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9 个结果
  • 简介:Accurateaerodynamicmeasurementsinthehypersonicflowoflargeaircraftmodelsintunnelshavepracticalsignificance,butposeasignificantchallenge.Novelaerodynamicforcemeasurementmethodshavebeenproposed,butlacktheoreticalsupport.Theformsoftheforcesignalstechniquesforsignalprocessingandcalculationofaerodynamicsareespeciallyproblematic.Atheoreticalstudyisconductedtoinvestigatethedynamicpropertiesbasedonmodelsofthedraw-rodsystemandslenderrods.Theresultsindicatethattheinertiaitemcanbeneglectedintherodgoverningequation;further,thesolutionsshowthatthesignalsofeachrodareacombinationofaerodynamicsignals(withaconstantvalue)andsinesignals,whichcanbeverifiedbyexperimentalshocktunnelresults.Signalprocessingandaerodynamicscalculationtechniquesarealsofoundtobeachievableviatheflatpartofthesignals.

  • 标签: 高超声速风洞 飞行器模型 气动测量 空气动力学计算 信号处理 计算技术
  • 简介:一个向轴的方向的大偏转有一张矩形的剖面图的可扩展的弄弯的横梁被调查。有弹性的横梁被假定满足Euler-Bernoulli假定并且用Ludwick类型材料做的。通过相当简化的集成,横梁的轴的紧张和弯曲在含蓄的明确的表达被介绍。包含的管理方程几何并且弄弯的横梁的材料非线性被射击方法导出并且解决。当横梁的起始的弯曲是零时,弄弯的横梁被堕落进一根直横梁,并且现在的模型获得的预言的结果与在开的文学的那些一致。数字例子进一步为弄弯的伸臂被给并且简单地支持在延伸之间的横梁,和couplings并且弯曲被作出对有利的裁决弄弯的横梁。

  • 标签: 大偏转 弄弯的横梁 Ludwick 类型材料 非线性 O343.5 74B20
  • 简介:套住的协调人口(CPT)现象在量精确大小发现了普遍申请。各种各样的图案基于相应于线性Zeeman效果的狭窄的反响的光谱被表明了完成高效。在这篇文章,非线性的Zeeman87在linlin安装的Rb被调查。我们观察重新切开为在一个大磁场的两根磁性的敏感、磁性的感觉迟钝的CPT反响的线的现象。在磁性的敏感的线的重新切开提起一个实际问题到磁强计当另一个在大磁场为应用程序显示出一个好潜力时,在linlin安装工作了。我们基于磁性的感觉迟钝的线的非线性的裂口建议一个图案并且测试它的表演。它与线性的相比提供一个大得多的测量范围,提供为一个大动态范围被比较喜欢的原子磁强计的一种选择。

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  • 简介:Byovercomingfabricationlimitations,wehavesuccessfullyfabricatedsilicatoroidmicrocavitieswithbothlargediameter(of1.88mm)andultra-high-Qfactor(of3.3×10~8)forthefirsttime,tothebestofourknowledge.Byemployingtheseresonators,wehavefurtherdemonstratedlow-thresholdKerrfrequencycombsonasiliconchip,whichallowustoobtainarepetitionrateaslowas36GHz.Suchalowrepetitionratefrequencycombcannowbedirectlymeasuredthroughacommercializedoptical-electronicdetector.

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  • 简介:Conventionalorganicsolarcell’s(OSC)architectures,includingrigidtransparentsubstrate(Glass),conductiveelectrode(Indiumtinoxide,ITO)andsmallworkingareas,arewidelyutilizedinorganicphotovoltaicfields.However,suchastructureaswellasconventionalspin-coatingmethodobviouslyrestricttheirindustrialapplication.Inthisarticle,wereportthedepositionofsilvernanowires(AgNWs)ontheflexiblesubstratebyslot-dieprinting.TheobtainedAgNWsfilmsexhibitedahightransmittanceandalowresistance,andwerefurtherusedasthetransparentconductiveelectrodeofOSCs.Atypicalconjugatedpolymer,poly[(2,5-bis(2-hexyldecyloxy)phenylene)-alt-(5,6-difluoro-4,7-di(thiophen-2-yl)benzo[c][1,2,5]thiadiazole)](PPDT2FBT),wasusedastheactivematerialtofabricatelarge-area(7cm~2)solarcellsbyaslot-diecoatingprocess.Thepowerconversionefficiency(PCE)couldreach1.87%initiallyandfurtherincreasedto3.04%bythermalannealing.ComparedtotheperformanceofreferencecellonITOsubstrate,theresultindicatedthattheAgNWscouldbedevelopedasanalternativesubstituteofconductiveelectrodetofabricatethelarge-areaflexibleOSCsbyroll-to-rollprinting.

  • 标签: 聚合物太阳能电池 银 nanowires 槽死 大区域 灵活底层
  • 简介:Westudythedynamicbehaviorofaquartzcrystalresonator(QCR)inthickness-shearvibrationswiththeuppersurfacecoveredbyanarrayofmicro-beams(MBs)underlargedeflection.ThroughtakingintoaccountthecontinuousconditionsofshearforceandbendingmomentattheinterfaceofMBs/resonator,dependencesoffrequencyshiftofthecompoundQCRsystemversusmaterialparameterandgeometricalparameterareillustratedindetailfornonlinearandlinearvibrations.Itisfoundthatthefrequencyshiftproducesalittleright(left)translationforincreasingelasticmodulus(length/radiusratio)ofMBs.Moreover,thefrequencyright(left)translationdistancecausedbynonlineardeformationbecomesmoreseriousinthesecond-ordermodethaninthefirst-orderone.

  • 标签: 石英晶体谐振器 共振频率 厚度剪切 大挠度 模态 微梁
  • 简介:Thenumericalquadraturemethodsfordealingwiththeproblemsofsingularandnear-singularintegralscausedbyBurton-Millermethodareproposed,bywhichtheconventionalandfastmultipoleBEMs(boundaryelementmethods)for3Dacousticproblemsbasedonconstantelementsareimproved.Tosolvetheproblemofsingularintegrals,aHadamardfinite-partintegralmethodispresented,whichisasimplifiedcombinationofthemethodsproposedbyKirkupandWolf.Theproblemofnear-singularintegralsisovercomebythesimplemethodofpolartransformationandthemorecomplexmethodofPART(ProjectionandAngular&RadialTransformation).Theeffectivenessofthesemethodsforsolvingthesingularandnear-singularproblemsisvalidatedthroughcomparingwiththeresultscomputedbytheanalyticalmethodand/orthecommercialsoftwareLMSVirtual.Lab.Inaddition,theinfluenceofthenear-singularintegralproblemonthecomputationalprecisionsisanalyzedbycomputingtheerrorsrelativetotheexactsolution.ThecomputationalcomplexitiesoftheconventionalandfastmultipoleBEMareanalyzedandcomparedthroughnumericalcomputations.Alarge-scaleacousticscatteringproblem,whosedegreeoffreedomsisabout340,000,isimplementedsuccessfully.Theresultsshowthat,thenearsingularityisprimarilyintroducedbythehyper-singularkernel,andhasgreatinfluencesontheprecisionofthesolution.TheprecisionoffastmultipoleBEMisthesameasconventionalBEM,butthecomputationalcomplexitiesaremuchlower.

  • 标签: 奇异积分 边界元法 声学问题 数值积分 HADAMARD 计算精度
  • 简介:Forafullychaotictwo-dimensional(2D)microcavitylaser,wepresentatheorythatguaranteesboththeexistenceofastablesingle-modelasingstateandthenonexistenceofastablemultimodelasingstate,undertheassumptionsthatthecavitysizeismuchlargerthanthewavelengthandtheexternalpumpingpowerissufficientlylarge.Itistheoreticallyshownthattheseuniversalspectralcharacteristicsarisefromthesynergisticeffectoftwodifferentkindsofnonlinearities:deformationofthecavityshapeandmodeinteractionduetoalasingmedium.OurtheoryisbasedonthelinearstabilityanalysisofstationarystatesfortheMaxwell–Blochequationsandaccountsforsingle-modelasingphenomenaobservedinrealandnumericalexperimentsoffullychaotic2Dmicrocavitylasers.

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