Application of SiC-Si functionally gradient material to thermoelectric energy conversion device

Because of its high–temperature chemical stability, SiC ceramic is a promising material for high-temperature device applications such as thermoelectric energy converters. However, the electrical conductivity of SiC ceramic is too low for it to be used as a thermoelectric energy converter at the cold junction. Therefore, we propose a SiC-Si functionally gradient material (FGM) in order to improve the electrical conductivity of the SiC ceramic at the cold junction. An SiC rod was fired in a temperature gradient furnace. One end of the SiC rod was maintained at 2473 K and the other end was maintained at 1973 K for 30 min. After firing, the porous SiC edge fired at 1973 K was dipped into molten Si in order to infiltrate molten Si into the porous SiC. The microstructure of the FGM is classified into three regions: the SiC-Si composite material; the porous SiC ceramic; and the densified SiC ceramic. The electrical conductivity, the Seebeck coefficient and the thermal conductivity for each region of SiC-Si FGM was measured at 300 K; a figure of merit was calculated. The figure of merit of the SiC-Si FGM at the cold junction, at room temperature, was 10⁸ times higher than that of a nongradient SiC ceramic.     

树脂热解炭制备碳化硅晶须

用自制的配合醛树脂热解和炭源，用ＳＩＯ２超细汾作原，根据碳热还原原理，利用常规加热和微波加热两种方式，分别制备了直径在纳米级的ＳｉＣ晶须，Ｘ射线衍射、透射电检测结果表明：制备工艺和条件对ＳｉＣ晶须的性质有较大的影响。     

补偿元件对载体催化元件输出特性的影响

阐述了矿井瓦斯传感器－载体催化元件在应用中，补偿元件发挥的作用和工作原理，着重分析了补偿元件对载体催化元件输出特性的影响，探讨了提高线性补偿效果的方法。     

Pb（Sc1／2Ta1／2）O3铁电体的有序结构和介电性质）

通过铌铁矿预合成法制备Ｐｂ（Ｓｃ１／２Ｔａ１／２）Ｏ３（ＰＳＴ）陶瓷，经适当的热处理获得了钙钛矿化合物Ｂ位离子的高有序和高无序试样，ＰＳＴ陶瓷的介电性质研究结果表明，高有序试样（Ｓ＝０．７７）的居里温度为２９℃，并具有较低的介电常数表现出普通铁电体性质特征，而高元序试样（Ｓ＝０）具有很高的介电常数，并表现出明显的弥散性相转变和Ｔｍ的频率色散行为，即高介电常数的驰豫铁电体性质。文中还利用ＸＲＤ，ＳＥ     

Development of an integrated model for airflow in building spaces

In building energy simulation, an integrated modelling of airflow in the building needed. Therefore, in this paper two approaches are used for building energy simulation: zonal network for modelling of the building segments and Computational Fluid Dynamics (CFD) for modelling of the airflow. It is noted that a synchronize solution process is needed for the building and the CFD equation-sets. For this purpose an iterative procedure is used to corresponding solution of these equations.     

我国低浓度磷肥的发展策略和过磷酸钙生产的技改方向

从我国磷矿资源以中低品位磷矿居多,低浓度磷肥本身含有作物所需中微量元素,低浓度磷肥制造成本低及我国农民长期的使用习惯,论述低浓度磷肥在我国存在的必要性。过磷酸钙企业目前存在规模小、分散、生产技术落后、污染严重、废弃物利用率低等问题,提出过磷酸钙生产的技改方向,如无熟化造粒技术,采用浓酸矿浆法并同时采用集散微机自控技术,主要设备实行定型化、系列化等,以增强企业的竞争力。     

马钢10#高炉高Al2O3炉渣冶炼实践

针对10#高炉炉渣中Al2O3高的特性,通过对炉渣性能的分析,调整操作制度,改善炉渣性能,加强炉前管理等,使10#高炉生产水平明显提高.     

基于故障树与灰关联分析的鱼雷故障诊断

将灰色关联度与故障树联合运用于鱼雷故障诊断,为鱼雷的故障诊断提供了一种新途径。在鱼雷动力系统故障树诊断模式识别中,运用灰色系统理论中的灰关联分析,通过进行关联度计算及排序,对各种故障模式发生的可能性大小作出了判断,从而为处理故障的轻重缓急、控制故障的发生以及改进系统的可靠性提供了理论依据。实例诊断表明,这种方法是有效可行的,并且诊断结果可靠。     

虚拟产品方案设计RQ评估模型关键技术研究

产品设计方案RQ评价模型是虚拟原型逼真设计模型实现的重要模块之一,建立RQ评估模型的目的就是要寻求一种满足用户需求的最佳设计方案,本文对用户满意度的计算模型进行了研究,建立了基于神经网络(ANN)的设计方案RQ评估模型,对设计方案的RQ进行评估,该模型已应用于仪表新产品开发决策支持系统中。     

4-(N-异丙氨基)-苯甲酸的合成研究

对分子中既具有吸电子基,又具有给电子基的化合物4-(N-异丙氨基)-苯甲酸进行了合成,具体的合成步骤和反应条件为:50mL水中加入3g(0.022mol)对氨基苯甲酸,再加入无水碳酸钾1.5g(0.011mol),调整pH约为8,使成羧酸盐,经过滤后加入2-溴丙烷2.5g(0.02mol),加热回流12h,直至下层的2-溴丙烷基本消失,冷却,得灰白色固体,重结晶并用活性炭脱色,得白色晶体4-(N-异丙氨基)-苯甲酸。