原子-振子散射振转激发跃迁几率的理论计算

在相互作用表象中,利用角动量耦合理论,导出了原子-振子散射的含时量子计算公式,并计算了He-H₂体系的振转激发态-态跃迁几率和分散射截面。结果表明:(1)相互作用表象波函数在坐标空间中具有较高的定域性,随时间演化几乎不变形,因此在计算散射量时具有很高的精度,与标准的密耦合(CC)法的计算结果符合很好;(2)增加的振动部分对计算时间的影响取决于对一势能矩阵的积分,而在该积分中仅含基态的计算就能给出较为理想的散射截面,与CC法相比节省近一倍的计算时间。 关键词：     

CH4+O2体系中碰撞-诱导O2(X3∑-g→a1Δg)跃迁几率计算

采用从头计算二阶自旋-轨道多组态准简并微扰理论计算了CH4+O2体系中O2分子X3∑-g-a1Δg,X3∑-g-b1∑+g和b1∑+g-a1Δg的碰撞-诱导跃迁几率,分析了O2分子振动对跃迁几率的影响,并与O2+H2模型的结果做了比较.     

Sm2+掺杂的无机光谱烧孔材料量子效率研究

本文由光谱烧孔的发光动力学方程出发,推导了脉冲光烧孔并选通的情况下量子效率的表达式.在77K下测量了以不同功率的560nm脉冲光烧孔并选通的条件下,孔深随烧孔脉冲数目的变化,验证了烧孔的量子效率与选通光强度的关系.在相同的烧孔条件下测量了BaF(Cl,Br):Sm²⁺与SrF(Cl,Br):Sm²⁺的孔深随脉冲数目的变化,验证了量子效率与⁵D_J-⁷F₀跃迁几率的关系.     

BaFClxBr1－x:Sm2+中5D2→7F0跃迁几率及其对烧孔效率的影响

本文以BaFClxBr1－x:Sm2+中5D2→7F0的跃迁几率随x变化为中心对BaFClxBr1－x:Sm2+体系4f5d带的激发光谱、5D2→7F0跃迁的荧光衰减随温度的变化特性、5D2→7F0的跃迁几率等进行了研究。从而得出结论:在BaFClxBr1－x:Sm2+中,随Br含量的增大,4f5d带与5D2能级更加接近,使7F0→5D2的吸收截面增大,从而可能提高在5D2:能级烧孔的效率。     

Xe9+离子4d9-4d85p跃迁的理论研究

 利用多组态Dirac-Fock(MCDF)方法，通过对Xe⁹⁺离子4d⁹-4d⁸5p跃迁的系统计算，研究了电子相关效应对Xe⁹⁺离子4d⁹-4d⁸5p跃迁的影响，给出了相应的跃迁能和辐射跃迁几率，并与最新的实验观测和其它理论计算结果进行了比较。计算结果表明：电子的关联效应显著。根据计算结果和实验结果的一致性和两个规范下所得的跃迁几率的一致性，可以认为本文的计算结果是可信的。     

Xe9+离子4d9-4d85p跃迁的理论研究

利用多组态Dirac-Fock(MCDF)方法,通过对Xe9+离子4d9-4d85p跃迁的系统计算,研究了电子相关效应对Xe9+离子4d9-4d85p跃迁的影响,给出了相应的跃迁能和辐射跃迁几率,并与最新的实验观测和其它理论计算结果进行了比较。计算结果表明：电子的关联效应显著。根据计算结果和实验结果的一致性和两个规范下所得的跃迁几率的一致性,可以认为本文的计算结果是可信的。     

分子高激发振动态的理论研究

简要综述了分子高激发振动态的理论研究方法和研究进展.介绍了李代数方法在高激发振动态能级的归属和分类、分子高激发振动态动力学以及分子内振动能量弛豫和分子解离等方面的应用.随后,作者对分子高激发振动态研究领域今后的发展方向作了展望.     

激光金等离子体中Au47+、Au53+的离子结构和光谱分析

根据扩展的相对论多组态狄拉克-福克（Dirac-Fock）理论,采用“多功能相对论原子结构程序（GRASP^2）”,考虑量子电动力学（QED）效应和布雷特（Breit）修正,选用二参量费米有限核电荷分布和扩展平均能级模型,并考虑组态问的相互作用和电偶极跃迁,计算了类锗Au^47＋、类铁Au^53＋的跃迁波长,跃迁几率和振子强度,计算的波长与实验值符合较好。研究表明,在类锗^47＋、类铁Au^53＋的跃迁中,3d-4f是一条较强的跃迁通道。计算所得的波长值对金等离子体的能级寿命、电荷态分布和平均电离度研究有一定的参考价值。     

CH4+O2体系中碰撞-诱导O2（X3∑g-→a1△g)跃迁几率计算

采用从头计算二阶自旋-轨道多组态准简并微扰理论计算了CH4+O2体系中O2分子X3∑-g-a1Δg, X3∑-g-b1∑+g和b1∑+g-a1Δg的碰撞-诱导跃迁几率,分析了O2分子振动对跃迁几率的影响,并与O2+H2模型的结果做了比较.     

A～100区奇奇核手征候选带的检验

基于一个粒子与一个空穴和三轴转子相耦合的手征图像, 可得到关于理想手征带的6条判据. 利用6条判据, 检验了100区奇奇核的两个候选手征带: ¹⁰⁴Rh和¹⁰⁶Rh的候选手征带. 研究表明虽然¹⁰⁴Rh的双带比¹⁰⁶Rh更简并, 但¹⁰⁶Rh比¹⁰⁴Rh满足更多的理想手征判据. 这表明具有部分能级近简并(<50keV)的双带结构并不一定比保持恒定能量差(200—300keV)的双带接近理想手征带.     

用动力学方法研究原子分子碰撞过程中的统计平均问题

动力学李代数方法在研究原子分子碰撞问题中是一种很重要的方法.在计算过程中我们用密度算子导出了物理量的统计平均值.同时我们用时间演化算子计算了振转能量的跃迁几率.作为例子我们用此方法计算了H2和He的碰撞问题.     

Lie algebraic approach of a charged particle in presence of a constant magnetic field via the quadratic invariant

In this paper we consider the problem of a charged harmonic oscillator under the influence of a constant magnetic field. The system is assumed to be isotropic and the magnetic field is applied along the z-axis. The canonical transformation is invoked to remove the interaction term and the system is reduced to a model containing the second harmonic generation. Two classes of the real and complex quadratic invariants (constants of motion) are obtained. We have employed the Lie algebraic technique to find the most general solution for the wave function for both real and complex invariants. Some discussions related to the advantage of using the quadratic invariants to solve the Cauchy problem instead of the direct use of the Hamiltonian itself are also given.     

Vibrational energy transfer in a collinear HF-HF collision involving low-lying states in the presence of infrared laser beam

An approximate method for the vibration-vibration (V-V) energy transfer process during collinear collisions of two HF molecules involving low-lying states in the presence of infrared laser beam using a quasi-energy approach (non-perturbative) is presented. The effect of radiation on V-V process is investigated by changing the laser field detuning and power for various values of collision velocities.     

电磁交叉场分析器中非线性传输的Lie代数分析

用李代数方法分分析了带电粒子在电磁交叉场分析器中的非线性传输,结果近似到三级近似.分析过程为:首先建立粒子在电磁交叉场分析器中的运动的Hamilton函数,然后将Hamilton函数在平衡轨道附近展开成幂级数,最后计算粒子的非线性轨迹到三级近似.根据需要,还可以推导出更高级的近似解.     

Algebraic methods applied to the study of energy transfer in anharmonic systems

We make use of two different methodologies to study the transition probabilities in a molecular anharmonic system in the presence of an external perturbation. For the first method, we use a series expansion of the displacement coordinate keeping up to fourth order terms; for the second method we use a deformed algebra to approximate the anharmonic Hamiltonian via a harmonic oscillator's Hamiltonian written in terms of deformed operators. We evaluate vibrational transition probabilities as a function of the collision energy and compare the results obtained with the two approaches.     

Lie Algebraic Approach to Energy Transfer for Collinear Collision of Two Anharmonic Diatomic Molecules

An anharmonic oscillator algebra model is used to study the collinear collisions of two diatomic molecules. The transition probability for vibration-vibration energy transfer is presented. For an application of the method, we talk about the collision of N2＋CO, N2＋O2, and N2＋N2. Through long time averaging, the transition probability changes to the function of total energy of the system. Comparing the results with the quantum results, we can see that the dynamical Lie algebraic method is useful for describing the anharmonie diatomic molecular collision.     

Quantum-dynamical study of the translational-vibrational energy transfer in the collinear collisions of atoms with triatomic molecules

A quantum-dynamical method is described for investigating the translational-vibrational energy transfer that occurs in the collinear collision of an atom with a linear triatomic molecule. The technique is applied to the computation of vibrational transition probabilities for the collinear collisions of helium atoms with CO₂, OCS and HCN over a range of energies. Realistic potentials are used for the triatomic molecules while simple exponential or Morse potentials are used to describe the helium-molecule interaction. The effects of varying the atomic masses and the potential function parameters are examined. It is found, that the symmetric stretch vibrational modes of CO₂, OCS and HCN are preferentially excited (or relaxed), by collision with the atom, over the asymmetric stretch modes.     

静电分析器非线性轨迹的Lie代数分析

介绍了Lie代数的方法，用Lie代数方法分析了静电分析器对束流传输过程的非线性影响，其计算结果分析到三级近似. 首先给出了静电分析器的哈密顿函数，然后将哈密顿函数展开为齐次多项式的和，再求Lie映射，最后得到粒子轨迹各级近似解.     

Determination of transition probabilities by laser-induced breakdown spectroscopy with curve-of-growth measurements

A method for the measurement of transition probabilities using laser-induced plasmas as spectroscopic sources is presented. To check its validity, the method is applied to 19 Ni II lines, most of them with known A_ki values. The method is based on the measurement of curves of growth using samples with varying concentrations of the element of interest (here, nickel-copper alloys with nickel contents in the range 0.11-27 at%). The plasma is characterized by a reduced set of parameters, obtained by usual techniques (Boltzmann plot and Stark shift) combined with the curve-of-growth methodology. The transition probabilities are determined by fitting experimental curves of growth to calculations based on the plasma parameters. The use of curves of growth allows eliminating the systematic error due to the self-absorption in the measurement of transition probabilities, and is applicable to intense as well as very weak lines.