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多原子光碎片的点群对称相关、定位和取向<英文>
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作者 赖善桃 丘应楠 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 1990年第5期357-370,共14页
本文将二光子非共振激发的处理推广到允许始态和终态具有不同的点群对称性以及连续群对称性,本结果可以应用于原子,线性分子,对称陀螺分子和非对称陀螺分子,作者的前一文中关于二光子电偶极跃迁的形式现已应用于D_(3h)点群.
关键词 多原子分子 光激发 点群对称性
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Symmetries and Exact Solutions of the Breaking Soliton Equation 被引量:4
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作者 陈美 刘希强 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第11期851-855,共5页
With the aid of the classical Lie group method and nonclassical Lie group method,we derive the classicalLie point symmetry and the nonclassical Lie point symmetry of (2+1)-dimensional breaking soliton (BS)equation.Usi... With the aid of the classical Lie group method and nonclassical Lie group method,we derive the classicalLie point symmetry and the nonclassical Lie point symmetry of (2+1)-dimensional breaking soliton (BS)equation.Usingthe symmetries,we find six classical similarity reductions and two nonclassical similarity reductions of the BS equation.Varieties of exact solutions of the BS equation are obtained by solving the reduced equations. 展开更多
关键词 breaking soliton equation SYMMETRY similarity reductions exact solutions
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Lie Point Symmetry Algebras and Finite Transformation Groups of Baroclinic Mode for Rotating Stratified Flows
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作者 元青青 楼森岳 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第5期878-882,共5页
The transformation groups and symmetries of the baroclinic mode for rotating stratified flow can be obtained via the standard approach. Applying the symmetry group on some special solutions, the newly obtained results... The transformation groups and symmetries of the baroclinic mode for rotating stratified flow can be obtained via the standard approach. Applying the symmetry group on some special solutions, the newly obtained results disprove a known conjecture. 展开更多
关键词 rotating stratified flows SYMMETRIES nonequivalent barotropic exact solutions
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Kac-Moody-Virasoro Symmetry Algebra of (2+1)-Dimensional Dispersive Long-Wave Equation with Arbitrary Order Invariant
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作者 张焕萍 李彪 陈勇 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第3期450-454,共5页
By Lie symmetry method, the Lie point symmetries and its Kac-Moody-Virasoro (KMV) symmetry algebra of (2+1)-dimensional dispersive long-wave equation (DLWE) are obtained, and the finite transformation of DLWE is given... By Lie symmetry method, the Lie point symmetries and its Kac-Moody-Virasoro (KMV) symmetry algebra of (2+1)-dimensional dispersive long-wave equation (DLWE) are obtained, and the finite transformation of DLWE is given by symmetry group direct method, which can recover Lie point symmetries. Then KMV symmetry algebra of DLWE with arbitrary order invariant is also obtained. On basis of this algebra the group invariant solutions and similarity reductions are also derived. 展开更多
关键词 Kac Moody Virasoro symmetry algebra dispersive long-wave equation symmetry reduction group invariant solutions
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General Formulations of Finite-field Method Classifiedby Symmetry for Molecular Linear and Nonlinear Polarizabilities
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作者 陈锡华 林晨升 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2001年第5期369-380,共12页
The formulations of the finite-field approach to calculate the linear and non-linear optical coefficients (i, (ij, (ijk and (ijkl of a molecular system with different symmetries have been deduced and summarized. The p... The formulations of the finite-field approach to calculate the linear and non-linear optical coefficients (i, (ij, (ijk and (ijkl of a molecular system with different symmetries have been deduced and summarized. The possible choices of the energy sets of the 48 frequent point groups have been optimized and categorized into 11 classes. With the restriction of symmetry operators, a minimum of 9, no more than 21 energy points have to be calculated in order to determine the coefficients, except in the case of the first class to which C1 point group belongs and in which the 34 non-relative energy points selected in our uniform and general scheme are all needed. The symmetric operators that cause some of the tensor components to vanish have been demonstrated as well. 展开更多
关键词 nonlinear optical polarizability finite-field approach point group symmetry
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Symmetry properties of tetraammine platinum(II) with C_(2v) and C_(4v) point groups
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作者 MOGHANI Ghorban Ali ASHRAFI Ali Reza HAMADANIAN Masood 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2005年第3期222-226,共5页
Let G be a weighted graph with adjacency matrix A=[aij]. An Euclidean graph associated with a molecule is defined by a weighted graph with adjacency matrix D=[dij], where for i≠j, dij is the Euclidean distance betwee... Let G be a weighted graph with adjacency matrix A=[aij]. An Euclidean graph associated with a molecule is defined by a weighted graph with adjacency matrix D=[dij], where for i≠j, dij is the Euclidean distance between the nuclei i and j. In this matrix dii can be taken as zero if all the nuclei are equivalent. Otherwise, one may introduce different weights for different nuclei. Balasubramanian (1995) computed the Euclidean graphs and their automorphism groups for benzene, eclipsed and staggered forms of ethane and eclipsed and staggered forms of ferrocene. This paper describes a simple method, by means of which it is possible to calculate the automorphism group of weighted graphs. We apply this method to compute the symmetry of tetraammine platinum(II) with C2v and C4v point groups. 展开更多
关键词 Weighted graph Euclidean graph Tetraammine platinum(II)
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Sm^(3+)掺杂NaYF4和BiPO4单颗粒微米晶体发光偏振特性研究
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作者 岳新 叶洳言 +2 位作者 郭雅欣 李朋 李峰 《激光与光电子学进展》 CSCD 北大核心 2023年第11期312-319,共8页
本研究利用搭建的高精度单颗粒偏振光谱表征系统,测量了六方相Na YF_(4):Sm^(3+)和单斜相Bi PO4:Sm^(3+)单颗粒微米晶体的偏振发光特性,并结合偏振庞加莱球法和偏振拟合法对偏振发光峰进行了分析。结果表明,两种晶相中的Sm^(3+)离子均... 本研究利用搭建的高精度单颗粒偏振光谱表征系统,测量了六方相Na YF_(4):Sm^(3+)和单斜相Bi PO4:Sm^(3+)单颗粒微米晶体的偏振发光特性,并结合偏振庞加莱球法和偏振拟合法对偏振发光峰进行了分析。结果表明,两种晶相中的Sm^(3+)离子均发射部分偏振光,不同的是,六方相发光峰的线偏角精确沿着或垂直于结晶c轴,而单斜相发光的线偏角与结晶c轴存在非平行或正交的夹角。基于局部点群对称性和晶体宏观对称性,揭示了六方相发光峰的正交线偏角起源于光学跃迁偶极子绕结晶c轴的旋转对称分布,而单斜相中偶极子不具备旋转对称性,导致其发光峰的线偏角随机取向。该发现对于利用晶体结构获得具有理想偏振发光特性的稀土单颗粒晶体具有指导意义。 展开更多
关键词 稀土单颗粒光谱 偏振发光 晶体结构 点群对称性
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原子簇La_(8-x)Ba_xCuO_6的原子磁矩和自旋极化的电子结构研究
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作者 陈丽 李华 +2 位作者 董建敏 潘凤春 梅良模 《物理学报》 SCIE EI CAS CSCD 北大核心 2004年第1期254-259,共6页
利用MS Xα方法研究了化合物La2 -yBayCuO4 的原子磁矩和自旋极化的电子结构 .理论计算得到母相氧化物La2 CuO4 的Cu原子磁矩为 0 37μB,与实验值 0 4 8± 0 15 μB 基本一致 .研究结果显示 ,由于Ba原子对部分La的替代 ,使构成... 利用MS Xα方法研究了化合物La2 -yBayCuO4 的原子磁矩和自旋极化的电子结构 .理论计算得到母相氧化物La2 CuO4 的Cu原子磁矩为 0 37μB,与实验值 0 4 8± 0 15 μB 基本一致 .研究结果显示 ,由于Ba原子对部分La的替代 ,使构成化合物的基本原子簇La8-xBaxCuO6 的点群对称性降低 ,分子轨道简并度解除 ,轨道杂化效应增强 ,减弱了氧化物的 (准 )二维特性 ,导致Cu O层与其近邻原子层的耦合增强 ,因此影响了原子层间的电荷迁移方向 ,对Cu O层中载流子的性质有重要影响 .由于Ba掺杂在化合物中产生的空穴 ,不仅进入O格点 ,也同时进入Cu格点 ,对Cu O层上Cu和O原子价态、磁矩以及电子态密度分布有重要影响 .研究结果认为 ,由于掺杂产生的空穴对化合物超导电性的影响具有两面性 :初期掺杂有利于产生超导电性 ;当掺杂较多时抑制超导电性 .这是导致La2 14体系的超导转变温度Tc 随掺杂量y的变化 (即Tc y拱形曲线 )的一个重要原因 . 展开更多
关键词 电子结构 自旋极化 原子磁矩 态密度 超导电性 钡原子 镧原子 轨道杂化效应 轨道简并度 点群对称性
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