简介:Wefindanasymptoticexpressionforthecharacteristictimescalesofdecorrelationprocessesinweaklycompressibleandisothermalturbulence.ThisresultisusedintheEddy-DampedQuasi-NormalMarkovianequationtoderivethescalingsofcompressibleenergyspectra:(1)iftheacousticwavesaredominant,thecompressibleenergyspectraexhibit?7/3scaling;(2)iflocaleddystrainingisdominant,thecompressibleenergyspectraarescaledas?3.Meanwhile,theenergyspectraofincompressiblecomponentsdisplaythesamescalingof?5/3asthoseinincompressibleturbulence.Thedirectnumericalsimulationsofweaklycompressibleturbulenceareusedtoexaminethescaling.
简介:Therearethreemainproblemsintheweaklynonlineartheoryofhydrodynamicstability:(1)Thera-diusofconvergencewithrespecttotheperturbationparameteristoosmallandthereisnoconcreteestimationforit.(2)Thesolutionhasaspecialstructure,thusingeneral,itcannotsatisfytheinitialconditionposedbymanypracticalproblems.(3)Whenthelinearpartofitssolutiondoesnotcorrespondtoaneutralcase.therearemorethanonewayindeterminingtheLandauconstants,andpracticallynooneknowswhichisthebestway.Inthispaper,problems(1)and(2)aresolvedtheoretically,andwaysforitsimprovementhavebeenproposed.Bycomparingthetheoreticalresultswiththoseobtainedbynumericalsimulations,problem(3)hasalsobeenclari-fied.
简介:TheECRwaveheatingisnowaroutinemethodforplasmaheatingandprofilecontrolinfusiondevicesandalsoinplasmaapplications.TheoreticalstudyofECRwavepropagationandabsorptionbeganveryearlyin1950's.Basictheoreticalworkhadaccomplishedin1970~1980.Fortoroidaldeviceslikethetokamak,thefundamentalO-modeandX-modewithnearlyperpendicularpropagationwereusedveryoften.ForpureO-modeandX-modewithkx=O,
简介:ThispapeerstudiestheknowndensitytheoremofArrow-Barankin-Blackwell.Thefollowingmainresultisobtained:IfXisaHausdorfflocallyconvexTopologicalspaceandCbelongtoXisaclosedconvexconewithboundedbase,thenforeverynonemptyweaklycompactconvexsubsetA,thesetofpositiveproperefficientpointsofAisdenseinthesetofefficientpointsofA.
简介:Inthispaperthedynamicsofaweaklynonlinearsystemsubjectedtocombinedparametricandexternalexcitationarediscussed.TheexistenceoftransversalhomoclinicorbitsresultinginchaoticdynamicsandbifurcationareestablishedbyusingtheaveragingmethodandMelnikovmethod.Numericalsimulationsarealsoprovidedtodemonstratethetheoreticalanalysis.
简介:Coherentdiffractionimaging(CDI)andptychographytechniquesbypassthedifficultyofhavinghigh-qualityopticsinX-raymicroscopybyusinganumericalreconstructionoftheimagethatisobtainedbyinvertingthediffractedintensityrecordedbyacharge-coupleddevicearray.However,thereconstructionoftheimagefromtheintensitydataobtainedfromaweaklydiffractingspecimenisknowntobedifficultbecauseoftheobviousreductioninsignal-to-noiseratio(SNR).Inthiscase,thespecimenonlyslightlymodifiestheprobediffractionpattern,resultingindifficultyintheidentificationofthedetailedstructureofthespecimenfromthereconstructedimagebecauseofthepoorcontrastandsharpnessoftheimage.Toaddressthissituation,amodificationintheimageretrievalalgorithmsusedintheiterativereconstructionoftheimageissuggested.Thismodificationshoulddoublethepresenceofhighspatialfrequenciesinthediffractionpatterntoenhancethecontrastandedgedetectioninexistingimagingtechniques.
简介:在这研究,在参量的刺激下面的twodimensional震荡系统的几乎肯定稳定性的足够的条件被调查。考虑的系统被假定由二个微弱地联合的分系统构成。开车行动被认为是静止随机的过程令人满意各态历经的性质。二次的形式的性质与界限一起被使用让特征值获得,在一种关上的形式,为系统的几乎肯定的稳定性的足够的条件。关键词几乎肯定的稳定性-各态历经的过程-为特征值汉语图书馆分类O3252000数学题目分类15A22固定-15A18-15A39由美国的国家科学基金支持的陈丽群工程交流了(没有。CMMI0758632)
简介:Inthispaper,usingthecontextofcompletepartialmetricspaces,somecommonfixedpointresultsofmapsthatsatisfythegeneralized(φ,ψ)-weakcontractiveconditionsareobtained.Ourresultsgeneralize,extend,unify,enrichandcomplementmanyexistingresultsintheliterature.Examplearegivenshowingthevalidatyofourresults.
简介:Inthispaper,thetheoryofmajorefficiencyformultiobjectiveprogrammingisestablished.Themajor-efficientsolutionsandweaklymajor-efficientsolutionsofmultiobjectiveprogramminggivenhereareParetoefficientsolutionsofthesamemultiobjectiveprogrammingproblem,buttheconverseisnottrue.Inaceratinsense,thesesolutionsareinfactbetterthananyotherParetoefficientsolutions.Somebasictheoremswhichcharacterizemajor-efficientsolutionsandweaklymajor-efficientselutionsofmultlobjectiveprogrammingarestatedandproved.Furthermore,theexistenceandsomegeometricpropertiesofthesesolutionsarestudied.
简介:在这篇论文,我们基于没有任何凸状结构,在拓扑的空格印射的微弱地概括的KKM建立一些新概括KKM类型定理。作为应用,一些得最高分的战略不平等和为一个抽象概括向量平衡问题的平衡点的一条存在定理在拓扑的空格被证明。在这篇论文介绍的结果在最近的文学统一并且概括一些已知的结果。关键词微弱地概括了印射的KKM-概括KKM类型定理-微弱地概括了斜伪凸-(W,S,K)印射对-概括向量平衡2000苏布杰克特先生分类91B50-91A44-91A13由国家天赋支持了中国(号码10771058)和湖南的科学基础省的自然科学基础(号码09JJ6013)。
简介:NonlinearSchrodingerequation(NSE)arisesinmanyphysicalproblems.Itisaveryimportantequation.Alotofworksstudiedthewellposed,theexistenceofsolutionofNSEetc.Andtherearemanyworksstudiedthenumericalmethodsforit.Recently,sincethedevelopmentofinfinitedimensionaldynamicsystemthedynamicalbehaviorofNSEhasbeeninvestigated.Thepaper[1]studiedthelongtimewellposedness,theexistenceofuniversalattractorandtheestimateofLyapunovexponentforNSEwithweaklydamped.Atthesametimeitwasneedtostudythelargetimenewcomputationalmethodsandtodiscussitsconvergenceerrorestimate,theexistenceofapproximateattractorsetc.InthispapewestudytheNSEwithweaklydamped(1.1).Weassume,where0<λ<2isaconstant.Ifwewishtoconstructthehigheraccuracycomputationalscheme,itwillbedifficultthatstaighfromtheequation(1.1).Thereforewestartwith(1.4)andusefullydiscreteFourierspectralmethodwithtimedifferencetodisscus
简介:在这份报纸,我们给微分形式的弱WT2班的定义,然后获得它的弱反向的H?lder不平等。作为应用,我们给更高的integrability结果的一个其他的证明弱A泛音张肌由于B。Stroffolini。