库普-库珀施密特方程 库普库珀施密特方程KaupKupershmidt Equation是一个非线性偏微分方程   u  x  t   x    u  x  t   x     u  x  t   x  u  x  t            u  x  t   x    u  x  t   x    u  x  t     u  x  t   x  displaystyle frac partial uxtpartial xfrac partial uxtpartial xfrac partial uxtpartial xuxtfrac partial uxtpartial xfrac partial uxtpartial xuxtfrac partial uxtpartial x