学科分类
/ 25
500 个结果
  • 简介:寻找和刻画各类有代表性的特殊本原矩阵的指数集,国内外都已有许多结果.这里研究和刻画d个环点的n阶极小本原矩阵的指数集为{[n/d]+n-2,[n/d]+n-1,…,n-2d-1}.

  • 标签: 极小本原矩阵 本原指数 环点
  • 简介:让{X,Xn;n鈮?1}i.i.d的一个序列是随机变量,前=0,前2=蟽2<鈭?给Sn=X1+X2+吗?+Xn,Mn=最大k鈮鈭k鈭?n鈮?1。让n=O(1/木头木头n)。在这份报纸,我们证明那,为b>?1,

  • 标签: 切断法 随意变量 叠对数定律 序列
  • 简介:FournewtaxanediterpenoidswereisolatedfromthebarkofTaxusyunnanensis.Theirstructureswereelucidatedasthenewskeletonwith5/7/6/4memberedringsbyspectralanalysisand2DNMRshiftcorrelationexperiments.

  • 标签: skeleton membered TAXUS BENZOYL belongs fused
  • 简介:Inthispaper,weinvestigatethecouplingofnaturalboundaryelementandfiniteelementmethodsofexteriorinitialboundaryvalueproblemsforhyperbolicequations.Thegoverningequationisfirstdiscretizedintime,leadingtoatime-stepscheme,whereanexteriorellipticproblemhastobesolvedineachtimestep.Second,acircularartificialboundaryFRconsistingofacircleofradiusRisintroduced,theoriginalprobleminanunboundeddomainistransformedintothenonlocalboundaryvalueprobleminaboundedsubdomain.AndthenaturalintegralequationandthePoissonintegralformulaareobtainedintheinfinitedomainΩ2outsidecircleofradiusR.Thecoupledvariationalformulationisgiven.Onlythefunctionitself,notitsnormalderivativeatartificialboundaryΓR,appearsinthevariationalequation,sothattheunknownnumbersarereducedandtheboundaryelementstiffnessmatrixhasafewdifferentelements.Suchacoupledmethodissuperiortotheonebasedondirectboundaryelementmethod.Thispaperdiscussesfiniteelementdiscretizationforvariationalproblemanditscorrespondingnumericaltechnique,andtheconvergenceforthenumericalsolutions.Finally,thenumericalexampleispresentedtoillustratefeasibilityandefficiencyofthismethod.

  • 标签: 耦合 自然边界元 有限元 双曲型方程 外边界问题 变分方程
  • 简介:Inthiswork,anewmethodtodealwiththeunconnectedpixelsinmotioncompensatedtemporalfiltering(MCTF)ispresented,whichisdesignedtoimprovetheperformanceof3Dliftedwaveletcoding.Furthermore,multipledescriptionscalablecoding(MDSC)isinvestigated,andnovelMDSCschemesbasedon3Dwaveletcodingareproposed,usingtheliftingimplementationoftemporalfiltering.TheproposedMDSCschemescanavoidthemismatchprobleminmultipledescriptionvideocoding,andhavehighscalabilityandrobustnessofvideotransmission.Experimentalresultsshowedthattheproposedschemesarefeasibleandadequatelyeffective.

  • 标签: Multiple description SCALABLE coding (MDSC) MOTION
  • 简介:这篇论文为3D在一张无穷地长圆柱的嘴在亚声的流动的全球存在和稳定性上涉及这个问题稳定的潜在的流动方程。如此的一个问题被Courant-Friedrichs显示在[8,p。377]:通过管的流动应该是被考虑一稳定,isentropic,无旋与圆柱的对称流动并且应该由与适当边界条件解决3D潜力流动方程坚定。由介绍一些合适加权的H?lder空格并且建立priori估计,当在否定无穷的亚声的流动的国家被给时,作者在一张3D嘴证明亚声的潜在的流动的全球存在和稳定性。关键词亚声的流动-潜在的流动方程-Bessel功能-加权的H?lder空格-全球存在2000苏布杰克特先生分类35L70-35L65-35L67-国家Basic支持的76N15工程中国(号码2006CB805902)的研究节目,中国(号码10871096)的国家自然科学基础和为江苏大学的先进才能的研究基础。

  • 标签: 稳定性问题 亚音速流动 无限长 三维 喷嘴 圆柱
  • 简介:AnefficientroutetoprepareL-glucoseandL-galactoseisdescribed.TheL-sugarsareachievedbyusingthestrategyofswitchingthefunctionalgroupsatC1andC5ofD-glucoseandD-mannose.TheoxidationandreductionofthesilylenoletheratC1andthelead(IV)tetraacetatemediatedoxidativedecarboxylationatC5arethekeysteps.L-GlucoseandL-galactosearepreparedinaconvenientandinexpensiveway.

  • 标签: 半乳糖衍生物 D-葡萄糖 左旋 合成 D-甘露糖 甲硅烷基
  • 简介:研究算子本身的性质是研究算子不动点问题的一个重要方法.很多学者在二维的空间中,通过构造不同的压缩映射或者膨胀映射的条件,研究算子的不动点问题.在这篇文章中,我们将引入D-度量空间和D-Ⅲ膨胀映射的概念,在D-度量空间(三维的空间)中研究D-Ⅲ膨胀映射的不动点及公共不动点定理.

  • 标签: D-度量空间 D-Ⅲ型膨胀映射 弱匹配映射 不动点
  • 简介:Thefastions,producedinD-3Hefusionplasma,arethe14.7MeVprotonsand3.6MeVαparticles.Becausetheirslowingdowntimesarefinite,therefore,theydevelopacertainamountofadditionalbeta(fir)whichhastobesupportedbythemagneticfield.

  • 标签: 电流放大系数 快离子 聚变等离子体 质子 Α粒子
  • 简介:Anapproachforgeneratinginteractive3Dgraphicalvisualizationofthegeneticarchitecturesofcomplextraitsinmultipleenvironmentsisdescribed.3Dgraphicalvisualizationisutilizedformakingimprovementsontraditionalplotsinquan-titativetraitlocus(QTL)mappinganalysis.Interactive3DgraphicalvisualizationforabstractexpressionofQTL,epistasisandtheirenvironmentalinteractionsforexperimentalpopulationswasdevelopedinframeworkofuser-friendlysoftwareQTLNetwork(http://ibi.zju.edu.cn/software/qtlnetwork).Noveldefinitionofgraphicalmetasystemandcomputationofvirtualcoordinatesareusedtoachieveexplicitbutmeaningfulvisualization.Interactive3DgraphicalvisualizationforQTLanalysisprovidesgeneticistsandbreedersapowerfulandeasy-to-usetooltoanalyzeandpublishtheirresearchresults.

  • 标签: 遗传结构 数量性状基因座 三维图形可视化 复杂性状
  • 简介:Theadsorptionpropertytheoperatinglife,theoperatingexchangecapacityandregenerationofD412macroporousphosphonomethylaminachelatingresinforremovingCa2+,Mg2+andFe2+fromhighpHbrineofalkaliproductionbyionicmembranewereinvestigatedTheresinshowedgoodphysical-chemicalandkineticproperty,highexchangecapacity,excellentdurability.

  • 标签: 螯合树脂 盐水 隔膜
  • 简介:摘要现阶段,3D打印技术的快速发展和进步,引起了全球范围内的普遍关注。3D打印技术成熟性迅速提升,其打印速度及准确性也随之持续提升,同时所需打印成本有所减少。所以说,相当一部分人觉得3D打印技术必然会引发“第三次工业革命”。

  • 标签: 3D打印技术 研究现状 关键技术
  • 简介:Inthispaperwedeveloptwoconformingfiniteelementmethodsforafourthorderbi-waveequationarisingasasimplifiedGinzburg-Landau-typemodelford-wavesuperconductorsinabsenceofappliedmagneticfield.UnlikethebiharmonicoperatorA2,thebi-waveoperator□~2isnotanellipticoperator,sotheenergyspaceforthebi-waveequationismuchlargerthantheenergyspaceforthebiharmonicequation.Thisthenmakesitpossibletoconstructloworderconformingfiniteelementsforthebi-waveequation.However,theexistenceandconstructionofsuchfiniteelementsstronglydependsonthemesh.Inthepaper,wefirstcharacterizemeshconditionswhichallowandnotallowconstructionofloworderconformingfiniteelementsforapproximatingthebi-waveequation.Wethenconstructacubicandaquarticconformingfiniteelement.Itisprovedthatbothelementshavethedesiredapproximationproperties,andgiveoptimalordererrorestimatesintheenergynorm,suboptimal(andoptimalinsomecases)ordererrorestimatesintheH~1andL~2norm.Finally,numericalexperimentsarepresentedtoguagetheefficiencyoftheproposedfiniteelementmethodsandtovalidatethetheoreticalerrorbounds.

  • 标签: 有限元方法 方程模型 超导体 模误差估计 波动方程 能量空间
  • 简介:thehydroxya-patite粒子的机械性质上的水吸着的损坏效果增强了Bis-GMA/TEGDMA共聚物(HA/Bis-GMA/TEGDMA)用3D被预言了有限房间模型。聚合物矩阵上的可塑剂效果被看作它的幼仔的模量的一个变化。三个不同房间模型被用来决定在debondingdamage上改变粒子内容,分裂期间力量和潮湿集中的影响。压力分发模式被检验了,压力转移模式澄清了。幼仔Bis-GMA/TEGDMA的模量和破裂力量合成也有或没有损坏的考虑用模型被预言。有thedebonding损坏的考虑的以前的结果在对存在文学的好同意是试验性的数据。我们的建议模型和一条其他的途径的防护效果被讨论。FCC房间模型也被扩大了预言批评负担为损坏并且undamaged合成题目到3点曲折测试。

  • 标签: 水吸附 牙齿复合材料 界面松懈工艺 有限元法 单元细胞模型
  • 简介:TheexistenceandorbitalinstabilityofstandingwavesforthegeneralizedthreedimensionalnonlocalnonlinearSchr¨odingerequationsisstudied.Bydefiningsomesuitablefunctionalsandaconstrainedvariationalproblem,wefirstestablishtheexistenceofstandingwaves,whichrelysontheinnerstructureoftheequationsunderconsiderationtoovercomethedrawbackthatnonlocaltermsviolatethespace-scaleinvariance.Wethenshowtheorbitalinstabilityofstandingwaves.Theargumentsdependupontheconservationlawsofthemassandoftheenergy.

  • 标签: 薛定谔方程组 不稳定性 非线性SCHRODINGER方程 局部非线性 轨道 三维