Experimental results show that that the best process conditions are following : the weight ratio of nitric acid and acetic anhydride is 5 : 1 , the current intensity is 500 ma , voltage is 150v , the reaction time is 30 min , then , the graphite compounds are cleaned with water till the ph = 6 - 7 and dried at 60 实验表明,硝酸:乙酸酐为1 5 、电流强度为500ma ,电压为150v ,反应30分钟后,水洗至中性后于60下烘干,制得可膨胀石墨,经900高温处理后,可获得性能良好的膨胀石墨制品。
The simulation program has been implemented to simulate the procedure of hxmt detecting x - ray source . the simulation result has been used to analyze the overlay region in celestial sphere , the variation of photon current intensity and the variation of the angle between sun and orbit , which demonstrate the reason why to select a 550 km height and 43o inclination low earth orbit as hxmt ' s orbit 利用仿真程序,实现了仿真一个正在预研的天文卫星? ?硬x射线调制望远镜hxmt观测x射线源的过程,分析了天球覆盖、 hxmt接收的光子流强度的变化和太阳轨道面夹角的变化,说明了选取高度为550km ,倾角43o的近地圆轨道作为hxmt的运行轨道是合理的选择。