振动改善全同立构聚丙烯注塑试样的力学性能

为了研究振动场对全同立构聚丙烯力学性能的影响，研制了压力振动注射装置，研究了不同熔体温度下，振动频率、振动压力对iPP F401注塑试样的拉伸强度、冲击强度和断裂伸长率的影响，并进行了WAXD和DSC测试。结果表明：振动除了提高试样结晶度外，还会诱导晶型的变化，即除α晶，还有β晶生成。随着振动频率和振动压力的增加，振动试样的拉伸强度和冲击强度得到明显改善，其最大增幅分别为26．1％和168％。     

高抗冲聚苯乙烯挤出发泡研究

采用自由挤出发泡工艺研究了两种高抗冲聚苯乙烯(HIPS)低发泡的成型配方，讨论了发泡剂DDL、SBS和硬脂酸钙[Ca(St)2]的用量对发泡制品的影响，利用SEM电镜和生物显微镜观察了制品的泡孔结构。结果表明，发泡剂用量为0．5份，SBS用量为10份和Ca(St)2用量为3份时，制品的泡孔比较均匀，机械性能良好。两种HIPS做发泡制品时效果基本一致。     

煤化工有机废渣萃取处理的研究进展

煤化工有机废渣是煤化工生产过程中产生的有毒有害的有机固体废弃物,有强烈的刺激性气味,对人类及环境都有巨大的危害,一般归属于危险废物。为了更加有效地处理这些废渣,在分析国内外煤化工有机废渣处理技术的基础上,对煤化工有机废渣的各种萃取处理技术——普通溶剂萃取分离法、超临界萃取分离法、溶剂油萃取分离法、离子液体溶剂萃取分离法、切换溶剂萃取法等进行了详细介绍,并比较了各方法的优缺点,对比分析了各类萃取溶剂、萃取工艺,以期为未来煤化工有机废渣的处理提供参考。     

Epoxy resins possessing flame retardant elements from silicon incorporated epoxy compounds cured with phosphorus or nitrogen containing curing agents

New silicon-containing epoxy compounds were obtained by reacting a bisphenol-A type epoxy and an o-cresol-formaldehyde novolac type epoxy with diphenylsilandiol and triphenylsilanol, respectively. The reactions were performed with tin(II) chloride as a catalyst at 140-170 °C. With various feeding ratios of reactants, the epoxy compounds contained various silicon contents. The thermal stability and the flame retardant property of the cured epoxy resins were improved with this incorporation of silicon. Synergistic effects of phosphorus/silicon and nitrogen/silicon on enhancing limited oxygen index values were also observed for the epoxy resins from the silicon-containing epoxy compounds cured with phosphorus- and melamine-containing agents.     

二段硫化条件对共聚型氯醚橡胶性能的影响

研究了二段硫化条件对共聚型氯醚橡胶(ECO)性能的影响。二段硫化后，ECO的100％定伸应力增大，拉伸强度和邵尔A型硬度先增大后减小，扯断伸长率、扯断永久变形及撕裂强度减小；耐热性能变化不大；常温下的耐油性能提高。高温短时的二段硫化有利于降低压缩永久变形。当二段硫化温度超过150℃，交联密度先增大后减小，且温度越高减小得越快。     

Preparation and characterization of thermoplastic vulcanizate/silica nanocomposites

This article describes the preparation, characterization, and properties of thermoplastic vulcanizate (TPV)/silica nanocomposites. The nanocomposites were prepared by the melt blending of TPV and maleic anhydride grafted polypropylene (mPP) into organically modified SiO₂ (m‐SiO₂), treated with n‐hexadecyl trimethylammonium bromide as a grafting agent for TPV during the melt mixing. The thermal stability and storage modulus of the 1 wt % m‐SiO₂ containing TPV/mPP/m‐SiO₂ nanocomposite were higher than those of pristine TPV. The most important observation was obtained from dynamic mechanical analysis, which revealed that the glass‐transition temperature of the polypropylene phase of the nanocomposites increased (in comparison with that of virgin TPV), whereas the ethylene–propylene–diene monomer phase remained almost the same. The adhesion strength between the TPV/mPP/m‐SiO₂ nanocomposites and steel also increased with increasing m‐SiO₂ content. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2058–2063, 2005     

红外成像区域法自动调焦聚焦区域的研究

在红外成像区域法自动调焦系统中,聚焦区域选择很重要。为此,对一组红外图像进行实验仿真,选择相同大小、不同位置的聚焦区域观察其对调焦评价函数曲线的影响,以及选择同一聚焦位置、不同大小的聚焦区域观察其对调焦评价函数曲线的影响,通过分析得出聚焦区域选择的基本原则。     

Web Block Extraction System Based on Client-Side Imaging for Clickable Image Map

We propose a new Web information extraction system. The outline of the system and the algorithm to extract information are explained in this paper. A typical Web page consists of multiple elements with different functionalities, such as main content, navigation panels, copyright and privacy notices and advertisements. Visitors to Web pages need only a little of the pages. A system to extract a piece of Web pages is needed, our system enables users to extract Web blocks only by setting clipping areas with their mouse. Web blocks are clickable image maps. Imaging and detecting hyperlink areas on client-side are used to generate image maps. The specialty of our system is that Web blocks perfect layouts and hyperlinks on the original Web pages. Users can access and manage their Web blocks via Evernote, which is a cloud storage system. And HTML snippets for Web blocks enable users to easily reuse Web contents on their own Web site.     

Second-order tracking control for leader-follower multi-agent flocking in directed graphs with switching topology

This paper investigates the flocking problem for leader-follower multi-agent systems in directed graphs with switching topology. A decentralized state control rule, namely, a second-order protocol, is designed for each agent to track the leader. And it is proved that the proposed control scheme can effectively estimate the tracking error of each agent when the leader is active. Particularly, to ensure the tracking error can be estimated, the following two questions are solved: (1) How many agents are needed to connect to the leader? (2) How should these connections be distributed? Finally, a simple example is also given to verify the effectiveness of the proposed theorems.     

Freight train gauge-exceeding detection based on three-dimensional stereo vision measurement

We present a method for freight train gauge-exceeding detection based on three-dimensional (3D) stereo vision measurement. To reach high measurement accuracy under large-scale situation, the factors which influence the 3D measurement error are analyzed in detail. Algorithm to accurately extract the laser stripe feature projected by the measurement system is described. With the obtained stripe features, the 3D structure of the freight train can be reconstructed with nonlinear optimization procedure. Specially designed targets are used to identify the global coordinate system for gauge-exceeding detection. A prototype has been developed and the reliability and accuracy have been demonstrated by external field experiment.