学科分类
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16 个结果
  • 简介:让N是组G的正常亚群。假定积极整数m>n是N与的二种最长非中央的G-conjugacy班尺寸(m,n)=1。这份报纸的目的是决定N的结构并且在m是方形的那个假设下面在N给N-conjugacy元素的班尺寸免费。

  • 标签: 正规子群 共轭类 互素 mgt 正整数 非中心
  • 简介:市场过去对大规模WDN系统的偏爱现在转向了100G,2013年上半年40G网络的部署已经开始降温,100G获得了越来越多的认可,成为最主要的技术趋势。2013年第二季度,100G的销售额就已经超过了40G,Ovum预计2012~2018年间,100G都会稳居领先地位。

  • 标签: WDN系统 40G网络 海底光缆 光网络
  • 简介:BystudyingthespectralpropertiesoftheunderlyingoperatorcorrespondingtotheM/G/1queueingmodelwithoptionalsecondserviceweobtainthatthetime-dependentsolutionofthemodelstronglyconvergestoitssteady-statesolution.Wealsoshowthatthetime-dependentqueueingsizeatthedeparturepointconvergestothecorrespondingsteadystatequeueingsizeatthedeparturepoint.

  • 标签: 泛函分析 服务模式 排队 时间依赖解 服务模型 光谱特性
  • 简介:Graphitedusthasanimportanteffectonthesafetyofhigh-temperaturegas-cooledreactors(HTR).Theflowfieldinthesteamgeneratorwasstudiedbythecomputationalfluiddynamics(CFD)method,withtheresultsindicatingthatthefrictionvelocityinthewindwardandtheleewardoftheheattransfertubesisrelativelylowandishigheratthesides.Furtheranalysisoftheresuspensionofgraphitedustindicatesthattheresuspensionfractionreachesnearlyzeroforparticleswithadiameterlessthan1μm,whereasitwillincreasesastheheliumvelocityinthesteamgeneratorincreasesforparticlesizelargerthan1μm.Moreover,theresuspensionfractionincreasesastheparticlesizeincreases.Theresultsalsoindicatethatresuspensionoftheparticleswithsizeslargerthan1μmexhibitedobviousdifferencesindifferentpartsofthesteamgenerator.

  • 标签: 蒸汽发生器 HTR-10 再悬浮 粉尘 石墨 高温气冷反应堆
  • 简介:G是有限群,为复数域。要想找到所有不可约CG-模,一种方法是把正则CG-模CG进行直和分解,这在G的阶数比较小时不难做到,但当G的阶数比较大时计算起来比较繁琐。对于任意自然数n,本文给出了循环群Cn和二面体群D2。的正则CG-模CG的不可约模的直和分解,和这些不可约模间的同构关系。我们的方法是先构造出不可约的CG-子模,满足直和条件,从而得到正则CG-模CG的不可约模的直和分解。再运用模论知识得到这些不可约模间的同构关系。

  • 标签: 不可约CG-模 正则CG-模 范德蒙矩阵 直和分解
  • 简介:Thecreationandpropagationoflongitudinalacousticphonons(LAPs)inhighqualityhematitethinfilms(α-Fe2O3)epitaxiallygrownondifferentsubstrates(BaTiO3,SrTiO3,andLaAlO3)areinvestigatedusingthefemtosecondpump–probetechnique.Transientreflectionmeasurements(?R/R)indicatethephoto-excitedelectrondynamics,andtheinitialdecaylessthan1psandtheslowdecayof~500psareattributedtotheelectron-LOphononcouplingandelectron–holenonradiativerecombination,respectively.LAPsinα-Fe2O3filmcanbecreatedbyultrafastexcitationoftheligandfieldstate,suchastheligandfieldtransitionsunder800-nmexcitationaswellastheligandtometalcharge-transferwith400-nmexcitation.Thestrainmodulationsofthesoundvelocityandtheout-of-planeelasticpropertiesaredemonstratedinα-Fe2O3filmondifferentsubstrates.

  • 标签: 声学声子 赤铁矿 薄膜 位场转换 α-Fe2O3 电子动力学
  • 简介:Inthispaper,westudytheexistenceanduniquenessofsolutionstostochasticdifferentialequationsdrivenbyG-Brownianmotion(GSDEs)withintegral-Lipschitzcoefficients.

  • 标签: 随机微分方程 布朗运动 积分 驱动
  • 简介:Thesymmetryenergywhichcharacterizestheisospindependenceoftheequationofstateofasymmetricnuclearmatter,playsacrucialroleinunderstandingavarietyofissuesinnuclearphysicsandastrophysics,suchasheavyioncollisions,exoticnuclei,stabilityofsuperheavynuclei,fusioncrosssections,thestructures,compositionandcoolingofneutronstars[1??5].Muchtheoreticalandexperimentalefforthasbeenmadetoconstrainthedensitydependenceofsymmetryenergy.Uptonow,wehavegotsomebasicknowledgeaboutthesymmetryenergyatlowdensities,whileathighdensitiesweevendonotknowitsvariationtendencyasafunctionofdensity.Theproblemremainsunsolvedduetothedifficultyofnucleon-nucleoninteractionsandmany-bodyproblems.

  • 标签: DENSITY-DEPENDENT SYMMETRY ENERGY
  • 简介:Thehighrepetitionrate10J/10nsYb:YAGlasersystemanditskeytechniquesarereported.Theamplifiersinthissystemhaveamulti-passV-shapestructureandtheheatintheamplifiersisremovedbymeansoflaminarwaterflow.Inthemainamplifier,thelaserisfour-pass,andanapproximately8.5J/1Hz/10nsoutputisachievedintheprimarytest.Thefar-fieldoftheoutputbeamisapproximately10timesthediffractionlimit.Becauseofthehigherlevelsofamplifiedspontaneousemission(ASE)inthemainamplifier,theoutputenergyislowerthanexpected.Attheendwediscusssomemeasuresthatcanimprovethepropertiesofthelasersystem.

  • 标签: YB:YAG V-shape AMPLIFIER WATER-COOLED 10 J
  • 简介:<正>一、中考要求1.了解:对称,平移和旋转的基本概念;2.理解:图形平移,对称,旋转的基本性质,理解对应点所连线段在图形平移,旋转及对称变换中的性质;3.掌握:按要求通过简单平移,旋转作出简单的平面图形,如轴对称的图形,探索简单图形之间的轴对称

  • 标签: 专题复习 轴对称图形 对应点 平面直角坐标系 平面图形 等腰梯形
  • 简介:Thecopolymerizationsofethylenewith10-undecen-1-olhavebeeninvestigatedusingvanadiumprecatalysts,bis(imino)pyrrolylvanadium(III)complexes1-3,2,5-C4H2N(CH=NR)2VCl2(THF)2[R=C6H5(1),2,6-iPr2C6H3(2),C6F5(3)],andtheiminopyrrolylandβ-diketiminateonesforcomparison.Thepolarmonomerwaspretreatedbydiethylaluminiumchloride(presentalsoasthecocatalyst)beforethecopolymerization.ThemonomerreactivityratioswereevaluatedusingtheFineman-Rossmethod.Theligandstructureconsiderablyinfluencedthecatalyticactivityandtolerancetowardsthepolarmonomer,thepolarmonomerincorporationandthemolecularweightsoftheresultantcopolymers.Thebis(imino)pyrrolylvanadiumcomplexesexhibitedpromisingcatalyticperformanceforthecopolymerization,andahighcatalyticactivityupto3.84kg/mmolv·hwithahighcomonomerincorporationof14.0mol%wasachievedbycomplex3undermildconditions.

  • 标签: 钒配合物 助催化剂 共聚合 吡咯基 亚氨基 乙烯
  • 简介:利用密度泛函理论(DFT)中的B3LYP方法,在6-311G(d)基组的水平上系统研究了CaSin(n=1-10)团簇的几何构型、稳定性与光谱(红外与拉曼)性质.研究结果表明,CaSin团簇构型是在CaSin-1构型上戴帽1个原子而形成的;当n≥4,CaSin团簇的最低能量结构均为立体构型;Ca原子的掺杂降低了体系的化学稳定性;CaSi3与CaSi5是幻数结构;在相同的观察频段内,CaSi3团簇的红外与拉曼活性在低频段均表现较好,而在高频段拉曼活性则表现较差,与之不同的是CaSi5团簇的红外与拉曼活性在整个频段内都表现的较好.

  • 标签: CaSin团簇 结构与稳定性 光谱性质
  • 简介:QuantumdynamicscalculationsforthetitlereactionH(2S)+S2(X3-Σg)→SH(X2Π)+S(3P)areperformedbyusingagloballyaccuratedoublemany-bodyexpansionpotentialenergysurface[J.Phys.Chem.A1155274(2011)].TheChebyshevrealwavepacketpropagationmethodisemployedtoobtainthedynamicalinformation,suchasreactionprobability,initialstate-specifiedintegralcrosssection,andthermalrateconstant.Itisfoundnotonlythatthereisareactionthresholdnear0.7eVinbothreactionprobabilitiesandintegralcrosssectioncurves,butalsothatboththeprobabilityandcrosssectionincreasefirstlyandthendecreaseasthecollisionenergyincreases.Theexistenceoftheresonancestructureinboththeprobabilityandcrosssectioncurvesisascribedtothedeeppotentialwell.Thecalculationoftherateconstantrevealsthatthereactionoccurringonthepotentialenergysurfaceoftheground-stateHS2isslowtotakeplace.

  • 标签: 反应概率 动力学计算 上海 量子 表面 截面曲线