The evaluation of transition matrix elements for atomic excitations by a screened Coulomb potential

We have developed a FORTRAN code for calculating screened potential matrix elements for transitions between atomic bound states. In the applied procedure, the target wave functions can be arbitrarily chosen, and a wide class of screening potentials can be applied. The program includes subroutines for the calculation of the modified Bessel functions of fractional order and their derivatives for a broad range of argument and order.     

电离辐射影响评价中的生物剂量率限值

比较分析了近年来国际上主要研究机构/组织在生物剂量评估工作中剂量率限值的研究成果。欧洲ERICA项目和PROTECT项目使用FREDERICA效应数据库中的辐射效应数据估计单个生物物种的关键毒理数据EDR10,使用不同物种的EDR10与剂量率数据,建立物种敏感分布(SSD)曲线,采取物种敏感分布法推算出生物的筛选剂量率。在此基础上,结合我国放射生态学研究现状,提出了我国生物剂量率限值研究的相关建议。     

冲击噪声下基于子空间拟合的DOA估计新算法

研究了在对称α稳定分布(Symmetric α-stable,SαS)冲击噪声背景下的基于子空间拟合的多目标DOA估计算法.由于SαS冲击噪声造成传统DOA算法性能下降,提出了基于分数低阶矩统计量的FLOM-SSF/NSF算法和Screened Ratio原理的SR-SSF/NSF算法.计算机仿真表明两种算法都能有效地改善SαS型冲击噪声对DOA估计的影响,有更好的稳健性,其中SR-SSF/NSF算法性能略好于FLOM-SSF/NSF算法.     

屏蔽子网型防火墙内部路由器的性能改进算法

基于屏蔽子网型防火墙体系结构,针对其内部路由器,提出了一种性能改善方案。在保证防火墙防范效用的前提下,提高了内部网络与非军事区网络间的数据吞吐量,调和了防火墙自身关于效率与效用的矛盾。     

屏蔽子网型防火墙系统的安全隐患分析

本文分析了屏蔽子网型防火墙系统的体系结构特点，通过一个实例，剖析了屏蔽子网型防火墙存在的安全隐患，并给出了初步的安全建议。     

The range of penetration and the backscattering coefficient by using both the analytic and the stochastic theoretical ways of electron slowing down in solid targets: Comparative study

The aim of this paper is to determine the best theoretical way (stochastic or analytic) to use in the study of the range of penetration and the backscattering coefficient of electron impinging in solid target, by adopting the same input in the form of collision cross-sections. For this purpose, differential elastic cross sections has been calculated by using our semi-empirical model [A. Bentabet, Z. Chaoui, A. Aydin, A. Azbouche, Vacuum 85 (2010) 156]; and that of inelastic cross sections has been calculated by using Gryzinski’s excitation function. Moreover, in stochastic case, the obtained quantities are calculated by using both Monte Carlo schemes based on continuous slowing down approximation (CSDA) and on individual electron scattering events methods.     

DFP系列屏蔽泵的设计和运行情况

为满足特殊需要，东方泵业根据以往在屏蔽泵方面的设计、制造和运行经验，专门设计制造了一批专用屏蔽泵，经几个月的实际运行，证明其性能优良、运行可靠，能满足现场运行要求。