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158 个结果
  • 简介:在CCSD(T)/6-311G(d,p)∥B3LYP/6-311G(d,p)水平上给出了反应C2H3+NO2的详细势能面信息,并列出了中间体和过渡态的几何构型.通过深入分析反应路径及反应机理,得到5个能量可行的产物和6条反应通道,其中产物C2H3O+NO的形成更有利,而产物CH2CO+HNO则是次要产物,其他产物在通常条件下可以忽略.

  • 标签: C2H3 NO2 反应势能面 乙烯自由基 过渡态 二氧化氮
  • 简介:IntroductionTherecentdiscoveryofaclassofcarboncontainingmoleculesknownasthefulereneshasproducedaseriesofmaterialswithawideran...

  • 标签: FULLERENES ESR Carbon centered RADICAL
  • 简介:利用量子化学从头计算法RHF/4-31G基组对氢氰酸的硼氢化反应进行了理论研究.IRC分析表明:氢氰酸与甲硼烷通过“类四中心”过渡态,直接加成生成产物.排除了另两种反应机理的可能性:(1)甲硼烷直接进攻碳-氮π键,经三中心过渡态生成产物;(2)首先形成直线型分子复合物,然后靠分子内氢迁移重排生成产物

  • 标签: 硼氢化反应 反应机理 内禀反应坐标法 氢氰酸 甲硼烷
  • 简介:LetT=(T(t))t≥0beaboundedC-regularizedsemigroupgeneratedbyAonaBanachspaceXandR(C)bedenseinX.WeshowthatifthereisadensesubspaceYofXsuchthatforeveryx∈Y,σu(A,Cx),thesetofallpointsλ∈iRtowhich(λ-A)^-1Cxcannotbeextendedholomorphically,isatmostcountableandσr(A)NiR=Ф,thenTisstable.AstabilityresultforthecaseofR(C)beingnon-denseisalsogiven.Ourresultsgeneralizetheworkonthestabilityofstronglycontinuoussenfigroups.

  • 标签: G-正半群 稳定性 巴拿赫空间 生成子 强连续
  • 简介:Thispaperreportstwolanthanidecomplexesofformula(C9H7)Ln(C8H8)·(THF)2whereLnisProrNd,C9H7isindenyl,andC8H8iscyclooctatetraene(COT).ThecomplexeswerepreparedbythereactionofLnCl3withK(C9H7)andK2(C8H8)inTHF.(C9H7)Pr(C8H8)·(THF)2crystallizesinTHFat-15℃inthemonoclinicspacegroupP21:withunitcelldimensionsa=8.446(0),b=10.083(2),c=13.407(3),β=105.48(1)°,V=1100.43(35)3,Dc=1.52g/cm3andZ=2.ThefinalRvalueis0.033,Rwvalueis0.030,respectively.In(C9H7)Pr(C8H8)·(THF)2afive-memberedringcentroidofC9H7,theC8H8ringcentroidandthetwooxygenatomsfromthetwoTHFmoleculesformadistortedtetrahedralgeometryaroundthemetal.

  • 标签: complexes monoclinic membered C8H8)Ln C8H8)Pr C9H7
  • 简介:TwospectralsequencesaredronedrespectivelyforcohomologiesH^P(Ωf1k-,0)andH^P(Af,k-,0)ofsingularitiesofC^∞mappings.Theyarefinitelydimensiionalnewinvarancesunderrightequivalencesandcontacttransformationsrespectively.FormuLaetobecomputedbylinearalgebrsareproved.

  • 标签: 谱序列 上同调 奇异性 C^∞映射
  • 简介:LetGbeasecondcountablelocallycompactgroupoidwithHaarsystem{λuH},HbeaclosedsubgroupoidcontainingG^0withHaarsystem{λuH}.T.MasudaintroducedtheC^*-Groupoiddynamicsystem(G,A,α)anditsreducedcrossedproductCrea(G,A)in[2]:whereAisC^*-algebraαisthekomomorphismG→Aut(A).InthispapertheauthorintroducestheC^*-groupoiddynamicsystems(H,A,α/H)and(H\G2,A,^-α)inducedby(G,A,α)andprovesthatC*red(H,A)andC^*red(H\G^2,A)arestronglyMoritaequivalentMoreovertheinducedrepresentationfromC^*red(H,A)toC^*red(G,A)isgot.

  • 标签: C^*-群力学系统 听觉系统 群代数 交叉乘积
  • 简介:ThispapershowsthattheC1-curvedfiniteelementdevelopedbyBernadoningeneralcannotsatisfytheessentialboundaryconditionsonapproximateboundary.Furthermore,amodifiedC1-curvedfiniteelementisgiven,whichiscompatiblewiththeelementofArgyristriangleandcansatisfythehomogeneousDirichletboundaryconditionsonapproximateboundary.

  • 标签: Curved boundary DOMAIN Argyris TRIANGLES C1-curved
  • 简介:C19-DITERPENOIDALKALOIDSOFDELPHINIUMMOLLIPILUM¥SuoMingZHANG;QingYuOu(LanzhouInstituteofChemicalPhysics,ChineseAcademyofSci?..

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  • 简介:TheCprogramminglanguageisexpressiveandflexible,butnotsafe;asitsexpressivepowerandflexibilityareobtainedthroughunsafelanguagefeatures,andimproperuseofthesefeaturescanleadtoprogrambugswhosecausesarehardtoidentify.SinceCiswidelyused,anditisimpracticaltorewriteallexistingCprogramsinsafelanguages,sowaysmustbefoundtomakeCprogramssafe.ThispaperdealswiththeunsafefeaturesofCandpresentsasurveyonexistingsolutionstomakeCprogramssafe.Wehavestudiedbinary-levelinstrumentationtools,sourcecheckers,source-levelinstrumentationtoolsandsafedialectsofC,andpresentacomparisonofdifferentsolutions,summarizedthestrengthsandweaknessesofdifferentclassesofsolutions,andshowmeasuresthatcouldpossiblyimprovetheaccuracyoralleviatetheoverheadofexistingsolutions.

  • 标签: C语言 程序设计语言 信息安全 编译工具
  • 简介:ThispaperintroducestheconceptoflocalC-cosins-familyandinverstigateitsbasicproperties,Inparticular,acharacterizationofthecompleteinfinitesimalgeneratorofalocalC-cosinefamilyisobtained,AsanapplieationofthistheorytothesecondordersbstractCauchyproblems,acharacterizationofthelocalC-well-posednessoftheseproblemsisgivenintermsofthelocalC-cosinefamilytheory.

  • 标签: 余弦族 完全生成元 二阶柯西问题 半群
  • 简介:LetιbeatriangulationofapolygonaldomainDR2withverticesV={v1:1≤i≤N,}andRSk(D,τ)={u∈Ck(D):(T∈τ,u|τisarationalfunction}.Thepurposeofthispaperistostudytheexist-enceandconstructionofCμ-rationalsplinefunctionsonanytriangulationτforCAGD.TheHermiteprob-lemHμ(V,U)={findu∈

  • 标签: TRIANGULATION spline CAGD polygonal rational vertex
  • 简介:Thispaperderivesfirstordernecessaryandsufficientconditionsforunconstrainedconed.c.Programmingproblemswheretheunderlinedspaceispartiallyorderedwithrespecttoacone.Theseconditionsaregivenintermsofdirectionalderivativesandsubdifferentialsofthecomponentfunctions.Moreover,conjugatedualityforconed.c.Optimizationisdiscussedandweakdualitytheoremisprovedinamoregeneralpartiallyorderedlineartopologicalvectorspace(generalizingtheresultsin[11]).

  • 标签: 锥d.c.最优化 共轭对偶 弱对偶定理 次梯度 多目标优化 方向导数
  • 简介:TheinteractionbetweenC60’sinsolidC60hasbeencalculatedby(exp-6-1)potential,andthecauseandthecontrolledfactorofthehighrapidrotationsofC60’swerediscussed.InordertodescribethedisordereddegreeofC60rotation,anequivalentMisintroduced.Thephasetransitionsatthe~260Kandatthe~90KarestudiedfromtheviewpointofC60rotation.Thepotentialbarriersoftheorderedrotationbelowthe~260Kandthedisorderedrotationabovethe~260Khavebeengiven,andtheeffectoftheexternalpressureonthetemperatureofphasetransitionhasalsobeengiven.

  • 标签: FULLERENE C60 MOLECULAR ROTATION phase TRANSITION
  • 简介:A.simplicialmesh(triangulation)isconstructedthatgeneralizesthetwo-dimensional4-directionmeshtoR~m.Thismesh,withsymmetric,shift-invariantvaluesatthevertices,isshowntoadmitaboundedC~1interpolantifandonlyifthealternatingsumofthevaluesattheverticesofany1-cubeiszero.Thisim-pliesthaiinterpolationattheverticesofanm-dimensional,simplicialmeshbyaC~1piecewisepolynomialofdegreem+1withonepiecepersimplexisunstable.

  • 标签: invariant INTERPOLATION TRIANGULATION PIECEWISE symmetric cube