排序方式: 共有23条查询结果,搜索用时 15 毫秒
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The all-electron full potential augmented plane-wave plus local orbital (APW_Io) method with the local-density approximation (LDA) is used to calculate the static equation of state (EOS) and elastic constants of crystalline GaSe. After the full relaxation of atomic positions, the calculated band structure at ambient pressure is consistent with the experimental data to the extent expected to give the known limits of LDA one-electron energies. The equilibrium lattice parameters found here exhibit the usual LDA-induced contraction. However, constrained with the experimental cell volume, the interlayer separation exhibits an expansion due to the LDA underestimate of the weak interlayer bonding. The calculated values of elastic constants are in good agreement with acoustic measurements. The pressure derivatives of the lattice constants derived from the theoretical elastic constants are in very good agreement with x-ray spectra measurements. Two analytical EOSs have been determined at pressures up to 4.5 GPa. The pressure evolution of the structure indicates that the layer thickness decreases slightly under pressure. 相似文献
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发展了针对非局域热动平衡等离子体的K壳层电离平衡模型。模型中详细计算了各原子过程参数,并通过求解速率方程的稳态解得到各电离态的布居分布。在此基础之上,研究了谱线强度比值对等离子体温度、密度的依赖关系。最后,我们根据此模型的计算结果,分析了在神光II装置上获得的内爆靶丸掺Ar发射光谱实验数据,推断出靶丸芯区电子温度随时间的演化过程。 相似文献
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使用平均原子模型研究了电四极及更高阶跃迁对高温稠密金等离子体辐射不透明度的贡献.计算并讨论了在不同温度密度条件下,电四极,电八极,电十六极跃迁对束缚-束缚跃迁的影响.计算了密度为96.405 g/cm3时,不同温度条件下,电四极,电八极跃迁对Rosseland平均不透明度的贡献.考虑了电四极、电八极跃迁后金等离子体不透明度的相对改变最大分别为4.67%和1.5%,并和其它文献的理论结果进行了比较. 相似文献
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DTA模型计算高温氟化钠等离子体的辐射不透明度 总被引:1,自引:0,他引:1
使用细致谱项模型(detailed term accounting,DTA)计算了局域热动平衡(local thermodynamic equilibrium,LTE)近似下氟化钠等离子体密度为0.01?g/cm3的等密度系列的谱分辨不透明度以及Rosseland和Planck平均不透明度,分析了钠和氟离子L→M跃迁对不透明度的贡献以及温度的升高对于两种元素的L→M跃迁吸收峰的影响. 相似文献
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Open M-shell Opacity of Bromine Plasma in Comparison of the Detailed Level Accounting Model with the Average Atom Model 下载免费PDF全文
The open M-shell opacity of a hot bromine plasma has been calculated by using a detailed level accounting (DLA) model. One-electron orbitals obtained by solving the fully relativistic Dirac-Fock equations are used to obtain the atomic levels and the radiative transition oscillator strengths. Only the level mixing within the same electron configuration is considered to reduce the complexity of the calculations. Detailed comparisons have been made between the results of the DLA and average atom (AA) models. Good agreements are found for both the M-shell transition arrays and the Planck mean opacity but there are differences for the line positions in the 2p → 3d absorption region due to the statistical treatment for the one-electron orbitals in the AA model. 相似文献
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讨论了使用MCHF方法优化径向波函数以获取大量原子参数的方法,由得到的波函数计算了FeXXI离子的相对论与非相对论能级,将计算能级与已有的实验结果进行了比较,对电偶极,磁偶极以及电四极的振子强度进行了非相对论与相对论修正的计算,对非相对论计算的振子强度,长度与速度两种表示符合较好。 相似文献
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稠密、冷铝等离子体的辐射不透明度研究 总被引:1,自引:0,他引:1
使用细致谱项模型、联合组态相互作用方法和R 矩阵方法计算了处于局域热动平衡条件下的稠密、冷铝等离子体的辐射不透明度 .组态相互作用方法用于获得束缚 束缚吸收截面所需要的偶极跃迁振子强度 ,R矩阵方法用于获得光电离截面 .对于温度在 6— 12eV、密度为 0 .36mg/cm3 的铝等离子体 ,计算得到的吸收系数在波长为 0 .35 1,0 .5 2 7和 1.0 5 4 μm处与实验结果符合较好 ,而温度在 3— 6eV时 ,理论计算比实验结果大. The radiative opacity has been investigated by using detailed term accounting approximation for dense, cold aluminum plasmas under local thermodynamic equilibrium. The configuration interaction scheme has been used to obtain the relevant atomic parameters for bound-bound absorption, such as excitation energies and oscillator strengths. R-matrix method has been used to obtain the photoionization cross sections. For aluminum plasmas of density 0.36 mg/cm 3, temperature of 6-12 eV, the... 相似文献