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简介：Basedontheextendedmappingdeformationmethodandsymboliccomputation,manyexacttravellingwavesolutionsarefoundforthe(3+1)-dimensionalJMequationandthe(3+1)-dimensionalKPequation.Theobtainedsolutionsincludesolitarysolution,periodicwavesolution,rationaltravellingwavesolution,andJacobianandWeierstrassfunctionsolution,etc.

简介：WeproposetwokindsofnewJaynesCummingsmodelsrelatingtotwo-photonprocessbyusingthesupersymmetricunitarytransformation.Thecorrespondingenergyeigenvaluesandeigenvectorsareobtained.

简介：题目：少量管冻结稳态温度场数学模型目的：少量任意布置冻结管冻结的稳态温度场无解析解。建立任意布置少量管冻结稳态温度场模型，获得解析解，解决人工冻结温度场理论问题。创新点：1．基于势函数叠加原理，确立人工地层冻结中少量管冻结稳态温度场的通用求解方法；2．建立任意布置的3根和4根非等温冻结管下冻结稳态温度场数学模型，获得其解析解通解及特解。方法：1．通过理论分析，将冻结管简化为热汇点源，确定人工地层冻结热势的拉普拉斯方程表述；2．应用势函数叠加原理建立少量管冻结稳态温度场的通用求解方法；3．建立少量管冻结稳态温度场的数学模型，通过理论推导获得温度场解析解；4．通过数值模拟，验证所提方法、数学模型和解析解的正确性和准确性。结论：1．将冻结管简化为点源（热汇），其冻结形成的热势场服从拉普拉斯方程，其解即为热势函数；2．多根冻结管冻结时，将单根冻结管的热势函数叠加，由冻结管的位置决定每根冻结管的热流，再根据边界条件定解。这一方法（即势函数叠加法）可以用于任意布置冻结管冻结稳态温度场解析解的求解：3．将冻结管简化为点源导致获得的解析解存在一定的误差，但误差仅发生在冻结管附近极小的范围内，并且误差微小，完全满足工程上的精度要求。

简介：Spatiallyexplicitmodelshavebecomewidelyusedintoday'smathematicalecologyandepidemiologytostudythepersistenceofpopulations.Forsimplicity,populationdynamicsisoftenanalysedbyusingordinarydifferentialequations(ODEs)orpartialdifferentialequations(PDEs)intheone-dimensional(1D)space.Animportantquestionistopredictspeciesextinctionorpersistenceratebymeanofcomputersimulationbasedonthespatialmodel.Recently,ithasbeenreportedthatstableturbulentandregularwavesarepersistentbasedonthespatialsusceptible-infected-resistant-susceptible(SIRS)modelbyusingthecellularautomata(CA)methodinthetwo-dimensional(2D)space[Proc.Natl.Acad.Sci.USA101,18246(2004)].Inthispaper,weaddressotherimportantissuesrelevanttophasetransitionsofepidemicpersistence.Weareinterestedinassessingthesignificanceoftheriskofextinctionin1Dspace.Ourresultsshowthatthe2Dspacecanconsiderablyincreasethepossibilityofpersistenceofspreadofepidemicswhenthedegreedistributionoftheindividualsisuniform,i.e.thepatternof2Dspatialpersistencecorrespondingtoextinctionina1Dsystemwiththesameparameters.Thetrade-offsofextinctionandpersistencebetweentheinfectionperiodandinfectionrateareobservedinthe1Dcase.Moreover,nearthetrade-off(phasetransition)line,anindependentestimationofthedynamicexponentcanbeperformed,anditisinexcellentagreementwiththeresultobtainedbyusingtheconjecturedrelationshipofdirectedpercolation.Wefindthattheintroductionofashort-rangediffusionandalong-rangediffusionamongtheneighbourhoodscanenhancethepersistenceandglobaldiseasespreadinthespace.

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简介：三线性二方程的骚乱为k建模吗？蔚，k？蠅和k？1并且非线性的k？1个模型被用于空气动力学、热的汽轮机流动预言。在片上的wake和热转移系数的压力侧面与试验性的数据相比。好同意与线性k被获得吗？1当模特儿。没有重要修正与非线性的模型一起被观察。在片的条款弄醒的运输方程的平衡也被介绍。线性、非线性的k？1个模型被评估预言描述汽轮机流动的三维的旋涡。模拟证明经过旋涡是损失的主要起源。关键词骚乱模型-数字模拟-turbomachineryCLC数字O357.5

简介：InordertodevelopthepracticalapproximationmodelssuitabletoflowfieldsatlowMachnumberwithlargetemperaturedifference,theinfluenceofdifferenceinapproximationmodelsonnumericalsolutionswasinvestigatedbysolvingthenaturalconvectioninthe3-Denclosureswithverticalsidewallsdifferentiallyheatedandtheheatedbottomwallusing3approximationmodels,thatisBoussinesqapproximation,lowMachNumberapproximationandapproximationmodelproposedbyMlaouah.Asresultsofthesimulation,theeffectsofthedifferencesinthethreeapproximationmodelsonthenumericalsolutionsbecomeclear.

简介：Acombinedphysicalmodelofbubbelgrowthispropsedalongwithacorrespondingbubblegrowthmodelforbinarymixturesonsmoothtubes.UsingthegeneralmodelofWangetal.^[1].andthebubblegrowthmodelforbinarymixtures,ananalyticalmodelfornucleatepoolboilingheattransferofbinarymixturesonsmoothtubesisdeveloped.Inaddition,nucleatepoolboilingheattransferofpureliquidsandbinarymixtruesonahorizontalsmoothtubewasstudiedexperimentally.Thepureliquidsandbinarymixturesincludedwatermethanol,ehanol,andtheirbinarymixtures.Theanalyticalmodelsforbothpureliquidsandbinarymixturesareingoodagreementwiththeexperimentaldata.