简介：Broadband（1.6–18THz）terahertztime-domainspectroscopy（THz-TDS）andtime-resolvedterahertzspectroscopy（TRTS）wereperformedona54μmthickchalcogenideglass(As30Se30Te40)samplewithatwo-colorlaser-inducedairplasmaTHzsystemintransmissionandreflectionmodes,respectively.Twoabsorptionbandsat2–3and5–8THzwereobserved.TRTSrevealsanultrafastrelaxationprocessofthephotoinducedcarrierresponse,welldescribedbyarateequationmodelwithafiniteconcentrationofmid-bandgaptrapstatesforself-trappedexcitons.ThephotoinducedconductivitycanbewelldescribedbytheDrude–Smithconductivitymodelwithacarrierscatteringtimeof12–17fs,andweobservesignificantcarrierlocalizationeffects.Afastrefractiveindexchangewasobserved100fsbeforetheconductivityreacheditsmaximum,with2ordersofmagnitudelargeramplitudethanexpectedfortheopticallyinducedTHzKerreffect,indicatingthatfreecarriersareresponsibleforthetransientindexchange.

简介：Thenonlinearbehaviorofacantileveredfluidconveyingpipesubjectedtoprincipalparametricandinternalresonancesisinvestigatedinthispaper.Theflowvelocityisdividedintoconstantandsinusoidaiparts.Thevelocityvalueoftheconstantpartissoadjustedsuchthatthesystemexhibits3:1internalresonancesforthefirsttwomodes.Themethodofmultiplescalesisemployedtoobtaintheresponseofthesystemandasetoffourfirst-ordernonlinearordinary-differentialequationsforgoverningtheamplitudeoftheresponse.TheeigenvaluesoftheJacobianmatrixareusedtoassessthestabilityoftheequilibriumsolutionswithvaryingparameters.Thecodimension2derivedfromthedouble-zeroeigenvaiuesisanalyzedindetail.Theresultsshowthattheresponseamplitudemayundergosaddle-node,pitchfork,Hopf,homoclinicloopandperiod-doublingbifurcationsdependingonthefrequencyandamplitudeofthesinusoidalflow.Whenthefrequencyofthesinusoidalflowequalsexactlyhalfofthefirst-modefrequency,thesystemhasaroutetochaosbyperiod-doublingbifurcationandthenreturnstoaperiodicmotionastheamplitudeofthesinusoidalflowincreases.

简介：ByusinganewgenerallyprojectiveRiccatiequationmethodandwiththehelpofsymboliccomputation,weconsideranonlinearGross-Pitaevskiiequationwithweakbiasmagneticandtime-dependentlaserfields.Asaresult,somenewsolitonsolutions,rationalfunctionsolution,andperiodicsolutionsareobtained.

简介：Aself-adaptiveprecisealgorithminthetimedomainwasemployedtosolve2-Dnonlinearcoupledheatandmoisturetransferproblems.Byexpandingvariablesatadiscretizedtimeinterval,thevariationsofvariablescanbedescribedmoreprecisely,andanonlinearcoupledinitialandboundaryvalueproblemwasconvertedintoaseriesofrecurrentlinearboundaryvalueproblemswhicharesolvedbyFEtechnique.Inthecomputation,noadditionalassumptionandthenonlineariterationarerequired,andacriterionforself-adaptivecomputationisproposedtomaintainsufficientcomputingaccuracyforthechangesizesoftimesteps.Inthenumericalcomparison,thevariationsofmaterialpropertieswithtemperature,moisturecontent,andbothtemperatureandmoisturecontentaretakenintoaccount,respectively.Satisfactoryresultshavebeenobtained,indicatingthattheproposedapproachiscapableofdealingwithcomplexnonlinearproblems.

简介：BasedonageneralanalysisofGreenfunctionsinthereal-timethermalfieldtheory,wehaveproventhatthefour-pointamputatedfunctionsinanNJLmodelinthefermionbubblediagramapproximationbehavelikeusualtwo-pointfunctions.WeexpoundthethermaltransformationsofthematrixpropagatorsforascalarboundstateintheFFbasisandintheRAbasisrespectively.Theresultingphysicalcausal,advancedandretardedpropagatorsarerespectivelyidenticaltocorrespondingonesderivedintheimaginary-timeformalism,andthisshowsonceagainthecompleteequivalenceofthetwoformalismsofthermalfieldtheoryonthediscussedproblemintheNJLmodel.

简介：在tetrahydrofuran(THF)的生活cationic戒指洞聚合期间的单体集中的方便即时监视与甲基triflate(MeOTf)开始了的A为平衡单体集中的运动调查和决心被开发了([M]e)经由在在联合的situFTIR光谱学与一颗钻石付小费给的稀释全部的反射(ATR)沉浸探查。聚合率从ln的线性斜坡是关于单体集中和开始者集中的第一份订单([M]<潜水艇class=“a-plus-plus”>0-[M]e)/([M]-[M]在在各种各样的溶剂的不同温度的e)对聚合时间。[M]<潜水艇class=“a-plus-plus”>当与增加聚合温度指数地增加了时，e与起始的单体集中线性地减少了。平衡强烈也取决于有单体的溶剂极性和它的相互作用。平衡聚合时间(t<潜水艇class=“a-plus-plus”>e)与增加溶剂极性减少了并且与增加线性地减少了[M]<潜水艇class=“a-plus-plus”>在有到当溶剂不在时的体积聚合的一样的点的不同斜坡的三溶剂的0。M的方程n，e=72.1/(0.14-0.04[M]e)被建立了为数字一般水准为预言提供一条简单、有效的途径以平衡状态的polyTHFs的分子的重量(Mn，在在0o犀?犀?犈?犈的THF的平衡生活cationic戒指洞聚合的e)？？

简介：Acouplednumericalmethodforthedirectnumericalsimulationofparticle-fluidsystemsisformulatedandimplemented,resolvinganorderofmagnitudesmallerthanparticlesize.Theparticlemotionisdescribedbythetime-drivenhard-spheremodel,whilethehydrodynamicequationsgoverningfluidflowaresolvedbythelatticeBoltzmannmethod(LBM).Particle-fluidcouplingisrealizedbyanimmersedboundarymethod(IBM),whichconsiderstheeffectofboundaryonsurroundingfluidasarestoringforceaddedtothegoverningequationsofthefluid.Theproposedschemeisvalidatedintheclassicalflow-around-cylindersimulations,andpreliminaryapplicationofthisschemetofluidizationisreported,demonstratingittobeapromisingcomputationalstrategyforbetterunderstandingcomplexbehaviorinparticle-fluidsystems.

简介：Thegroup-delaydispersionofanopticalfiberwasmeasuredwiththetime-of-flightmethod,usingfingerprint-likecharacteristicspectrafromamode-lockedfiberlasersource.Todeterminethegroup-delaydispersionuptothefourthorder,least-squaresfittingwasappliedtotheoveralltimewaveformmappedonthetimeaxisforthefingerprint-spectralbroadbandpulsesthroughalongopticalfiber.Theanalysisofall4003datapointsreducedstatisticaluncertainty,andprovidedsecond-,third-,andfourth-orderdispersionwithuncertaintiesof0.02%,0.4%,and4%,respectively.

简介：Wedemonstratethatthemethodologyoffrequency-resolvedopticalgating(FROG)isapplicabletotime-resolvedreflectionspectroscopyofaplasmamirrorinthevacuum-ultraviolet(VUV)region.Ourrecentstudy[R.Itakuraetal.Opt.Express23,10914(2015)]hasshownthataVUVwaveformcanberetrievedfromaVUVreflectionspectrogramofaplasmamirrorformedonafusedsilica(FS)surfacebyirradiationwithanintensefemtosecondlaserpulse.Simultaneously,theincreaseinthereflectivitywithrespecttotheFresnelreflectionoftheunexcitedFSsurfacecanbeobtainedasatime-dependentreflectivityoftheplasmamirror.Inthisstudy,weupdatetheFROGanalysisprocedureusingtheleast-squaregeneralizedprojectionsalgorithm.Thisprocedurecanreachconvergencemuchfasterthanthepreviousoneandhasnoaliasingproblem.ItisdemonstratedthatasignificantlychirpedVUVpulseaslongas1pscanbepreciselycharacterized.

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简介：Inthispaper,weinvestigatetheglobalexistenceandlongtimebehaviorofstrongsolutionsforcompressiblenematicliquidcrystalflowsinthreedimensionalwholespace.TheglobalexistenceofstrongsolutionsisobtainedbythestandardenergymethodundertheconditionthattheinitialdataareclosetotheconstantequilibriumstateinH~2-framework.IftheinitialdatasinL~1-normarefiniteadditionally,theoptimaltimedecayratesofstrongsolutionsareestablished.WiththehelpofFouriersplittingmethod,onealsoestablishesoptimaltimedecayratesforthehigherorderspatialderivativesofdirector.

简介：

简介：Ahigh-orderleap-frogbasednon-dissipativediscontinuousGalerkintime-domainmethodforsolvingMaxwell'sequationsisintroducedandanalyzed.Theproposedmethodcombinesacenteredapproximationfortheevaluationoffluxesattheinterfacebetweenneighboringelements,withaNth-orderleap-frogtimescheme.Moreover,theinterpolationdegreeisdefinedattheelementlevelandthemeshisrefinedlocallyinanon-conformingwayresultinginarbitrarylevelhangingnodes.ThemethodisprovedtobestableundersomeCFL-likeconditiononthetimestep.Theconvergenceofthesemi-discreteapproximationtoMaxwell'sequationsisestablishedrigorouslyandboundsontheglobaldivergenceerrorareprovided.Numericalexperimentswithhigh-orderelementsshowthepotentialofthemethod.

简介：Afullycoherentfreeelectronlaser(FEL)seededwithahigher-orderharmonic(HH)pulsefromhigh-orderharmonicgeneration(HHG)issuccessfullyoperatedforasufficientlyprolongedtimeinpilotuserexperimentsbyusingatimingdriftfeedback.ForHHG-seededFELs,theseedinglaserpulseshavetobesynchronizedwithelectronbunches.DespiteseededFELsbeingnon-chaoticlightsourcesinprinciple,externallaser-seededFELsareoftenunstableinpracticebecauseofatimingjitterandadriftbetweentheseedinglaserpulsesandtheacceleratedelectronbunches.Accordingly,weconstructedarelativearrival-timingmonitorbasedonnon-invasiveelectro-opticsampling(EOS).TheEOSmonitormadeuninterruptedshot-to-shotmonitoringpossibleevenduringtheseededFELoperation.TheEOSsystemwasthenusedforarrival-timingfeedbackwithanadjustabilityof100fsforcontinualoperationoftheHHG-seededFEL.UsingtheEOS-basedbeamdriftcontrollingsystem,theHHG-seededFELwasoperatedoverhalfadaywithaneffectivehitrateof20%–30%.Theoutputpulseenergywas20μJatthe61.2nmwavelength.TowardsseededFELsinthewaterwindowregion,weinvestigatedourupgradeplantoseedhigh-powerFELswithHHphotonenergyof30–100eVandlaseatshorterwavelengthsofupto2nmthroughhigh-gainharmonicgeneration(HGHG)attheenergy-upgradedSPring-8CompactSASESource(SCSS)accelerator.WestudiedabenefitaswellasthefeasibilityofthenextHHG-seededFELmachinewithsingle-stageHGHGwithtunabilityofalasingwavelength.

简介：TypeIX-rayburstsarethemostfrequentthermonuclearexplosionsinnature,resultingfromthermonuclearrunawayonthesurfaceofanaccretingneutronstar[1].Thebreakoutreaction14O(α,p)17FfromthehotCNOcyclemayhaveaprominentimpactontheburstlightcurveandburstashes[2].However,insufficientexperimentalinformationisavailabletocalculateareliable,preciserateforthisreaction[3].Weproposedtoaddresstheexperimentalinvestigationofthe14O(α,p)17FusingTimeProjectionChamber(TPC)[4].