High Temperature Corrosion of Fe-C-S Cast Irons in Oxidizing and Sulfidizing Atmospheres

The corrosion behavior of spheroidal graphite and flake graphite cast irons was studied in oxidizing and sulfidizing atmospheres between 600 and 800℃ for 50 h. The corrosion rate in the sulfidizing atmosphere was faster than that in air above 700℃, due to the formation of the Fe0.975S sulfide. The corrosion rate of the spheroidal graphite cast iron was similar to that of the flake graphite cast iron.     

Strengths of Glass Spheres in Compression

The strengths of individual glass spheres of a commercial soda-lime-silica composition were measured in diametral compression for an extensive range of sizes. Standard plots for a two-parameter Weibull distribution yielded m values of ∼5 over a 400-fold range of volumes corresponding to a 50-fold range of surface areas. Various techniques related to the Weibull formulation, including normalization to a single specimen size, were applied to demonstrate the existence of a single flaw population in all of the sphere sizes. Dependence of the strengths on volume flaws for the diametral compression mode of testing was also confirmed.     

河流出口处短周期地貌变化的观测与模拟

中小型河流出口处地形变化的发生频率要比大河的高。这主要是由小河和大河的径流量及纳潮量的不同所引起的,尽管这两者之间波浪的作用力差不多。因此,对于小河的河口管理而言,更加频繁的现场监测是十分必要的。然而,目前还没有一种可以高频率地获取地形变化信息的监测系统。介绍一种利用安装在河口处的自动数码相机对中小型河流河口地形变化进行监测的方法。通过沙嘴左岸及右岸的数据,可以确定河口处的宽度。通过这一测量方法,在数值模型中所使用的参数也可以确定下来。     

Improved Real-time Implementation of Adaptive Gassian Mixture Model-based Object Detection Algorithm for Fixed-point DSP Processors

Foreground moving object detection is an important pocess in various computer vision applicatipons such as intelligent visual sur-veillance,HCI,object-based video compression,etc.One of the most successful moving object detection algorithms is based on Adaptive Gaussian Mixture Model (AGMM).Although AGMM-based object detection shows very good performance with respect to object detection accuracy,AGMM is very complex model requiring lots of floating-point arithmetic so that it should pay for expensive computational cost.Thus,direa implementation of the AGMM-based object detec-tion for embedded DSPs without floating-point arithmetic HW support cannot satisfy the real-time processing requirement.This paper pre-sents a navel real-time implementation of adaptive Gaussian mixture model-based moving object detection algorithm for fixed-point DSPs.In the proposed implementation,in addition to changes of data types into fixed- point ones,magnification of the Gaussian distribution tech nique is introduced so that the integer and fixed-point arithmetic can be easily and consistently utilized instead of real number and floating-point arithmetic in processing of AGMM algorithm.Experimental re-sults shows that the proposed implementation have a high potential in real-time applications.     

万向椭圆描述的Mean-Shift算法

传统的Mean-Shift算法在目标跟踪过程中,由于跟踪窗口尺度固定而不能很好适应目标的尺度变化,当目标尺度减小时,目标区域所提取的特征向量包含过多的背景干扰信息,目标尺度增大会使跟踪窗口偏离目标的质心,降低跟踪的鲁棒性。为此文中采用万向椭圆的方式对目标区域进行描述,减少背景干扰信息以突出目标模型,提取椭圆区域的加权颜色直方图为目标特征,采用尺度加减法自适应调整椭圆区域的大小,并在跟踪过程中根据运动轨迹动态调整椭圆方向,以增强跟踪的准确性。实验结果表明万向椭圆能够更好地描述跟踪目标的尺度和方向,在目标尺度变化比较平稳的情况下,尺度加减法能自适应调整跟踪窗口的尺度,可以取得良好的跟踪效果。     

Canonical transformation for a class of time-varying multivariable systems

This paper concerns the transformation of time-varying multivariable systems into canonical structures. The study employs differential matrix operators. It leads to a systematic and straightforward technique for developing canonical forms for time-varying multivariable systems that are uniformly observable and «lexicography-fixed’. It shows that canonical forms derived by other authors are special cases of the canonical form of this paper. The derived canonical forms are not unique. However, their structures are controlled by the designer     

Characterization of a Crude Kiwifruit Pectin Extract

Pectin was extracted from whole kiwifruit at a mean yield of 0.85%. The analytical properties of the crude kiwifruit pectin extract were compared with those of a commercially available apple pectin. The kiwifruit pectin exhibited a high gelling temperature of 90°C.     

钛基纳米润滑添加剂的减摩抗磨及自修复特性对比

针对恶劣工作环境会加剧机械设备摩擦副间的磨损而降低其服役寿命的问题,对比研究3种纳米添加剂TiO2、TiN和TiC在不同工况下的摩擦学性能及其自修复性能。根据SH-T0762-2005标准润滑油摩擦因数测定法,并利用MRS-10A型四球磨损试验机磨斑测量光镜、激光共聚焦显微镜和能量色散谱仪(EDS)对磨损表面进行表征,探讨其润滑抗磨及自修复机理。结果表明:钛基纳米添加剂的加入很好地改善了润滑油的抗磨减磨性能,并使其具有一定的自修复性能;当钛基纳米质量分数为0.5%时,其减摩抗磨性能达到最佳。3种纳米添加剂中,对润滑油减摩抗磨性能改善效果最好的是纳米TiO2,而自修复效果最好的则为纳米TiN。故纳米TiN和纳米TiO2作为润滑油添加剂,具有较好的减摩抗磨和自修复能力。     

应用突函数差异算法进行癌症分类的基因选择

研究了有关癌症分类的基因选择问题。开发了集成的基于平滑剪切绝对偏差罚分的SVM—特征选择方法,直接最小化分类器的性能。为解决优化问题,应用了突函数差异算法(difference of convex functionsal-gorithms,DCA)这一进行非突连续优化的通用框架,致使连续线性规划算法有限收敛。真实数据集上的先验实验表明算法达到了预想目标:在压缩大量属性的同时,保持了较小分类差错。     

Ethylene formation from methionine as a method to evaluate oxygen free radical scavenging and metal inactivation by cosmetics

It has been proposed that oxygen free radicals are involved in skin aging. This paper describes a new method for the evaluation of oxygen free radical scavenging by cosmetic products. It is based on the measurement, by gas chromatography, of ethylene produced during the oxidation of methionine by the hydroxyl radical. OH· is produced by an iron catalyzed superoxide-driven Fenton reaction in which superoxide is obtained by photochemical oxygen reduction. The cosmetic is applied, together with methionine, riboflavine, NADH, FeCl₃ and EDTA, on a glass microfibre filter and submitted to UVA exposure through a quartz cell. Ethylene is then measured from aliquots of the atmosphere inside the cell. Catalase or Desferal completely inhibits ethylene production. SOD or high concentrations of hydroxyl radical scavengers (Mannitol, DMSO etc. ) afford a partial protection. Thus the efficiency of O₂⁻·, H₂O₂ and OH· scavengers and iron chelators can be measured. The main advantage of this test is that it is performed in conditions which simulate skin during UV exposure (e.g. air and UV exposed thin layer). Furthermore, as it is non-invasive, it can also be applied to human skin in vivo.