基于DM6467的图像并行处理系统的研究

针对图像的处理过程中运算量较大的特点,设计了一种基于双DSP并行处理图像数据的系统。为验证并行处理系统的性能,设计了基于两片高性能的数字图像处理芯片的并行处理平台上测试TSP的问题。结果表明了并行DM6467硬件平台的算法运行效率更高,收敛速度更快,种群有更好的相异度。证明了提出的双DSP并行处理平台针对并行运算具有很好的应用前景。     

化学氧自救器结构对生氧剂的影响

化学氧自救器是一种在有毒或缺氧环境下用于逃生的自救工具,其原理是通过人体呼出的CO2和H2O,与生氧剂发生化学反应后生成氧气供人呼吸。通过总结国内外化学氧自救器的结构形式,对比分析了不同呼吸气路结构、排气方式及生氧罐的物理结构等因素对生氧剂利用率的影响。     

评价熔窑内玻璃液澄清过程的定量指标

评价熔窑内玻璃液澄清过程的定量指标胡桅林，赵国昌，过增元（清华大学工程力学系１０００８４）张灵生，王家垠，马志斌（陕西彩色显象管总厂）ＱｕａｎｔｉｔａｔｉｖｅＥｖａｌｕａｔｉｏｎｆｏｒＲｅｆｉｎｉｎｇＰｒｏｃｅｓｓｏｆＧｌａｓｓＭｅｌｔｉｎＴａｎｋＦ...     

室内微型组合导航计算机设计

通过对室内导航技术的分析,结合嵌入式控制技术和和微机电系统(micro electro mechanical systems,MEMS)技术,提出了基于MEMS惯性/视觉的室内微型组合导航计算机设计方案。该方案以室内导航的性能需求为基础,设计了以MEMS惯性传感器和摄像头为主要传感器电路,并融合各模块数据完成了计算机系统设计。测试结果表明该系统能够正确采集前方障碍物的距离信息和运动信息,体积小,可靠性高,满足室内导航的要求。     

热电厂用溴化锂吸收式热泵设计软件开发

热电厂安装溴化锂吸收式热泵能够回收循环水余热,提高电厂循环效率。本文介绍了热电厂用溴化锂吸收式热泵的工作原理和系统构造,分析了热泵设计过程,并应用C＋＋Builder开发热泵设计计算程序,为电厂用溴化锂吸收式热泵的应用提供设计工具。     

氧化预处理延缓超滤膜污染试验研究

分析了膜前氧化对超滤膜污染规律和水中有机组分构成的影响,并对延缓膜污染的机理与方法进行探讨。结果表明,试验所用3种氧化剂KMnO4、高锰酸钾复合盐(PPC)、H2O2均能延缓膜污染进程,在投加量为1 mg.L-1条件下,预处理效果PPC>KMnO4>H2O2;KMnO4和PPC对UV254的去除效果优于溶解性有机物,表明2种氧化剂优先去除含有双键的疏水性有机物;通过研究氧化剂投加量对比紫外吸光度变化的影响,说明氧化作用使水中腐殖质类成分向非腐殖质类成分转化。     

Investigating the addition of silicon oxide to carbon: Effects of amount and heat treatment on anti-aggregation and electrochemical performance of Pt catalysts

Small nanoparticles offer high surface areas and are certainly desirable for electrocatalytic reactions and fuel cells. However, the drawback of using small nanoparticles is their tendency towards particle aggregation. This paper aims to inhibit platinum agglomeration by adding silicon oxide to a carbon support for enhanced catalytic activity in low-temperature fuel cells. The catalysts are characterized by X-ray diffraction and transmission electron microscopy. Physical characterization and cyclic voltammetry techniques at room temperature are used to assess the effects of silicon oxide amount, post-heating temperature, and holding time on particle size and dispersion of active components, and the catalysts’ activity towards the methanol oxidation and oxygen reduction reactions. It is found that using a support of carbon powder with 3 wt.% silicon oxide can enhance the electrochemically active surface area of Pt catalysts and their activity towards the anodic oxidation of methanol and reduction of oxygen. The active components are also more resistant than Pt/C to agglomeration upon heating.     

位移测量装置的设计与实现

系统采用十六位单片机作为核心控制器件,实现磁棒小范围位移的精确测量。本设计首先采用DDS芯片AD9851得到一个频率为100kHz的正弦信号,并且采用THS4503芯片进行差分输出,驱动线性可变差动变压器的原边;差动变压器两个副边的输出信号分别经过IN118芯片放大后,进行半波整流、电子滤波,得到稳定的直流电压,实现磁棒位移信号的实时采集。对两路直流信号分别进行A／D转换,并送入单片机分析处理,最后将计算结果用LCD显示。整个系统结构合理,设计简洁,性能稳定,有较强的抗干扰能力。     

Enhancement of anodic oxidation of formic acid on palladium decorated Pt/C catalyst

A palladium decorated Pt/C catalyst, Pt@Pd/C, is prepared by a colloidal approach with a small amount of platinum as core. It is found that the catalyst shows excellent activity towards anodic oxidation of formic acid at room temperature and its activity is 60% higher than that of Pd/C. Decoration of palladium shell on the platinum core is supported by XPS results. Due to the use of platinum as core, active components are dispersed very well and the particle sizes are smaller than those of Pd/C. The cyclic voltammetry measurement clearly shows synthetic electro-oxidation effects of formic acid on Pt@Pd/C. It is speculated that the high performance of Pt@Pd/C may result from the unique core-shell structure and synergistic effect of Pt and Pd at the interface. The preparation method for Pt@Pd/C reported in this work will provide additional options for the design of catalysts for direct formic acid fuel cell (DFAFC).     

XPS研究不饱和聚酯人工加速老化行为

对不饱和聚酯试样进行实验室人工加速老化,利用X射线光电子能谱(XPS)探讨其表面的化学结构变化,分析其老化机理.结果表明,材料经热氧老化,主链受氧气攻击生成烷氧自由基,烷氧自由基进一步形成C-O和CO,而CO经过再氧化生成OCO,热氧老化后不饱和聚酯的表面基团主要为C-O和OCO;材料经氙灯老化,前期的老化基团变化与热氧老化相似,后期变化主要以OCO基团的降解为主,并生成更多的自由基,引发大分子链的进一步降解;光是不饱和聚酯材料老化降解的主要因素.