化油器的检查与调整

化油器,因工作过程中诸多具体因素的影响,工作一段时间后,原始的调整数据都会有程度不同的变化,因此,对化油器应定期检查和调整。其主要内容有: 因为一般汽油中均含有胶质物。胶质物的沉积,会使量孔或喷口逐渐变小。此外,汽油中其他杂质会使量孔和喷口磨损而变大。量孔和喷口尺寸的变化,会显著     

Ignition-proof properties of a high-strength Mg-Gd-Ag-Zr alloy

<正>A high-strength Mg-15.3Gd-l.8Ag-0.3Zr(GQ152K,mass fraction) alloy was prepared by conventional ingot metallurgy process.The solution and aging(denoted as T6) treated alloy exhibits remarkable mechanical properties with ultimate tensile strength of 421 MPa and tensile yield strength of 309MPa.It has higher igniting temperature of 1208 K.Moreover,it can stand against flame at 1203 K for over 6 min in vertical burning tests, and its flammabiUty behavior is very similar to that of 6101A1 alloy.Vertical burning tests appear to be able to directly study the flammability behavior of Mg alloys and it appears to be a good approach to study the flammability behavior of Mg alloys in an aircraft fire accident.     

Effects of cooling rates on microstructures and mechanical properties of Nb-Ti microalloyed steel

The mechanical properties and microstructure of as-cast Nb-Ti microalloyed steel at different temperatures and cooling rates are investigated in this paper. The III brittle zone (700?C900°C) is revealed. The reduction of the hot ductility is due to the film-like proeutectoid ferrite or the Nb(C, N) precipitates along the austenitic grain boundaries. In the temperature range of 850?C1 000°C, with the increase of the cooling rate, the hot ductility decreases. However, in the range of 650?C850°C, the appearance of large volume fractions of ferrite on austenite grain boundaries minimizes the effect of cooling rate on hot ductility. When the cooling rate is 10°C/s, austenite transforms more quickly to ferrite and at a lower temperature a larger amount of ferrite nucleates and precipitates in the grain, which leads to a sharper improvement in the hot ductility at 650°C.     

地地战役战术导弹毁伤效能评估系统研究

采用概率密度积分和统计试验相结合的毁伤效能建模方法,构建了地地战役战术导弹毁伤效能仿真数学模型,提出了目标描述模型设计的基本思路,建立了基于弹丸终点效应的毁伤破片场模型,研制开发由射击精度、目标描述、毁伤效果模拟等功能模块组成的软件系统,为作战指挥人员进行地地战役战术导弹毁伤效能评估提供了仿真技术手段,有效提高了地地战役战术导弹的辅助决策水平.