小流量灰浆泵组合密封设计

用于输送含有细小颗粒流体的小流量（0．5～5t／h）氢氧化钙浆液泵的机械密封，极易被溶液中含有的固体颗粒磨损而丧失密封性能。针对这一问题，提出了一种背叶片加上橡胶波纹管机械密封组合的密封结构，并辅之以溢流结构来保护电机，从而解决了灰浆泵的密封问题，延长了泵的使用寿命，使泵装置的体积大大缩小，且易于维修。本文阐述了这种组合密封结构的原理及尺寸设计。     

基于信道特征提取的物理层安全密钥生成方法

物理层密钥具有降低密钥分发、更新和维护的难度的特点,针对无线传感器网络中节点传输信息易遭受窃听攻击的问题,基于物理层安全中的"一次一密"理论,提出了一种物理层密钥生成方法,主要包含信道估计、特征提取、密钥生成与协商。在半双工通信模式下,根据信道估计阶段相干时间的长短,对训练序列的长度进行动态调整,提高信道估计的一致性。仿真试验与对比分析结果表明,窃听节点生成密钥与合法节点生成密钥的一致性始终维持在较低水平,降低了遭受窃听攻击的风险。     

挤压轮失效分析及热处理工艺改进

挤压轮（H13钢）的早期破坏是影响连续挤压生产成本及效率的重要因素。对挤压轮的破坏方式及原因进行了分析，研究了不同M/B下组织的力学性能，并根据挤压轮内外组织的差异，对挤压轮的热处理工艺进行了改进，使挤压轮的寿命提高了1.5倍。     

国际上LIMS的最新进展与发展趋势

本文介绍了在经济全球化和IT热潮下国际上实验室信息管理系统（LIMS）的最新进展和发展趋势，在仪器联结、仪器控制、光谱采集、光谱处理和化学结构方面的突破，以及生物科学与IT结合诞生出来的新学科－－生物信息学（Bioinformatics）。     

复杂环境下机器人的行为学习研究

机器人为实现在复杂环境下的探索任务,必须具有自主学习其行为策略的能力.本文将Q学习与基于案例的学习结合,实现机器人在复杂环境下的自学习能力.     

Chaff Jamming Recognition of Radar

A modified chaff jamming recognition method of radar is investigated using grey relational analysis (GRA) based on the difference in echo correlation characteristics between a complex rigid target and chaff cloud in time domain.Slice method (SM),a novel modeling approach,is proposed to construct an electromagnetic scattering model of chaff cloud in a scenario with slowly moving platform that is targeted.The diffusion characteristics and echo characteristics of the chaff cloud are analyzed.The GRA of a real target and chaff cloud shows that the adjacent return waves have a good correlation for the target but a weak correlation for chaff cloud.Since the correlation degree of chaff cloud's echo is far lower than that of a complex rigid target's,the chaff jamming can be identified by setting a reasonable threshold.Simulation results are presented to verify the effectiveness of this method.     

基于空间曲线啮合轮的同平面多轴输出微小减速器研究进展

微小减速器是微小机械系统的重要组成部分,是目前重要研究领域之一。介绍了基于空间曲线啮合轮传动机构而设计的同平面多轴输出微小减速器,包括不同特点的两种结构形式,即基于正多边形轴分布的串联式多轴输出微小减速器和并联式多轴输出微小减速器,并例举了应用实例。最后,归纳了其工业化应用需研究的主要方向。     

Influence of poly(n‐octadecyl acrylate) on mechanical properties,melting behavior,and morphology of polypropylene/aluminum trihydroxide composites

Poly(n‐octadecyl acrylate) (PnOA) was used as an interfacial compatibilizer for improving the performance of polypropylene/alumina trihydrate (PP/ATH) composites in this study. The influences of PnOA on the properties of fire‐retardant PP/ATH composites were evaluated by tensile and impact tests, differential scanning calorimetry (DSC), scanning electron microscope (SEM) observation, thermogravimetric analysis, and mass flow rate tests. The results suggested that PnOA significantly improved the mechanical properties and rheological behavior of the PP/ATH composites. SEM observation helped formulate reasons for these differences. A pronounced difference in DSC curves was detected for the composites with and without PnOA when the temperature is near the melt temperature of PnOA. Tentative theoretical explanation was also provided based on related DSC and SEM analysis. PnOA is a promising new compatibilizer for polyolefin composites with aluminum trihydrate as a flame retardant. Copyright © 2011 John Wiley & Sons, Ltd.     

Superior reinforcement in polyamide 1010/multiwalled carbon nanotube composites realized by high‐rate drawing and incorporation of compatibilizer

To realize the full potential of carbon nanotubes (CNTs) in polymer/CNT nanocomposites, many complicated chemical treatments have been developed to modify the CNTs. Nevertheless, the reinforcing efficiency is still not satisfactory in most cases. In this study, a dramatically improved mechanical enhancement is obtained for polyamide 1010/multiwalled carbon nanotube (MWNT) composites simply by exerting high‐rate drawing and incorporating a commercially available compatibilizer. For the fibers prepared at high draw ratio, their tensile strength and modulus are improved by 137 and 132%, respectively, through adding only 0.5 wt% MWNTs. In particular, the increase in strength is at a very high level for the case of non‐covalent interaction since CNTs could be stretched to failure according to theoretical calculation. It is demonstrated that this reinforcement is mainly attributed to the compatibilizer inducing good dispersion, and the high‐rate drawing inducing strong interfacial interaction and orientation of MWNTs. Copyright © 2012 Society of Chemical Industry