesmonotonouslyatahighairpressure,whileatalowairpressureitfirstdecreasesandthenincreases.Wealsocomparethepulseenergytransmissionforthefrequencyof2.45GHzwiththecaseof5.8GHz.

  • 标签: 能量传输 微波脉冲 空气击穿 BOLTZMANN 击穿阈值 脉冲能量
  • 简介:HL-2Atokamakwillbeequippedwitha75GHz/1MW/1sECRHsystem.Thepaperdescribesthedesignofthetransmissionsystem(Fig.1),whichismadeupwithatransmissionline,anequatoriallauncher.Thepaperdescribesthedesignofmaincomponentsofthesystemsuchas,waveguides,ellipsoidalsurfacemirrors,achemicalvapor(CVD)diamondwindow,asteeringmirror.

  • 标签: HL-2A ECRH 传输系统 概念设计 波导 椭球镜
  • 简介:Taperedfiberswithdiametersrangingfrom1to4μmarewidelyusedtoexcitethewhispering-gallery(WG)modesofmicrocavities.Typically,thetransmissionspectrumofaWGcavitycoupledtoawaveguidearoundaresonanceassumesaLorentziandipmorphologyduetoresonantabsorptionofthelightwithinthecavity.Inthispaper,wedemonstratethatthetransmissionspectraofaWGcavitycoupledwithanultrathinfiber(500–700nm)mayexhibitbothLorentziandipsandpeaks,dependingonthegapbetweenthefiberandthemicrocavity.Byconsideringthelargescatteringlossofoff-resonantlightfromthefiberwithinthecouplingregion,thisphenomenoncanbeattributedtopartiallyresonantlightbypassingthelossyscatteringregionviaWGmodes,allowingittobecoupledbothtoandfromthecavity,thenmanifestingasLorentzianpeakswithinthetransmissionspectra.Thisimpliesthesystemcouldbeimplementedwithinabandpassfilterframework.

  • 标签:
  • 简介:Thispaperinvestigatestheoreticallytheelectronictransmissionspectraofthethreeterminalpyrenemolecularbridgeandthequantumcurrentdistributiononeachbondbythetight-bindingmodelbasedonnonequilibriumGreen'sfunctionandthequantumcurrentdensityapproach,inwhichoneπmolecularorbitalistakenintoaccountpercarbonatomwhentheenergylevelsandHOMO-LUMOgapareobtained.Thetransmissionspectrashowthattheelectronictransmissionofthethreeterminalpyrenemolecularbridgedependsobviouslyontheincidentelectronicenergyandthepyreneeigenenergy.Thesymmetricalandoscillationpropertiesofthetransmissionspectraareillustrated.Anovelplus-minusenergyswitchingfunctionisfound.Thequantumcurrentdistributionshowsthattheloopcurrentsinsidethepyreneareinduced,andsomebondcurrentsaremuchlargerthantheinputandtheoutputcurrents.Thereasonswhytheloopcurrentsandthelargerbondcurrentsareinducedarethephasedifferenceoftheatomicorbitsandthedegeneracyofthemolecularorbits.ThecalculationsillustratethatthequantumcurrentdistributionsareingoodagreementwithKirchhoffquantumcurrentconservationlaw.

  • 标签: 三端可调直流稳压器 扩流工作 电控自动变速器 电流分布
  • 简介:Forapreviouslysimulatedeight-broadbandnegative-refraction-indexchiralmetamaterial,weuseS-parameterretrievalmethodstodeterminethecomplexeffectivepermittivity,permeability,andtheimpedance.Wealsocalculatethefigureofmerit,whichisdefinedastheratiooftherealandtheimaginaryrefractioncomponents,andcompareitwiththoseoffishnetmetamaterials.Thesimulationresultsshowthatourchiralmetamaterialexhibitshightransmissionandimpedancematchingtoavacuum.Also,wedeterminethattheelectricandmagneticdipolesofthesurfaceplasmonsplayanimportantroleindeterminingthenineresonancefrequencies.Therefore,thisinvestigationprovidesanexperimentalbasisfordevelopingmetamaterialdeviceswithmultipleandbroadresonancefrequencybands.

  • 标签: 阻抗匹配 材料模拟 手征材料 高真空 传输 有效介电常数
  • 简介:散布的光被发现在阳极的氧化铝的photonic水晶的传播系列上有大影响。事件光被遵守布拉格法律的分叉的隧道或毛孔的一个常规数组使衍射。传播光的紧张与因为增加的孔,增加蚀刻时间或扩大scatterers减少。紧张的变化和在多孔的氧化铝膜对发生角度的传播系列的剧降的宽度从象胶体的photonic水晶那样的另外的photonic水晶显示出相当不同的特征。[从作者抽象]

  • 标签: 阳极氧化铝 光子晶体 光散射 散射传输光谱
  • 简介:Whenadielectricmeta-atomisplacedintoasubwavelengthmetallicaperture,20-foldenhancedelectromagnetictransmissionthroughtheapertureisrealizedatthemeta-atom’sresonantfrequency.Additionally,whentheincidentelectromagneticpowerincreases,thermalenergygatheredbythemeta-atom,whichisconvertedfromelectromagneticlosses,cancausethemeta-atom’stemperaturetoincrease.Becauseofthehightemperaturecoefficientofthemeta-atom’sresonantfrequency,thistemperatureincreasecausesablueshiftinthetransmissionpeak.Therefore,thisfrequency-dependentenhancedelectromagnetictransmissionevenproducesanonlineareffectatlowincidentpowers.Overanincidentpowerrangefrom0to20dBm,measuredandsimulatedspectranearthemeta-atom’sresonantfrequencyshowdistinctlynonlineartransmission.

  • 标签: SUBWAVELENGTH metal APERTURE ELECTROMAGNETIC power RESONANCE
  • 简介:Wecomprehensivelycharacterizethetransmissionperformanceofm-aryquadratureamplitudemodulation(m-QAM)signalsthroughasiliconmicroringresonatorintheexperiment.Usingorthogonalfrequency-divisionmultiplexingbasedonoffsetQAM(OFDM/OQAM)whichismodulatedwithm-QAMmodulations,wedemonstratelow-penaltydatatransmissionofOFDM/OQAM64-QAM,128-QAM,256-QAM,and512-QAMsignalsinasiliconmicroringresonator.Theobservedopticalsignal-to-noiseratio(OSNR)penaltiesare1.7dBfor64-QAM,1.7dBfor128-QAM,and3.1dBfor256-QAMatabit-errorrate(BER)of2×10-3and3.3dBfor512-QAMataBERof2×10-2.Theperformancedegradationduetothewavelengthdetuningfromthemicroringresonanceisevaluated,showingawavelengthrangeof0.48nmwithBERbelow2×10-3.Moreover,wedemonstratedatatransmissionof191.2-Gbit/ssimultaneouseightwavelengthchannelOFDM/OQAM256-QAMsignalsinasiliconmicroringresonator,achievingOSNRpenaltieslessthan2dBataBERof2×10-2.

  • 标签:
  • 简介:Inrealmultiple-inputmultiple-output(MIMO)systems,theperfectchannelstateinformation(CSI)maybecostlyorimpossibletoacquire.Butthechannelstatisticalinformationcanbeconsideredrelativelystationaryduringlong-termtransmission.Thestatisticalinformationcanbeobtainedatthereceiverandfedbacktothetransmitteranddonotrequirefrequentupdate.Byexploitingchannelmeanandcovarianceinformationatthetransmittersimultaneously,thispaperinvestigatestheoptimaltrans-missionstrategyforspatiallycorrelatedMIMOchannels.Anupperboundofergodiccapacityisderivedandtakenastheper-formancecriterion.Simulationresultsarealsogiventoshowtheperformanceimprovementoftheoptimaltransmissionstrategy.

  • 标签: 偏相关MIMO系统 信道统计信息 最优传输策略 遍历容量
  • 简介:Pump-probedifferentialreflectionandtransmissionspectroscopyisaveryeffectivetooltostudythenonequilibriumcarrierdynamicsofgraphene.Thereportedsignofdifferentialreflectionfromgrapheneisnotexplicitlyexplainedandnotconsistent.Here,westudythedifferentialreflectionandtransmissionsignalsofgrapheneonadielectricsubstrate.Theresultsrevealthesignofdifferentialreflectionchangeswiththeincidentdirectionoftheprobebeamwithrespecttothesubstrate.Theobtainedtheorycanbeappliedtopredictthedifferentialsignalsofothertwo-dimensionalmaterialsplacedonvariousdielectricsubstrates.

  • 标签:
  • 简介:Lattice,charge,orbital,andspinarethefourfundamentaldegreesoffreedomincondensedmatter,ofwhichtheinteractivecouplingderivestremendousnovelphysicalphenomena,suchashigh-temperaturesuperconductivity(high-T_cSC)andcolossalmagnetoresistance(CMR)instronglycorrelatedelectronicsystem.Directexperimentalobservationofthesefreedomsisessentialtounderstandingthestructure-propertyrelationshipandthephysicsbehindit,andalsoindispensablefordesigningnewmaterialsanddevices.Scanningtransmissionelectronmicroscopy(STEM)integratingmultipletechniquesofstructureimagingandspectrumanalysis,isacomprehensiveplatformforprovidingstructural,chemicalandelectronicinformationofmaterialswithahighspatialresolution.Benefitingfromthedevelopmentofaberrationcorrectors,STEMhastakenabigbreakthroughtowardssub-angstromresolutioninlastdecadeandalwaysstepsforwardtoimprovethecapabilityofmaterialcharacterization;manyimprovementshavebeenachievedinrecentyears,therebygivinganindepthinsightintomaterialresearch.Here,wepresentabriefreviewoftherecentadvancesofSTEMbysomerepresentativeexamplesofperovskitetransitionmetaloxides;atomic-scalemappingofferroelectricpolarization,octahedraldistortionsandrotations,valencestate,coordinationandspinorderingarepresented.WeexpectthatthisbriefintroductionaboutthecurrentcapabilityofSTEMcouldfacilitatetheunderstandingoftherelationshipbetweenfunctionalpropertiesandthesefundamentaldegreesoffreedomincomplexoxides.

  • 标签: 透射电子显微镜 过渡金属氧化物 像差校正 扫描 强关联电子系统 空间分辨率