保持几何特征的自适应弹性二次曲线模型

物体形状特征的准确提取往往受到图像获取、目标分割等过程中各种因素的影响,因而需要构造一种鲁棒的形状表现来保有其本质特征。揭示弹性二次曲线(EQW)模型中能量权重因子和样条重叠度因子与形状几何特性间的关系,提出一种自适应保持几何特征的EQW形状表现模型,并将该模型与交互式Live Wire算法相结合,应用至图像分割中,对于各种模态图像中的目标进行分割实验。直观上,本文方法能够在去除噪声同时较好地保持目标形状的显著特征;量化结果方面,交互式分割误差保持在较小稳定范围内,引入EQW模型带来的时间开销亦在可接受范围内。     

基于像素差异的金属腐蚀区域分割仿真研究

研究基于图像的金属腐蚀区域分割问题,提高分割区域的准确性。针对传统基于金属本身与腐蚀颜色的区别,利用像素差异的变化进行腐蚀区域的分割,因当腐蚀颜色与金属的本体颜色相差不是很大,或者在边沿发生像素的混淆时,利用差异边缘像素相减的方法很难完整分割腐蚀区域的问题。为了解决上述问题,提出利用空间像素差异距离聚类的金属腐蚀区域图像分割算法。通过计算差异像素之间的差异距离概率,将差异像素特征进行严格划分,对划分后的结果进行排序计算,详细描述混淆边沿信息,对腐蚀区域进行完整分割。实验证明,改进方法能够对金属腐蚀造成的细微区域完整分割,取得了满意的效果,为金属腐蚀区检测提供了参考。     

基于复杂网络理论的高校内部理工医文合作研究分析

运用复杂网络理论的基本原理和有关方法,对理工医文等学科、专业之间的合作规律和人员合作方式进行探讨,以某高校2005-2010年医工合作情况作为实例展开研究,采用5年的合作数据作了计算分析,研究了高校内部理工医文开展学科交叉工作的特点及其运行情况、医工交叉合作中存在问题,客观分析其原因,提出了解决的办法,为今后开展高校系统的理工医文交叉合作,建设电子化交叉平台.     

基于S7-300 PLC的运动定位系统设计

本文利用西门子组态软件WinCC及编程软件S7-300PLC实现了二维平面的快速准确定位。并对系统的平台构架、硬件选型、功能实现,实时监控做了具体的分析与设计。本系统实现了本地控制与远程监控,运行操作方式灵活可靠。自投入使用以来,各项功能正常,达到了设计要求。     

Reaction of water vapor and oxygen with liquid uranium

The reactions of water vapor and oxygen with liquid uranium were studied by modulated molecular-beam mass spectrometric methods. Equivalent pressures of the reactant fluxes on the surface ranged from 6×10 ^–6 to 2×10^–4 torr. Temperatures up to 1570 K were investigated. The metal surface was kept clean during reaction by mechanical removal of the oxide formed with a tungsten needle. For the clean liquid uranium surface, a water reaction probability of 0.4 was deduced both from measurement of the reaction-product hydrogen signal and by the temperature dependence of the scattered reactant signal. Based solely on the latter measure, a reaction probability of 0.6 was estimated for oxygen. The reaction probabilities on the clean surface were temperatureindependent. They decreased as the coverage of the surface by islands of oxide increased and, for water, appeared to approach a value of 0.08 for a surface completely covered with an oxide estimated to be 500 Å thick. Bombardment of the surface during reaction with argon ions produced an increase in the reactivity on solid uranium but had a negligible effect on the reaction probability for the liquid.     

硫酸盐还原菌腐蚀的微生物防治研究进展

综述了硫酸盐还原菌腐蚀领域的微生物防治措施的研 究进展，并对微生物菌种的选择、防治机理以及应用等方面进行了探讨.     

Preparation of micro-arc oxidation coatings on magnesium alloy and its thermal shock resistance property

1. Introduction Due to their high specific strength, good electro-magnetic shielding characteristics, high damping characteristics, good cast ability, and excellent pol-ishing capability, magnesium alloys are extensively used in aeronautical, automobile, and electro- communication industries [1-3]. But magnesium has some disadvantages, such as low chemical stability, high negative electric potential, and low hardness, so it is necessary to use surface disposal to accommo-date the demand for re…     

浅析高速线材轧制的稳定性

在高速线材轧制过程中，轧件易发出偏斜和扭转，如果能够实现自动找正，则可保证顺利轧制。通过分析高速线材生产中的椭圆——圆孔型系统的受力条件，证明椭圆——双心圆孔型系统有更好的稳定性和找正作用，为高速线材孔型设计提供了稳定性依据。     

Electrochemical investigation of the iron-containing and no iron-containing AB5-type negative electrodes

The electrochemical behaviour of LaNi_3.55Mn_0.4Al_0.3Co_0.75−xFe_x (x = 0, 0.15, 0.55, 0.75) intermetallic compounds has been studied and presented [C. Khaldi, H. Mathlouthi, J. Lamloumi, A. Percheron-Guégan, Int. J. Hydrogen Energy 29 (2004) 307–311; C. Khaldi, H. Mathlouthi, J. Lamloumi, A. Percheron-Guégan, J. Alloys Compd. 360 (2003) 266–271; C. Khaldi, H. Mathlouthi, J. Lamloumi, A. Percheron-Guégan, J. Alloys Compd. 384 (2004) 249–253]. It has been deduced that the LaNi_3.55Mn_0.4Al_0.3Co_0.4Fe_0.35 compound has interesting electrochemical properties. In this paper we present the electrochemical study of LaNi_3.55Mn_0.4Al_0.3Co_0.4Fe_0.35 compound properties compared with the parent LaNi_3.55Mn_0.4Al_0.3Co_0.75 compound. Several techniques, such as, the chronopotentiometry, the constant potential discharge (CPD), the cyclic voltammetry (CV) and the linear polarization (LP) were applied to characterize these electrochemical properties. The electrochemical discharge capacity of the LaNi_3.55Mn_0.4Al_0.3Co_0.75 alloy increases to reach 294 mAh g⁻¹ after few cycles only (five cycles). However, the activation of the LaNi_3.55Mn_0.4Al_0.3Co_0.4Fe_0.35 alloy takes more than 20 cycles to be achieved and the obtained maximum discharge capacity is 194 mAh g⁻¹. The hydrogen diffusion coefficient D_H was determined by constant potential discharge and cyclic voltammetry techniques. The obtained values of the LaNi_3.55Mn_0.4Al_0.3Co_0.75 and LaNi_3.55Mn_0.4Al_0.3Co_0.4Fe_0.35 compounds are 6.29 × 10⁻¹¹ and 7.62 × 10⁻¹¹, and 2 × 10⁻⁸ and 7.5 × 10⁻⁸ cm² s⁻¹ by CPD and CV techniques, respectively. The exchange current density values, determined by a linear polarization technique, are 44 and 27 mA g⁻¹, respectively, for LaNi_3.55Mn_0.4Al_0.3Co_0.75 and LaNi_3.55Mn_0.4Al_0.3Co_0.4Fe_0.35 alloys.     

超声波检测混凝土结构抗冻性的方法研究

依据固体结构动弹模与表面波速度的关系，采用超声波检测混凝土冻融试件的动弹模，并与共振法测出的动弹模进行对比，总结出其内在相关规律，建立起预报混凝土动弹模的回归主程，由测得的波速计算出相应的动弹模，再利用动弹模之比评估出混凝土结构的抗冻性。初步试验和研究表明，此方法研究思路切实可行，符合混凝土冻融特性的基本变化规律，能够实现从度件测试向结构检测的发展，可供混凝土耐久性检测工程参考。