激光对红外成像反舰导弹的对抗能力分析

首先从导引头激光接收功率密度是否大于其饱和阈值的角度推导出激光最大干扰距离的表达式,并将其与激光直视距离比较取小提出激光对抗距离的上限;然后从受干扰后的导弹是否还对目标构成威胁的角度推导出激光对抗距离的下限;接下来对影响激光对抗距离范围的各个因素分别进行分析;最后结合告警装置作用距离对激光对抗武器系统的响应时间进行了规定。分析结果表明：增强舰船机动性、增大激光器输出功率、增大发射望远镜孔径、改善激光光束品质、缩短系统响应时间能够有效提高激光武器系统对抗红外成像制导导弹的能力。     

抗恶劣环境加固显示器设计技术

介绍了加固显示器的类型,分析了显示器在恶劣环境下的特性,根据不同的特性给出了具体的设计技术,主要介绍了宽温技术、抗振动冲击技术、电磁兼容技术等。     

贵安国家级新区轨道交通线网规划研究与实践

以贵州省贵安新区的轨道交通线网规划为例,分析跨越城市行政界线的国家级新区轨道交通线网规划应注意的两大重点问题,即如何合理确定规划范围以及轨道交通的发展模式。线网规划打破行政区划限制,从区域一体化角度提出以大贵阳都市区轨道交通线网引导贵安新区发展,并通过构建市域快线和市区普线的双层次线网,以加强贵安新区与贵阳市中心城的快速联系,支持贵安新区核心片区发展,支撑贵阳-贵安同城协调化发展目标的实现。     

中小型绕线式异步电机可控硅串级调速系统的研究

本文通过分析目前国内中小型绕线式异步电机的调速现况,提出将转子电压提高,以达到取消逆变变压器及启动电阻,将转差功率直接回馈电网进行可控硅串级调速的可能性;提出了选择最佳转子开路电势的原则,并在一台改制的7.5kW 样机上进行了试验.试验结果证实,所提出的研制方案是经济实用和可靠的,电机的调速范围可达4.1∶1以上.     

泡沫沥青厂拌冷再生混合料级配优化设计

基于对泡沫沥青厂拌冷再生拌和机理的分析,提出了泡沫沥青冷再生混合料级配设计时RAP级配采用水洗法筛分是合适的。不同级配混合料的室内性能试验表明：4．75mm的通过率在45％以上时,混合料具有更优的强度和水稳定性能,较低的0．075mm的通过率（小于6％）,并不意味着混合料性能不满足规范要求。在此基础上提出了适合工程实际的优化级配范围。     

京杭运河二通道钱塘江出口船闸闸门涌潮作用力研究

分析了二通道钱塘江出口处水域设计条件下涌潮高度与潮差、低潮位的关系,采用低潮位下50 a一遇的涌潮高度作为船闸闸门涌潮作用力试验的边界条件,得到船闸闸门所受的涌潮作用力和分布特征,涌潮对船闸闸门的最大作用力发生在低潮位附近,引航道喇叭形的出口将会加大涌潮对闸门的作用力。     

Analysis and Comparison of Range-Range Positioning Mode and Hyperbolic Positioning Mode

Three key factors are discussed, which affect positioning accuracy of range-range positioning mode and hyperbolicpositioning mode.Based on the error elliptical theory, the expressions of positioning error and of positioning geometric factor ofrange-range positioning mode and hyperbolic positioning mode are derived, and the positioning error and the blind positioningarea of two different positioning modes are analyzed. According to the requirement of navigation area, an optimum positional     

改善设备使用条件 确保调车作业安全

介绍了铁路无线平面调车设备的特点,指出了日常使用中常出现的几种故障现象,提出了相应的解决办法。     

A computational approach for fatigue crack propagation in ship structures under random sequence of clustered loading

The authors have developed a simulation program, CP-System, for multiple cracks propagating in a three-dimensional stiffened panel structure, where through-the-thickness crack propagation is formulated as a two-dimensional in-plane problem, and the crack propagation behavior is simulated by step-by-step finite element analyses. In order to evaluate the fatigue lives of marine structures accurately, it is necessary to take into account the load histories induced by sea waves, which may be composed of a random sequence of certain clustered loads with variable stress range. In the proposed crack growth model, the crack opening and closure behavior is simulated by using the modified strip yielding model, and the effective tensile plastic stress intensity range, ΔK _RP, is calculated by considering the contact of plastic wake along the crack surfaces. The adequacy of the proposed crack growth model is examined by comparison with fatigue tests under non-constant-amplitude loading. The usefulness of the developed method is demonstrated for a ship structural detail under certain simulated load sequences. It is shown that the fatigue crack growth of a ship structure is significantly retarded due to the load interaction effects, so that the conventional method for fatigue life assessment may predict a relatively conservative fatigue life of a structure.     

Design of Fin-propeller Test Set-up and Analysis of Roll Stabilization Ability

Presents the fin-propeller test set-up to solve the problem of roll stabilization with ships in full speed range, withwhich, tests were run in water rank for acquisition of data, and concludes from data acquired that the fin-propeller test set-up produces more lift than simple fin, and provides lateral thrust as well, and it is therefore an effective roll stabilization devicefor ships in full speed range.