Light composite elliptic springs for vehicle suspension

For composites to compete in vehicle suspension applications, it is essential to control their failure by utilising their strength in principal direction instead of shear. This can be achieved efficiently by employing a new configuration instead of existing one. This study marries between an elliptical configuration and the woven roving composites.

In this paper, the influence of ellipticity ratio on performance of woven roving wrapped composite elliptical springs has been investigated both experimentally and numerically. A series of experiments was conducted for composite elliptical springs with ellipticity ratios (a/b) ranging from one to two. Typical failure histories of their failure mechanism are presented and discussed. In general, this study demonstrated that composites elliptical spring can be used for light and heavy trucks and meet the requirements, together with substantial weight saving. The results showed that the ellipticity ratio significantly influenced the spring rate and failure loads. Composite elliptic spring with ellipticity ratios of a/b 2.0 displayed the highest spring rate.     

面向决策的一体化建模方法及其在兵力筹划中的应用

在对军事决策问题的主要特点进行分析的基础上，提出从军事概念模型到数学模型再到定性推理模型的一体化建模思想．以空军航空兵遂行直接航空火力支援任务为想定背景，根据EATI模板，利用基于UML的Rose工具依次对想定任务的实体、任务、交互等进行分析；对于兵力筹划中的结构化问题建立了机会约束多目标规划数学模型；对于非结构化问题则构造了推理机，推理机体现了定量与定性相结合的决策分析思想．最后，以一个实例验证文章思路的可行性．     

低热固相反应在材料合成中的应用

介绍了低热固相反应机制的研究进展、反应特点及影响低热固相反应的一些因素。重点阐述了低热固相反应在纳米材料、有机合成、电池材料、气敏材料以及其它一些功能材料中的应用。阐明低热固相反应确实是新型材料制备的一种简便、有效并有光明前景的方法。     

Growth mechanism of NaClO3 and NaBrO3 crystals from aqueous solutions

A study of growth rates of NaClO₃ and NaBrO₃ has been carried out using a small growth cell by in situ observation. Normal growth rates of (100) faces of NaClO₃ and (111) faces of NaBrO₃ along 〈110〉 direction are measured under relatively high supersaturation ranging from 3–8%. In the initial stages of growth, (100), (110) and (111) faces develop in NaClO₃ and gradually all the faces are replaced by the (100) faces only. In the case of NaBrO₃, mostly (111) faces develop with occasional occurrence of small (100) faces at the intersection of (111) faces. The growth mechanisms are investigated from growth rate vs supersaturation plots and from the observations of surface features. In the present supersaturation range, the growth mechanism appears to be due to two-dimensional growth mechanism.     

Synthesis of Ti2SnC from Ti/Sn/TiC powder mixtures by pressureless sintering technique

Ti/Sn/TiC powder mixtures were first employed to synthesize Ti₂SnC powder by pressureless sintering in the temperature range of 950–1250 °C at vacuum atmosphere. Ti₂SnC began to form at 950 °C, its content increased with increasing temperature. High purity of Ti₂SnC was obtained by sintering the mixtures with deficient Sn and TiC at 1200 °C for 15 min. A reaction mechanism was proposed to explain the formation of Ti₂SnC. The Ti₂SnC powder was characterized by scan electron microscopy (SEM) and X-ray diffraction (XRD). Using the above mixtures and process, the Ti₂SnC ceramic powder can be obtained on a larger scale.     

水滑石形成机理与形貌控制的研究现状

综述了水滑石生长机理研究的几种典型理论和影响水滑石形貌、尺寸和结构控制的因素,重点介绍了不同制备方法对形貌特征的影响。     

WHDF增强密实(抗裂)剂对改进面板砼抗裂性能的影响

WHDF增强密实(抗裂)剂,是一种应用于面板堆石坝面板混凝土抗裂的高性能外加剂。笔者运用化学热力学和动力学等研究方法,从砼的微观结构着手,研究水泥水化机理,把水泥水化程度和水化产物与外加剂的抗裂作用机理结合起来研究,使得WHDF抗裂剂能促进水泥水化程度,优化水化产物和协同激发砼中活性混合材料与Ca(OH)2进行二次水化,从而提高砼中凝胶量,降低孔隙率,改善水泥石及其与骨料界面的结构,增强凝胶的粘结力,使砼具有良好的抗裂性能。湖北小溪口电站等近十个水电工程的面板混凝土掺用WHDF后,混凝土表面平滑光泽,均无收缩裂缝产生。     

大功率电力电子装置试验方法及其等效机理

大功率电力电子装置试验方法的理论研究一直处于混沌状态,需要有系统化的理论指导。该文基于电力电子装置的特点,分析了试验目标与层次的确定、物理试验方法、可靠性试验等,提出“数字辅助试验”的概念。建立用于试验等效机理研究的数学模型,提出试验等效的原则,分别阐述了用于试验等效性分析的解析法、灵敏度法、目标函数优化法和相似理论法,给出等效机理的评价方法,并分析了试验装置的设计原则和方法。为今后各种大功率电力电子装置的试验方法及等效机理的研究提供了理论基础。     

PLC在并联机构中实现的定位控制技术

本文介绍一种用PLC高速输出方式控制并联机构中的三组滚珠丝杆的准确定位方法，较精确地解决了虚拟轴机床中的电主轴定位问题。     

光触媒TiO2催化机理及空气净化方法探悉

研究了光触媒TiO2催化净化方法和具有光催化TiO2装置的中央空调系统.提出了光催化TiO2净化装置在中央空调系统中应用的技术方案.对光催化TiO2装置的催化作用机理、反应过程以及对环境的净化功能和净化效率进行了论述.