基于CATV的一站式电子政务系统的构建

电子政务是Internet网络上的综合应用,利用外交互式技术在CATV网络上构建一站式电子政务是充分利用现有的CATV网络资源的最好选择;在CATV网络上构建电子政务最关键的是要建立起安全的信息通道,安全的信息通道的建立必须借助于PKI技术.     

天然气吸附储存脱附过程的动态模拟

通过热动力学计算,认识了脱附过程当中储罐内温度剖面分布的典型特征:储罐轴心处的温度下降幅度最大。分析了脱附过程当中储罐壁的热交换、吸附剂的导热系数以及储罐内的初始压力对储罐内的温度剖面的影响。结论是加强储罐外壁的热交换、增大吸附剂的导热系数皆能改善吸附储罐内的温度剖面。     

高阶统计量地震子波估计建模

本文在反射系数序列为非高斯、平稳和统计独立的随机过程,地震子波为非因果、混合相位的假设条件下,分别应用滑动平均(MA)和自回归滑动平均(ARMA)模型对地震记录进行建模,并采用运算代价较小的基于高阶累积量的线性化求解方法——累积量矩阵方程法进行了子波提取和模型适应性的研究。数值模拟结果和实际地震数据处理结果表明:自回归滑动平均(ARMA)模型比滑动平均(MA)模型具有参数节省、模型更为高效的特点;累积量矩阵方程法可以有效地压制加性高斯噪声,但对累积量样本估计的准确性要求较高;如果累积量样本估计的误差和方差适度,结合自回归滑动平均(ARMA)模型描述的累积量矩阵方程法可以高效、准确地估计出地震子波。     

Modeling and performance evaluation of a cellular mobile network

An analytic model of cellular mobile communications networks with instantaneous movement is investigated in this paper. This cellular mobile network is showed to be equivalent to a queueing network and furthermore the equilibrium distribution of this cellular mobile network is proved to have a product form. The explicit expressions for handoff rates of calls from one cell to another, the blocking probability of new calls and handoff calls are then obtained. Actual call connection time (ACCT) of a call in this cellular mobile network is characterized in detail, which is the total time a mobile user engages in communications over the network during a call connection and can be used to design appropriate charging schemes. The average ACCT for both complete call and incomplete call, as well as the probability for a call to be incomplete or complete, are derived. Our numerical results show how the above measures depend on the new call arrival process for some specific reserved channels numbers in each cell. The results presented in this paper are expected to be useful for the cost analysis for updating location and paging in cellular mobile network.     

光学材料的激光微加工研究进展与应用前景

综述了国内外在光学材料激光微加工方面的研究成果和应用状况，并展望了其发展前景。     

Simulations of Temperature Field in HFCVD Diamond Films over Large Area

A three-dimensional model was developed to investigate the influence of various hot filaments parameters on substrate temperature fields that significantly affect the nucleation and growth of diamond films over large area by hot-filament chemical vapordeposition (HFCVD). Numerical simulated results indicated that substrate temperature varies as a function of hot filamentsnumber, radius, temperature, emissivity, the distance between filaments, and the distance between substrate and filamentsarrangement plane. When these filaments parameters were maintained at the optimal values, the homogeneous substrate temperature region of 76 mm×76 mm with the temperature fluctuation no more than 5% could be obtained by a 80 mm×80 mmhot filaments arrangement plane. Furthermore, the homogeneous region could be enlarged to 100 mm×100 mm under thecondition of supplementary hot filaments with appropriate parameters. All of these calculations provided the basis for speciallyoptimizing the hot filaments parameters to dep     

Discussion on "the fractal effect of irregularity of crack branching on the fracture toughness of brittle materials" by Xie Heping

International Journal of Fracture 41 (1989) 267–274     

激光抛光技术的发展与展望

介绍激光抛光技术的发展历史,阐明激光抛光的应用现状及未来的发展前景,论述了激光抛光的工艺特点和作用机理,将激光抛光技术与其它抛光技术进行了全面的对比,指出激光抛光的优势及其存在的问题。     

应用粒子动态分析仪研究水力旋流器流场

利用粒子动态分析仪(PDA),对水力旋流器内固相颗粒流场做了全面的测定,得出水力旋流器内固相颗粒的流态、浓度及粒度分布,为进一步查清水力旋流器的工作机理提供了重要理论依据。