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.
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。
简介:Thepaperfirstdiscussesshortcomingsofclassicaladjacent-framedifference.Secondly,basedontheimageenergyandhighorderstatistic(HOS)theory,backgroundreconstructionconstraintsaresetup.Underthehelpofblock-processingtechnology,backgroundisreconstructedquickly.Finally,backgrounddifferenceisusedtodetectmotionregionsinsteadofadjacentframedifference.TheDSPbasedplatformtestsindicatethebackgroundcanberecoveredlosslesslyinaboutonesecond,andmovingregionsarenotinfluencedbymovingtargetspeeds.Thealgorithmhasimportantusagebothintheoryandapplications.
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.
简介:Normally,itisdifficulttodirectlymeasurethebandgapsofperovskitebasedonmethylammonium(MA)orformamidinium(FA)athightemperaturesduetomaterialdecomposition.Wepreventthedecompositionbykeepingthesynthesizedperovskitefilms(MAPbI3andMAPbI3)inorganiciodidevapors,thenmeasurethein-situresistanceofthefilmsatvariedtemperatures,andfurtherevaluatethebandgapsofthesetwomaterials.Theevaluatedbandgapsareconsistentwiththeresultsfromultraviolet-visible(UV-vis)absorptionspectrum.ThebandgapofMAPbI3decreaseswithtemperatureabove95℃,whereasthatofFAPbI3firstincreaseswithtemperaturefrom95℃to107℃andthendecreaseswithtemperatureabove107℃.
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.
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。
简介:AnewSOI(SiliconOnInsulator)highvoltagedevicewithStepUnmovableSurfaceCharges(SUSC)ofburiedoxidelayeranditsanalyticalbreakdownmodelareproposedinthepaper.Theunmovablechargesareimplementedintotheuppersurfaceofburiedoxidelayertoincreasetheverticalelectricfieldanduniformthelateralone.The2-DPoisson'sequationissolvedtodemonstratethemodulationeffectoftheimmobileinterfacechargesandanalyzetheelectricfieldandbreakdownvoltagewiththevariousgeometricparametersandstepnumbers.AnewRESURF(REduceSURfaceField)conditionoftheSOIdeviceconsideringtheinterfacechargesandburiedoxideisderivedtomaximizebreakdownvoltage.Theanalyticalresultsareingoodagreementwiththenumericalanalysisobtainedbythe2-DsemiconductordevicessimulatorMEDICI.Asaresult,an1200Vbreakdownvoltageisfirstlyobtainedin3μm-thicktopSilayer,2μm-thickburiedoxidelayerand70μum-lengthdriftregionusingalineardopingprofileofunmovableburiedoxidecharges.
简介:Ahigh-Qmicrowavephotonicfilterusingasemiconductoropticalamplifier(SOA)-basedmode-lockingfiberringlaserisproposed,analyzedandexperimentallydemonstrated.Theproposedmicrowavephotonicfiltercanrealizeahigh-Qfrequencyresponse,itiscompactwithoutanopticalsource,anditcanbeeasilytunedbyadjustinganopticalvariabledelaylineinaringcavity.AresultwithaQ-factorofabout236andarejectionratioofabout45dBisobtained.Themeasuredresultsandthetheoreticalestimationsagreeverywell.
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.
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。