回归方程为，M=M0 * exp(-k2 * t) + aP0 * k1/(k2-k1) * (exp(-k1 * t) - exp(-k2 * t))
用spss13.0非线性拟合曲线估计参数a、k1和k2
analyze---->regression---->Nonlinear Regreesion----->dependent ---->model expression---->parameter 全部设置好，最后出来对话框
Incorrect variable name:either the name is more than 64 characters,or it is not defined by a previous command
不知何故？附件里是数据，请大家帮忙！