DP980+Z烘烤硬化值与退火温度的关系

摘要：为了研究退火温度对镀锌DP980+Z烘烤硬化值的影响，退火温度控制在760～820℃之间，系统分析退火温度对烘烤硬化值的影响。通过准静态拉伸试验机测量烘烤硬化值及抗拉强度，采用lepara试剂对组织中的马氏体进行着色，利用金相显微镜及图像处理软件测量马氏体的体积分数；采用扫描电镜观察DP980+Z的双相组织特点，并且将组织图片通过CAD转化成有限元图进行网格划分，建立代表性体积单元（RVE），通过有限元分析铁素体、马氏体强度对烘烤硬化值的影响。在同样的变形量情况下，DP980+Z的原始屈服强度越高，烘烤硬化值越高。     

节理岩体的代表单元集合体模型及弹性参数预测

本文明确提出了节理岩体“代表单元集合体”的概念和模型，通过对节理岩体的“代表单元集合体”进行数值模拟，研究了节理岩体的“代表单元集合体”的变形特性，建立了节理岩体的弹性模型，提出了预测节理岩体宏观等效弹性参数的计算机模拟方法，并将其应用于岩体工程稳定性分析中。     

平纹织物复合材料的弹性模量预测

利用细观力学的代表体积元(RVE)法,预测了平纹织物复合材料的弹性模量。建立了表征RVE形态的数学模型,分析了细观结构与宏观性能之间的关系,编制了从组分材料的弹性性能推测复合材料的弹性性能的预测程序。对理论预测进行了实验验证,理论值与实测值在一定误差范围内能较好吻合,说明此预测方法具有一定的可靠性。     

一种光时分制交换时隙分配计算算法

介绍了一种专为时分复用系统设计的时院分配计算算法。这种算法中主要用到的技术是从一个话务矩阵的各行选出一个区别代表的系统方法。对于任何话务矩阵，这种算法的分配效率都能达到１００％，所产生的模式矩阵个数最多为ｎ２－２ｎ＋２个（对于ｎ×ｎ矩阵）。     

浅议进一步发挥军事代表在武器装备全寿命费用管理中的作用

阐述了军事代表参与武器装备全寿命费用管理的现状和作用,提出了提高军事代表费用管理参与率的措施.     

基于多代表点学习的RSKNN分类算法

RSKNN 算法是一种基于变精度粗糙集理论的 k-近邻改进算法,该算法能够保证在一定分类精度的前提下,有效地降低分类的计算量,提高分类效率。但由于 RSKNN 算法只是简单地将每个类中的样本划分成一个核心和边界区域,并没有根据数据集本身的特点进行划分,因而存在极大的局限性。针对存在的问题,提出一种多代表点学习算法,运用结构风险最小化理论对影响分类模型期望风险的因素进行分析,并使用无监督的局部聚类算法学习优化代表点集合。在UCI公共数据集上的实验表明,该算法比RSKNN算法具有更高的分类精度。     

2008-2009 年江苏省闪电特征分析及应用研究

统计了江苏省气象部门雷电探测系统2008-2009年闪电记录,对江苏省闪电强度、闪电频数等闪电特征进行分析,得出江苏省的雷电流强度和闪电分布都有明显的时空差异,并且闪电频数和强度在空间分布上基本呈相反分布;同时利用地闪记录与雷暴日数的关系,得出了适用于江苏13个地级市的地闪密度计算公式.     

Aspects of surface and environment protection in German mining areas

Hard coal mining in the German Ruhr district has a tradition of more than 200 years. Starting in the south near the river Ruhr with mining of seams near to the surface, mining wandered to the north with coal seams deeper and deeper. In the same way all environmental effects of mining wandered from south to north, as there are abandoned mining sites, contaminated areas, burning mining dumps, subsided areas and gas accesses at day ground. This all happened in a very high populated area with more than four million inhabitants. Therefore Germany has a long tradition in solving environmental problems of mining activities. The very good interaction of mine authority, mining companies and the mine workers' union is the main reason why the problems of decreasing mining activities in Germany were solved without economic, environmental or social hazards.     

多代表点的加权近邻分类算法

传统的KNN算法存在分类效率低等缺点.针对这些缺点,本文提出一种高效的结合多代表点思想的加权KNN算法,利用变精度粗糙集上下近似区域的概念,结合聚类算法生成代表点集合构造分类模型,再运用结构风险最小化理论优化分类模型并对影响分类模型的因素进行分析.分类过程中根据测试样本与各代表点的相似度,得到测试样本的相对位置.其中属于样本点下近似区域的测试样本可直接判断其类别.若测试样本在其他区域,则根据测试样本与各代表点的相对位置对各代表点覆盖范围内的样本进行加权后判断测试样本的类别.在文本分类领域的数据集上进行实验,结果表明该算法能有效的提高分类模型的性能.     

An application of MODIS data to snow cover monitoring in a pastoral area: A case study in Northern Xinjiang, China

Snow is an important land cover on the earth's surface. It is characterized by its changing nature. Monitoring snow cover extent plays a significant role in dynamic studies and prevention of snow-caused disasters in pastoral areas. Using NASA EOS Terra/MODIS snow cover products and in situ observation data during the four snow seasons from November 1 to March 31 of year 2001 to 2005 in northern Xinjiang area, the accuracy of MODIS snow cover mapping algorithm under varied snow depth and land cover types was analyzed. The overall accuracy of MODIS daily snow cover mapping algorithm in clear sky condition is high at 98.5%; snow agreement reaches 98.2%, and ranges from 77.8% to 100% over the 4-year period for individual sites. Snow depth (SD) is one of the major factors affecting the accuracy of MODIS snow cover maps. MODIS does not identify any snow for SD less than 0.5 cm. The overall accuracy increases with snow depth if SD is equal to or greater than 3 cm, and decreases for SD below 3 cm. Land cover has an important influence in the accuracy of MODIS snow cover maps. The use of MOD10A1 snow cover products is severely affected by cloud cover. The 8-day composite products of MOD10A2 can effectively minimize the effect of cloud cover in most cases. Cloud cover in excess of 10% occurs on 99% of the MOD10A1 products and 14.7% of the MOD10A2 products analyzed during the four snow seasons. User-defined multiple day composite images based on MOD10A1, with flexibilities of selecting composite period, starting and ending date and composite sequence of MOD10A1 products, have an advantage in effectively monitoring snow cover extent for regional snow-caused disasters in pastoral areas.