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Based on the multi-configuration Dirac-Fock self-consistent field method, a scenario has been presented to calculate the fine-structure energy levels of C^2+ and Si^2+ excited states (31 D2 and 33D1,2,3). The Breit interactions and quantum electrodynamics corrections are added as perturbations. The present calculation results are found to be in excellent agreement with the experimental data. By means of the precise calculation procedure, we elucidate that four competitive mechanisms influence the interesting fine-structure splittings in C^2+ and Si^2+, such as spin-orbit interactions, relativistic corrections of exchange interactions, the Breit interactions and electron correlation effects. Furthermore, the mechanism of relativistic correction of exchange interactions has been studied clearly. We elucidate that the inner shell 2p1/2,3/2 orbitals are essential to relativistic corrections of exchange interactions which are crucial for the final anomalous fine-structure splittings.  相似文献   
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青波  程诚  高翔  张小乐  李家明 《物理学报》2010,59(7):4547-4555
从第一原理出发计算原子结构有多种理论方法,它们都是基于变分原理的,其关键是构建一组最适合描述真实物理体系的且适用于变分原理的准完备基.本文阐明了如何利用全相对论计算程序GRASPVU,通过单组态Dirac-Fock计算以及多组态Dirac-Fock自洽场计算建立准完备基.然后利用该准完备基进行组态相互作用计算以充分考虑关联作用;在此基础上,进一步考虑电磁相互作用的延迟效应和量子电动力学等修正.该准完备基对原子结构和电磁跃迁等物理量可进行精密的理论计算.最简单的He体系的能级和跃迁速率等物理量的计算值与目前最准确的理论计算值以及精密的实验测量值符合很好,验证了本文提出的方案的适用性.本文计算是全相对论的,可推广到相对论效应很重要的高Z类He体系,以面向重离子储存环相关实验测量.同时该方案也适用于其他任何多电子原子体系;对Mg进行了精密理论计算,阐明了其33D,43D精细结构次序变化的机理.  相似文献   
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The most accurate measturements in physical sciences will be precision spectroscopic experiments which are based on the usage of most narrow lines in cooperation with interference phenomena. We present a novel experimental observation of "a sharp absorption resonance line" with much more broad laser lights. The mechanism of such a novel phenomenon will be elucidated and its implications will be discussed.  相似文献   
4.
程诚  高翔  青波  张小乐  李家明 《中国物理 B》2011,20(3):33103-033103
Using the multi-configuration Dirac-Fock self-consistent field method and the relativistic configuration-interaction method,calculations of transition energies,oscillator strengths and rates are performed for the 3s 2 1 S 0-3s3p 1 P 1 spinallowed transition,3s 2 1 S 0-3s3p 3 P 1,2 intercombination and magnetic quadrupole transition in the Mg isoelectronic sequence(Mg I,Al II,Si III,P IV and S V).Electron correlations are treated adequately,including intravalence electron correlations.The influence of the Breit interaction on oscillator strengths and transition energies are investigated.Quantum electrodynamics corrections are added as corrections.The calculation results are found to be in good agreement with the experimental data and other theoretical calculations.  相似文献   
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This paper develops and analyses a novel numerical scheme to price European options under regime switching model which is governed by a system of partial differential equations(PDEs).To numerically solve these PDEs,we introduce a fitted finite volume method for the spatial discretization,coupled with the Crank-Nicolson time stepping scheme.We show that this scheme is consistent,stable and monotone,and hence the convergence of the numerical solution to the viscosity solution of the continuous problem is guaranteed.Numerical experiments are presented to demonstrate the accuracy,efficiency and robustness of the new numerical method.  相似文献   
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分别用乙二胺、二乙胺、三乙胺将自制的以甲基丙烯酸缩水甘油酯(GMA)为单体、乙二醇二甲基丙烯酸酯(EDMA)为交联剂的整体柱修饰为弱、强阴离子交换整体柱。考察了该整体柱的性能,选择出分离蛋白质(牛血清白蛋白、溶菌酶和谷胱甘肽)的最佳实验条件,并在最佳分离条件下考察了这些蛋白质在整体柱上的色谱行为和该整体柱对纤维素降解酶的分离纯化情况。实验结果表明,该整体柱性能良好,可以实现对纤维素降解酶的快速分离与纯化。同时,实验也证明采用梯度洗脱可以实现对某些蛋白质的分离纯化。  相似文献   
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