Frontiers of materials research--electronic and optical materials proceedings of the symposia N: frontiers of materials research, A: high Tc superconductors, and D: optoelectronic materials and functional crystals of the C-MRS international 1990 conference, Beijing, China, 18-22 June 1990 - Kong, Meiying; Huang, Liji (C-MRS international 1990 symposia proceedings, 1991)