简介：Anumericalmethod,theso-calledmultiplemonopole(MMoP)method,basedonthegeneralizedmultipoletechnique(GMT)isproposedtocalculatethebandstructuresofin-planewavesintwo-dimensionalphononiccrystals,whicharecomposedofarbitrarilyshapedcylindersembeddedinasolidhostmedium.Tofindtheeigenvalues(eigenfrequencies)oftheproblem,besidesthesourcesusedtoexpandthewavefields,anextramonopolesourceisintroducedwhichactsastheexternalexcitation.Byvaryingtheexcitationfrequency,theeigenvaluescanbelocalizedastheextremepointsofanappropriatelychosenfunction.BysweepingthefrequencyrangeofinterestandtheboundaryoftheirreduciblefirstBrillouinzone(FBZ),thebandstructurescanbeobtained.Sometypicalnumericalexampleswithdifferentacousticimpedanceratiosandwithinclusionsofvariousshapesarepresentedtovalidatetheproposedmethod.

简介：WhenthePoissonmatrixofPoissonsystemisnon-constant,classicalsymplecticmethods,suchassymplecticRunge-Kuttamethod,generatingfunctionmethod,cannotpreservethePoissonstructure.Thenon-constantPoissonstructurewastransformedintothesymplecticstructurebythenonlineartransform.ArbitraryordersymplecticmethodwasappliedtothetransformedPoissonsystem.TheEulerequationofthefreerigidbodyproblemwastransformedintothesymplecticstructureandcomputedbythemid-pointscheme.Numericalresultsshowtheeffectivenessofthenonlineartransform.

简介：Inorganiclayeredmaterialsareaclassofadvancedfunctionalmaterialsthathaveattractedconsiderableattentionbyvirtueoftheirpracticalapplicationsinawidevarietyoffields.Systematicstudiesofstructure,design,synthesis,andfabrication

简介：平行的Liesegang模式猛抛当包含的答案一同沉淀时，乐队们被获得在一个1D胶化矩阵的离子interdiffuse。形成的节俭地可溶的盐，显示磁盘的美丽的层化猛抛对1D试管轴垂直。Liesegang结构从他们的分数维的性质的观点被分析。几何Liesegang模式与象时间，乐队间距和乐队宽度法律那样的著名实验法律在一致被构造。扩散的起始的集中上的乐队间距的依赖(外部)并且不动(内部)电解质(一0并且B0，分别地)被拿跟随Matalon-Packter法律。数学分数维的尺寸和盒子计数尺寸是计算的。分数维的尺寸被发现与增加A增加0并且减少的B0。我们也与雏晶的随机的分发分析马赛克模式，在他们的分数维的性质上比古典Liesegang胶化方法，和报告在不同条件下面成长。最后，乐队在多重谱线被组织的复杂Liesegang模式被学习，并且分数维的性质与复合增加，这被显示出。

简介：Intheunderwater-shockenvironment,cavitationoccursnearthestructuralsurface.Thedynamicresponseoffluid-structureinteractionsisinfluencedseriouslybythecavitationeffects.Itisalsothedifficultyinthefieldofunderwaterexplosion.Withthetraditionalboundaryelementmethodandthefiniteelementmethod(FEM),itisdifficulttosolvethenonlinearproblemwithcavitationeffectssubjectedtotheunderwaterexplosion.Tosolvethisproblem,undertheconsiderationofthecavitationeffectsandfluidcompressibility,withfluidvisciditybeingneglected,a3Dnumericalmodeloftransientnonlinearfluid-structureinteractionsubjectedtotheunderwaterexplosionisbuilt.Thefluidspectralelementmethod(SEM)andtheFEMareadoptedtosolvethismodel.AftercomparisonwiththeFEM,itisshownthattheSEMismoreprecisethantheFEM,andtheSEMresultsareingoodcoincidencewithbenchmarkresultsandexperimentresults.Basedonthis,combinedwithABAQUS,thetransientfluid-structureinteractionmechanismofthe3Dsubmergedsphericalshellandshipstiffenedplatessubjectedtotheunderwaterexplosionisdiscussed,andthecavitationregionanditsinfluenceonthestructuraldynamicresponsesarepresented.Thepaperaimsatprovidingreferencesforrelevantresearchontransientfluid-structureinteractionofshipstructuressubjectedtotheunderwaterexplosion.

简介：Inperiodiccellularstructures,novelpatterntransformationsaretriggeredbyareversibleelasticinstabilityundertheaxialcompression.Basedonthedeformation-triggerednewpattern,periodiccellularstructurescanachievespecialmechanicalproperties.Inthispaper,thedesignedarchitecturematerialswhichincludeelastomermatrixescontainingemptyholesorfilledholeswithhydrogelmaterialaremodeledandsimulatedtoinvestigatethemechanicalpropertyoftheperiodicmaterials.Byanalyzingtherelationshipbetweennominalstressandnominalstrainofperiodicmaterial,andthecorrespondingdeformedpatterns,theinfluenceofgeometryandshapesoftheholesonthemechanicalpropertyofarchitecturematerialisstudiedinmoredetails.Wehopethisstudycanprovidefutureperspectivesforthedeformation-triggeredperiodicstructures.

简介：Analfistulaisoneofthethreegreatestanorectaldiseaseswithahighprevalence.Thetraditionaltreatments(e.g.,surgery)forfistulahavelimitationsduetodamagetotheinternalanalsphincterofpatients.Withrecentadvancesinbiomaterials,treatmentsbasedonbiomaterialfilling(e.g.,scleraproteininjection,fistulaplug)haveemergedasnoveltherapiesforfistula.Theanalfistulaplug(e.g.,basedonsmallintestinalsubmucosa(SIS))hasattractedincreasingattentionbecauseofshorttermhealingrateandbiocompatibility.However,challengesremainforthismethodsuchasplugfallingasobservedinclinics.Toaddressthis,thispaperanalyzesthecaseofSISfallingunderphysiologicalconditionfrommechanicalpointofviewusingANSYSsimulation.Itthenproposesthreenewgeometricalstructuresforfistulaplugandcomparestheirmechanicalbehavior(e.g.,axialstress,reactionofconstraint)withthatofclinicallyusedstructure(coneshape).Basedonthesimulation,itoptimizesthegeometricparametersoffistulaplug.Theapproachdevelopedherecanhelptoimprovethedesignoffistulaplugforbetterclinicaltreatments.

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简介：Corrosionisoneoftheimportantstructuralintegrityconcernsofagingaircraft,anditisestimatedthatasignificantportionofairframemaintenancebudgetsisdirectedtowardscorrosion-relatedproblemsforbothmilitaryandcommercialaircraft.Inordertobetterunderstandhowenvironmentalfactorsinfluencethecorrosiondamageinitiationandpropagationonaircraftstructureandtopredictpre-corrosiontestpiecesoffatiguelifeandstructuralintegrityofaneffectiveapproach,thispaperuses...

简介：Thevelocityprofile,turbulenceintensityprofile,streakystructureandburstingfrequencyinturbulentboundarylayersoveraflatplatewithcompliantcoatingswereinvestigatedbyLaserDopplerAnemometryandcondi-tionalsamplingtechniques.Thisexperimentledtotheconclusionsthatinboundarylayerflowsonacompliantwall,ascomparedwiththatonarigidwall,theloglawregionwasextendedfurtherawayfromthewall,andthatthemaximumvalueofeachturbulenceintensityprofileinthenearwallregionwasreducedandtheburstingfrequencyobviouslydecreasedwiththecompliantcoatings.Onepointworthyofnoticewasthattheaboveresultswereverymuchlikethoseofpolymerdragreductionexperiments.

简介：Astheoffshoreindustriesmovefromshallowtodeepwatersinexcessof1000m,therehasbeenrapiddevelopmentofoceanengineeringpractices.Innovationsintheoreticalandappliedmechanicshavebeenessentialinthisshiftandinunderpinningtheexploitationofoffshoreoilandgasandrenewableenergyresourcesworldwide.Understandingandpredictingphysicalmechanismsofstructure-soilinteractionsarevitalforthestabilityandsafetyofoffshoreengineeringstructures.Accordingly,inthisspecialissueofTheoretical&AppliedMechanicsLetters(TAML),eight

简介：Hamiltonianstructureofarigidbodyinacircularorbitisestablishedinthispaper.Withthereductiontechnique,theHamiltonianstructureofarigidbodyinacircularorbitisderivedfromLie-Poissonstructureofsemidirectproduct,andHamiltonianisderivedfromJacobi’sintegral.TheabovemethodcanbegeneralizedtoestablishtheHamiltonianstructureofarigidbodywithaflexibleattachmentinacircularor-bit.Atlast,anexampleofstabilityanalysisisgiven.

简介：Thecurrentstructure-preservingtheory,includingthesymplecticmethodandthemultisymplecticmethod,paysmostattentionontheconservativepropertiesofthecontinuoussystemsbecausethattheconservativepropertiesoftheconservativesystemscanbeformulatedinthemathematicalform.But,thenonconservativecharacteristicsarethenatureofthesystemsexistinginengineering.Inthisletter,thestructure-preservingapproachfortheinfinitedimensionalnonconservativesystemsisproposedbasedonthegeneralizedmulti-symplecticmethodtobroadentheapplicationfieldsofthecurrentstructure-preservingidea.Inthenumericalexamples,twononconservativefactors,includingthestrongexcitationonthestringandtheimpactonthecantilever,areconsideredrespectively.Thevibrationsofthestringandthecantileverareinvestigatedbythestructure-preservingapproachandthegoodlong-timenumericalbehaviorsaswellasthehighnumericalprecisionofwhichareillustratedbythenumericalresultspresented.

简介：Asemi-analyticalmethodofsolvingtheproblemofdynamicstressconcentrationofarbitraryundergroundstructureundertheeffectofblastwaveswasintroduced.UsingtheFouriertransformtheory,theshockwaves(intheformsofSH-waves)canbeconvertedintofrequencybands.Afteremployingcomplexfunctionsandconformalmapping,theadmittancefunctionsofvariousundergroundstructureswereobtained.Then,theproblemofthetimedomaindynamicstressresponseofundergroundstructurecanbeeasilysolvedthroughtheFourierinversetransform.Atlast,theresultsandcurvesofthedynamicstressforthesquare,triangleandhorseshoecavitywerepresented.

简介：Thetimedomainparameteridentificationmethodofthefoundation-structureinteractionsystemispresented.Onthebasisofbuildingthecomputationmodeandthemotionequationofthefoundation-structureinteractionsystem,thesystemparameteridentificationmethodwasestablishedbyusingtheextendedKalmanfilter(EKF)techniqueandtakingtheunknownparametersinthesystemastheaugmentstatevariables.Andthetimeparameteridentificationprocessofthefoundation-structureinteractionsystemwasimplementedbyusingthedataofthelayerfoundation-storehouseinteractionsystemmodeltestonthelargevibrationplatform.Thecomputationresultshowsthattheestablishedparameteridentificationmethodcaninducegoodparameterestmation.

简介：基于颤动的精力harvester是实质上在一个有限频率范围工作的一个共鸣器。增加工作频率范围是一个挑战性的问题。这份报纸为提高经由内部回声收获的精力揭示新奇可能性。内部回声精力harvester被建议。刺激连续地作为Gaussian白噪音，一个秒顺序过滤器定义的有颜色的噪音，狭窄乐队的噪音，和指数地相关的噪音被假定。相应平均root-mean-square产量电压被计算。数字结果证明内部回声增加操作带宽和产量电压。

简介：在这份报纸，为混乱系统的一个一般的类的一个新基于被动的同步方法被建议。基于Lyapunov理论和线性矩阵不平等(LMI)途径，基于被动的控制器被介绍使同步错误系统不仅被动而且asymptotically稳定。建议控制器能被解决LMI代表的一个凸的优化问题获得。模拟为Genesio-Tesi混乱系统和Qi混乱系统学习被介绍表明建议计划的有效性。关键词基于被动的同步-线性矩阵不平等(LMI)-混乱系统-Lyapunov理论汉语图书馆分类O151.25-O3692000数学题目分类34C28-34H10-37B25由陈丽群交流了

简介：ByusingtheformuladerivedinPart(Ⅰ),theinstantresponseofanunrestrainedplanarframestructuresubjectedtotheimpactofamovingrigid-bodyareevaluatedandanalysed.Theimpactforce-timehistorybetweenthestructureandthemovingrigid-body,shearforceandbendingmomentdistributionalongthebeams,axialforcedistributionalongthebarswerecalculated.Thewavepropagationphenomenaofthelongitudinalwaveinthebars,theflexuralandshearwavesinthebeamswerealsoanalysed.Thenumericalresultsshowthatthetimedurationofimpactforceiscontrolledbytheflexuralwaveandthelongitudinalwave;thesheareffectinbeamsshouldnotbeneglectedintheimpactresponseanalysisofstructures.

简介：活跃的腱，由一个排水量致动器和一个并置的力量传感器组成，被Preumont和他的同事首先介绍稀释大灵活空间结构，和他们采用的控制算法的颤动是不可分的力量反馈。这篇论文论述一新比例积分(PI)强迫反馈算法完成更大的抑制为没有结构的要求的结构的比率当模特儿。控制系统的稳定性被显示出，并且类似于JPL-MPI的结构的模拟为空格结构的颤动控制表明建议算法的有效性。

简介：Thecoordinationpolymer,(Nd(H2O)5)2(2,6-AQDS)3·2H2Owhere2,6-AQDS=2,6-anthraquinonedisulfonate,hasbeensynthesisedviaahydrothermalroute.Structurally,itconsistsoflayersofmonomericNdpolyhedrawhicharelinkedby2,6-AQDSanionsformingapolymeric,three-dimensionalnetwork.EachNdatomisninecoordinate,bondingtofivewatermoleculesandtofouroxygenatomsfromfour2,6-AQDSanionswhichinturnpillarthelayersbybridgingtwoNdatomsinonelayer,andcoordinatingtoasingleNdintheother.