Tipei Li was born in Chongqing in 1939, graduated from the Department of Engineering Physics, Tsinghua University in 1963. He was elected a Member of Chinese Academy of Sciences in 1997. Areas of Research: particle astrophysics and observational cosmology Achievement and Experience:
From 1963 to 1977, Li was engaged in the investigation of the constitution and interactions of high energy cosmic rays at mountain level . Since the late 1970s, he has been devoted to establishing experimental high energy astrophysics research in China: developing the high flying balloon system, balloon-borne detectors, and the hard X-ray modulation telescope HXMT, which is the China’s first astronomy satellite and Li is its Principal Investigator. In the early 1980s, Li, in collaboration with Wolfendale, put forward a statistical model of galactic γ-rays, which gave a quantitative estimation of high energy γ-rays produced by the interaction of cosmic rays with the interstellar medium for the first time and pointed out that about half of the sources listed in the 2CG γ-ray sources catalogue released by COS-B mission are due to molecular clouds, not real discrete sources, and that the total mass of molecular hydrogen in the Galaxy is significantly overestimated by astronomers. This model has been confirmed by later observations. He，in collabrationn with Ma Y.Q., derived a formula for evaluating statistical reliability of on-off observation results, from which a reliable evaluation of the confidence levels of claims of positive detection of γ-ray lines in space astronomy was made for the first time. His formula has been widely applied in experiments of cosmic-ray physics and high-energy astrophysics. Li and Wu established the direct demodulation method for reconstruction of objects, which is a powerful technique for dealing with the inversion problem in various kind of experiments with high sensitivity and high resolution ability. Recent years, Li’s group found there exist systematic errors in published WMAP (Wilkinson Microwave Anisotropy Probe) maps and obtained new content of our universe from raw WMAP data, which has been confirmed by successive Planck mission.