Guangxi Key Laboratory for Relativistic Astrophysics;
School of Physical Science and Technology;
Guangxi University;
Nanning 530004;
China;
Key Laboratory of Space Astronomy and Technology;
National Astronomical Observatories;
Chinese Academy of Sciences;
Beijing 100101;
China;
School of Astronomy and Space Science;
University of Chinese Academy of Sciences;
Beijing 100049;
China;
gamma ray bursts:general; techniques:photometric; techniques:spectroscopic; methods:statistical;