简介:Recursiveformulationshavesignificantlyhelpedinachievingreal-timecomputationsandmodel-basedcontrollaws.Therecursivedynamicssimulator(ReDySim)isaMATLAB-basedrecursivesolverfordynamicanalysisofmultibodysystems.ReDySimdelvesuponthedecouplednaturalorthogonalcomplementapproachoriginallydevelopedforserial-chainmanipulators.Incomparisontothecommerciallyavailablesoftware,dynamicanalysesinReDySimcanbeperformedwithoutcreatingsolidmodel.TheinputparametersarespecifiedinMATLABenvironment.ReDySimhascapabilitytoincorporateanycontrolalgorithmwithutmostease.Inthiswork,thecapabilitiesofReDySimforsolvingopen-loopandclosed-loopsystemsareshownbyexamplesofroboticgripper,KUKAKR5industrialmanipulatorandfour-barmechanism.ReDySimcanbedownloadedforfreefromhttp://www.redysim.co.nrandcanbeusedalmostinstantly.
简介:Inthispapertheprocessofknowledgeaccumulationforaparticulartechnologyisstudied.Twocountries,saythetechnologyfollowerandthetechnologyfrontier,areconsidered.Thefrontier’sknowledgegrowthisdeterminedbyitsR&Deffortsonthetechnology.ThelevelofknowledgestockforthefollowercountryisaugmentedbyitsR&Dactivitiesforthetechnologyandabsorbingsomeoftheexternalknowledgethroughspilloverfromthefrontier.Theextenttowhichthefollowerisabletoexploittheexternalknowledgedependsontechnologicalgap,absorptivecapacity,absorptiontimeanddegreeofspillover.Newconceptssuchasnaturalandenhanceddegreeofspillover,backgroundandinnovativeknowledgeandabsorptionspeedareintroducedinthepresentworktodeeplyexploretheprocessofknowledgespillover.ThefactorsinfluencingtheknowledgedevelopmentinthelongtermaresimultaneouslystudiedinanintegratedstructureprovidedbytheSystemDynamicsapproach.Thisframeworkshowstheresponsestothechangesandprovidesthebasisforexaminingtheinteractionsamongthevariablesovertime.
简介:Nonlinearmetailogenicdynamicsisoneofthodifficultprob1emsthatcommonlyfacemoderncom-plcxscicnces.TheRussianfamousmetallogenjstA.D.Shcbeglov(1988)paidattentiontotheprob1emofnonlin-earmctal1ogenyandproposedthcconceptofnonlinearmcta11ogeny.HepointedoutthatthercjSane-cessityofamoredetailedandcomprchensive
简介:Theorganizationofthecanonicalgeneticcodeneedstobethoroughlyilluminated.Herewereorderthefournucleotides-adenine,thymine,guanineandcytosine-accordingtotheiremergenceinevolution,andapplytheorganizationalrulestodevisinganalgebraicrepresentationforthecanonicalgeneticcode.Underaframeworkofthedevisedcode,wequantifycodonandaminoacidusagesfromalargecollectionof917prokaryoticgenomesequences,andassociatetheusageswithitsintrinsicstructureandclassificationschemesaswellasaminoacidphysicochemicalproperties.Ourresultsshowthatthealgebraicrepresentationofthecodeisstructurallyequivalenttoacontent-centricorganizationofthecodeandthatcodonandaminoacidusagesunderdifferentclassificationschemeswerecorrelatedcloselywithGCcontent,implyingasetofrulesgoverningcompositiondynamicsacrossawidevarietyofprokaryoticgenomesequences.Theseresultsalsoindicatethatcodonsandaminoacidsarenotrandomlyallocatedinthecode,wherethesix-folddegeneratecodonsandtheiraminoacidshaveimportantbalancingrolesforerrorminimization.Therefore,thecontent-centriccodeisofgreatusefulnessindecipheringitshithertounknownregularitiesaswellasthedynamicsofnucleotide,codon,andaminoacidcompositions.
简介:Anewflowtheoryisestablishedthroughtheobjectivityrequirementonthefluiddynamics.Itwasknownthatinhomogeneousfluidmotiongaverisetoviscousforcewhiletheselectionofobserversondifferentspace-timepointswouldchangesuchaninhomogeneouscharacter.Therefore,whentheviscousforcewasconsideredasanobjectiveexistenceforeigntotheselectionofobservers,theforminvariancesofviscousforceandmomentumequationunderlocalrotationtransformationrequiredanewdynamicfield,namelythevortexfieldtobeintroduced.ThenthedynamicalequationsofallflowfieldswereobtainedthroughconstructingtheLagrangiandensityoffluidsystemandusingthevariationalapproachofenergy.
简介:TherelationshipbetweendissolutionrateandpHisdeterminedbycarryingoutdynamicexperimentsofhedenbergiteandgrossularitedissolution.Thedissolutionreactionequationsareestablished.Thedissolutionpro-cessesoftwomineralsaresimulatedbyusingthetheoryofmulti-phaseandmulti-componentchemicalequilibrium.Theresultsbringlighttothemechanismofdissolutionprocesses.Duetoincongruentdissolutionoftwomineralswhenthedissolutionprocessesreachametastablesupersaturationcriticalpointnewmetastablemineralscanbeformedinthesystem.TheexperimentsshowedthatdissolutionofgrossulariteandhedenbergiteconsumesH~+andthenmakespHvalueofsolutionhigh.Inturn,precipitationofmetastablemineralsmakespHvaluelow.Precipitationofmetastablemineralshasacatalyticeffectfordisso-lutionofreactingmineralsinspecialtime.PrecipitationanddissolutioncarriedoutalternatelyinthesystemanditcausesperiodicoscillationofpHvalueswithreactingtime.Thisisthe
简介:OnSodiumClusterCollisionDynamicsOnSodiumClusterCollisionDynamics¥ZhangFengshou;E.SuraudandR.GlowinskiAdistallce--dependenttig...
简介:Animportantfunctioningmechanismofbiologicalmacromoleculesisthetransitionbetweendifferentconformedstatesduetothermalfluctuation.Inthepresentpaper,abiologicalmacromoleculeismodeledastwostrandswithsidechainsfacingeachother,anditsstochasticdynamicsincludingthestatisticsofstationarymotionandthestatisticsofconformationaltransitionisstudiedbyusingthestochasticaveragingmethodforquasiHamiltoniansystems.ThetheoreticalresultsareconfirmedwiththeresultsfromMonteCarlosimulation.
简介:Westudyanonlinearlosslesspolarizer(NLP),afiber-baseddeviceabletocontrolthepolarizationofanopticalsignalwhilepreservingitsenergy.TheNLPexploitsthelosslesspolarizationattraction(LPA)generatedbytheKerrinteractionsbetweenthesignalandafullypolarizedcontinuouswave(CW)pump.Byemployingacopropagatingpump,weshowthattheeffectivenessofLPAdependsonthejointactionoftheKerrnonlinearityandthemutualdelaybetweensignalandpump.WefindtheoptimalpumpwavelengthplacementanddemonstratethattrueLPAoccursonlywithinalimitedrangeofdelayvalues.Thus,weexplainwhythecopropagatingNLPismoreflexibleandpowerefficientcomparedwiththetraditionalcounterpropagatingNLP.
简介:Faultisacomplexdynamicsystemcontrolledbythecouplingofrocktexture,reaction,fluidflow,stress,androckdeformationmechanism.Acoupledreaction-transport-mechanicaldynamicmodelforfaultsystemisestablishedanddescribedinthispaper.AnexampleispresentedfortheShuikoushandeposit,Hunan.Theresultsofdynamicsimulationindicatethattheevolutionandmagnitudeoffracturepermeabilityofdifferentrocksaredifferent,andthatfaultingcanenhancethespatialheterogeneityofrockpermeabilityandfacilitatefluidflowandmineralizationinlocalfaultzone.Thepressureforafaultusuallyshowsavariationmodeofaperiodicoscillationwithtime,whichreflectsthechaoticbehavioroftheevolutionofafault.
简介:
简介:Forthedynamicsofarigidbodywithafixedpointbasedonthequaternionandthecorrespondinggeneralizedmomenta,adisplacement-basedsymplecticintegrationschemefordifferential-algebraicequationsisproposedandappliedtotheLagrange’sequa-tionsbasedondependentgeneralizedmomenta.Numericalexperimentsshowthatthealgorithmpossessessuchcharactersashighprecisionandpreservingsysteminvariants.Moreimportantly,thegeneralizedmomentabasedLagrange’sequationsshowuniquead-vantagesoverthetraditionalLagrange’sequationsinsymplecticintegrations.
简介:所有液体动态方程在他们的当模特儿的规模下面是有效的,意味着免费路径例如粒子并且意味着Boltzmann方程的碰撞时间规模和NavierStokes(NS)方程的水动力学规模。当前的计算液体动力学(CFD)集中于部分微分方程(PDE)的数字答案,并且它的目的是得到这些管理方程的精确答案。在如此的一个CFD惯例下面,它是难的开发盖住流动物理从的一个统一计划对水动力学运动因为没有能用Boltzmann做光滑的转变到当模特儿的NS的如此的管理方程,连续地可伸缩。液体动力学的学习需要超出传统的数字部分微分方程。出现设计应用程序,例如为近空间的飞行和流动和热转移在的空气车辆设计微设备,确实要求煤气的动力学的概念的进一步的扩大到物理现实,而非传统的可区分的管理方程的更大的域。在当前的阶段,非平衡流动物理很好还没由于适当工具的缺乏被探索了或清楚地理解。不幸地在当前的数字PDE途径下面,它是难的由于有效PDE的缺席开发如此的一个有意义的工具。以便多尺度的构造和类似于构造管理方程的Boltzmann或NS的当模特儿的过程的multiphysics模拟方法,一个数字算法的发展应该基于物理建模的第一个原则。在这份报纸,而不是跟随传统的数字PDE路径,我们介绍为CFD算法开发的作为一个原则的直接建模。因为所有计算与有限房间分辨率在一个discretized空格被进行,要当模特儿的流动物理不得不在网孔尺寸和时间步骤规模被做。这里,CFD是差不多分离数字进化方程的直接构造,在网孔尺寸和时间步骤将玩的地方,在建模的动态角色处理。与在网孔之间的比率的变化,尺寸和本地粒子意味着免费路径,从到水动力学波浪繁殖的运动粒子运输和碰撞的计划愿望俘获流动物理。基于直接建模,流动运动的连续动力学�
简介:Reaction-diffusion(RD)equationwasoftenusedtoinvestigatethepatterndynamics,buttelegraphreaction-diffusion(TRD)systemwasseldomstudied.Inthispaper,theIzhikevichmodelwasmodifiedtoexplainsomebiologicalmechanismsbyRDandTRDinneuronalcluster.Thenanewconditionunderwhichthesystemlosesstabilitywasproposedandtheeffectofparameters,diffusion,memoryandsteadystatewereconsideredontheprocessofneuronalspiking.Themethodpresentedisanovelapproachtoinvestigatethepatterndynamicsofbiologicalsystems.Finally,simulationsarecarriedouttovalidateourtheoreticalresults.
简介:Northernpeatlandsstorealargeamountofcarbonandplayasignificantroleintheglobalcarboncycle.Owingtothepresenceofwaterloggedandanaerobicconditions,peatlandsaretypicallyasourceofmethane(CH4),averypotentgreenhousegas.ThispaperreviewsthekeymechanismsofpeatlandCH4production,consumptionandtransportandthemajorenvironmentalandbioticcontrolsonpeatlandCH4emissions.TheadvantagesanddisadvantagesofmicrometeorologicalandchambermethodsinmeasuringCH4fluxesfromnorthernpeatlandsarealsodiscussed.ThemagnitudeofCH4fluxvariesconsiderablyamongpeatlandtypes(bogsandfens)andmicrotopographiclocations(hummocksandhollows).Someanthropogenicactivitiesincludingforestry,peatharvestingandindustrialemissionofsulphurdioxidecancauseareductioninCH4releasefromnorthernpeatlands.FurtherresearchshouldbeconductedtoinvestigatetheinfluenceofplantgrowthformsonCH4fluxfromnorthernpeatlands,determinethewatertablethresholdatwhichplantproductioninpeatlandsenhancesCH4release,andquantifypeatlandCH4exchangeatplantcommunitylevelwithahighertemporalresolutionusingautomaticchambers.