自己编的闻邦椿书上的Riccati法求临界转速。转子模型为单跨双圆盘模型，没有加入去除奇点的算法，结果可能有奇点，没有提取振型。-Own Wen Bangchun Riccati law book　uates the critical speed. Rotor model for the single-span double-disc model, did not join the removal singularities algorithm, the results may have singularities, no extraction modes.