直喷式柴油机缸内热辐射多区(多维)模型的研究

以准维现象学多区喷雾燃烧模型和碳粒生成预测了模型为基础,建立了缸内空间辐射多区（多维）模型,并以Ｇ４１３５直喷式柴油机为研究对象,用蒙特卡洛（Ｍｏｎｔｅ－Ｃａｒｌｏ）法计算和分析了燃烧室壁面辐射热量的分布,结果表明,热流量分布规律和数值与柴油机缸内燃烧过程,有关试验结果相符。     

相同氧含量醇类混合燃料燃烧和排放特性差异研究

对一台4缸发动机燃用相同氧浓度的不同醇类混合燃料进行了试验研究,以对比不同三元燃料柴油机在相同转速不同负荷情况下的燃烧特性和常规排放的差异。试验结果表明:甲醇混合燃料在醇类混合燃料中获得最高的燃烧压力,而丁醇混合燃料的热释放率最高。与普通柴油相比,戊醇混合燃料在不同混合物中具有相对最佳的CO和未燃碳氢排放,甲醇混合燃料可获得最优的氮氧化物排放;乙醇混合燃料减小颗粒物效果明显,最大可以减少22.4%～55.6%的颗粒物数量浓度和3.4%～12.8%的颗粒物粒径,其中乙醇混合燃料的核态颗粒物和聚集态颗粒物排放量也最低,戊醇混合燃料达到最高(除高负荷外)。     

化学镀Co一W—P三元合金的研究

研究了镀液中各组分及pH值与镀层中钨、磷含量的关系,获得Co73W16P11合金镀层,并通过人工汗液浸泡试验比较了Co-W—P合金镀层与不锈钢、Co-P、Ni—W—P、Ni—P合金镀层的耐蚀性。     

通过凝固冷却速率调整Zn-1Mg-(0.5Mn,0.5Ca)合金的显微组织和显微硬度

生物可降解锌基合金,特别是添加合金元素的锌-镁(Zn-Mg)合金,已获得广泛研究以改善其力学性能和腐蚀性能.由于这些性能主要依赖于合金的显微组织,因此任何评价都应该从了解影响其形成的条件开始.本研究旨在探讨凝固冷却速率对Zn-1Mg-(0.5Ca,0.5Mn)(质量分数,％)合金瞬态凝固过程中显微组织演化的影响.结果表...     

Small Molecule Organic Nanostructures—Fabrication and Properties

Organic materials are of great interest for the development of low cost electronic and optoelectronic devices. Although majority of research on organic materials is concerned with synthesis of novel compounds and organic thin films, organic nanostructures are attracting increasing interest in recent years. We briefly review different growth methods of organic nanostructures, which can be roughly divided into vapor deposition methods and self-assembly techniques in solution. Then we highlight some interesting properties of organic nanostructures, as well as possible applications, includinf field emission, electronic and optoelectronic devices.     

The use of industrial engineering in Hong Kong manufacturing industry

This paper reports the results of a survey of the use and place of industrial engineering techniques in 29 manufacturing establishments in the light engineering, electronics, garment, and scientific equipment sectors of Hong Kong industry. The results are compared with those of similar surveys in Europe and North America. The conclusions are that the number and use of industrial engineering techniques and their place in the organization of manufacturing industry in the newly industrialized city-state of Hong Kong is comparable with that found some seven to ten years previously in the U.S.A. and Europe.     

线性开关磁阻电动机的二阶离散平滑滤波器跟踪控制

线性开关磁阻电动机的结构简单可靠，对于高精度和快速加工执行器是最好的选择。该文提出一种适合于计算机实现的简单的线性开关磁阻电动机控制算法。所提算法采用级联控制结构，外环采用二阶数字平滑滤波器实现控制，内环采用查表法实现电流的控制。离散二阶平滑滤波器实现了位置和速度的良好的跟踪，比例积分控制提高了系统的性能。采用查表的方法可以减少运算时间并实现了力和电流的非线性关系。仿真结果证明算法的有效性。     

电压暂降及其抑制技术

分析了电压暂降的起因及危害,讨论了电压暂降的抑制措施并对电压暂降的抑制技术进行了展望。