Xe54+离子与Xe原子碰撞过程中的辐射电子俘获及退激发辐射的理论研究

基于多组态Dirac-Fock理论方法和冲量近似, 对Xe⁵⁴⁺与Xe在197 MeV/u碰撞能量下, 炮弹离子的俘获及退激发过程进行了理论研究. 计算了炮弹离子从中性靶原子俘获一个电子到nl (n=1, 2, 3, 4, 5; l=s, p, d) 轨道上的辐射电子俘获截面和相应的辐射光子能量, 以及俘获末态退激发辐射跃迁的能量和概率. 结合这些计算结果, 进一步模拟了碰撞产生的炮弹离子的退激发X射线谱的结构, 并与兰州重离子加速器装置上的最新实验观测结果进行了比较, 符合得很好.     

大气折射对可见光波段辐射传输特性的影响

折射是影响辐射传输的重要因素. 为分析大气折射对辐射传输的影响, 基于Monte Carlo方法, 给出了考虑大气折射的矢量辐射传输模型, 实现了均匀气层和耦合面处光子随机运动过程的模拟, 实现了直射光及漫射光Stokes矢量、偏振度和辐射通量等参数的计算. 在考虑和不考虑大气折射两种条件下, 验证了模型的准确性; 在纯瑞利散射条件下, 讨论了大气折射对不同方向漫射光Stokes矢量的影响; 在不同太阳天顶角、大气廓线、气溶胶及含云大气条件下, 分析了大气折射对辐射传输过程的影响. 结果表明: 大气折射对漫射光Stokes矢量的影响主要体现在天顶角70°–110°区间, 且随着太阳入射角增大, 其影响更为显著; 不同大气廓线情形下, 大气折射对Stokes矢量的影响不一致, 其原因是不同大气廓线对应的折射率廓线存在差异. 含云及含气溶胶大气条件下, 大气折射对辐射传输的影响变弱, 沙尘型及海盐型气溶胶条件下, 折射对辐射传输的影响强于可溶型气溶胶情形; 不同形状气溶胶条件下, 大气折射对辐射传输的影响也存在显著差异; 不同云高条件下, 大气折射对漫射光Stokes矢量的影响无显著差异, 但随着云光学厚度增大, 大气折射的影响减弱.     

Ab initio investigation of the electronic and vibrational properties for the (CaLi)+ ionic molecule

A wide adiabatic study has been performed for numerous electronic states of CaLi⁺ molecular ion. The adiabatic potential energy curves and their spectroscopic constants (R_e, D_e, ω_e and T_e) have been calculated using an ab initio approach including a nonempirical pseudo-potential for the Ca and Li cores with the core polarisation potentials operator through full configuration interaction (FCI). Thereafter, the energies of vibrational levels and their spacing for all these states have been reported. In addition, the electric dipole moment curves have been investigated for the (1-19) Σ, (1-12) Π and (1-8) Δ electric states. Moreover it lets us check the extreme transition dipole moments (TDM). These behaviours of TDM are more accustomed to estimate the radiative lifetimes for all vibrational levels in 2¹Σ⁺ and 3¹Σ⁺ states. Also, the bound-bound and the bound-free contribution have been calculated precisely and by employing a Franck–Condon (FC) approximation.     

分形烟尘簇团粒子的消光特性研究

根据物质的电结构,将烟尘簇团粒子离散为一系列的偶极子,利用离散偶极子近似方法,获得了不同波长电磁波入射情况下分形烟尘簇团粒子不对称因子、吸收和散射效率因子的值.结合偶极子在电磁场中的力学性质,分析了烟尘簇团粒子在外加电磁场中所受的力和力矩,给出三种分形结构烟尘簇团粒子的电磁辐射压力及电磁辐射力矩效率因子随入射波波长变化的数值结果,分析了烟尘粒子对电磁能量吸收的宏观表现和微观机理.结果显示:入射波长、烟尘簇团粒子的分形维数及所含原始微粒数目都将影响烟尘粒子的消光特性.     

金属冲击温度测量中金属/窗口界面表观光谱辐亮度的再研究

 在冲击压缩下，理想接触的金属/窗口界面温度历史是时间无关的，因而一般认为界面的表观光谱辐亮度也是时间无关的。研究表明：（1）在冲击压缩下，将伴随金属对光的吸收系数减小和光学厚度增大。因此，在考虑辐射输运效应后，理想接触的金属/窗口界面处的表现光谱辐亮度是时间相关的。非常明显的时间相关过程自冲击波到达界面后持续约10 ns。（2）若把存在空间温度梯度的金属界面辐射看作是透光厚度内平均温度的等效辐射效应，其结果与辐射输运效应的计算结果是很相近的。     

Equation of motion for a radiating charged particle in classical electrodynamics

We propose classical equations of motion for charged particles in an electromagnetic field. These are general formulas for the particle acceleration that take the radiation-induced deceleration into account and contain no second derivatives of the particle velocity. In several particular cases considered, the new equations yield results coinciding with those known in the literature and experimentally verified. We show that in the range of ultrahigh energies, classical electrodynamics does not lead to inherent inconsistencies and in principle allows particle motion with energies exceeding the Pomeranchuk limit.Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 143, No. 1, pp. 112–130, April, 2005.     

负碳离子(2s~2p~3)和(2s~12p~4)的光离解

电子关联效应在负离子中的作用相当重要，本文讨论了负碳离子（２ｓ２ｐ３）和（２ｓ１２ｐ４）的能级结构、光谱跃迁、寿命和光离解通道等。碳负离子（１ｓ２２ｓ１２ｐ４）的双重态比四重态稳定，（２ｓ２ｐ３）和（２ｓ１２ｐ４）之间各辐射谱线波长位于超紫外区域的上限附近，其光谱强度很大的波长有６条，为研制Ｘ射线激光提供了有利的工作物质。     

Cross section measurements of the Pd(p, γ)Ag, Sn(p, γ)Sb, and Sn(α, γ)Te reactions relevant to the astrophysical rp- and γ-processes

Total cross section measurements for the ¹⁰²Pd(p, γ)¹⁰³Ag and ¹¹⁶Sn(p, γ)¹¹⁷Sb reactions have been performed in the proton energy range 2.6 to 4.25 MeV, and for the ¹¹²Sn(α, γ)¹¹⁶Te reaction over the alpha beam energy range 7.0 to 10.5 MeV. An activation technique was used in which gamma rays from decays of the reaction products were detected off-line by two hyper-pure germanium detectors in a low background environment. Where possible, reaction rates are derived and the results compared to those of calculations generated by the NON-SMOKER and the MOST statistical model codes so as to judge their applicability for describing the cross sections needed for network calculations of nucleosynthesis in explosive astrophysical environments via the γ- and rp-processes.     

用Technicolor理论研究稀有辐射衰变B_c→D_sγ

在一代Ｔｅｃｈｎｉｃｏｌｏｒ（ＴＣＩ）和带有一个无质量的标量二重态（ＴＣⅡ）模型下，计算荷电的哥尔斯通粒子对衰变Ｂ＿ｃ→Ｄ＿ｓγ的贡献，并把它们同标准模型的计算相比较，发现哥尔斯通粒子对电磁企鹅图的贡献很大（ＴＣＩ下），在ＴＣⅡ下贡献较小；而对弱湮没图的贡献可以忽略不计，还对同位旋三重态粒子π＋ｐ的质量进行了约束。预言将来在ＬＨＣ上能对不同模型下的分支比Ｂｒ（Ｂｃ→Ｄｓγ）的差异进行研究，进而对不同的模型进行检验。