The two theorems are proved that any ring can be extended into an algebraically closed ring and that the quaternionic skew field over a real closed field is algebraically closed.
证明了任一环有代数封闭的扩张环，且实封闭域上的四元数体是代数封闭的，给出了代数封闭环的若干性质。
2
For the beam transport system in storage ring, linear coupling is mainly caused by skew quadrupole and longitudinal solenoid field.