The theory is based on the complex hydromagnetic equations of nebula, which are simplified approximately to the equations of velocity.
把星云的复杂的磁流体动力学方程，近似简化为只与速度相关的方程，则得到一个可解的简单模型。
2
The characteristic of the emission caused in the special spiral magnetic field of hydromagnetic accretion disk is discussed mainly using the formula of curvature radiation.