基于层次模糊综合评价法的信息安全评价

信息安全问题已成为影响组织信息化发展的重要因素,为保障信息安全,需要定期对网络与信息系统的安全状况进行测评。文中以质检系统信息安全现状为例,建立信息安全多因素层次模糊评价模型,阐述了基于层次的模糊综合评价方法在信息安全管理中的运用,为信息安全测评提供了新的思路和方法。     

弹性分组环技术简介

弹性分组环(RPR)技术是一种新兴的城域网技术。本文主要讨论了弹性分组环的网络体系结构和他的技术特点和优势。弹性分组环技术集以太网的经济性、IP的智能化、光纤环网的丰富带宽和可靠性于一体，是目前宽带IP城域网运营商的最佳组网方案。     

长波长PIN／HBT集成光接收机前端噪声分析

文章研究磷化铟(InP)基异质结双极晶体管(HBT)和PIN光电二极管(PIN-PD)单片集成技术,利用器件的小信号等效电路详细计算了长波长PIN/HBT光电子集成电路(OEIC)光接收机前端等效输入噪声电流均方根(RMS)功率谱密度.分析表明:对于高速光电器件,当频率在100 MHz～2 GHz范围内时,基极电流引起的散粒噪声和基极电阻引起的热噪声起主要作用;频率大于5 GHz时,集电极电流引起的散粒噪声和基极电阻引起的热噪声起主要作用.在上述结论的基础上,文章最后讨论了在集成前端设计的过程中减小噪声影响的基本方法.     

电子帘加速器电子枪的研制

研究了电子帘加速器电子枪的束流传输特性,分析了影响束流纵向均匀性的几个因素,尤其对灯丝的下垂问题提出了一种理想的端约束模型.介绍了新研制的电子枪,其束流纵向不均匀度≤±10%.     

Hopping Wave Function in Quantum Kicked Systems

A model of a kicked particle in an infinite potential well is studied. We presented the wave functions of the system applying a direct perturbation method. Theoretical analyses and numerical calculations show that the wave function is discontinuous across each kicking instant. As an extension of this result, we find that the wave function of any periodically kicked system usually has this property. Therefore, at each kicking instant, the wave function chooses randomly between the limits on either side and may be hopping.     

开关电容滤波器的Z域设计

本文介绍了几种开关电容滤波器的Z域设计方法,并给出了设计实例。计算机模拟结果表明与设计指标相当吻合。     

Lewis acid mediated reactions of aldehydes with styrene derivatives: synthesis of 1,3-dihalo-1,3-diarylpropanes and 3-chloro-1,3-diarylpropanols

[reaction: see text] The reactions of aryl aldehydes with styrene derivatives, mediated by various boron Lewis acids, were investigated. 1,3-Dihalo-1,3-diarylpropanes were obtained in high yields with boron trihalides, while 3-chloro-1,3-diarylpropanols were obtained in good to excellent yields with phenylboron dichloride. Reactions involving nonenolizable aliphatic aldehydes, trans-cinnamaldehyde, and beta-substituted styrenes were also investigated for the first time.     

用于反坦克导弹研究的红外能量测试技术

简述红外能量测试技术在反坦克导弹研究上的应用,介绍其工作原理和测试方法。给出在实际测试应用中的例子,并提出有关测试和数据处理的技巧。