基于可变Cookie的跨域单点登录

针对单点登录中的跨域身份认证问题,提出了一种基于可变Cookie的方案解决跨域单点登录,使用随机数字生成票据,并作为传统加密算法的会话密钥对客户端的Cookie进行加密,采用现代加密算法在异域系统之间安全传递票据,每次认证产生新的票据并更新异域应用系统的Cookie。通过对票据产生和传输以及Cookie加密和常见攻击的安全性分析,可以实现跨域单点登录的功能并保证身份认证安全可信。     

一种雷达目标的动态雷达散射截面模拟

为了能够掌握动态目标的飞行特性,提出了一种模拟目标动态雷达散射截面(RCS)的方法。该方法根据雷达目标航迹相关数据,结合测量坐标系和目标坐标系转换原理,采用多层快速多极子算法,仿真建立了目标静态下的RCS数据库。同时,通过编程实现了目标动态RCS模拟程序,并通过分析得到动态目标RCS曲线。该结果表明,雷达目标的动态RCS模拟对掌握目标的飞行特性起到了一定的作用。该方法可以代替RCS实际测量过程,具有实现简单、操作性好等优点。     

基于线分割的立体匹配算法

给出一种改进的立体匹配算法。根据视差场的极限约束,采用图像线分割的匹配方法得到初始视差,由基于初始视差的交叉检测技术和可信度约束提取高可靠度的GCP点。针对视差图中的不可靠点,加入Bilateral Filter的自适应加权中值滤波,在由均值偏移图像分割算法得到的分割区域内,对像素的视差值进行投票,有效遏制局外点,得到更合理的视差图。在Middlebury test set上进行的测试结果表明,该算法具有较好的视差估计精度。     

一种改进的基于扩频信号的混响产生模型

提出了一种某一时刻有贡献的散射体数目随时间变化的方法,并将对散射信号的求和转换为对信号与散射特性函数的卷积,简化了计算方法。仿真中,利用扩频信号作为发射信号对海面混响进行了模拟,对比分析了混响的频谱与发射信号频谱之间的关系,验证了混响瞬时值和幅值包络的分布函数。仿真和分析结果表明,混响模型可以有效地模拟实际海洋混响。     

三弧段型面联接的数控加工

论述了三弧段型面曲线的形成及其曲线参数方程,编制了三弧段型面的数控加工宏程序,适用于各种不同参数的三弧段型面的加工,且能够满足加工精度的要求。     

Interferometer for cold neutrons

Design and setup of an interferometer for cold and ultracold neutrons are described. As neutron optical components three holographically produced gratings are arranged in triple Laue geometry. The gratings are adjusted during their recording process in photosensitized polymer slabs once for ever. Employing this device we measured the coherence function of a cold neutron beam by means of interferometry.     

Effect of combined shot-peening and PEO treatment on fatigue life of 2024 Al alloy

One of the most important objectives in the surface engineering of light-weight alloys is to enhance their fatigue properties, allowing both increased performance and an extended service life. This can be achieved by forming a hard surface layer while incorporating a favourable stress state. Single surface treatments, for example, Plasma Electrolytic Oxidation (PEO), are not always capable of creating optimal combinations of these characteristics, whereas greater durability can be achieved by applying mechanical pre-treatments prior to the coating. In this work, a combination of shot-peening pre-treatment with plasma electrolytic oxidation coating is studied as a means to improve the fatigue performance of 2024 T351 Al alloy. The shot-peening was carried out in a compressed air configuration using S110 gauge shot at 200% coverage with an intensity of 20 AlmenC. PEO coatings of 30 μm thickness were produced using pulsed bipolar current technology. Fatigue properties were evaluated by a four-point bending technique at a stress ratio of 0.1. Hardness, residual stress and microstructure of the surface layers were studied by Knoop microhardness tests, fluorescence spectroscopy and SEM analyses, respectively. The effect of the combined shot-peening and PEO treatment is an increased fatigue limit and elevated microhardness when compared to aluminium treated only with PEO.     

利用线性抽样方法重建Dirichlet边界条件声波散射区域

线性抽样方法是考虑一个第一类线性积分方程中的参数从区域内部趋近散射区域边界时,该方程的解趋近于无穷大。本文在此基础上就Dirichlet边界条件的声波反散射问题,利用积分方程理论严格证明了线性抽样方法对其的可用性,具体数值例子表明该方法是有效的。     

从EOS/MODIS数据中提取夜间强对流云团的闪电信息

主要探索用EOS/MODIS极轨卫星监测闪电的可行性,应用大气和云辐射原理以及云中水滴mie散射的原理,从EOS/MODIS的中红外通道及热红外通道中提取夜间强对流云团产生的闪电信息,并可由强对流卫星云图的云顶温度确定可能出现冰雹的区域,对减灾、预警提供宏观信息。     

熔炼炉壁中砌体的界面力学有限元矩阵对号入座法与热应力

矩阵对号入座法是曾庆元院士对有限元的重大贡献,这种界面力学热应力有限元矩阵对号入座法被应用到高炉砌体中去,对高炉内衬的热应力进行分析,获得成功。