摘要
亚秒级Ｕ 型爆首次由北京天文台２ ．６ － ３ ．８ＧＨｚ 高时间分辨（８ ｍｓ） 太阳射电频谱仪报道。本文对这些环状结构的时间和空间演化进行了研究，并和相关的光学、Ｘ
The subsecond type U bursts are first reported by Beijing Astronomical Observatory with solar radio spectrometer at 2.6-3.8GHz with high time resolution (8ms). The spatial and temporal evolution of these loop like structures are studied and compared with the relevant observations at optical, X ray, and radio bands.
