简介:WithMoS2assaturableabsorber,passiveQ-switchingandQ-switchedmode-lockingoperationsofaTm-dopedcalciumlithiumniobiumgalliumgarnet(Tm:CLNGG)laserwereexperimentallydemonstrated.TheQ-switchedlaseremittedamaximumaverageoutputpowerof62mWandhighestpulseenergyof0.72μJ.Q-switchedmodelockingwasalsoobtainedintheexperiment.TheresearchresultswillopenupapplicationsofMoS2atthemid-infraredwavelength.
简介:Byusingtheultrasound-assistedliquidphaseexfoliationmethod,Bi2Te3nanosheetsaresynthesizedanddepositedontoaquartzplatetoformakindofsaturableabsorber(SA),inwhichnonlinearabsorptionpropertiesaround2μmareanalyzedwithahome-mademode-lockedlaser.Withtheas-preparedBi2Te3SAemployed,astablepassivelyQ-switchedall-solid-state2μmlaserissuccessfullyrealized.Q-switchedpulseswithamaximumaverageoutputpowerof2.03Waregeneratedunderanoutputcouplingof5%,correspondingtothemaximumsingle-pulseenergyof18.4μJandpeakpowerof23W.Thedeliveredshortestpulsedurationandmaximumrepetitionrateare620nsand118kHzunderanoutputcouplingof2%,respectively.ItisthefirstpresentationofsuchBi2Te3SAemployedinasolid-stateQ-switchedcrystallinelaserat2μm,tothebestofourknowledge.Incomparisonwithother2Dmaterialssuitableforpulsed2μmlasers,thesaturableabsorptionperformanceofBi2Te3SAisprovedtobepromisingingeneratinghighpowerandhigh-repetition-rate2μmlaserpulses.
简介:AnovelSr2CuInO3Soxysulfidep-typesemiconductorphotocatalysthasbeenpreparedbysolidstatereactionmethodanditexhibitsintriguingvisiblelightabsorptionpropertieswithabandgapof2.3eV.Thep-typesemiconductorcharacterofthesynthesizedSr2CuInO3SwasconfirmedbyHallefficientmeasurementandMott-Schottkyplotanalysis.First-principlesdensityfunctionaltheorycalculations(DFT)andelectrochemicalmeasurementswereperformedtoelucidatetheelectronicstructureandtheenergybandlocations.Itwasfoundthattheas-synthesizedSr2CuInO3Sphotocatalysthasappreciateconductionandvalencebandpositionsforhydrogenandoxygenevolution,respectively.Photocatalytichydrogenproductionexperimentsunderavisiblelightirradiation(λ>420nm)werecarriedoutbyloadingdifferentmetalandmetal-likecocatalystsonSr2CuInO3SandRhwasfoundtobethebestoneamongthetestedones.
简介:MeisymmetryandMeiconservedquantityforanon-holonomicsystemofnon-Chetaev'stypewithunilateralconstraintsintheNielsenstylearestudied.Thedifferentialequationsofmotionforthesystemaboveareestablished.ThedefinitionandthecriteriaofMeisymmetry,conditions,andexpressionsofMeiconservedquantitydeduceddirectlyfromtheMeisymmetryaregiven.Anexampleisgiventoillustratetheapplicationoftheresults.
简介:Thedevelopment,theunderlyingtechnologyandthecurrentstatusofthefullydiode-pumpedsolid-statelasersystemPOLARISisreviewed.Currently,thePOLARISsystemdelivers4Jenergy,144fslonglaserpulseswithanultra-hightemporalcontrastof5×1012fortheASE,whichisachievedusingaso-calleddoublechirped-pulseamplificationschemeandcross-polarizedwavegenerationpulsecleaning.Bytightlyfocusing,thepeakintensityexceeds3.5×1020Wcm-2.TheseparameterspredestinePOLARISasascientifictoolwellsuitedforsophisticatedexperiments,asexemplifiedbypresentingmeasurementsofacceleratedprotonenergies.Recently,anadditionalamplifierhasbeenaddedtothelaserchain.Intheramp-upphase,pulsesfromthisamplifierarenotyetcompressedandhavenotyetreachedtheanticipatedenergy.Nevertheless,anoutputenergyof16.6Jhasbeenachievedsofar.
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简介:HighlytexturedHeusleralloyMn46Ni42Sn11Sb1ribbonswerepreparedbymeltspinning.TheannealedhighMncontentMn46Ni42Sn11Sb1ribboncross-sectionmicrostructure,crystalstructure,martensitictransformation(MT),andmagnetoresistance(MR)propertieswereinvestigated.TheMRintheannealedribbonwasassessedbythemagneticfielddirectionperpendiculartotheribbonsurfacewiththemagneticfieldupto30kOe.Thelargenegativevalueof25%forMRwasobtainedat244K.Theexchangebias(EB)effectsoftheas-spunandannealedribbonswereinvestigated.Afterannealing,theEBeffectshavebeenimprovedbyabout25Oeatthetemperatureof50K.Themagnetizationshaveincreasedapproximatelyby10%morethantheas-spunribbon.
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简介:基于计算机串口通信和功率型金属氧化物半导体场效应晶体管,设计研制了程控产生单次快前沿负高压脉冲的信号发生器。其性能指标为高压脉冲幅度一100~-1000V,脉冲宽度40ns~2μs,脉冲前沿随脉冲幅度和宽度变化,可小于30ns,输出负载为50Ω作为一种模拟源,该高压脉冲信号发生器已用于小功率气体放电管的高压保护特性实验研究中。