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简介：Thetotalefficiencyofpowerplantsdependsontheenergyconversioninacombustorandaturbine.Considerablyhigherenergytransferratescanbeobtainedfromapulsedcombustion.butunsteadyflowofasinglejetcombustorreducestheturbineefficiency.Therefore.twopulsecombustorsweresetinparallelandconnectedtoasettlingchamberthatsuppliesaflowwithconstantpressuretotheturbine.Theaimofinvestigationspresentedhereisademonstrationoftechnicalfeasibilityforindustrialapplicationsandtoshowthebenefitsobtainedfromthepulsecombustors.

简介：Wepresentaninterferometrysetupandthedetailedfringeanalysismethodforintenseshortpulse(SP)laserexperiments.Theinterferometryschemewasrefinedthroughmultiplecampaignstoinvestigatetheeffectsofpre-plasmasonenergeticelectronsattheJupiterLaserFacilityatLawrenceLivermoreNationalLaboratory.Theinterferometerusedafrequencydoubled(λ=0.527μm)0.5pslongopticalprobebeamtomeasurethepre-plasmadensity,aninvaluableparametertobetterunderstandhowvaryingpre-plasmaconditionsaffectthecharacteristicsoftheenergeticelectrons.Thehardwareofthediagnostic,dataanalysisandexampledataarepresented.ThediagnosticsetupandtheanalysisprocedurecanbeemployedforanyotherSPlaserexperimentsandinterferograms,respectively.

简介：Theoreticalandexperimentalresearchoflowfrequencypulsecompressionandchannelmatchinshallowwatersoundchannelwerecarriedoutbasedon2000-WinterYellowSeaexperiment.Usingpulsecompressionmethod,signalswithhighsignaltonoiseratio(SNR)werereceivedoverrangeof110kilometersintheexperiment.TheSNRgainintheprocessisconsistentwiththetheoreticalprediction.Theexperimentalmeasurementindicatedthatthechannelishighlycoherentoveralengthof500s.ChannelmatchmethodwasusedtocompensatethedegradationofpulsecompressionSNRcausedbythemulti-pathpropagation.AndtheSNRgaininthechannelmatchprocesscanbetheoreticallypredicted.ExperimentalresultsshowthatlowfrequencypulsecompressionandchannelmatchmethodcanbeusedinshallowwatersoundchanneltoimprovetheSNR.

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简介：Thedischargeoperationregimeofpulsemodulatedatmosphericradiofrequency(RF)glowdischargeinheliumisinvestigatedonthedutycycleandfrequencyofmodulationpulses.Thecharacteristicsofradiofrequencydischargeburstintermsofbreakdownvoltage,alpha(α)-gamma(γ)modetransitionvoltageandcurrentaredemonstratedbythedischargecurrentvoltagecharacteristics.TheminimumbreakdownvoltageofRFdischargeburstwasobtainedatthedutycycleof20%andfrequencyof400kHz,respectively.Theα-γmodetransitionofRFdischargeburstoccursathighervoltageandcurrentbyreducingthedutycycleandelevatingthemodulationfrequencybeforetheRFdischargeburstevolvingintotheignitionphase,inwhichtheRFdischargeburstcanoperatestablyintheγmode.ItproposesthattheintensityandstabilityofRFdischargeburstcanbeimprovedbymanipulatingthedutycycleandmodulationfrequencyinpulsemodulatedatmosphericRFglowdischarge.

简介：Gapinducedpie-pulseinhibition(Gap-PPI)ofacousticstartlereflexhasbeenusedasameasurementoftinnitusinanimalmodels.However,whetherthistestissensitivetodetecttinnitusinhumansisstillunclear.Basedonthetestingprocedureusedinanimalstudies,ahumansubjecttestingmethodwasformulatedandconductedtoinvestigateifasimilarresultcouldbefoundintinnituspatients.Audiologicandtinnitusassessmentsandacousticstartlereflexmeasurementswereperformedonseventinnitussubjectsandnineagematchedsubjectswithouttinnitus.TherewasnosignificantdifferencefoundbetweenthecontrolandtinnitusgroupontheGap-PPlacrossthefrequenciesevaluated.Theamplitudeofthestartleresponseinthetinnitusgroupwithnormalhearingthresholdswassignificantlyhigherthanthecontrolgroupandthosewithtinnitusandhearingloss.Thispreliminaryresultsuggeststhathyperexcitabilityinthecentralauditorysystemmaybeinvolvedintinnitus.Therewasnocorrelationbetweenhearingthresholdsandtheincreasedamplitudeofstartleresponse.

简介：Wehavedevelopedanewradiographysetupwithashort-pulselaser-drivenx-raysource.Usingaradiographyaxisperpendiculartobothlong-andshort-pulselasersallowedoptimizingtheincidentangleoftheshort-pulselaseronthex-raysourcetarget.Thesetuphasbeentestedwithvariousx-raysourcetargetmaterialsanddifferentlaserwavelengths.Signaltonoiseratiosarepresentedaswellasachievedspatialresolutions.ThehighqualityofourtechniqueisillustratedonaplasmaflowradiographobtainedduringalaboratoryastrophysicsexperimentonPOLARs.

简介：AYAGsupershortpulselaser(355nm,35ps)isusedasanexposuresourceandthemicrowavedielectricspectri,techniqueisusedtoquicklydetectthephotoelectrondecayprocessinAgXmicrocrystals,becausethefreephotoelectronlifetimeanddecayprocesscandecidethesensitivityandotherefficienciesofsilverhalidematerial.TheresultshowsthatthefreephotoelectronaveragelifetimesofKodak-100andFuji-100colourfilmsamplesare8.5and9.5ns,respectively.

简介：Theeffectsoflinearfallingrampresetpulserelatedtoaddressingoperationinanalternatingcurrentplasmadisplaypanel(ACPDP)werestudied.Thewallchargewaveformsweremeasuredbytheelectrodebalancemethodina12-inchcoplanarACPDP.Thewallchargewaveformsshowtherelationshipbetweenthesloperatioofthefallingrampresetpulseandthewallchargesattheendofthefallingrampresetpulsewhichinfluencestheaddressingstability.Thentheeffectsofthesloperatioofthelinearfallingrampresetpulseontheaddressingvoltageandaddressing,timewereinvestigated.Theexperimentalresultsshowthattheminimumaddressingvoltageincreaseswiththeincreaseofthesloperatioofthefallingrampresetpulse,andsodoestheminimumaddressingtime.Basedontheexperimentalresults,theoptimizationoftheaddressingtimeandthesloperatioofthefallingramppulseisdiscussed.

简介：Thereareseveralpetawatt-scalelaserfacilitiesaroundtheworldandthefidelityofthepulsestotargetiscriticalinachievingthehighestfocusedintensitiesandthehighestpossiblecontrast.TheUnitedKingdomhasthreesuchlaserfacilitieswhicharecurrentlyopenforaccesstotheacademiccommunity:OrionatAWE,AldermastonandVulcan&Astra-GeminiattheCentralLaserFacility(CLF),STFC(ScienceandTechnologyFacilitiesCouncil)RutherfordAppletonLaboratory(RAL).Thesefacilitiesrepresentthetwomainclassesofpetawattfacilities:themixedOPCPA/Nd:glasshigh-energysystemsofOrionandVulcanandtheultra-short-pulseTi:SapphiresystemofAstraGemini.Manyofthetechniquesusedtoenhanceandcontrolthepulsegenerationanddeliverytotargethavebeenpioneeredonthesefacilities.Inthispaper,wepresentthesystemdesignswhichmakethispossibleanddiscussthecontrastenhancementschemesthathavebeenimplemented.

简介：Wehaveoptimizedtheinputpulsewidthandinjectiontimetoachievethehighestpossibleoutputpulseenergyinadouble-passlaseramplifierusingtwoNd:YAGrods.Forthispurpose,wehaveextendedtheFrantz–Nodvikequationbysimultaneouslyincludingbothspontaneousemissionandpumpenergyvariation.Theeffectivepumpenergyoftheflashlampwas8.84Jforeachgainmedium.Theenergyof1Jcouldbeamplifiedtoanoutputenergyof12.17Jwiththemaximumachievedextractionefficiencyof63.18%whenaninputpulsehavingapulsewidthof168μsissent10μsaftertheabsorbedpumpenergybecomesthemaximumvalue.

简介：AcancelingrangesidelobesschemehasbeensuggestedbyYangGuangzheng,etal.,(1997)thistechnologyisbasedonthefactthatallsidelobeofgroupcorrelationfunctionofidealsetsarezero.Atfirst,thispapergivesthebestidealsets(i.e.thebestbiphasecodesetswhosemaximalsidelobenotmorethan2)forallcodelengthN≤12,whichhavebeenobtainedfrombinarysequencesbymeansofthebestcodessievingmethodsuggestedbyYangGuangzheng,etal.(1997)ComputersimulationforgroupcorrelationpropertyofbestidealsetsforcodelengthN=12onvariousconditionsismade.Simulationresultshowsthatthesidelobelevelofbestidealsetwithnoweightingiszero,underconditionofzero-Dopplershiftandhasultra-lowsidelobeonDopplerupto5kHzwithnoweightingandwhosetoleranceofphaseandamplitudedistortionisbiggertoo.

简介：Wereportonthedesignandperformanceofafiberlasersystemwithadaptiveacousto-opticmacropulsecontrolforanovelphotocathodelaserdriverwith3Dellipsoidalpulseshaping.Thelasersystemincorporatesathreestagefiberamplifierwithanintegratedacousto-opticalmodulator.Adigitalelectroniccontrolsystemwithfeedbackcombinesthefunctionsofthearbitrarymicropulseselectionandmodulationresultinginmacropulseenvelopeprofiling.Asabenefit,anarrowtemporaltransparencywindowofthemodulator,comparabletoalaserpulserepetitionperiod,effectivelyimprovestemporalcontrast.Inexperiments,wedemonstratedrectangularlaserpulsetrainprofilingattheoutputofathree-cascadeYb-dopedfiberamplifier.

简介：一个不规则的分割的区域编码算法基于脉搏，联合神经网络(PCNN)被介绍。PCNN有联合脉搏、可变的阀值，有近似灰色的价值的这些邻近的象素能同时通过被激活的性质。一个人能得出PCNN有的优点认识到地区性的分割，和细节的一个结论原来的图象能被分割图象的参数调整完成，并且同时，小分割的区域能被避免。为不规则的分割的区域的更好的近似，Gram-Schmidt方法，一组orthonormal基底函数被从一组线性独立的起始的底构造工作，被采用。因为重建的orthonormal方法，重构图象的质量能极大地被改进，进步图象传输将也是可能的。

简介：用极化的做镱的锁模式的纤维激光敏感隔离乾和极化控制器(PC)被报导。在正常分散，纤维激光能由调整PC的位置以多脉搏状态震荡。在极化状态isn鈥檛改变了的条件上，从单身者的做镱的锁模式的纤维激光变化的产量由增加泵力量搏动到多脉搏。纤维激光能由小心地调整PC1和PC2完成不同多脉搏输出。CLC数字TN253这个工作被中国(栅栏号码60577019和号码60137010)的国家科学基金支持了。

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