一种基于单片机的变电站控制保护系统的实现

以单片机８０３１ 为核心组成的采集、保护和通信模块，通过ＲＳ４８５ 的连接，与４８６ 工控微机构成了分布式３５ ｋＶ 变电站的自控系统，实现变电站的计量、保护和控制等功能，以达到变电站的无人值守或少人值守。     

Fatigue behaviour of a phenolic matrix composite

This paper presents results of a fatigue life investigations carried out in plate specimens of a fibre-glass-reinforced phenolic matrix composite. Tensile and Young's modulus data were obtained at four different testing temperatures (room temperature, 100, 150 and 200 °C). The fatigue S−N data were obtained at room temperature only and for two stress ratio values (R=0 and 0.4). Fatigue and tensile behaviour was assesesed in the composite with the fibres aligned in the longitudinal loading direction. The results were obtained for two values of volume fraction (0.28 and 0.42) and three different glass surface treatments. A detailed comparison of fatigue results is given taking into account several fatigue parameters and also the testing variables. Results of observations of SEM fracture surfaces are also presented.     

换热网络数值模拟稳定性分析

换热网络的数值模拟在换热网络的定量分析中起着重要作用。但在模拟计算中,有时表现出数值稳定性差。提高数值稳定性的方法,目前多通过改善算法来实现。本文通过对换热网络数值模拟的误差分析,提出了误差放大因子的概念,并依此选择迭代变量。通过对迭代变量的选择,达到提高换热网络数值模拟稳定性的目的。     

IEA joint trials: New lessons from old plantations

Two international trials of potential biomass species families and clones planted in 1985 have been analyzed to determine changing patterns in growth, diseases, and insects. In the Swedish trial, with close spacing and short rotations, Salix viminalis clones gave the best average yield of 17.4 Mg/Ha/yr on the first coppice rotation. In the Minnesota, USA trial, with wider spacings and a longer rotation Populus alba hybrid clones gave the best average yields of 5.5 Mg/Ha/yr. The most important disease and insect problems encountered were Septoria musiva stem cankers on some Populus clones; frost die back in some Salix clones; and the leaf blotch miner, Fenusa dohrnii, on most Alnus families. Recommendations for future international cooperation in field trials are presented.     

校企合作是高等职业教育改革与发展的必由之路

校企合作是高等职业教育发展的重要趋势之一,是与现代化大生产、现代科学技术和现代高等教育发展相适应的一种客观要求.加强校企合作已成为高职院校制定面向21世纪发展战略的重要内容.高校和企业联合举办高职学院是新的发展时期对校企合作认识的深化,也是高校和企业之间开展全方位和深层次合作的最佳切入点.文章所阐述的校企合作主要指在人才培养、科学研究、技术开发、生产经营以及资源综合利用等多方面的协作.     

On the Protective Properties of Electrostatically Spraged Fluoroplastic and Epoxy Coatings

The protective and insulating properties of fluoroplastic and epoxy coatings applied by high-voltage electrostatic spraying were studied. The epoxy coatings were found to be less permeable than the fluoroplastic ones, yet they cannot be used to protect metal parts in corrosive environment because of their low chemical resistance.     

钛对耐硫变换催化剂性能的影响

利用常压微反色谱、程序升温还原（ＴＰＲ）等技术研究了钛对耐硫变换催化剂性能的影响，结果表明：（１）钛能明显提高耐硫变换催化剂的活性，尤其是在低于６２３Ｋ时活性提高最为明显；（２）工业侧流试验后，含钛样品的保留活性及活性保留率均高于Ｋ８－１１；（３）催化剂中添加助剂ＴｉＯ２后，能显著提高对原料气中Ｈ２Ｓ含量变化的适应能力，因此可以拓宽对原料气的选择范围，对工业生产有着十分重要的现实意义。     

重油催化裂化装置轴流风机的损坏与修复

广州分公司炼油厂重油催化裂化装置四机组轴流风机在 1998年 9月由于入口消音器故障引发重大事故 ,严重影响了装置生产。该文主要针对其损坏的原因、情况和修复方法作了探讨和论述     

MTPM—一种在多Transputer系统上实现OPS5并行匹配的方案

并行匹配是并行处理产生式系统的重要内容之一。本文针对现有RETE匹配算法,提出了一种自行设计的在多Transputer系统上实现OPS5并行匹配的方案,并重点讨论了实现MTPM中的一些技术问题.试验表明,MTPM提供了一条发掘产生式系统固有并行性的可能途径.     

Electrical characterization of porous BaTiO3 using impedance spectroscopy in humid condition

The humidity response characteristics of La doped BaTiO₃ with different sintered densities and room temperature electrical conductivities were investigated using complex impedance measurement. The samples with low density and high resistivity showed the large and nearly linear sensitivity to the change of humidity. The impedance spectra of samples, when exposed to high humidity, can exhibit microstructure-related features, even though they do not give rise to a noticeable characteristic change when exposed to low humidity. The observed impedance patterns were dependent upon the density, and hence the oxidation kinetics of BaTiO₃.