If one or more electrons are removed, the remaining positively charged structure is called a positive ion. 如果移去一个或多个电子，剩下来带正电荷的结构就称为正离子。
The experimentally measured temperature dependence of retrograde velocity of vacuum arcs can be explained by the ion jet model for retrograde motion of vacuum arcs. 实验测得的后退速度的温度关系可用真空电弧后退运动的正离子喷流模型加以解释。
