[en] In this paper, analytic formulae of the bound-free (photoelectric) Gaunt factor for nl from 6s to 10l are given. The formulae are obtained by using hydrogen-like Coulomb wave functions. Analytic results are presented and agree very well with those of numerical method. The formulae are useful to calculate conveniently the bound-free cross-sections and absorption coefficients in plasma simulations

[en] Based on the HFR method for bound states and Distorted-Wave method for continuous states, photoionization cross sections that describe level to level transitions of He-like Rb and He-like Nb ions have been calculated. In the calculation, configuration interactions between bound states have been considered. The included configurations of the process are 1s nl→1s εl +- 1 (1≤n≤6,0≤l≤n-1), and the energy range of free electron is 0∼10 times the ionization energy. The computational error and the data accuracy are discussed. Also the results that have been summed over final states are provided

[en] Based on the HFR method and considering configuration interaction between bound states, some problems and inadequacies what may be occurred in the calculation of photoionization cross sections by using Cowan's theory are discussed, and correct method is given to solve these problems. Using the method, photoionization cross sections of Li, Na and Cs atoms are calculated and compared with references. The difference and relationship between the orbital-orbital and the summed level-level photoionization cross sections are discussed and analysed theoretically

[en] A model is developed to calculate the emission spectrum of non-local thermodynamic equilibrium (LTE) plasmas. The collisional-radiative model is adopted for non-LTE population calculations. Configuration-averaged rate coefficients that are needed in the rate equations are obtained based on the first-order perturbation theory. The Hartree-Fock-Slater self-consistent-field method is used to calculate electron wavefunctions. The present model is applied to the calculation of isoelectronic line-ratio of Cr and Ti, which is useful for plasma electron temperature diagnosis

[en] A method is presented to calculate the spectral-resolved opacity for non-local-thermodynamic-equilibrium plasmas. With the present method, the configuration population is obtained by solving the rate equations within the framework of configuration-averaged approximation in which the cross sections are calculated based on the first-order perturbation theory. The transition properties are calculated by using the unresolved transition array model. As the illustration, the frequency-dependent opacities of Al and Au plasmas are calculated and compared with the simulation results of the super configuration collisional radiative code. General agreements are obtained and there are some discrepancies for opacity of high-Z elements. (author)

[en] In this paper, analytic formulae are given to account for the plasma effect on the atomic energy levels using the Debye shielding potential. The formulae are obtained by using hydrogen-like wavefunctions. However, the present results agree well with those of the numerical method not only for hydrogen-like ions but also for multi-electron ions. The formulae are also useful to determine conveniently the maximum orbit of ions in plasmas.(author)

[en] A collisional-radiative model is developed for population calculations of plasmas in non-local thermodynamic equilibrium. The rate equations in detailed configuration accounting are solved to obtain ion populations. The configuration averaged rate coefficients are used in the rate equations. The cross sections are calculated based on the first perturbation theory. Wavefunctions required in cross section calculations are obtained by the Hartree-Fock-Slater self-consistent-field model. This kinetic model is applied to low- and medium-Z as well as high-Z plasmas. The results are compared with those of other theoretical models and experiments. The comparisons show that the present results of the mean charge state for low- and medium-Z elements agree well with other theoretical ones, while for high-Z elements, the present mean ionization stages are about two stages lower than the experimental ones

[en] The fabrication of nanotips has been driven by the increasing industrial demands in developing high-performance multifunctional nanodevices. In this work, we proposed a controlled, rapid as well as low cost nanomolding-necking technology to fabricate gold nanotips arrays. The geometries of gold nanotips having cone angle range of ∼28–77° and curvature radii of <5 nm can be prepared by tailoring the diameters of raw nanorods in nanomolding process or modulating the necking temperature. Molecular dynamics simulation reveals that the formation of the nanotip geometry is determined by the interplay between dislocation-based and diffusion-based deformation mechanisms, intrinsically arising from the nonlinear dependence of atom diffusion on temperature and sample size. The good controllability, mass production and low cost of the developed nanomolding-necking technology make it highly promising in developing nanodevices for a wide range of applications, such as probing, sensing, antireflection coating and nanoindentation. (paper)

[en] Graphical abstract: N-doped hierarchical porous carbons with high rate capacitive performance are prepared by a combination method of nano-SiO_2 template/KOH activation. - Highlights: • A mass produced nano-SiO_2 is used to prepared hierarchical porous carbon. • N-doped hierarchical porous carbon materials are easily prepared. • The NHPCs materials exhibit a very high capacitance of up to 260.5 F g"−"1. • The NHPC-800 sample shows very high rate capability. • Hierarchical porosity and N-doping synergistically enhances the whole capacitance. - Abstract: In this work, nitrogen-doped hierarchical porous carbon materials (NHPCs) are prepared by a two-step method combined of a hard template process and KOH-activation treatment. Low cost and large-scale commercial nano-SiO_2 are used as a hard template. The hierarchical porosity, structure and nitrogen-doped surface chemical properties are proved by a varies of means, such as scanning electron microscopy, transition electron microscopy, N_2 sorption, Raman spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy. When the prepared NHPCs materials are used as the electrode materials for supercapacitors in KOH electrolyte, they exhibit very high specific capacitance, good power capability and excellent cyclic stability. NHPC-800 carbon shows a high capacitance of 114.0 F g"−"1 at the current density of 40 A g"−"1, responding to a high energy and power densities of 4.0 Wh kg"−"1 and 10 000 W kg"−"1, and a very short drain time of 1.4 s. The excellent capacitive performance may be due to the synergistic effect of the hierarchical porosity, high effective surface area and heteroatom doping, resulting in both electrochemical double layer and Faradaic capacitance contributions

[en] The radiative opacities of hot dense sodium fluoride (NaF) plasma have been studied in the case of local thermodynamic equilibrium (LTE). The spectrally resolved opacity in the case of T=50eV and ρ=0.01g/cm³ is taken as an example to illustrate the absorption structures of the NaF plasma. The transitions from L to M shells of sodium and fluoride are the main contributions for the plasma absorptions. The isodense opacities of NaF plasma are studied at a density of 0.01g/cm³ and temperatures of 20-60eV. Detailed comparisons among the results of the detailed term accounting (DTA), detailed configuration accounting (DCA), unresolved transition array (UTA) and average atom (AA) model codes, which have been developed independently in China in the past few years, are performed for both the spectral resolved and mean opacities. Good agreements are found at a temperature of 40eV and a density of 0.01g/cm³, but discrepancies appear at a temperature of 50eV and a density of 0.01g/cm³