The dissociation does not always occur spontaneously, it may be induced by the monomer. 离解反应也不总是自发进行的，它也能被单体所诱导。
The behavior of forming and cracking of carbenium ions was analyzed and the reaction pathway of propylene formation was summarized. 通过分析正碳离子的生成与裂解反应特点，探讨了丙烯的生成规律。
