摘要
Since the discovery of high T_c oxide superconductor, scientists and engineers aredeeply concerned with the possibility of its application to the electric machine withstrong operating current at high magnetic fields. Because of the serious problem ofweak link in the sintered bulk materials processed by regular ceramic powder technolo-gy, the critical current density at 77.3 K is low and it gets much lower with theincreasing magnetic field. Scientists look forward to heighening J_c of the high T_c ma-
基金
Project supported by the National Center for R & D on Superconductivity of China.
