简介:Inthiswork,wereviewthedevelopingprogressoftwo-dimensionalterahertztime-domainspectroscopy(THz-TDS)anditsdiverseapplications,includinganalyzingthepolarizationofTHzradiationfromalaser-inducedplasmasourceandstudyingthecorrespondingphysicalmechanism,andcharacterizingtheopticalpropertiesofcrystals,etc.
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]。
简介:在这篇论文,我们学习Cauchy问题和二维的可压缩的流动的Stokes近似方程的外面的问题的答案的大时间asymptotic行为。
简介:Inthispaper,theoceanacousticchannelisconsideredasatime-variantchannel.Inordertoanalysetheconjointtime-shift-fre-quency-delaydistributionorthefadingandspreadstatisticalcharacteristicsofthechannel.TheTDWVS(TwoDimensionalWigner-VilleSpectrum)ofthetime-variantchannelisdefined.TherelationbetweentheWVS(Wigner-VilleSpectrum)oftheinputandtheoutputofthechannelisdiscussedandsomeexamplesforthespecificchannelareshown.Finally,theapplicationsonthedetectionofsignalsinnoiseusingtheWVSandTDWVSaregivenandtheadvantageisobvious,whenthedetectedsignalislinearfrequency-modulationsignal.
简介:Isochronousmassspectrometry(IMS)instorageringsisapowerfultoolformassmeasurementsofexoticnuclewithveryshorthalf-livesdowntoseveraltensofmicroseconds,usingamulticomponentsecondarybeamseparatedin-ightwithoutcooling.However,theinevitablemomentumspreadofsecondaryionslimitstheprecisionofnuclearmassesdeterminedbyusingIMS.
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。
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.
简介:Inthisarticleweconsiderthefullydiscretetwo-levelfiniteelementGalerkinmethodforthetwo-dimensionalnonstationaryincompressibleNavier-Stokesequations.ThismethodconsistsindealingwiththefullydiscretenonlinearNavier-StokesproblemonacoarsemeshwithwidthHandthefullydiscretelineargeneralizedStokesproblemonafinemeshwithwidthh<
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.
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.
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.
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.