简介：图G是一个简单，图G的补图记为^－G，如果G的谱完全由整数组成，就称G是整谱图，鸡尾酒会图CP（n）=K2n-nK2（K2n是完全图）和完全二部图Kα,α都是整谱图^[1]。^—μ1表示图类^－αKα,αUβCP（b）的一个主特征值，本文确图了当^-μ1=2b＋1时，图类中^－αKα,αUβCP（b）的所有的整谱图。

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简介：theAlternatingSegmentCrank-Nicolsonschemeforone-dimensionaldiffusionequationhasbeendevelopedin[1],andtheAlternatingBlockCrank-Nicolsonmethodfortwo-dimensionalproblemin[2].Themethodshavetheadvantagesofparallelcomputing,stabilityandgoodaccuracy.Inthispaperforthetwo-dimensionaldiffusionequation,thenetregionisdividedintobands,aspecialkindofblock.ThismethodiscalledthealternatingBandCrank-Nicolsonmethod.

简介：一个单圈图G的邻接矩阵是奇异的当且仅当G含完美匹配和4m(m∈N)阶圈,或G和从G中删去唯一圈中的顶点及其关联边后得到的导出子图均不含完美匹配.单圈图的邻接矩阵的最大行列式是4.

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简介：Inthisarticle,thegeneralcentrallimittheoremandBerry-Esseenboundsforfinite-populationU-statisticswithdegreemareestablishedundertheveryweakconditions,TheseresultssubstantiallyimprovethoseofZhaoandChen’s(1987).

简介：设图G是一个简单图，图G的补图记为^-G，如果G的谱都是整数，就称G是整谱图．鸡尾酒会图CP（n）=K2n-nK2（K2n是2n阶完全图）和完全图Kα都是整谱图．本文确定了图类^-αKα∪βCP（b）中的所有整谱图．

简介：Thecoordinationproblemofasupplychaincomprisingonesupplierandoneretailerundermarketdemanddisruptionisstudiedinthisarticle.Anovelexponentialdemandfunctionisadopted,andthepenaltycostisintroducedexplicitlytocapturethedeviationproductioncostcausedbythemarketdemanddisruption.Theoptimalstrategiesareobtainedfordifferentdisruptionscaleunderthecentralizedmode.Forthedecentralizedmode,itisprovedthatthesupplychaincanbefullycoordinatedbyadjustingthepricediscountpolicyappropriatelywhendisruptionoccurs.Furthermore,theauthorspointoutthatsimilarresultscanbeestablishedformoregeneraldemandfunctionsthatrepresentdifferentmarketcircumstancesifcertainassumptionsaresatisfied.

简介：数学学习离不开思维，数学探索需要通过思维来实现，在初中数学教学中逐步渗透数学思想方法，有助于培养学生的思维能力，形成良好的数学思维习惯，既符合新课程标准的要求，也是进行数学素质教育的一个切入点．

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简介：Thispaperisconcernedwiththestatisticalmodelingofthedependencestructureofmultivariatefinancialdatausingthecopula,andtheapplicationofcopulafunctionsinVaRvaluation.Aftertheintroductionofthepurecopulamethodandthemaximumandminimummixturecopulamethod,authorspresentanewalgorithmbasedonthemoregeneralizedmixturecopulafunctionsandthedependencemeasure,andapplythemethodtotheportfolioofShanghaistockcompositeindexandShenzhenstockcomponentindex.Comparingwiththeresultsfromvariousmethods,onecanfindthatthemixturecopulamethodisbetterthanthepureGaussiancopulamethodandthemaximumandminimummixturecopulamethodondifierentVaRlevel.

简介：Modelinglog-mortalityratesonO-UtypeprocessesandforecastinglifeexpectanciesareexploredusingU.S.data.IntheclassicLee-Cartermodelofmortality,thetimetrendandtheage-specificpatternofmortalityoveragegrouparelinear,thisisnotthefeatureofmortalitmodel.Toavoidthisdisadvantage,O-Utypeprocesseswillbeusedtomodelthelog-mortalityinthispaper.Infact,thismodelisanAR(1)process,butwithanonlineartimedriftterm.BasedonthemortalitydataofAmericafromHumanMortalitydatabase(HMD),mortalityprojectionconsistentlyindicatesapreferenceformortalitywithO-UtypeprocessesoverthosewiththeclassicalLee-Cartermodel.Bymeansofthismodel,thelowboundsofmortalityratesateveryagearegiven.Therefore,lengtheningofmaximumlifeexpectanciesspanisestimatedinthispaper.

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简介：让(u?弈吗？？

简介：关于一般的图的完美匹配计数的问题已证实是NP—hard问题。但Pfaffian图的完美匹配计数问题（以及其它相关问题）却能够在多项式时间内解决。由此可见图的Pfaffian性的重要性。在这篇文章中，我们研究了若干种影响图的Pfaffian性的运算．

简介：<正>新的《数学课程标准(实验稿)》中强调:"教材所选择的素材应尽量来源于自然、社会与科学中的现象和实际问题".因此,以其他学科知识为素材的中考数学题——学科渗透型试题,近几年来倍受命题者的关注.所谓学科渗透型试题包含两层含义:一是运用数学知识解决其他学科的问题;

简介：给出了一些新的紧图，并对不是超紧的紧图作了一些讨论．

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简介：Amathematicalmodelofapredator-preymodelwithIvlev'sfunctionalresponseconcerningintegratedpestmanagement(IPM)isproposedandanalyzed.Weshowthatthereexistsastablepest-eradicationperiodicsolutionwhentheimpulsiveperiodislessthansomecriticalvalues,Furthermore,theconditionsforthepermanenceofthesystemaregiverl.Byusingbifurcationtheory,weshowtheexistenceandstabilityofapositiveperiodicsolution.Theseresultsarequitedifferentfromthoseofthecorrespondingsystemwithoutimpulses.Numericalsimulationshowsthatthesystemweconsiderhasmorecomplexdynamicalbehaviors.Finally,itisprovedthatIPMstrageyismoreeffectivethantheclassicalone.