Rapid determination of ferulic acid and identification of its structure in rhizome of Phragmites communis by GC-TOFMS 不同生境芦苇tRNA的分离纯化及氨酰化特性研究 PRINCIPAL COMPONENT ANALYSIS AND FUZZY CLUSTER ANALYSIS FOR DIFFERENT ECOTYPES OF REED(PHRAGMITE SCOMMUNIS TRIN)BASAD ON THEIR INDEXES The Effects of Boric Acid and Gibberellic Acid on the Growth of Fiber of Phragmites cormmuhis Trin