Math model of metal heating under action by laser beam智慧樹知到期末考試答案章節(jié)答案2024年1

Mathmodelofmetalheatingunderactionbylaserbeam智慧樹知到期末考試答案+章節(jié)答案2024年1simulationstrategy,alsoknownassimulationalgorithm.Thesimulationstrategiesapplicabletodiscrete-eventsystemsare（）.

答案:two-eventschedulingmethod;activityscanningmethod;processinteractionmethod;three-phasemethod.Assumingthattheenergydensityoftheopticalfieldisρ(v),theexcitedabsorptionprobabilityofaparticletransitioningfromalowerenergystateφ1toahigherenergystateφ2is（）;aparticletransitioningfromahigherenergystate.φ2toalowerenergystateφ1are（）and（）,respectively.（）

答案:A21;B12ρ(v);B21ρ(v)Systemsimulationhasthreebasicactivities,namely,systemmodeling,simulationmodelingandsimulationexperiments,linkingthesethreeactivitiesisthesystemsimulationofthethreeelements,thatis,（）.

答案:Thesystem;Computer(hardwareandsoftware);ThemodelLaserlightsourcecomparedwithordinarylightsources,whichhasthreeadvantages:（）.

答案:Gooddirectionality;Highcoherence;HighmonochromaticityAccordingtothedifferentpumpingmethods,laserscanbemainlycategorizedinto（）.

答案:thermallypumpedlasers;Opticalpumpinglasers;electricallypumpedlasers;chemicallypumpedlasers,Accordingtothesystemstatewithtimechangeiscontinuousorintermittent,canbedividedinto（）.

答案:Continuoussystem;DiscretesystemTrytocitecommontypesofmodelockingmethods:（）.

答案:passivemodelocking;activemodelocking;synchronouspumpingmodelocking;self-lockingmodeThethreebasicprocessesofradiationenergyexchangeis:（）.

答案:spontaneousemission;excitedabsorption;excitedemissionTheHe-Nelaserisatypicalfourenergylevelsystemwiththreemainexcitationspectrallines,whoseexcitationspectrallinesandwavelengthsare（）.

答案:3S→2P0.6328μ;2S→2P1.15μ;3S→3P3.39μThefollowingpost-processingtechniquesareuniquetoSLAmoldingtechnology（）.

答案:dischargeuncuredphotosensitiveresinThequeuingsystemcanbesimplifiedasA/B/C/D/E,whereAisthearrivalmode;Bisthe（）.

答案:servicemodeThefollowingWitnessmodelingelementsarepassive（）.

答案:BufferLightradiatedbyatomicexcitationhasthesame（）aslightradiatedbyexternallyinducedexcitation.①frequency,②angleofdivergence,③quantumstate,④polarization,⑤directionofpropagation

答案:①③④⑤Accordingtothequantumtheoryofprimitives,primitivescanemitlightbymeansofauto-radiationandstimulatedradiation.Thelightproducedbythemischaracterizedby:（）

答案:Thelightofthesamefrequencyradiatedbythetwosubprimariesisincoherent,whilethelightradiatedbythesubprimarystimulusiscoherentwiththeincominglight.3Dprintingbelongsto（）manufacturing.

答案:augmentationDopplerbroadeninghasoccurredin（）media.

答案:liquidsThetwomainrolesofthelaserresonantcavityistoprovide（）.

答案:feedbackamplificationandselectivemodeThefollowingstatementsaboutSLSareincorrect（）.

答案:SLSmoldingtechnologydoesnotprintmetalparts.(CorrectAnswer)simulationclockrepresentsthevariableofsimulationtime.simulationclockinWitnesssimulationsystemisrepresentedbythesystemvariable（）.

答案:TIMEThesubstancesthatproducelaserlightinNd+3:YAGandTi+3:sapphire(titanium-dopedsapphire)lasersare（）,respectively.

答案:NdandTiionsThechirpedpulsereferstodifferent{frequency}componentsbeingindifferentpartsofthepulseinatimesequence.Thegroupvelocitydispersioncompensationelementonthechirpedpulsetoproduce（）effect.

答案:CompressionTodosimulationexperiments,ifyouwanttograduallyobservethesimulationmodelrunningprocess,choose(C)runmode;ifyoudonotwanttowatchthesimulationanimation,youcanchoose（）runmode.

答案:BatchThelargertheQfactorofthelasercavity,thehighertheoutputmonochromaticityofthecavity,i.e.（）.

答案:thesmallertheoutputspectralbandwidthWhichofthefollowing3Dprintingtechniquesismostusedinmetaladditivemanufacturing（）.

答案:SLMThefollowingstatementsabout3Dprintingmaterialsareincorrect（）.

答案:Thefinertheparticlesizeofmetalpowderfor3Dprintingmetal,theeasieritistoachievethedesiredmoldingeffect.AconcavecavitywithaconcavemirrorofradiusRequaltothecavitylengthLisa（）.

答案:CriticalcavityStabilizedcavityofapieceofmirrorradiusofcurvatureR1=4L,theothersideofthemirrortofindtheradiusofcurvatureoftherangeofvaluesis（）.

答案:R2>LorR2<-3LThebasicprincipleofQ-tuningis:inthepumpingprocessinmostofthetimetheresonantcavityisinthelowQvalueorhighlossstate,sothequevalueisveryhigh,cannotbeoscillated,andthusinthelaserontheenergyleveloftheparticlenumbercontinuestoaccumulatetoacertainmomentthenumberofreversedparticlestoreachthemaximumvalue,theQvalueofasudden（）,theestablishmentoflaseroscillations,andtheoutputofthepulsedlaser.

答案:IncreaseatotalfocalcavitysymmetryL=0.40m,λ=0.6328{m,beamwaistradius,56cmfromthewaistofthebeameffectivecross-sectionradiusof（）.

答案:0.6mmAneventisaninstantaneouschangeofeventsthatchangesthestateofasystem.Itgenerallyreferstothebeginningandendofanevent.Eventscanbecategorizedasnecessaryevents,conditionalevents,andsystemevents.Where（）generallydoesnotappearinthefutureeventstable.

答案:FELInahelium-neonlaser,thelaserjumpoccursbetweentheenergylevelsof（）,andtheheliumatombecomesthemainmechanismfortheexcitationoftheneonatom.

答案:NeonatomThegeneralstepsofsystemsimulationare:（）.

答案:researchsystem,definetheproblemThethreebasicconceptsinsystemsimulationaresystem,（）andsimulation.

答案:ModelAnactivityisadurationwithaspecifiedlengthanditsstarttimeisdetermined.Themainactivitiesofthequeuingsystemis（）.

答案:serviceactivityThe"original"methodofsolvingsimplesystemproblemsis（）,withthehelpofexperimentcangreatlyimprovetheefficiencyandaccuracyofthemethod.

答案:analyticalsolutionTomakeacavitylengthL=60cmsymmetricstabilizedcavity,theradiusofcurvatureofthemirrortotakethevalueoftherangeRis（）.

答案:>30cmIn1983,AmericanscientistChuckHullinvented（）3Dprintingtechnology.

答案:SLAIfaparticleofasubstancehasastationarygroundstateE1(BouyguesnumberN1)andanexcitedstateE2(BouyguesnumberN2),thefollowing（）arenon-thermalequilibriumstatesorBouyguesnumberinversions.

答案:N2>N1Incontinuousoperationlasersteadystate（）

答案:thegaincoefficientisequaltothethresholdgaincoefficientWhendidtheearliest3Dprintingtechnologyappear?（）

答案:earlytwentiethcenturyThefar-fielddivergenceangleofthesymmetricconfocalcavityfundamentalmodeis（）。

答案:IntheWitnesssystem,randomvariablessuchascustomerarrivalintervals,serviceevents,breakdownintervals,andrepairtimesaregeneratedbytherandomdistributionfunctionitprovides.Correspondthestandarddistributions:normal,binomial,Poisson,negativeexponentialandapplicablescenariosas（）.

答案:MachineprocessingtimeTherelationshipbetweentheEinsteincoefficientofspontaneousradiationandtheaveragelifetimeτoftheexcitedstateE2is（）。

答案:Thelongitudinalmodespacingoftheresonantcavityis（）。

答案:TherelationshipbetweenEinsteincoefficientsA21andB21is（）

答案:Forthesamemedium,thesmallsignalgaincoefficientvarieswith（）。

答案:ExcitationpowerThecharacteristicsoflasercavityoscillationmodeare（）。

答案:Thedivergenceangleofthelaserbeamforeachmode.;Thesimpleharmonicfrequencyofthemode.;Therelativepowerlossexperiencedbythemodeduringoneroundtripinthecavity.;Theelectromagneticfieldtheoryofthemode.Symmetricconfocalcavitybasemodelightwaistfor（）。

答案:He-Nelasersbelongtothetypical（）system.

答案:fourenergylevels,TheDopplerbroadeningoftheCO2spectrallineis53MHz,andtheextremevalueofthespectrallinefunctioncorrespondingtothecentralfrequencyis（）。

答案:1.7×10-9sRubylaserisatypical（）system。

答案:ThreeenergylevelTheresonantfrequencyofthelongitudinalmodeoftheresonantcavityis（）。

答案:Q-modulatedlaserscanusuallyobtain（）magnitudeshortpulses.

答案:nsNaturalbroadeningiscausedby（）.

答案:excitedstateshaveacertainlifetimeWhatistheDuffing’sequationusedtocalculateelectrondisplacement?（）

答案:Whenalaserpropagatesfromonemediumtoanotherwithadifferentrefractiveindex,a(C)willappearattheinterfacebetweenthemedia（）。

答案:ReflectionandrefractionAtacertaintemperature,theoddsofspontaneousradiationare（）timesgreaterthantheoddsofexcitedradiation

答案:Whattypeoflaserdoesthecarbondioxidelaserbelongto?（）

答案:GaslaserParticlenumberreversaldistributionstatemicroscopicparticlessatisfy（）

答案:Negativetemperaturedistribution

答案:allWhenthepulseenergyiscertain,thenarrowerthepulsewidth,itmeansthetimeenergydensitywithtimeasthedenominator（）.

答案:ThegreaterThecollisionalbroadeningspectrallineis（）。

答案:LorentzianlinearThethresholdconditionistheformationoflaser（）。

答案:sufficientnecessarycondition.Forauniformlybroadenedmedium,thesmall-signalgaincoefficientatthecentercenterfrequencyisG0(v0),andwhenI=Is,saturationissignificant,andthenon-small-signalcenter-frequencygaincoefficientis:（）.

答案:Theonethatcanexplaintheexperimentalcurveof