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227 个结果
  • 简介:Inthisarticle,wemainlydiscusstheasymptoticbehaviorformulti-dimensionalcontinuous-timerandomwalkinrandomenvironmentwithholdingtimes.Byconstructingarenewalstructureandusingthepoint'environmentviewedfromtheparticle',underGeneralKalikow'sCondition,weshowthelawoflargenumbers(LLN)andcentrallimittheorem(CLT)fortheescapespeedofrandomwalk.

  • 标签: 时间随机环境 随机游动 渐近性质 保温 中心极限定理 渐近行为
  • 简介:ThepaperdealswiththestronglydampednonlinearwaveequationofKirchhofftype.Theexistenceofaglobalattractorisprovenbyusingthedecomposition,andmoreover,thestructureoftheglobalattractorisestablished.Ourresultsimprovethepreviousresults.

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

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  • 简介:DynamicbehaviorofsinglepileembeddedintransverselyisotropiclayeredmediaisinvestigatedusingthefiniteelementmethodcombinedwithdynamicstiffnessmatricesofthesoilderivedfromGreen’sfunctionforringloads.Theinfluenceofsoilanisotropyonthedynamicbehaviorofpilesisexaminedthroughaseriesofparametricstudies.

  • 标签: PILE-SOIL system soil ANISOTROPY transversely ISOTROPIC
  • 简介:TheauthorsstudytheasymptoticbehaviorofthesmoothsolutionstotheCauchyproblemsfortwomacroscopicmodels(hydrodynamicanddrift-diffusionmodels)forsemiconductorsandtherelatedrelaxationlimitproblem.First,itisprovedthatthesolutionstothesetwosystemsconvergetotheuniquestationarysolutiontimeasymptoticallywithoutthesmallnessassumptionondopingprofile.Then,verysharpestimatesonthesmoothsolutions,independentoftherelaxationtime,areobtainedandusedtoestablishthezerorelaxationlimit.

  • 标签: 渐近状态 全局光滑解 半导体 流体动力学模型 柯西问题
  • 简介:Theelasticbehaviorofsaturatedporousmaterialsunderundrainedfreezingisinvestigatedbyusingaporomechanicalapproach.Thermodynamicequilibriaareusedtodescribethecrystallizationprocessofthepartiallyfrozensolutioninbulkstateandconfinedstateinpores.Byphasetransitionatfreezing,fusionenergy,thermalcontractionofsolid,solutionandicecrystals,volumechangesofcrystallizationbuildupremarkableporepressurethatinducesexpansionorshrinkageofsolidmatrix.Owingtothelowerchemicalpotentialwhenporewatermixeswithsalts,fewericeformsinpores.Penetrationoficeintotheporousmaterialsincreasesthecapillarypressure,butlimitse?ectontheporeliquidpressureandthestrainofsolidmatrix.Onthecontrary,theporepressureinducedbysolutiondensityrisesassaltconcentrationincreasesandcausessignificantshrinkageofsolidmatrix.

  • 标签: 多孔材料 弹性行为 不排水 冻结 饱和 固体基质
  • 简介:许多尝试被做了为学习微粒媒介的行为为不同参数和某些组成的模型发现各种各样的关系。所有这些模型基于连续媒介的概念。用象分离元素方法那样的一个数字方法,一个人能弄明白什么正在发生通过一玷污粒子的不连续的媒介在介绍shear力量和变丑特征起主要作用。有易碎的粒子的媒介的行为与非易碎的粒子在这份报纸并且与集会的相比被学习。在这份报纸,夸张有弹性的模型被调查因为多角形的集会在二个不同测试系列塑造了粒子。另外,象卷紧张,磨擦的角度,膨胀性的角度和有弹性的模量那样的汇编的不同的宏参数的进化为非易碎、易碎的土壤粒子两个都在模拟测试期间被学习。在结束,参量的研究在集会行为上在粒子破裂的力量的效果上被执行。

  • 标签: 离散元素建模 微粒破碎 双曲弹性模型 颗粒学
  • 简介:Photoisomerization(trans-cis)ofazoaromaticcompoundshasbeeninvestigatedextensivelyusingabsorptionspectroscopysince1950s[1].Byirradiationwithlightofwavelengthλ1orλ2,thegeometricconfigurationoftheazobondinazobenzenebasedcompoundscanbereversiblyswitchedfromtranstocis.Thetwostateshavedistinctabsorptionspectra.Thisfeaturewouldallowreversiblestorageofdataonthebasisofcisandtransstateswiththeaidofλ1andλ2.However,thecisstateisthermodynamicallyunstablewithrespecttothetransstate,thereforeathermalrelaxationprocessoccursinthedark(atroomtemperature).Thisthermalback-reactionstronglylimitsthelifetimeofthecisstate,anditisinfluencedbythesubstituentR1andR2,catalysts,temperature,andenvironment(solventpolarity,typeofpolymermatrix)[2].

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  • 简介:Thethermalprotectionmaterialsandstructuresarewidelyusedinhypersonicvehiclesforthepurposeofthermalinsulation,andtheirmechanicalbehaviorisoneofthekeyissuesindesignandmanufactureofhypersonicvehicles.ItisourgreatpleasuretopresentthesevenpapersinthisspecialsubjectofTheoretical&AppliedMechanicsLetters(TAML)andintroducethe

  • 标签: 力学行为 热防护材料 专题 结构 高超声速飞行器 高超音速飞行器
  • 简介:InthisarticlewestudyholomorphicisometriesofthePoincar'ediskintoboundedsymmetricdomains.EarlierwesolvedtheproblemofanalyticcontinuationofgermsofholomorphicmapsbetweenboundeddomainswhichareisometriesuptonormalizingconstantswithrespecttotheBergmanmetric,showinginparticularthatthegraphV0ofanygermofholomorphicisometryofthePoincar'ediskΔintoanirreducibleboundedsymmetricdomainΩ€CNinitsHarish-Chandrarealizationmustextendtoanaffine-algebraicsubvarietyVC×CN=CN+1,andthattheirreduciblecomponentofV∩(Δ×Ω)containingV0isthegraphofaproperholomorphicisometricembeddingF:Δ→Ω.Inthisarticlewestudyholomorphicisometricembeddingswhichareasymptoticallygeodesicatageneralboundarypointb∈Δ.Startingwiththestructuralequationforholomor-phicisometriesarisingfromtheGaussequation,weobtainbycovariantdifferentiationanidentityrelatingcertainholomorphicbisectionalcurvaturestotheboundarybehaviorofthesecondfundamentalformσoftheholomorphicisometricembedding.Usingthenonpositivityofholomorphicbisectionalcurvaturesonaboundedsymmetricdomain,weprovethatσmustvanishatageneralboundarypointeithertotheorder1ortotheorder21,calledaholomorphicisometryofthefirstresp.secondkind.Wedealwithspecialcasesofnon-standardholomorphicisometricembeddingsofsuchmaps,showingthattheymustbeasymptoticallytotallygeodesicatageneralboundarypointandinfactofthefirstkindwheneverthetargetdomainisaCartesianproductofcomplexunitballs.WealsostudytheboundarybehaviorofanexampleofholomorphicisometricembeddingfromthePoincar'ediskintoaSiegelupperhalf-planebyanexplicitdeterminationoftheboundarybehaviorofholomorphicsectionalcurvaturesinthedirectionstangenttotheembeddedPoincar'edisk,showingthatthemapisindeedasymptoticallytotallygeodesicatageneralboundarypointandofthefirstkind.Fo

  • 标签: 截面曲率 计算方法 高斯方程 应用数学
  • 简介:Thesurfaceofpolypropylene(PP)membranewasmodifiedbylowtemperatureplasmawithammonia.Theeffectofexposuretimewasinvestigatedbymeansofcontactanglemeasurement.Theresultsshowthatlowtemperatureammoniaplcsmatreatmentcanenhanceitshydrophilicity.Chinesehamsterovary(CHO)cellsattachmentonthemodifiedmembranewasenhancedandthegrowthrateonthemembranewasfasterthanunmodifiedone.

  • 标签: 聚丙烯 等离子体 CHO细胞 实验
  • 简介:Thisstudyconcernsatwo-dimensionalmodelandthecorrespondingvirtualcrackclosuretechnique(VCCT)implementedtosolvethegeneralboundaryvalueproblemsthatmayexplainwhyinterfacediscontinuityhaseffectsonthefracturebehaviorinthesuperconductor-substratesystem.Theinterfacialdiscontinuitycanbeclassifiedaccordingtothematerialproperties'continuityandtheirderivatives'continuityattheinterface.Fornonhomogeneoussuperconductorandsubstratespecimenswithvariousmaterialproperties,aVCCTmethodisdevelopedtocalculatetheirfracturebehavior.Furthermore,theeffectsofappliedmagneticfieldamplitudeandnonhomogeneousparametersareextensivelyandparametricallystudiedintwoactivationprocesses(zero-fieldcoolingandfieldcooling).Theintegrativeandcomputationalstudypresentedhereprovideafundamentalmechanisticunderstandingofthefracturemechanisminthesuperconductor-substratesystemandshedslightontherationaldesignofinterfacialcontinuity.

  • 标签: Superconductor-substrate SYSTEM INTERFACIAL DISCONTINUITY Fracture behavior