Improvement of characteristic of critical current density in Bi-2223 superconductor

测量了决定临界电流性质的Bi2223超导体的凝聚能密度，并讨论了形成超导体的可能性。结果表明，在低温下，Bi-2223超导体的电势与实际稀土-123超导体相当。此外，还研制了工作在液氮下的超导磁体，并成功地产生了1.3T的磁场。

The condensation energy density of Bi-2223 superconductor, which determined the property of the critical current, was measured and the possibility of superconductor was discussed. It was found that Bi-2223 superconductor had potential equal to the practical rare earth-123 superconductor at low temperatures. In addition, the superconducting magnet working at liquid nitrogen was fabricated and magnetic field of 1.3T was successfully generated.