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500 个结果
  • 简介:Inthiswork,wereviewthedevelopingprogressoftwo-dimensionalterahertztime-domainspectroscopy(THz-TDS)anditsdiverseapplications,includinganalyzingthepolarizationofTHzradiationfromalaser-inducedplasmasourceandstudyingthecorrespondingphysicalmechanism,andcharacterizingtheopticalpropertiesofcrystals,etc.

  • 标签: 太赫兹时域光谱 应用 二维 光谱仪 太赫兹辐射 等离子体源
  • 简介:数字建模在上短暂电磁的散布由atwo维(2D)位于演变时间的不平的表面的柱体被usingtime域积分方程介绍。一个逐渐变细的高斯脉搏事件波浪的建议特殊选择把截断错误从不平的表面移开。另外,一种二水平的平均技术被利用从行进解决不可分的方程的过程的时间克服不稳定性。在表面水流分布之间的优秀通讯,以及thefar地区地,由建议方法计算了,那由与反的分离Fourier转变计划联系的时刻的传统的方法获得了表明建模的精确性。

  • 标签: 散射 粗糙表面 光学 折射
  • 简介:Byusingthecontinuationtheoremofcoincidencetheory,theexistenceofapositiveperiodicsolutionforatwo-patchescompetitionsystemwithdiffusionandtimedelayandfunctionalresponse{x′(t)=x1(t)[a1(t)-b1(t)x1(t)-c1(t)y(t)/[1+m(t)x1(t)]]+D1(t)[x2(t)-x1(t)],;x′2(t)=x2(t)[a2(t)-b2(t)x2(t)-c2(t)∫-r^0k(s)x2(+s)ds]+D2(t)[x1(t)-x2(t)],;y′(t)=y(t)[a3(t)-b3(t)y(t)-c3(t)x1(t)[1+m(t)x1(t)]]isestablished,whereai(t),bi(t),ci(t)(i=1,2,3),m(t)andDi(t)(i=1,2)areallpositiveperiodiccontinuousfunctionswithperiodw>0,risanonnegativeconstantandk(s)isacontinuousnonnegativefunctionon[-r,0]。

  • 标签: 开拓定理 叠和理论 存在性 正周期解 两斑块扩散时滞竞争系统 功能反应
  • 简介:Inthispaper,theoceanacousticchannelisconsideredasatime-variantchannel.Inordertoanalysetheconjointtime-shift-fre-quency-delaydistributionorthefadingandspreadstatisticalcharacteristicsofthechannel.TheTDWVS(TwoDimensionalWigner-VilleSpectrum)ofthetime-variantchannelisdefined.TherelationbetweentheWVS(Wigner-VilleSpectrum)oftheinputandtheoutputofthechannelisdiscussedandsomeexamplesforthespecificchannelareshown.Finally,theapplicationsonthedetectionofsignalsinnoiseusingtheWVSandTDWVSaregivenandtheadvantageisobvious,whenthedetectedsignalislinearfrequency-modulationsignal.

  • 标签: ocean WIGNER FADING SPECTRUM MULTIPATH TRIGGERING
  • 简介:在这篇论文,我们在二一致machinesM_i上认为半是联机版本,i=1,2,在最大的工作的处理时间预先被知道的地方。速度s_i(s_1=1,1≤s_2=s)与机器M_i被联系。我们的目标是最大化C_(min)。我们给C_(min2)算法并且证明它的竞争比率是至多(2s+1)/(s+1)。我们也宣称C_(min2)算法是紧张的并且在C_的竞争比率之间的差距(min2)算法和最佳的价值不比0.555大。我们的结果与一致,那给由,是明显的他为s=1。

  • 标签: 竞争比 调度 半在线 完工时间 联合机床
  • 简介:Isochronousmassspectrometry(IMS)instorageringsisapowerfultoolformassmeasurementsofexoticnuclewithveryshorthalf-livesdowntoseveraltensofmicroseconds,usingamulticomponentsecondarybeamseparatedin-ightwithoutcooling.However,theinevitablemomentumspreadofsecondaryionslimitstheprecisionofnuclearmassesdeterminedbyusingIMS.

  • 标签: Isochronous MASS SPECTROMETRY
  • 简介:two-time-level,三维的数字海洋发行量模型(命名MASNUM)与一个二水平的、单个步的Eulerian提交向后时差计划被建立。大规模海洋的运动的一个数学模型基于协调的地面追随者,Boussinesq,海洋动力学的平均Reynolds的原始方程。一个简单却很实际的Eulerian提交向后方法被采用为barotropic和baroclinic模式作为时差方法代替大多数比较喜欢的跳蛙游戏计划。提交向后方法具有精确性的秒顺序,由每时间步要求一仅仅功能评估计算地有效,并且没有在三水平的计划固有的计算模式。这个方法比跳蛙游戏计划优异因为稳定性的最大的时间步骤这样象在蹒跚的网孔的跳蛙游戏计划的一样两次大计算效率能被加倍。一个空间变光滑方法被介绍在数字集成控制非线性的不稳定性。模仿赤道的Rossbysoliton的繁殖的一个理想的数字实验被执行测试振幅和这个新模型的阶段错误。这个发行量模型的表演进一步被验证与一地区性(西北太平洋)并且一伪全球(有排除的北极海洋的全球海洋模拟)模拟实验。这二个数字实验与观察显示出相当好的同意。在这二个实验的稳定性的最大的时间步也在采用跳蛙游戏计划的这个模型和那个模型之间被调查并且比较。

  • 标签: 环流模型 时间差分 数字海洋 验证 分割 非线性不稳定
  • 简介:三个功能的模特儿,多项式,光谱分析,和修改AR当模特儿,基于从双向卫星时间和频率转移导出的数据顺序在恰当、预言的钟偏差被学习并且比较。柔韧的当量被使用,它控制无关的观察的重要影响。一些结论证明柔韧的评价的预言精确比LS的好。从弄平的观察计算的预言精确比从采样观察计算了高。作为在钟偏差顺序的明显的时期变化的一个计数,多项式模型的预言的价值是难以置信的。光谱分析模型的预言精确是很低的,但是主要时期能是坚定的。6小时的推测间隔的预言RMS是1ns左右,当修改AR模型被使用时。

  • 标签: 时间预报 时间传送 卫星 动态大地测量
  • 简介:Inthispaper,wefocusonthereal-timeinteractionsamongmultipleutilitycompaniesandmultipleusersandformulatereal-timepricing(RTP)asatwo-stageoptimizationproblem.Atthefirststage,basedoncostfunction,weproposeacontinuoussupplyfunctionbiddingmechanismtomodeltheutilitycompanies’profitmaximizationproblem,bywhichtheanalyticexpressionofelectricitypriceisfurtherderived.Atthesecondstage,consideringthatindividuallyoptimalsolutionmaynotbesociallyoptimal,weemployconvexoptimizationwithlinearconstraintstomodelthepriceanticipatingusers’dailypayoffmaximum.Substitutetheanalyticexpressionofelectricitypriceobtainedatthefirststageintotheoptimizationproblematthesecondstage.Usingcustomizedproximalpointalgorithm(C-PPA),theoptimizationproblematthesecondstageissolvedandelectricitypriceisobtainedaccordingly.WealsoprovetheexistenceanduniquenessoftheNashequilibriuminthementionedtwostageoptimizationandtheconvergenceofC-PPA.Inaddition,inordertomakethealgorithmmorepractical,astatisticalapproachisusedtoobtainthefunctionofpriceonlythroughonlineinformationexchange,insteadofsolvingitdirectly.TheproposedapproachoffersRTP,powerproductionandloadschedulingformultipleutilitycompaniesandmultipleusersinsmartgrid.Statisticalapproachhelpstoprotectthecompany’sprivacyandavoidtheinterferenceofrandomfactors,andC-PPAhasanadvantageoverLagrangianalgorithmbecausetheformerneednotobtaintheobjectionfunctionofthedualoptimizationproblembysolvinganoptimizationproblemwithparameters.Simulationresultsshowthattheproposedframeworkcansignificantlyreducepeaktimeloadingandefficientlybalancesystemenergydistribution.

  • 标签: smart grid real-time PRICING customized PROXIMAL
  • 简介:GeneratinggroundmotionbytwonewtechniquesofaddingharmonicwaveinthetimedomainandapproximatingtoresponsespectrumasawholeCHANG...

  • 标签: RESPONSE SPECTRUM PEAK GROUND acceleration PEAK
  • 简介:Inthisarticleweconsiderthefullydiscretetwo-levelfiniteelementGalerkinmethodforthetwo-dimensionalnonstationaryincompressibleNavier-Stokesequations.ThismethodconsistsindealingwiththefullydiscretenonlinearNavier-StokesproblemonacoarsemeshwithwidthHandthefullydiscretelineargeneralizedStokesproblemonafinemeshwithwidthh<

  • 标签: 有限元GALERKIN法 NAVIER-STOKES方程 偏微分方程 时间离散化
  • 简介:Timesynchronizationtechniques,especiallyonthepulsepersecond(PPS)temporalbasis,haveattractedgrowingresearchinterestsinrecentyears.Inthispaper,wehaveproposedandexperimentallydemonstratedahigh-precisiontwo-waytimetransfer(TWTT)systemtorealizelong-distancedisseminationof1PPSsignalgeneratedbyahydrogenmaser.Adense-wavelength-division-multiplexing(DWDM)systemandbi-directionalerbium-dopedfiberamplifiers(Bi-EDFAs)havealsobeenadoptedtosuppresstheimpactofRayleighbackscatteringandoptimizethesignaltonoiseratio(SNR)aswell.Wehavetheoreticallyanalyzedthesystematicdelayindetail.Theultimaterootmeansquare(RMS)variationoftimesynchronizationaccuracyissub-26psandthetimedeviationcanbereducedtoaslowas1.2psat100sand0.253psat12000s,respectively.

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  • 简介:Thefinite-dmerencetime-domam(FDTD)methodisproposedforanalyzingthesurfaceacousticwave(SAW)propagationintwo-dimensional(2D)piezoelectricphononiccrystals(PCs)atradiofrequency(RF),andalsoexperimentsareestabhshedtodemonstrateitsanalysisresultofthePCs’bandgaps.TheFDTDmethodtakesthepiezoelectriceffectofPCsintoaccount,inwhichperiodicboundaryconditionsareusedtodecreasememory/timeconsumptionandtheperfectlymatchedlayerboundaryconditionsareadoptedastheSAWabsorberstoattenuateartificialreflections.TwoSAWdelaylinesareestabhshedwith/withoutpiezoelectricPCslocatedbetweeninterdigitaltransducers.Byremovingseveralechoeswithwindowgatingfunctionintimedomain,delaylinestransmissionfunctionisachieved.ThePCs’transmissionfunctionsandbandgapsareobtainedbycomparingtheminthesetwodelaylines.WhenAluminum/128°YX-LiNbO3isadoptedasscatterandsubstratematerial,thePCs’bandgapiscalculatedbythisFDTDmethodandCOMSOLrespectively.ResultsshowthatcomputationalresultsofFDTDagreewellwithexperimentalresultsandarebetterthanthatofCOMSOL.

  • 标签: 时域有限差分法 压电效应 声表面波 声子晶体 时域分析 二维
  • 简介:Atwo-dimensional(2D)opticaltrue-timedelay(TTD)beam-formingsystemusingacompactfibergratingprism(FGP)foraplanarphasedarrayantenna(PAA)isproposed.Theopticalbeam-formingsystemmainlyconsistsofaTTDunitbasedonthesamecompactFGP,onetunablelaserforelevationbeamsteering,andacontrolledwavelengthconverterforazimuthbeamsteering.AplanarPAAusingsuch2DopticalTTDunithasadvantagessuchascompactness,lowbandwidthrequirementfortunablelasersources,andpotentialforlarge-scalesystemimplementations.Theproof-of-conceptexperimentresultsdemonstratethefeasibilityoftheproposedscheme.

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  • 简介:动物们两个两个在一起。好哇!好哇!动物们两个两个在一起。六象和袋鼠,他们两个为了避雨都逃进了方舟。

  • 标签: 英语 课外教材 光碟教学 初等教育
  • 简介:BackgroundTwo-dimensionalspeckletrackingimaging(2D-STI)andreal-timethree-dimensionalechocardiography(RT-3DE)havemoreadvantagesinevaluatingleftventricular(LV)systolicdyssynchronythantraditionalechocardiographictechniques.ThestudyaimedtoevaluateLVdyssynchronyparametersbyboth2D-STIandRT-3DE,andthecorrelationbetweenthesetwotechniques.MethodsAtotalof43chronicheartfailure(CHF)patientsand27healthyvolunteerswereenrolled.Therewere23dyssynchronyparametersselectedtoevaluateleftventricularsystolicsynchronization,involving15from2D-STIand8fromRT-3DE.ResultsFewofthedyssynchronyparametersshowednegativecorrelationswithLVejectionfraction(LVEF)intheCHFgroup.Thedifferencebetweentimetopeak-systolicradialstrainoftheanteroseptalandposteriorsegmentsatthelevelofpapillarymuscles[AS-P(RS)]from2D-STIshowedpositivecorrelationswithpartsoftheparametersfromRT-3DE(P<0.05).ConclusionsLVsystolicdysfunctiondoesnotcorrelatewithdyssynchrony.Moreover,thereisaweakassociationbetween2D-STIandRT-3DEinassessmentofleftventriculardyssynchrony.

  • 标签: 超声心动图 成像技术 收缩功能 同步性 左心室 评价