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  • 简介:TheV^t-integralasdefinedin[2],whichiseqnivalenttoM^2-integrslasdefinedinTrigonometreseriesbyZygmundisusedtosumtrigonometricseiesin[1].Inthispaper,someconvergenttheoremsofV^2-integralareestablished.

  • 标签: V^t-积分 单调性 收敛定理 振动函数 三角序列
  • 简介:Thedelaydifferentialequationwithpiecewiseconstantargumentx′(t)+a(t)x(t)+b(t)x([t-k])=0isconsidered,wherea(t)andb(t)arecontinuousfunctionson[—k,∞),b(t)≥0,kisapositiveintegerand[·]denotesthegreatestintegerfunction.Somenewoscillationandnonoscillationconditionsareobtained.

  • 标签: 延迟微分方程 分段常数 振动方程 连续函数
  • 简介:为有抑制Δ~2x_n+p_nΔx_n+F的非线性的延期差别方程的一些新摆动标准(n,x_(n-τ),Δx_(n-σ))=0,n=0,1,2,...,(*)被给。我们的结果部分解决摆姿势在的开的问题[数学。Bohemica,125(2000),421-430]。另外,我们将为(*)的特殊情况建立一些新摆动标准,它在文学改进一些知道thewell的结果。

  • 标签: 二阶微分方程 振荡 非线性 时滞 阻尼
  • 简介:1.IntroductionConsiderthefirstorderdifferentialequationwithdeviatingargUmelltTheoscillationofEq.(1)wasstudiedextensivelyinthelastthreedecades.See,forexamDleif--101andthereferencescitedtherein.In1972Ladas.LakshlnhanthamanddeceivedApril1,1997.Re~AugUBt...

  • 标签: OSCILLATION DIFFERENTIAL EQUATION deviating ARGUMENT
  • 简介:ByRiccatitransformation,weestablishsomenewoscillationcriteriaforaclassofevenorderdelaydifferentialequationswithnonlinearterm.Insomesense,theresultsobtainedextendsomeknownresultsintheliterature.

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  • 简介:AclassofnonlinearcoupledsystemforElNino-SouthernOscillation(ENSO)modelisconsidered.Usingtheasymptotictheoryandmethodofvariationaliteration,theasymptoticexpansionofthesolutionforENSOmodelsisobtained.

  • 标签: 非线性模型 渐近理论 ENSO模型 模型理论
  • 简介:Weproposeaphotonicstructurestackedsequentiallybyone-dimensionalphotoniccrystalsandcavities.Thewholestructureiscomposedofsingle-negativeanddouble-negativematerials.TheopticalWannier–Starkladder(WSL)canbeobtainedinalowfrequencyregionbymodulatingthewidthsofthecavitiesinorder.Wesimulatethedynamicalbehavioroftheelectromagneticwavepassingthroughtheproposedphotonicstructure.Duetothedispersivecharacteristicsofthemetamaterials,averynarrowWSLcanbeobtained.Thelong-periodelectromagneticBlochoscillationisdemonstratedtheoreticallytohaveaperiodonamicrosecondtimescale.

  • 标签: 一维光子晶体 材料组成 振荡理论 磁布 微腔 光子结构
  • 简介:Strongasymmetricalvorticesappearontheleewardofslenderbodyathighanglesofattack,whichhasveryunfavorableeffectonthestabilityandcontroloftheaircraft.Amethodisdevelopedtocontrolthesideforceofslenderbodyathighanglesofattack,andisverifiedinwindtunnel.Athin-filmtriangularself-excitedoscillationflagisfixedatthetipoftheslenderbodymodelwhosesemi-apexangleis10°.Sideforceisapproximatelylinearlyproportionaltoroll-settingangleofself-excitedoscillationflagathighanglesofattack,andtheslopoffittingstraightlineobtainedbytheleastsquaremethodis-0.158.Thelinearrelationshipbetweensideforceandroll-settingangleprovidesconveniencefordevelopingsideforcecontrollawofslenderbodyathighanglesofattack.Experimentaldatashowsthatthesideforcecoefficientsvarylinearlywithroll-settingangleswhenaspecificplasticself-excitedoscillationflagisusedasthecontrolflag.Therangeofsideforcecoefficientandroll-settingangleare,respectively,-3.2to3.0and-20°to20°.Thedeviceissimple,effective,andisofgreatpotentialinengineeringapplication.

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