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125 个结果
  • 简介:1.联系生活实例,认识杠杆是一根在力的作用下,可绕固定点转动的硬棒,能从常见的工具中辨识出杠杆.

  • 标签: 杠杆 生活实例 定点转动
  • 简介:Wegiveaconstructionofthemaximum,andtheminimumofthesetofnondecreasmgapproxmantsinthediscretecase,whereisapositiveconoexfunction.Acharacterizationofthatsetisalsoobtained.

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  • 简介:On △I=4 Bifurcation PhenomenaOn△I=4BifurcationPhenomena¥ZhangJingye;YangSunandMikeGuidryTheexperiments-bythenew7--raydetector...

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  • 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:Inthispaperwestudytheaverageσ-Kwidthandtheaverageσ-linearwidthoftheunitballofl1x(R)inl2α(R).Theexactvaluesofthesewidthsarecalculatedandanoptimalsubspacewiththeoptimallinearopera-tor(fortheσ-linearwidth)areidentified.

  • 标签: exact inequality opera subspace AVERAGE R)IN
  • 简介:Thispaperstudiestheinteractionofshockandgradientwave(soundwave)ofsolutionstothesystemofinviscidisentropicgasdynamicsasamodelforthecorrespondingproblemsfornonlinearhyperbolicsystems.Theproblemcanbereducedtoaboundaryvalueprobleminawedgeddormain,ByusingthemethodofconstructingasymptoticsolutionsandNewton'siterationprocessitisprovedthatifaweakshockhitsagradientwave,thenthegrandientwavewillsplitintotwogradientwaves,whiletheshockcontinusespropagating.Inthispapertheauthorreducestheproblemtoastandardformandconstructsasymptoticsolutionoftheproblem.Theexistenceofthegenuinesolutionwillhegiveninthefollowingpaper.

  • 标签: 震动交感 声波 气体动力学 数学模型
  • 简介:Theauthorintroducesanotionofweak1sequencesandcharacterizessuchsequencesbymeansofhomologicalmethods.ThisnotionextendsthenotionofweekM-sequencesandthusextendsthenotionsofgeneralizedCohen-MacaulaymodulesandBuchsbaummodulestomoregeneralcases.

  • 标签: Noetherian局部环 上同调群 Koszul同调群 M序列
  • 简介:ThemultivariatesplineswhichwerefirstpresentedbydeBooorasacompletetheoreticalsystemhaveintriguedmanymathematicianswhohavedevotedmanyworksinthisfieldwhichisstillintheprocessofdevelopment.Theauthorofthispaperisinterestedintheareaofinter-polationwithspecialemphasisontheinterpolationmethodsandtheirapproximationorders.ButsuchB-splines(bothunivariateandmultivariate)donotinterpolateddirectly,soIap-proachedthisprobleminanotherwaywhichistoextendmyinterpolatingsplineofdegree2n-1inunivariatecase(See[7])tomultivariatecase.Iselectedtriangulatedregionwhichisinspiredbyothermathematicians’works(e.g.[2]and[3])andextendtheinterpolatingpolynomialsfromunivariatetom-variatecase(See[10])Inthispapersomeresultsinthecasem=2arediscussedandprovedinmoreconcretedetails.Basedonthesepolynomials,theinterpolatingsplines(itisdefinedbymeaspiecewisepolynomialsinwhichtheunknownpar-tialderivativesaredeterminedundercertaincontinuousconditions)arealsodiscussed.Theapproximationordersofinterpolatingpolynomialsandofcubicinterpolatingsplinesareinverstigated.Welunitedourdiscussionontherectangulardomainwhichispartitionedintoequalrighttriangles.Astothecaseinwhichtherectangulardomainispartitionedintounequalrighttrianglesaswellasthecaseofmorecomplicateddomains,wewilldiscussinthenextpa-per.

  • 标签: univariate MULTIVARIATE partitioned interpolation discussion DETAILS
  • 简介:TheauthorsconsiderthemultilinearoscillatorysingularintegraloperatordefinedbyTA1,A2,…,Akf(x)=∫R^ne^ip(x,v)k/∏/j=1Rmi(Ajix,y)(Ω(x-y))/(│x-y│^n+M)f(y)dy,whereP(x,y)isareal-valuedpolynomialonR^n×R^n,Ωishomogeneousofdegreezero,Rmj(Aj;x,y)denotesthemj-thorderTaylorseriesremainderofAjatxexpandedabouty,M=k/∑j=1mj,ItisshownthatifΩbelongstothespaceLlog^+L(S^n-1)andhasvanishingmomentuptoorderM,then‖TA1,A2,…,Akf‖q≤ck/∏/j=1(∏/│α│=mj‖D^αAj‖rj)‖f‖p,providedthat1

  • 标签: 多重线性摆动 积分算子 单一性 极大算子
  • 简介:1.运用实例分析,认识运动的物体能够做功,所具有的能量称为动能.2.通过探究实验,知道动能的大小与物体的质量和运动速度有关.能运用动能与质量、速度的关系解释简单的生活现象.

  • 标签: 动能 机械能 势能 运动速度 探究实验 生活现象
  • 简介:让G是为一套素数的一个可分离的组,让N是G的正常亚群,并且让是我特性(即,无法缩减的部分特性)N。我们为G的我特性的数字获得一个必要、足够的条件在上拿可能的最大的|G:N||G:N|

  • 标签: 正规子群 字符 最大数目 OVER 充分必要条件 素数
  • 简介:令人满意的概括我收缩或I-nonexpansive类型调节的军士muting自我地图的新班的普通的固定的点结果被建立。我们使用他们获得统一,延长,并且补充著名结果的几不变的近似结果。

  • 标签: 共同固定点 自映射 不变量逼近 收缩
  • 简介:主要引进了伪i-内射半模的定义,并根据对偶原则,参照k-投射半模及内射模的结论,得到了伪i-内射半模的一些很好的性质,从而实现了把环中内射模的某些性质在半环中内射半模方面的部分推广.

  • 标签: i-正则同态 伪i-内射半模 真正合序列 可吸收半模
  • 简介:Carbonnanotubeswithjunctionsmayplayanimportantroleinfuturenanoelectronicsandfuturenanodevices.Inparticular,junctionsconstructedwithmetalandsemiconductingnanotubeshavepotentialapplications.Basedontheorthogonaltight-bindingmoleculardynamicsmethod,wepresentourstudyofthestructurestabilityofI-typecarbonnanotubejunctions.

  • 标签: 碳纳米管 结构稳定性 纳米器件