简介：求婚基于做高度的耳纤维放大器和标准单个模式的纤维(SMF)是一种新奇光脉搏压缩技术。我们与6.34的耳离子集中使用了放大器

简介：Wereportedonthegenerationofthedual-wavelengthrectangularpulseinanerbium-dopedfiberlaser(EDFL)withatopologicalinsulatorsaturableabsorber.Therectangularpulsecouldbestablyinitiatedwithpulsewidthfrom13.62to25.16nsandfundamentalrepetitionrateof3.54MHzbyproperlyadjustingthepumppowerandthepolarizationstate.Inaddition,weverifiedthatthepulseshapeofthedual-wavelengthrectangularpulsecanbeaffectedbythetotalnetcavitydispersioninthefiberlaser.Furthermore,byproperlyrotatingthepolarizationcontrollers,theharmonicmode-lockingoperationofthedual-wavelengthrectangularpulsewasalsoobtained.Thedual-wavelengthrectangularpulseEDFLwouldbenefitsomepotentialapplications,suchasspectroscopy,biomedicine,andsensingresearch.

简介：Brief-pulsestimulationat50Hzhasbeenshowntoterminateafterdischargesobservedinepilepsypatients.However,theoptimalpulsestimulationparametersforterminatingcorticalelectricalstimulation-inducedafterdischargesremainunclear.Inthepresentstudy,weexaminedtheeffectsofdifferentbrief-pulsestimulationfrequencies(5,50and100Hz)oncorticalelectricalstimulation-inducedafterdischargesin10patientswithrefractoryepilepsy.Resultsdemonstratedthatbrief-pulsestimulationcouldterminatecorticalelectricalstimulation-inducedafterdischargesinrefractoryepilepsypatients.Inconclusion,(1)abrief-pulsestimulationwasmoreeffectivewhentheafterdischargedidnotextendtothesurroundingbrainarea.(2)Ahigherbrief-pulsestimulationfrequency(especially100Hz)wasmorelikelytoterminateanafterdischarge.(3)Alowcurrentintensityofbrief-pulsestimulationwasmorelikelytoterminateanafterdischarge.

简介：Thevariationinarccharacteristicsandbehaviorofmetaltransferwiththechangeinpulseparametershasbeenstudiedbyhighspeedvideocameraduringpulsecurrentflux-coredarcwelddeposition.Acomparativestudyofsimilarnaturehasalsobeencarriedoutduringflux-coredarcwelddepositioninglobularandspraytransfermodes.Theeffectofpulseparametershasbeenstudiedbyconsideringtheirmeancurrentandarcvoltage.Thearccharacteristicsstudiedbyitsrootdiameter,projecteddiameterandlength,andthebehaviorofmetaltransfernotedbythemetaltransfermodelandthedropletdiameterhavebeenfoundtovarysignificantlywiththepulseparameters.TheobservationmayhelpinunderstandingthearccharacteristicswithrespecttothevariationinpulseparameterswhichmaybebeneficialinusingpulsecurrentFCAWtoproducedesiredweldquality.

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简介：Weestablishtheexponentialstabilityoffasttravelingpulsesolutionstononlinearsingularlyperturbedsystemsofintegraldifferentialequationsarisingfromneuronalnetworks.Ithasbeenprovedthatexponentialstabilityoftheseorbitsisequivalenttolinearstability.LetLbethelineardifferentialoperatorobtainedbylinearizingthenonlinearsystemaboutitsfastpulse,andletσ(L)bethespectrumofL.Thelinearizedstabilitycriterionsaysthatifmax{Reλ:λ∈σ(L),,λ≠0}≤-D,forsomepositiveconstantD,andλ=0isasimpleeigenvalueofL(ε),thenthestabilityfollowsimmediately(see[13]and[37]).Therefore,toestablishtheexponentialstabilityofthefastpulse,itsufficestoinvestigatethespectrumoftheoperatorL.Itisrelativelyeasytofindthecontinuousspectrum,butitisverydifficulttofindtheisolatedspectrum.Therealpartofthecontinuousspectrumhasauniformlynegativeupperbound,henceitcausesnothreattothestability.Itremainstoseeiftheisolatedspectrumissafe.Eigenvaluefunctions(see[14]and[35,36])havebeenapowerfultooltostudytheisolatedspectrumoftheassociatedlineardifferentialoperatorsbecausethezerosoftheeigenvaluefunctionscoincidewiththeeigenvaluesoftheoperators.Therehavebeensomeknownmethodstodefineeigenvaluefunctionsfornonlinearsystemsofreactiondiffusionequationsandfornonlineardispersivewaveequations.Butforintegraldifferentialequations,wehavetousedifferentideastoconstructeigenvaluefunctions.WewillusethemethodofvariationofpararaeterstoconstructtheeigenvaluefunctionsinthecomplexplaneC.Byanalyzingtheeigenvaluefunctions,wefindthattherearenononzeroeigenvaluesofLin{λ∈C:Reλ≥-D}forthefasttravelingpulse.Moreover,λ=0issimple.Thisimpliesthattheexponentialstabilityofthefastorbitsistrue.

简介：Ti-richgarnetisfoundwithincalciticijolitefromtheOkacarbonatitecomplexinCanada,whichischaracterizedby58%–73%andraditecomponent（2.12wt.%–4.18wt.%TiO2）andclassifiedasmelanite.Thegarnetdisplayscomplexzoningandcontainsabundanthighfieldstrengthelements（HFSEs）andrareearthelements（REEs）.Threegroups（Ⅰ,Ⅱ,Ⅲ）havebeenidentifiedbasedontheirpetrographicnature.ComparedtogroupsⅡandⅢ,GroupⅠgarnetcorescontainhigherTiO2,MgO,HFSE,andREEandlowerSiO2abundances.Thedistinctchemicalandpetrographicsignaturesoftheinvestigatedgarnetscannotbeattributedtosimpleclosedsystemcrystallization,buttheyareconsistentwiththemulti-pulsemagmamixing.CombinedwithpreviouslyreportedU-Pbagesforapatitefromthecalciticijolite,atleastthreestagesofmagmaevolutionandsubsequentmixinghavebeeninvolvedinthegenerationofcalciticijoliteatOka.Theearly-formedmeltthatgeneratedGroupIgarnetcorewaslatermixedwithatleasttwosmall-volume,moreevolvedmelts.Theintermediatestagemeltformedtheremaininggarnetalongwithsomepyroxene,calcite,nepheline,andapatiteat127±3.6Ma.Theyoungest,mostevolvedmeltgeneratedthemajorityofpyroxene,calcite,nepheline,andapatitewithinthecalciticijoliteat115±3.1Ma.

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简介：Neutronusuallyappearswithgamma,whichisrequiringthedetectorhasthecapabilityofngammadiscrimination.Pulseshapediscrimination(PSD)isacommonapproachofn,gammajudgment,butrequiredacomplexprocesstoselectasuitablediscriminationfactor,andpoorperformanceinthelowenergyrange.AmethodbasedonthetimeintervalofadjacentSignalswasdisruptedandadoptedtocomparetopulseshapediscriminationinthefastneutrondetectionmethod.AgoodagreementbetweentheadoptedmethodandPSDmethodwasachieved,includingthetotalcountratioandneutroncountratio.Thecomparisonprovesthecorrectnessofthetheoreticalderivationandvalidatesthemethodinpractice.TheadvantagesandlimitationsofthemethodbasedontimeIntervalofadjacentsignalswereanalyzed.Themethodprovidesaneffectivewaytoconfirmthecalibrationoftheneutrondetectionofaliquidscintillationdetector.Also,asasimplewayonlyrequiringthetimeinformationaboutevents,thedescribedmethodhaslargeapplicationpotentialinsomecaseoffastneutronfluxorintensitymeasurement.

简介：Afast-speedpulsedetectorbasedonn-typeSi-Schottkydiodemountedinthewaveguideisinvestigated.Therelationofthefast-speedpulsedetectorbetweenresponsetimeand3dBbandwidthisanalyzed.Byadoptingthetunablecircuit,thematchedbandwidthisachievedaswideaspossible.Experimentalresultsshowthatthepulseresponsetimeofthedetectorislessthan150pswithinrandomcarriersignal500MHzbandwidthrangebetween35GHzto39GHzviatuningcircuit.Thedetectorisveryeasytooperatebecauseitdoesnotneedbiascurrentorsynch-pulsesource.

简介：Weproposeaproof-of-principleexperimenttotestanewschemetoproduceasingle-cycleradiationpulseinfree-electronlasers(FELs).Here,afewα-BBOcrystalswillbefirstusedtoproduceanequallyspacedlaserpulsetrain.Then,thelaserpulsetrainilluminatesthecathodetoproduceafrequency-chirpedelectronbunchtraininaphotocathoderfgun.Finally,thefrequency-chirpedelectronbunchtrainpassesthroughataperedundulatortoproduceaquasi-single-cycleTHzpulse.Thisexperimentshouldallowcomparisonandconfirmationofpredictivemodelsandscalinglaws,andthepreliminaryexperimentalresultswillalsobediscussed.

简介：Autler-Townes(在)在飞米第二光电子光谱ofthree水平Li-2分子切开理论上用时间依赖者被调查量波浪包方法。与合适的飞米秒激光脉搏，切开的AT的三座山峰能在thephotoelection光谱被观察。切开的AT源自强烈超短波的激光pluses引起的快速的Rabi摆动。分子的电离动力学上的激光参数的效果也被讨论。

简介：Oxygen-containingdefectsareveryimportantforalteringthenonlinearoptical(NLO)propertiesofgraphene.Toinvestigatethecorrelationbetweenoxygen-containingdefectsandthesynergisticNLOresponseingraphenebasednanocomposites,weattachedCdSnanocrystalsonthesurfaceofgraphene(G)andpreparedG/CdSnanohybrids(NHs)consistingofvariousoxygen-containingfunctionalgroupsviaachemicalmethod.TheNLOabsorptionandrefractionofG/CdSNHsundersinglepulselaserirradiationareenhancedby10.8timeswiththeconcentrationdecreaseofsurfaceoxygen-containinggroups,whichmightbeattributedtothelocalfieldeffectsandsynergeticeffectsstemmingfromchargetransferbetweenthetwocomponents.However,theopticalnonlinearityisdecreasedwithfurtherconcentrationdecrease,whichmightarisefromsp~2fragmentinterconnectionandsurfacedefectsintheNHs.TheNLOabsorptiontransformationfromtwo-photonabsorptiontosaturableabsorptionwithoxygendecreaseisobserved,andintensity-relatedNLOabsorptionandrefractioninNHsarealsodiscussed.Meanwhile,theG/CdSNHsexhibitsuperiorNLOproperties,implyingpotentialapplicationsofNHmaterialinNLOdevices.

简介：AQ-switcheddistributedBraggreflectorfiberlaserusingagraphenepassivesaturableabsorberisproposedinacavityconsistingofafiberBragggratingandFaradayrotatormirrorasendmirrors,togetherwithahighlydopederbium-dopedfiberasagainsource.ThelaserhasaQ-switchedthresholdofabout28mWandatunablerepetitionrateof10.4-18.0kHzwithvaryingpumppower.Theshortestpulsewidthobtainedfromthesystemis3.7μs,withamaximumpulseenergyandpeakpowerof22.2nJand3.4mW,respectively.

简介：Two-dimensional（2D）materialshaveemergedasattractivemediumsforfabricatingversatileoptoelectronicdevices.Recently,few-layermolybdenumdisulfide（MoS2）,asashining2Dmaterial,hasbeendiscoveredtopossessboththesaturableabsorptioneffectandlargenonlinearrefractiveindex.Herein,takingadvantageoftheuniquenonlinearopticalpropertiesofMoS2,wefabricatedahighlynonlinearsaturableabsorptionphotonicdevicebydepositingthefew-layerMoS2ontothemicrofiber.WiththeproposedMoS2photonicdevice,apartfromtheconventionalsolitonpatterns,themode-lockedpulsescouldbeshapedintosomenewsolitonpatterns,namely,multiplesolitonmolecules,localizedchaoticmultipulses,anddouble-scalesolitonclusters.Ourfindingsindicatethatthefew-layerMoS2-depositedmicrofibercouldoperateasapromisinghighlynonlinearphotonicdevicefortherelatednonlinearopticsapplications.

简介：Wedemonstratedexperimentallytheformationofmonoenergeticbeamsofacceleratedelectronsbyfocusingfemtosecondlaserradiationwithanintensityof2×1017W/cm2ontotheedgeofanaluminumfoil.Theelectronshadenergydistributionspeakinginthe0.2–0.8MeVrangewithenergyspreadlessthan20%.Theaccelerationmechanismrelatedtothegenerationofaplasmawaveasaresultofself-modulationinstabilityofalaserpulseinadenseplasmaformedbyaprepulse(arriving12nsbeforethemainpulse)isconsidered.One-dimensionalandtwo-dimensionalParticleinCell(PIC)simulationsofthelaser–plasmainteractionshowedthateffectiveexcitationofaplasmawaveaswellastrappingandaccelerationofanelectronbeamwithanenergyontheorderof1MeVmayoccurinthepresenceofsharpgradientsinplasmadensityandinthetemporalshapeofthepulse.

简介：Theperiod-oneoscillationproducedbyanexternalopticalpulseinjectiondrivensemiconductorlaserisappliedtoclockrecoveryandfrequencydivision.Byadjustingtherepetitionrateorinjectionpoweroftheexternalinjectionopticalpulsestolockthedifferentharmonicfrequenciesoftheperiod-onestate,theclockrecoveryandthefrequencydivision(thesecondandthirdfrequencydivisions)areachievedexperimentally.Inaddition,infrequencylockingrangesof2GHzand1.9GHz,thesecondandthirdfrequencydivisionsareobtainedwiththephasenoiselowerthan-100dBc/Hz,respectively.Ourexperimentalresultsareconsistentwellwiththenumericalsimulations.

简介：基于小世界网络在一个pulse-coupledintegrate-and-fire神经原模型变老和自我组织的criticality的效果被学习了。我们给老化网络，平均最短的路径长度，我们的网络的直径，和聚类的系数的度分发，并且发现我们的神经原模型显示幂定律行为，并且与然后增加的连接增加的棕土，老化的效果变得越来越小。这证明如果大脑以自我组织的criticality状态工作，它能减轻老化引起的一些效果。

简介：Indouble-pulselaser-inducedbreakdownspectroscopy(DP-LIBS),thecollinearfemtoseconddouble-pulselaserconfigurationisexperimentallyinvestigatedwithdifferentinitialsampletemperaturesusingaTi:sapphirelaser.Theglasssampleisablatedtoproducetheplasmaspectroscopy.Duringtheexperiment,thedetectedspectrallinesincludetwoNa(I)lines(589.0nmand589.6nm)andoneCa(I)lineatthewavelengthof585.7nm.Theemissionlinesaremeasuredatroomtemperature(22°C)andthreehigherinitialsampletemperatures(Ts=100°C,200°C,and250°C).Theinter-pulsedelaytimerangesfrom-250psto250ps.Theinter-pulsedelaytimeandthesampletemperaturestronglyinfluencethespectralintensity,andthespectralintensitycanbesignificantlyenhancedbyincreasingthesampletemperatureandselectingtheoptimizedinter-pulsetime.Forthesameinter-pulsetimeof0ps(single-pulseLIBS),theenhancementratioisapproximately2.5atTs=200°CcomparedwiththatobtainedatTs=22°C.Forthesameinter-pulsetimeof150ps,theenhancementratiocanbeupto4atTs=200°CcomparedwiththatobtainedatTs=22°C.Thecombinedenhancementeffectsofthedifferentinitialsampletemperaturesandthedouble-pulseconfigurationinfemtosecondLIBSaremuchstrongerthanthatofthedifferentinitialsampletemperaturesorthedouble-pulseconfigurationonly.

简介：Anall-fiberopticallaserpulsemulti-passstretcherusingachirpedfiberBragggrating(CFBG)isdemonstrated.Pulsesfroma1053-nmmode-lockedfiberseedoscillatorarestretchedbymultiplepassingthroughachirpedfibergratingsetinafiberregenerativeamplifierstructure.Westretchthepulsefrom16psto1.855nsafterittransmitssevenloopsinthestretcher.Themainfactorsthataffectthestretchingresultsarediscussed.