EFFECT OF MICRO-GALLIUM ON THE INTERGRANULAR SEGREGATINN OF PHOSPHORUS IN CARBON STEELS

The effect of small amounts of gallium on the intergranular segregation of phosphorus in carbon steels is discussed, with the help of the impact test, fracture morphology and micro-structure analyses, combined with composition analysis on the fracture surfaces by Auger electronspectrometer. The results show that gallium in the steel with a content of gallium more than ten thou-sandth can suppress, to some extent, the intergranular segregation of phosphorus and retard the tempering process. As a result, the temper embrittlement of the steel disappears and the embrittlement transition temperature declines.     

The Effect of Additions in the Fermented Solution on Bubble Coalescence

This paper presents a detail study of bubble coalescence in inorganic salts and organic compounds of fermented solution ,and preliminary analyses the principle of bubble coalescence.The experiments show that the relationship between the solute concentration and coalescence frequency reveals the existence of sharp transition concentration.     

Research on Dynamics of Installation Way for Active Isolation Actuator on Flexible Foundations

The dynamic characteristic of active isolation atuator on flexible foundations was studied under the installation of parallel structure and foundation cancellation.The influencing relationships between active isolation force of the different installation ways and passive isolation system and flexible foundation were analyzed and compared.Scientific basis for selecting installation ways of active isolator is provided in this paper.     

Parsimonious Covering Probability Model for Turbogenerator Vibration Faulty Diagnosis

The turbogenerator vibration faults have the character of variety. Many faults often occur synchronously. This paper introduces a diagnosing model based on parsimonious covering theory and probability. A model for turtogenerator's fault diagnosis is proposed. The availability of this method is proved by two fault diagnosis examples of turbogenerator. The results show that the model proposed can be used for multi_fault diagnosis together. It may make up shortage for some of expert systems and neural networks in some aspect. From the practice,this model has higher reliability and practicability.     

A PRACTICAL PWM CONTROL METHOD OF CURRENT SOURCE GTR INVERTER

According to the principle that the orbit of stator current vector in complerplane should be as close to a circle as possible, the PWM control pattern is derived and determined. The control method is realized by using a micro-computer.     

以粮温实测数据为例探讨低温储粮的可行性

通过对高大平房仓粮温进行跟踪检测，分析比较了粮温变化情况，并探讨了低温储粮的可行性。     

锌元素对籼稻成熟胚愈伤组织绿苗分化率的影响

本实验就锌元素对籼稻成熟胚愈伤组织绿苗分化率的影响进行了研究，结果指出：(1)锌元素能明显提高籼稻成熟胚愈伤组织绿苗分化频率，且使用浓度范围较广(0.5～10μmol/L)，其中以锌浓度1μmol/L效果较好；(2)在本实验范围内各籼稻品种对锌元素的反应是一致的，但品种间差异很大，其中中早14绿苗分化率较高；(3)锌脉冲试验指     

拖拉机－挂车机组非线性系统随机响应分析

推导了随机激励下参数频变系统的统计线性化方法。利用该方法对铁牛－６５４拖拉机挂车机组非线性系统进行了平稳激励下随机振动响应的计算，计算结果表明，把拖拉机挂车机组作为非线性系统来处理可显著地提高振动分析的精度。