简介:Nonlineardynamicalsystemsaresometimesundertheinfluenceofrandomfluctuations.Itisdesirabletoexaminepossiblebifurcationsforstochasticdynamicalsystemswhenaparametervaries.Acomputationalanalysisisconductedtoinvestigatebifurcationsofasimpledynamicalsystemundernon-Gaussianα-stableLévymotions,byexaminingthechangesinstationaryprobabilitydensityfunctionsforthesolutionorbitsofthisstochasticsystem.ThestationaryprobabilitydensityfunctionsareobtainedbysolvinganonlocalFokker-Planckequationnumerically.Thisallowsnumericallyinvestigatingphenomenologicalbifurcation,orP-bifurcation,forstochasticdifferentialequationswithnon-GaussianLévynoises.
简介:Linearsystemsarisingfromimplicittimediscretizationsandfinitedifferencespacediscretizationsofsecond-orderhyperbolicequationsonL-shapedregionareconsidered.Weanalysetheuseofdomaindeocmposilionpreconditioner.sforthesolutionoflinearsystemsviathepreconditionedconjugategradientmethod.Fortheconstant-coefficientsecond-orderhyperbolicequaionswithinitialandDirichletboundaryconditions,weprovethattheconditionnumberofthepreconditionedinterfacesystemisboundedby2+x22+0.46x2wherexisthequo-tientbetweenthelimeandspacesteps.Suchconditionnumberproducesaconvergenceralethatisindependentofgridsizeandaspectratios.Theresultscouldbeextendedtoparabolicequations.
简介:Basedontherangespaceproperty(RSP),theequivalentconditionsbetweennonnegativesolutionstothepartialsparseandthecorrespondingweightedl_1-normminimizationproblemarestudiedinthispaper.Differentfromotherconditionsbasedonthesparkproperty,themutualcoherence,thenullspaceproperty(NSP)andtherestrictedisometryproperty(RIP),theRSPbasedconditionsareeasiertobeverified.Moreover,theproposedconditionsguaranteenotonlythestrongequivalence,butalsotheequivalencebetweenthetwoproblems.First,accordingtothefoundationofthestrictcomplementaritytheoremoflinearprogramming,asufficientandnecessarycondition,satisfyingtheRSPofthesensingmatrixandthefullcolumnrankpropertyofthecorrespondingsub-matrix,ispresentedfortheuniquenonnegativesolutiontotheweightedl_1-normminimizationproblem.Then,basedonthiscondition,theequivalenceconditionsbetweenthetwoproblemsareproposed.Finally,thispapershowsthatthematrixwiththeRSPoforderkcanguaranteethestrongequivalenceofthetwoproblems.
简介:Thepurposeofthepresentpaperistoevaluatetheerroroftheapproximationofthefunc-tionfL1[0,1]byKantorovich-BernsteinpolynomialsinLp-metric(0
简介:让b=(b_1,···,b_m),b_i∈Λ_(β_i)(R~n),1≤i≤m,0<β_i<β,0<β<1,[b,T]f(x)=∫_(R~n)(K是aCalderon-Zygmund的b_1(x)-b_1(y))···(b_m(x)-b_m(y))K(x-y)f(y)dy,核。在这篇论文,我们显示出那[b,T]从L~p(R~n)toF_p~被围住(β,∞)(R~n),以及[b,从L~p(R~n)的I_α]到F_q~(β,∞)(R~n),在哪儿1/q=1/p-α/n。
简介:(L减水乳酸)(PLLA)Poly,/pristine蛭石nanocomposites被准备由融化掺双轴的extruder,和热、机械的性质的蛭石分散状态的详细信息和蛭石的效果系统地被学习。当装载内容不超过3wt%时,结果证明在矩阵的蛭石的分散相当好。太古的蛭石能显然在nonisothermal结晶化期间改进融化结晶化温度。两结晶化时间跨度和PLLA的spherulitic尺寸由提高PLLA的主要成核在等温的结晶化状况下面与蛭石的增加的数量减少。并且增加的蛭石能也改进张力的模量和PLLA的Izod影响力量。为PLLA上的蛭石的起核心作用的效果的内在的机制被建议是在蛭石和PLLA之间的取向附生的结晶化和特定的相互作用。
简介:OpticallypureL-butyllactatewassynthesizedbynormaltransesterificationusingnafion-Hcatalystinmoderateyield.Variousreactionconditionswereinvestigated,includingthereactiontemperature,reactiontime,ratioofthestartingmaterialandamountofthenafioncatalyst.
简介:AsimplespectrophotometricassayofH2O2andglucoseusingAgnanoparticleshasbeencarriedout.RelyingonthesynergisticeffectofH2O2reductionandultraviolet(UV)irradiation,Agnanoparticleswithenhancedabsorptionsignalsweresynthesized.H2O2servedasareducingagentintheAgnanoparticlesformationinwhichAg+wasreducedtoAg0byO2àgeneratedviathedecompositionofH2O2inalkalinemedia.Ontheotherhand,photoreductionofAg+toAg0underUVirradiationsalsocontributedtothenanoparticlesformation.ThesynthesizednanoparticleswerecharacterizedbyTEM,XPS,andXRD.TheproposedmethodcoulddetermineH2O2withconcentrationsrangingfrom5.010à7to6.010à5mol/L.Thedetectionlimitwasestimatedtobe2.010à7mol/L.SincetheconversionofglucosetogluconicacidcatalyzedbyglucoseoxidasewascompaniedwiththeformationofH2O2,thesensingprotocolhasbeensuccessfullyutilizedforthedeterminationofglucoseinhumanbloodsamples.Theresultswereingoodagreementwiththosedeterminedbyalocalhospital.Thiscolorimetricsensorthusholdsgreatpromisesinclinicalapplications.
简介:theAlternatingSegmentCrank-Nicolsonschemeforone-dimensionaldiffusionequationhasbeendevelopedin[1],andtheAlternatingBlockCrank-Nicolsonmethodfortwo-dimensionalproblemin[2].Themethodshavetheadvantagesofparallelcomputing,stabilityandgoodaccuracy.Inthispaperforthetwo-dimensionaldiffusionequation,thenetregionisdividedintobands,aspecialkindofblock.ThismethodiscalledthealternatingBandCrank-Nicolsonmethod.