rheum palmatum 释义 大黄 例句 1·OBJECTIVE to comparing the contents of emodin and chrysophanol in Rheum Palmatum L. of different plant periods and cultivated methods, to offer a scientific basis for GAP. 目的测定不同生长期限和不同栽培方法的掌叶大黄中大黄素和大黄酚的含量，为大黄的GAP规范化种植提供参考依据。