Triterpenoid Constituents of Huperzia miyoshiana

Thirteen triterpenoids, including three new ones, miyoshianois A (1), B (2) and C (3), were isolated from Huperzia miyoshiana. The structures of these new compounds were established as 3-O-dihydroferuloyltohogenol (1), 16-oxo-3β,21β-dihydrox-y-serrat-14-en-24-ferulate (2) and 16-oxo-3a, 21β-dihydroxy-serrat-14-en-24-ferulate (3), respectively, on the basis of their spectroscopic analysis.     

HL—1装置等离子体中X波段的微波反锯齿振荡

一、引言 对电子回旋频率和等离子体频率的辐射研究表明,在HL-1装置的低密度放电过程中,存在着相对论电子束。本实验中,用一个在HL-1装置赤道面上垂直于纵向磁场方向的天线,观测了频率小于等离子体频率ω_(pe)的X波段的微波辐射。发现在这个频段除了可以接收到强的稳态超热辐射外,在一定的密度范围内,还能观测到幅度很大的反锯齿振荡。它们和软X射线锯齿,等离子体密度有一定的关系。下面将给出这些实验结果。