简介：Bycoincidencedegree,theexistenceofsolutiontotheperiodicboundaryvalueproblemoffunctionaldifferentialequationswithperturbation

简介：

简介：Inthispaper,weestablishanexistencecriterionoftriplepositivesolutionsofaclassofnonlinearfourth-orderthree-pointboundaryvalueproblembytheLeggettWilliamsfixedpointtheorem.Theinterestingpointisthatthenonlineartermisinvolvedwithalllow-levelderivatives.

简介：Accordingtotheclassicalelastictheory,thereisalwaysadiscontinuityofrotationangleontheinterfacebetweendifferentmaterials.Thisillogicresultcanbeovercomebythestraingradientplasticitytheory.Inthelightofthistheory,thereisagroupofboundarylayersolutionsnearthein-terface,whichhavemadeimportantadjustmentoftheclassicalresults.

简介：ThefeedbackstabilizationproblemofanonuniformTimoshenkobeamsystemwithrotorinertiaatthetipofthebeamisstudied.First,asaspecialkindoflinearboundaryforcefeedbackandmomentcontrolisappliedtothebeam'stip,thestrictmathematicaltreatment,asuitablestateHilbertspaceischosen,andthewell-posenessofthecorrespondingclosedloopsystemisprovedbyusingthesemigrouptheoryofboundedlinearoperators.Thentheenergycorrespondingtotheclosedloopsystemisshowntobeexponentiallystable.Finally,inthespecialcaseofuniformbeam,somesufficientandnecessaryconditionsforthecorrespondingclosedloopsystemtobeasymptoticallystablearederived.

简介：Inthisarticle,theauthorsdiscussedtheboundarybehaviorfortheCauchy-typeintegralswithvaluesinaCliffordalgebra,obtainedsomeSochocki–PlemeljformulaeandPrivalov–MuskhelishvilitheoremsfortheCauchy-typeintegraltakenoverasmoothsurfacebyrathersimplemethod.

简介：Inthispaper,thesimultaneouseffectsofboundarylayerandtopographyontheinstabilityofEadywaveareinvestigatedbyusinganewparameterizationoftheverticalvelocityatthetopofPBLandtheinfluencesofthestratificationofthePBL,roughnessandtheslopeofterrainareshown.Furthermore,theeffectsoftheboundarylayerfrictionandtopographyongeneralizedEadywavearealsoinvestigated.

简介：ThispaperdealswithaproblemproposedbyH.BrezisontheexistenceofpositivesolutionstotheequationΔu+u^(n+2)/(n-2)+f(x,u)=0undertheNeumannboundaryconditionDru=u^n/(n-2),wheref(x,u)isalowerorderperturbationofu^(n+2)/(n-2)atinfinity.

简介：Aunifiedapproachisgiventoseveralclassesofnonlinearboundaryvalueproblems,andsomepreviousexistencetheoremsareextended.

简介：我们在异构的表面上学习流电的水流。在电气化学，生产水流的氧化减小反应被一个非线性的椭圆形的边界价值问题通常建模。边界条件具有有周期性地改变参数的指数的类型。我们由首先一致构造近似这个问题，然后关于一致答案线性化。这近似比以前的近似或直接linearization更加精确。我们为两个建立集中估计二并且三维的大小写并且提供二维的数字实验。

简介：Thetraditionalone-dimensionalultrasonicbeamsteeringhastimedelayandisthusacomplicatedproblem.AnumericalmodelofultrasonicbeamsteeringusingNeumannboundaryconditioninmultiplysicsispresentedinthepresentpaper.Thismodelisbasedonthediscretewavenumbermethodthathasbeenprovedtheoreticallytosatisfythecontinuousconditions.Thepropagatingangleofnovelmodelisafunctionofthedistanceinsteadofthetimedomain.Thepropagatingwavefrontsatdesiredanglesaresimulatedwiththesinglelinesourcesforplanewave.Theresultindicatesthatanybeamanglecanbesteeredbydiscretelineelementsresourceswithoutanytimedelay.

简介：根据一系列重要历史的地图，即，华南海岛，Nansha岛，Zhongsha岛，Xisha岛，Yongxing岛和Shidao岛的地点地图，并且太平天国的岛(在1946由中华民国的内部的部的领土的管理部门转存)，并且中华民国的管理区域地图在1948出版了，包围华南海岛的击破的线在华南代表瓷器海边界它是连接与的两个，和延期，中国的陆地边界。在当稳固的线被用来代表陆地boundarya时，击破的线被用来代表水边界的那时间，通用方法在然后国际性地被认出的地图使用了。上述观察在为在华南海区域上的国际海上的定界线是有用的华南海提供瓷器海边界的历史、科学的证据。

简介：Astochasticmodelwasdevelopedtosimulatetheflowinheterogeneousmediasubjecttorandomboundaryconditions.ApproximatepartialdifferentialequationswerederivedbasedontheKarhunen-Loeve(KL)expansionandperturbationexpansion.Theeffectofrandomboundaryconditionsonthetwo-dimensionalflowwasexamined.Itisshownthattheproposedstochasticmodelisefficienttoincludetherandomboundaryconditions.Therandomboundariesleadtotheincreaseofheadvarianceandvelocityvariance.Theinfluenceoftherandomboundaryconditionsonheaduncertaintyisexertedoverthewholesimulatedregion,whiletherandomnessoftheboundaryconditionsleadstotheincreaseofthevelocityvarianceinthevicinityofboundaries.

简介：InthispaperanapproximateequationisderivedtodescribesmoothpartsofthestabilityboundaryforlinearHamiltoniansystems,dependingonarbitrarynumberofparameters.Withthisequation,wecanobtainparameterscorrespondingtothestabilityboundary,aswellastothestabilityandinstabilitydomains,pro-videdthatonepointonthestabilityboundaryisknown.Thendifferentialequationsdescribingtheevolutionofeigenvaluesandeigenvectorsalongacurveonthesta-bilityboundarysurfacearederived.Theseequationsalsoallowustoobtaincurvesbelongingtothestabilityboundary.Applicationstolineargyroscopicsystemsareconsideredandstudiedwithexamples.

简介：Glowdischargeisintroducedasanartificialdisturbancetoinvestigatetheevolutionoffirst-andsecond-modeinstabilitiesinahypersonicflatplateboundarylayer.ExperimentsareconductedinaMach6.5quietwindtunnelusingRayleighscatteringvisualizationandparticleimagevelocimetry(PIV).Detailedanalysisoftheexperimentalobservationsisprovided.Itisfoundthattheartificiallyintroduced17kHzdisturbance,whichbelongstothefirst-modefrequencyband,caneffectivelyenhancefirst-modewaves.Moreover,itcanenhancesecond-modewavesevenmoreintensely.Possiblemechanismstoexplainthisphenomenonarediscussed.

简介：Thispaperdescribesthenumericalsimulationofunsteadyflowsduetoincomingwakesand/orvaryingbackpressure,Thesolutionmethodisbasedupontheone-stepfinite-volumeTVDLax-Wendroffscheme.Dualtime-stepapproachandmultigridalgorithmareadoptedtoimprovethecomputationalefficiencyofthebaselinescheme.NumericalresultsforthetransonicunsteadyflowinachannelbumpandtheunsteadyflowinaflatplatecascadeandtheVKIcascadearepresented.

简介：Theglidingbehaviorofedgedislocationnearagrainboundary(GB)incopperunderpureshearstressesissimulatedbyusingmoleculardynamics(MD)method.Many-bodypotentialincorporatingtheembeddedatommethod(EAM)isused.ThecriticalshearstressesforasingledisocationtopassacrossGBsurfaceareobtainedatvaluesofσ_c=23MPa～68MPaand137MPa～274MPafor∑=165smallangletiltGBat300Kand20K,respectively.Thefirstresultagreeswiththeexper-imentalyieldstressσ_y(=42MPa)quitewell.ItsuggeststhattheremightbeoneofthereasonsofinitialplasticyieldingcausedbysingledislocationglidingacrossGB.Inaddition,theremightbepossibilitytoobtainyieldstrengthfrommicroscopicanal-ysis.Moreover,theexperimentalvalueofσ_yatlowtemperatureisgenerallyhigherthanthatatroomtemperature.So,theseresultsareinconformityqualitativelywithexperimentalfact.Ontheotherhand,the∑=25GBistoostronganobstacletothedislocation.Inthiscase,adislocationisabletopassacrossGBunderrelativelylowstressonlywhenitisdrivenbyotherdislocations.Thisistakentomeanthatdislocationpile-upmustbebuiltupinfrontofthiskindofGB,ifthisGBmaytakeeffectontheprocessofplasticdeformation.

简介：SequenceboundaryisstudiedindetailinreferencetothePermianGuadalupianLopingianboundary,basedonhighresolutioncorrelationofconodootzones.Aconceptualsynchronousstratigraphicboundary,correspondingtotheageofthesequenceboundarydatedintheconformableportionofthesequenceboundary,isdefinedasthesequencechronostratigraphicboundary(SCB).Thesequenceboundaryisprovedtobedualinnatureinregardstothesynchronyanddiachroneityofstratigraphicboundaries.Themeritsofthesequenceboundaryinstratigraphicsubdivision,correlationandclassificationareelucidatedincomparisonwiththelithostratigraphicboundary,thebiostratigraphicboundaryandthetraditionalapproachoftheglobalstratotypesectionandpoint(GSSP).ByintegratingthevirtuesofthesequenceboundaryandtheGSSP,itisproposedthattheGSSPshouldbeestablishedintheconformableportionoftherelatedsequenceboundary.Theboundaryestablishedinlightofthisapproachisdefinedas

简介：Thispapergivesanintroductionintothedissipationintegralmethod.Thegeneralintegralequationsforthethree-dimensionalcasearederved.Itisfoundthatforapracticalcalculationalgorithmtheintegralmonentumequationandtheintegralenergyequationaremsotuseful.UsingTwodifferentsetsofmeanvelocityprofilesthehyperbolicalcharacterofadissipationintegralmethodisshown.Testcasesfortwo-andthree-dimensionalboundarylayersareanalysedanddiscussed.Thepaperconcludeswithadiscussionoftheadvantagesandlimitsofdissipationintegralmethods.

简介：