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  • 简介:Timesynchronizationtechniques,especiallyonthepulsepersecond(PPS)temporalbasis,haveattractedgrowingresearchinterestsinrecentyears.Inthispaper,wehaveproposedandexperimentallydemonstratedahigh-precisiontwo-waytimetransfer(TWTT)systemtorealizelong-distancedisseminationof1PPSsignalgeneratedbyahydrogenmaser.Adense-wavelength-division-multiplexing(DWDM)systemandbi-directionalerbium-dopedfiberamplifiers(Bi-EDFAs)havealsobeenadoptedtosuppresstheimpactofRayleighbackscatteringandoptimizethesignaltonoiseratio(SNR)aswell.Wehavetheoreticallyanalyzedthesystematicdelayindetail.Theultimaterootmeansquare(RMS)variationoftimesynchronizationaccuracyissub-26psandthetimedeviationcanbereducedtoaslowas1.2psat100sand0.253psat12000s,respectively.

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  • 简介:劈啪作响的免职涂层在电子横梁(EB)上提供重要优点免职,包括的高收拾行李的密度,环境稳定性和极其低的损失。但是固有的高压缩的压力尽最大努力影响它的申请激光系统。这篇论文描述一篇小说扔的高损坏阀值激光镜子的技术可行性遥远的血浆劈啪作响技术。这种技术基于从目标遥远地产生集中的血浆然后有磁力地驾驶血浆到目标认识到劈啪作响的完整的制服。在目标电压和目标电流之间的伪独立提供我们很灵活的参数调节,特别为电影压力控制。免职条件被优化充分让步氧化并且低压缩压力单身者层HfO2和SiO2。为在1064nm的HfO2/SiO2激光镜子的43.8J/cm2的高损坏阀值被获得。第一次,劈啪作响的遥远的血浆成功地在与高效扔激光镜子被使用。

  • 标签: HFO2/SIO2 等离子体溅射 远程等离子体 溅射沉积 损伤阈值 高功率激光系统
  • 简介:Thepaperfirstdiscussesshortcomingsofclassicaladjacent-framedifference.Secondly,basedontheimageenergyandhighorderstatistic(HOS)theory,backgroundreconstructionconstraintsaresetup.Underthehelpofblock-processingtechnology,backgroundisreconstructedquickly.Finally,backgrounddifferenceisusedtodetectmotionregionsinsteadofadjacentframedifference.TheDSPbasedplatformtestsindicatethebackgroundcanberecoveredlosslesslyinaboutonesecond,andmovingregionsarenotinfluencedbymovingtargetspeeds.Thealgorithmhasimportantusagebothintheoryandapplications.

  • 标签: MOTION DETECTION BACKGROUND reconstruction Image energy
  • 简介:Low-DensityParity-Check(LDPC)codeisoneofthemostexcitingtopicsamongthecodingtheorycommunity.Itisofgreatimportanceinboththeoryandpracticalcommunicationsovernoisychannels.ThemostadvantageofLDPCcodesistheirrelativelylowerdecodingcomplexitycomparedwithturbocodes,whilethedisadvantageisitshigherencodingcomplexity.Inthispaper,anewap-proachisfirstproposedtoconstructhighperformanceirregularsystematicLDPCcodesbasedonsparsegeneratormatrix,whichcansignificantlyreducetheencodingcomplexityunderthesamede-codingcomplexityasthatofregularorirregularLDPCcodesdefinedbytraditionalsparseparity-checkmatrix.Then,theproposedgenerator-basedsystematicirregularLDPCcodesareadoptedascon-stituentblockcodesinrowsandcolumnstodesignanewkindofproductcodesfamily,whichalsocanbeinterpretedasirregularLDPCcodescharacterizedbygraphandthusdecodediteratively.Finally,theperformanceofthegenerator-basedLDPCcodesandtheresultantproductcodesisinvestigatedoveranAdditiveWhiteGaussianNoise(AWGN)andalsocomparedwiththeconventionalLDPCcodesunderthesameconditionsofdecodingcomplexityandchannelnoise.

  • 标签: 符号 解码 发电机 电子产品
  • 简介:Normally,itisdifficulttodirectlymeasurethebandgapsofperovskitebasedonmethylammonium(MA)orformamidinium(FA)athightemperaturesduetomaterialdecomposition.Wepreventthedecompositionbykeepingthesynthesizedperovskitefilms(MAPbI3andMAPbI3)inorganiciodidevapors,thenmeasurethein-situresistanceofthefilmsatvariedtemperatures,andfurtherevaluatethebandgapsofthesetwomaterials.Theevaluatedbandgapsareconsistentwiththeresultsfromultraviolet-visible(UV-vis)absorptionspectrum.ThebandgapofMAPbI3decreaseswithtemperatureabove95℃,whereasthatofFAPbI3firstincreaseswithtemperaturefrom95℃to107℃andthendecreaseswithtemperatureabove107℃.

  • 标签: 光敏材料 电阻测量 钙钛矿 太阳能电池 带隙 测定
  • 简介:Thisletterstudiesandanalyzestheworkingfeaturesofmaincircuitoftri-levelboostPowerFactorCorrect(PFC)converterandtheadvantagesoftri-levelswitchconverterinaspectsofbearinghigh-voltageofpowercomponents,overallsystemlossandmagneticcomponentselectionbaseduponthesingle-levelboostPFCswitchconverter.Besides,relyingontheapplicationofmi-croprocessorinpowerconvertertechnologyandDSP(DigitalSignalProcessing)chip'sstrongcal-culatingcapacity,theletterpresentstheadoptionofmodifiedschemeoftri-levelboostPFCconverterunderthecontrolofpredictivecontrolalgorithm.Moreover,theoperatingprincipleandcontrolmethodarespecified,theresultsofcircuittestandanalysisareprovidedandtheadvantagesofpre-dictivecontroltechnology-basedmulti-levelboostPFCconverterisverified.

  • 标签: 通信技术 数字信号处理 预测控制 微处理器
  • 简介:第一次,周期的装载电极和蘑菇类型波导被联合基于联合的不对称的intra-step-barrier改进旅行波浪electroabsorption调节的人(TWEAM)的表演两倍拉紧的量井(AICD-SQW)。周期的蘑菇类型TWEAM的电的调整反应被使用相等的电路模型获得,并且与常规蘑菇类型TWEAM对应物的模拟结果相比。相等的电路模型模拟结果显示为300m的作为模范的调整长度,有周期的传播线装载的蘑菇类型TWEAM能完成宽得多的带宽大约99.7GHz和43.1GHz比有为35和45结束的大约43GHz和33GHz的常规对应物分别地。

  • 标签: 行波电吸收调制器 输电线路 蘑菇 性能 负荷 波导
  • 简介:AnewSOI(SiliconOnInsulator)highvoltagedevicewithStepUnmovableSurfaceCharges(SUSC)ofburiedoxidelayeranditsanalyticalbreakdownmodelareproposedinthepaper.Theunmovablechargesareimplementedintotheuppersurfaceofburiedoxidelayertoincreasetheverticalelectricfieldanduniformthelateralone.The2-DPoisson'sequationissolvedtodemonstratethemodulationeffectoftheimmobileinterfacechargesandanalyzetheelectricfieldandbreakdownvoltagewiththevariousgeometricparametersandstepnumbers.AnewRESURF(REduceSURfaceField)conditionoftheSOIdeviceconsideringtheinterfacechargesandburiedoxideisderivedtomaximizebreakdownvoltage.Theanalyticalresultsareingoodagreementwiththenumericalanalysisobtainedbythe2-DsemiconductordevicessimulatorMEDICI.Asaresult,an1200Vbreakdownvoltageisfirstlyobtainedin3μm-thicktopSilayer,2μm-thickburiedoxidelayerand70μum-lengthdriftregionusingalineardopingprofileofunmovableburiedoxidecharges.

  • 标签: 硅绝缘体 SOI 击穿电压 固定接口 氧化层
  • 简介:Ahigh-Qmicrowavephotonicfilterusingasemiconductoropticalamplifier(SOA)-basedmode-lockingfiberringlaserisproposed,analyzedandexperimentallydemonstrated.Theproposedmicrowavephotonicfiltercanrealizeahigh-Qfrequencyresponse,itiscompactwithoutanopticalsource,anditcanbeeasilytunedbyadjustinganopticalvariabledelaylineinaringcavity.AresultwithaQ-factorofabout236andarejectionratioofabout45dBisobtained.Themeasuredresultsandthetheoreticalestimationsagreeverywell.

  • 标签: 光纤环形腔激光器 微波光子 主动锁模 滤波器 高Q值 SOA
  • 简介:这份报纸描述一个新方法与高反射率,宽思考带宽和高laserinduced损坏阀值设计一面激光镜子。镜子被HfO2/TiO2/SiO2的三材料高基于电场和所有电介质激光的温度地分发特征构造反射镜。TiO2/SiO2栈充当高反射镜(HR)并且拓宽思考带宽,当HfO2/SiO2栈被用于增加激光抵抗时。有34层的HfO2/TiO2/SiO2激光镜子被一篇小说制作遥远的血浆劈啪作响免职。为新镜子的零损坏可能性的损坏阀值直到39.6J/cm2(1064nm,12ns)。镜子的可能的激光损坏机制被讨论。

  • 标签: 激光损伤阈值 激光反射镜 设计 HFO2/SIO2 制造 等离子体溅射
  • 简介:Highspatialfrequencylaserinducedperiodicsurfacestructures(HSFLs)onsiliconsubstratesareoftendevelopedonflatsurfacesatlowfluencesnearablationthresholdof0.1J/cm2,seldomonmicrostructuresormicrogroovesatrelativelyhigherfluencesabove1J/cm^2.ThisworkaimstoenrichthevarietyofHSFLs-containinghierarchicalmicrostructures,byfemtosecondlaser(pulseduration:457fs,wavelength:1045nm,andrepetitionrate:100kHz)inliquids(waterandacetone)atlaserfluenceof1.7J/cm^2.TheperiodofSi-HSFLsintherangeof110–200nmisindependentofthescanningspeeds(0.1,0.5,1and2mm/s),lineintervals(5,15and20μm)ofscanninglinesandscanningdirections(perpendicularorparalleltolightpolarizationdirection).ItisinterestinglyfoundthatbesidesnormalHSFLswhoseorientationsareperpendiculartothedirectionoflightpolarization,bothclockwiseoranticlockwiserandomlytiltedHSFLswithamaximaldeviationangleof50°ascomparedtothoseofnormalHSFLSsarefoundonthemicrostructureswithheightgradients.RamanspectraandSEMcharacterizationjointlyclarifythatsurfacemeltingandnanocapillarywavesplayimportantrolesintheformationofSi-HSFLs.ThefactthatnoHSFLsareproducedbylaserablationinairindicatesthatmoderatemeltingfacilitatedwithultrafastliquidcoolingisbeneficialfortheformationofHSFLsbyLALs.Onthebasisofourfindingsandpreviousreports,asynergisticformationmechanismforHSFLsathighfluencewasproposedanddiscussed,includingthermalmeltingwiththeconcomitanceofultrafastcoolinginliquids,transformationofthemoltenlayersintoripplesandnanotipsbysurfaceplasmonpolaritons(SPP)andsecond-harmonicgeneration(SHG),andmodulationofSi-HSFLsdirectionbybothnanocapillarywavesandthelocalizedelectricfieldcomingfromtheexcitedlargeSiparticles.

  • 标签: HIGH spatial frequency LASER induced periodic
  • 简介:在这份报纸,消极地切换Q、锁模式的c切割在1.17m的做Nd的vanadate水晶self-Raman激光被使用Cr第一表明<啜class=“a-plus-plus”>4+:YAG。Nd的二晶体<啜class=“a-plus-plus”>3+:YVO4和Nd<啜class=“a-plus-plus”>3+:GdVO4被采用分别地产生激光。与13W的事件泵力量,在1.17m的678mW和852mW的平均产量力量分别地与1.8ns和2ns的切换Q的信封的持续时间被获得。锁模式的重复率分别地象2.3Hz和2.2GHz一样高。根据我们知道,切换Q的信封是最狭窄并且锁模式的重复率是最高目前在这块地里。另外,黄激光输出被使用解放也完成<潜水艇class=“a-plus-plus”>3O<潜水艇class=“a-plus-plus”>5频率加倍水晶。

  • 标签: 拉曼激光器 被动Q开关 倍频晶体 重复率 钒酸盐 锁模