基于SIMD—PRAM模型的分块图像匹配算法设计

该文研究了基于SIMD—PRAM计算模型的有限处理元阵列规模的并行计算算法设计,分析了求阵列和的并行算法性能,运用求阵列和、图像分块映射与四邻平移等方法提出了一种根据处理元局部可用资源进行分块计算的图像匹配算法。计算机模拟实验结果表明,该算法完整、高效地执行了图像匹配,具有良好的并行计算性能。     

发电厂商策略性报价的行为特性初探

发电厂商的行为特性对其报价策略的选取有重大影响。文中通过指数型效益函数计入发电厂商的风险取向，得到考虑竞价失败损失和发电厂商风险取向的最优报价策略。由于风险取向的不同，发电厂商的报价策略各不相同。但在统一出清电价下，无论发电厂商是何种风险类型，其最优报价在形式上均为在其运行成本减去竞价失败损失的基础上再加上一个提升量。在成本相同的情况下，风险进取者的报价高于风险回避者。避免竞价失败损失是发电厂商报价低于成本报价的根本原因。理论分析和数值算例都说明了上述结论，并用蒙特卡罗模拟验证了最优报价的正确性。     

基于分形几何模型的图象放大

鉴于自然物体图象具有分形特性，提出一种基于分形几何原理的放大图象的处理方法，它通过提取图象的分形参数，采用了随机中点位移法进行插值，运行实例表明该方法的放大效果良好     

氢蚀对Cr-Mo钢断裂韧性和裂纹行为的影响

选用经４００℃，２０ＭＰａ，１０５ｈ氢暴露后的Ｃｒ－Ｍｏ钢进行了拉伸试验、疲劳试验和断裂韧性试验。结果表明，氢蚀使Ｃｒ－Ｍｏ钢强度、塑性和断裂韧性均降低，也使断裂机制由韧窝型转变为解理脆性，氢蚀使疲劳裂纹扩展速率增加，门槛值降低。Ｃｒ－Ｍｏ钢氢蚀后，随应力比Ｒ的增加，疲劳裂纹扩展门槛值大幅度降低。     

一个基于语义的图像检索系统:VisEngine

介绍了一个基于语义的图像检索系统——VisEngine，该系统采用基于图像主要区域的图像分割方法，分别提取图像前景、背景和全局的视觉和抽象语义内容，构造相应的语义模板。接着把这些特征导入到一个面向对象的中间信息结构中，在此基础上进行多种方式的相似性匹配和检索。系统支持多种查询方式，用户交互界面自然友好。实验表明，VisEngine系统能有效地提高首次用户查询的正确性。     

三次Bézier曲线的自适应降阶

提出了一种基于选择分割点的三次B啨ｚｉｅｒ曲线的自适应降阶方法 ,并讨论了降阶后的误差计算方法 该方法的特色为依照拐点、曲率极大点的优先次序选择分割点 实验结果表明 ,该方法除了具有传统方法的端点插值和GC1连续的特点外 ,还具有得到的二次B啨ｚｉｅｒ曲线段数较少的优点     

Effect of AlP master alloy on grain refinement of primary silicon in eutectic Al-Si alloys

To obtain the finer primary silicon crystals, the proprietary Al-P master alloy was adopted to modify the eutectic Al-Si alloys and the most suitable modification process was made in the experiments. The SEM (Scanning Electron Microscope) and DSC (Differential Scanning Calorimeter) analysis indicate that the Al-P modifier has more advantages over Cu-P and Fe-P modifier in easily addition, no elemental alteration and less undercooling of primary silicon′s solidification, which suggests the Al-P master alloy is an effective modifier of eutectic Al-Si alloys.     

关于辅助沉积霍尔离子源的几个问题

本文目的在于改进霍尔源的设计,实现宽能、大束流、低气耗、低污染、能自动化控制的新一代霍尔源.     

Healing of hydrogen-attacked cracks in split specimens with recovering heat treatment in vacuum

The healing mechanism of hydrogen-attacked cracks in low carbon steel and Cr-Mo steel and its influencing factors during the healing process were studied by recovering heat treatment of split specimens in vacuum. The result showed that crack pacing turns much smaller under the condition of pure heating, especially for crack tips. The healing effect is well related to the length of cracks with the shorter in priority. By the primary mechanism of thermal diffusion, iron and carbon atoms must diffuse at the high speed in steel to realize that plasticity deformation energy exceeds and overcomes surface tensile force energy. In addition, phase transformation and stress-stain relationship also have positive effects on the process.     

Initial corrosion behaviors of AZ91 magnesium alloy in the presence of SO2

The effects of SO2 on the initial atmospheric corrosion of AZ91D magnesium alloy were investigated in laboratory. Met-allographic observation, SEM (Scanning Electron Microscopy), XRD (X-ray Diffraction) and XPS (X-ray Proton Spectrograph) were used to analyze and discuss the initial surface morphology of corrosion layers and corrosion products. The corrosion rate of the alloy increases with increasing the content of SO2. The initial attack has the characteristics of localized corrosion and preferentially concentrates on a phase. MgO and Mg(OH)2 form at first, which provide a protective layer, then the existence of SO2 decreases the pH of the thin solution on the alloy, accelerates dissolution process, and promotes the formation of MgSO3·6H2O and MgSO4·6H2O, meanwhile cracks were found on the corrosion products with corrosion continuation. These soluble corrosion products and the cracks provide the paths for filtering oxygen and corrosion pollutants into the matrix, which results in severe localized co