分子间散射问题的李代数处理——关于AB+CD系统的振动-振动能量传递

采用半经典近似方法所给出的关于AB+CD散射系统的相互作用势,构造系统的一种动力学代数h_(15), 利用这种代数计算了在非反应情况下系统的跃迁几率及势能的统计平均值,并在群参量的一次近似下探讨了跃迁过程中的选择定则。     

分子间散射问题的李代数处理 关于AB+CD系统的振动-振动能量传递

采用半经典近似方法所给出的关于AB+CD散射系统的相互作用势, 构造系统的一种动力学代数h_(15), 利用这种代数计算了在非反应情况下系统的跃迁几率及势能的统计平均值, 并在群参量的一次近似下探讨了跃迁过程中的选择定则。     

A+BC共线碰撞能量传递的动力学李代数结合中间绘景研究

在半经典近似下将动力学李代数方法和中间绘景结合应用于原子-双原子分子(非谐振子)共线碰撞中的平动-振动传能的研究。在群参量的一级近似下求解群参量的运动方程,进而确定时间演化算符。并以散射体系H₂+He为例,计算了H₂分子的振动跃迁几率,计算结果与精确量子力学计算结果符合得较好。     

凝胶化反应全过程的激光光散射跟踪研究

在苯乙烯（Ｓｔ） 二乙烯苯（ＤＶＢ）自由基共聚的凝胶化反应过程中定时取样，得到凝胶化点前后及至终点的一系列样品，然后用激光光散射技术，包括研究散射光强及其角度依赖性的静态光散射（ＳＬＳ）和研究散射光频移的动态光散射（ＤＬＳ），表征了这系列样品的重均分子量Ｍｗ、均方旋转半径Ｒｇ、第二维利系数Ａ２及流体力学半径Ｒｈ等静、动态参量及这些参量的变化规律，定量地描述了凝胶化反应全过程     

共线散射体系A+BC的平-振能量传递──无限维李代数处理方法

利用无限维李代数方法处理了在BC分子能谱中含有二级与三级非简谐项的散射体系A＋BC的平-振能量传递问题，获得了散射过程的含有主要动力学参量的跃迁矩阵元和跃迁几率的解析表达式     

氟代苯阳离子的理论研究

用B3LYP方法及6-311G(d,p)和6-311 G(d,p)基组,对十二种氟代苯阳离子做了理论研究,优化了它们的电子基态的结构,计算了对应分子的垂直电离势(VIP)和绝热电离势(AIP)．依据Jahn．Teller理论,计算确定了1,3,5-C6H3F^ 3和C6F^ 6离子分别具有C2v(2↑B)和D2h(2↑B2g)结构(对应分子分别为D3h和D6h结构)．其余十个离子的构型的对称点群与对应分子相同,但构型参数值有明显差别．自然布居分析计算表明这些离子的正电荷主要分布在与F原子相连的C原子和各H原子上．B3LYP／6-311 G(d,p)级别上计算的各氟代苯分子的VIP和AIP值和实验值符合得很好．     

量子反应散射的动力学李代数方法

用动力学李代数方法描述了量子反应散射问题 .对共线交换反应A BC→AB C ,得到了含有主要动力学参数的反应跃迁几率的解析表达式 .计算了共线反应散射过程H H2 (n =0 )→H2 (n′ =0 ) H的反应跃迁几率 .结果表明 ,动力学李代数方法对计算反应几率是非常有效的 .     

共振光散射法测定丁胺卡那霉素

研究了以达旦黄（TY）作为共振光散射探针测定市售药品中丁胺卡那霉素（AMK）的测定方法．该方法基于在pH=5．5的Britton—Robinson缓冲溶液中，达旦黄和丁胺卡那霉素结合后有强烈的共振光散射作用．在λ=482nm处，共振光散射强度（△IRLS）最大且光散射的强度与AMK的浓度在0．4～2．4mg·L^-1范围内成正比（相关系数r=0．9986），检出限为8．6×10^-3mg·L^-1．该方法简便、快速、灵敏，对1．0mg·L^-1的AMK溶液平行测定11次，RSD=2．57％．用于市售样品的分析测定，结果满意。     

用对称透射二维WAXS强度研究PET取向非晶态结构

用对称透射法，测试聚酯（ＰＥＴ）取向非晶试样的二维广角Ｘ射线散射相干强度Ｉ（Ｋ，α），将不同方位角α上的Ｉ（Ｋ，α）非晶重叠峰曲线进行计算分解，获得分子链间原子散射引起的二个峰为Ａ（Ｋ＝０．１２６），Ｂ（Ｋ＝０．１６９），分子链内原子散射引起五个峰分别为Ｃ（Ｋ＝０．３０４），Ｄ（Ｋ＝０．５５３），Ｅ（Ｋ＝０．３７４），Ｆ（Ｋ＝０．４６５），Ｇ（Ｋ＝０．６０６），Ｋ单位为ｎｍ＾－１，分析了它们的结构     

LiNbO3晶体中Pr3+离子的配位场能级计算

在C3v点群对称场中，运用双层点电荷配位场（DSCPCF）模型计算了LiNbO3晶体中Pr^3＋离子的40个配位场能级，与实验值相比，其均方根偏差为19．94cm^-1，优于文献值（44．22cm^-1）．所得晶体场参数也明显好于文献值，说明双层点电荷模型能更好地拟合实验结果，对于研究C3v对称场中稀土离子的光谱特性具有非常重要的意义．     

反应碰撞的动力学李代数描述

提出一种李代数方法描述分子反应碰撞问题．给出了含有主要动力学参量的S-矩阵元、分子碰撞跃迁几率以及反应体系能量统计平均值随时间演化的解析表达式．讨论了一个简单排斥势场中的原子-双原子分子共线反应体系，以阐明这种新方法的要点。     

取代苯体系的二阶非线性光学性质:动力学李代数方法

提出了一种动力学李代数方法来研究取代苯体系的非线性光学性质. 对于给定的PPP模型(Pariser-Parr-Pople)哈密顿量, 生成了一个动力学李代数. 依据这些代数元构造出演化算子作为群参数的函数, 通过求解一组非线性微分方程能够得到这些群参数. 再按照统计力学中的密度算子公式给出取代苯分子体系偶极矩的统计平均值. 于是导出二阶极化率的表达式. 与其他量子力学计算结果比较, 表明这种动力学李代数方法在预言有机共轭分子的非线性光学性质上同样有用.     

Statistical mechanics of energy transfer in gas–surface scattering: A dynamical Lie algebraic approach

The dynamical Lie algebraic (DLA) method is used to describe statistical mechanics of energy transfer in rotationally inelastic molecule–surface scattering. Statistical average values of an observable for the scattering system are calculated in terms of density operator formalism in statistical mechanics. Employing a cubic expansion procedure of molecule–surface interaction potential leads to generation of a dynamical Lie algebra. Thus these statistical average values as a function of the group parameters can be obtained analytically in this formulation. The group parameters can be found from solving a set of coupled nonlinear differential equations. The DLA method, which has no need for determination of transition probabilities in advance as made routinely in the calculation, offers an efficient alternative to the method for computing the statistical average values. This method is much less computationally intensive because most of calculations can be analytically carried out. The average final rotational energies and their dependence on the main dynamic variables and the average interaction potential are presented for the rotationally inelastic scattering of NO molecules from a flat, static Ag(111) surface. Direct comparison is made between the predictions of this model calculation and experiment. The model reproduces well the degree of rotational excitation and correlation between the average final translational and the average rotational energies. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001     

“Basis” lie algebra of electronic fock space: Application to evaluation of matrix elements of spin tensor operators

A new set of generators of the operator algebra over the electronic Fock space is introduced. It is shown that with this set of generators the “basis” Lie algebra can be associated and that the operator algebra of the Fock space is the homomorphic image of the corresponding universal enveloping algebra. The algebraic structure revealed is used for deriving the reduction formulas for the elements of the simplest spin tensor operators between the Gelfand states.     

Dynamic Lie algebraic formulation of second‐order optical nonlinearity for substituted benzenes

A dynamic Lie algebraic (DLA) formulation is applied to the study of nonlinear optical properties of the substituted benzenes. We have described the generation of the dynamic Lie algebra for the model Hamiltonian used in the present study. In terms of these elements of the dynamic algebra we express the evolution operator as a function of the group parameters, which can be determined by means of solving a system of coupled nonlinear differential equations. Thus, in terms of the density matrix operator formalism in statistical mechanics we obtain the statistical averages of the electric polarization and then derive readily an expression for the hyperpolarizability of the paradisubstituted benzenes. Comparisons with experimental observations and other quantum calculations of the hyperpolarizabilities for the paradisubstituted benzenes are made qualitatively and quantitatively. These results imply that the DLA method appears useful in describing the nonlinear optical phenomena in the substituted benzene molecules. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem 93: 335–343, 2003     

Application of the Lie algebraic approach to diffractionally and rotationally inelastic molecule–surface scattering

The Lie algebraic approach of Alhassid and Levine [Phys. Rev. A 18 , 89 (1978)] is applied to the molecule–surface scattering. Specially, the diffractionally and rotationally inelastic scattering of a diatomic molecule from a solid surface is dealt with. Within the framework of the close-coupling method, we construct a Hamiltonian for the scattering system and use it to generate a dynamical algebra h₆. By solving equations of motion for the group parameters, the scattering wave functions near the surface are obtained. Computed transition probabilities of diffractively and rotationally inelastic scattering of H₂ from LiF(001) surface with the use of Lie algebraic method are seen to agree well with the coupled-channel calculations. The Lie algebraic method thus appears to have a wide range of validity for describing the dynamics of gas–surface scattering. © 1997 John Wiley & Sons, Inc. Int J Quant Chem 63: 981–989, 1997     

Extension of the A-UNIFAC model to mixtures of cross- and self-associating compounds

In the present work an extended UNIFAC group contribution model is used to calculate activity coefficients in solutions containing alcohols, water, carboxylic acids, esters, alkanes and aromatic hydrocarbons. The limiting expressions for the association contribution to the activity coefficients at infinite dilution are presented and discussed. A new set of interaction parameters between associating and non-associating functional groups is reported. This set of parameters is applied in the association model to predict vapor–liquid, liquid–liquid equilibrium and infinite dilution activity coefficients.     

Application of dynamical Lie algebraic method to atom–diatomic molecule scattering

The dynamical Lie algebraic approach developed by Alhassid and Levine combined with intermediate picture is applied to the study of translational–vibrational energy transfer in the collinear collision between an atom and an anharmonic oscillator. We find that the presence of the anharmonic terms indeed has an effect on the vibrational probabilities of the oscillator. The computed probabilities are in good agreement with those obtained using exact quantum method. It is shown that the approach of dynamical Lie algebra combining with intermediate picture is reasonable in the treating of atom–anharmonic oscillator scattering.