陀螺定向的方法之一，它是通过测定陀螺灵敏部经过中天(分划板零刻画线)的时刻t和摆幅a，确定真北方向。 这种方法用于记录恒星中天的时刻，是测时的主要方法。
由陀螺仪寻北中天法的基本原理出发，提出了一种固定照准部的初寻北半周期中天法。
Based on the principle of period transit method, semi-period transit method of collimation is proposed to improve the north-seeking speed and the automatic degree.
结果：采用真空冷冻干燥法加工成的天麻中天麻素的含量明显高于使用传统的水煮烘干法加工成的天麻，外观品质好。
RESULTS: The content of gastrodin of Rhizoma Gastrodiae processed by vacuum freeze drying was significantly higher than that by boil with water and oven drying.
应用推荐