临界态,是指从一种物理现象或状态变化为另外一种物理现象或状态时的中间转折点.相对应的,我们把涉及临界态的问题称为临界问题,这类问题是高考和各种类型考试的重点和难点.若物理过程中涉及两个临界状态,我们称之为双临界问题.在双临界问题中一般至少存在两个临界条件:若这两个临界条件都是某一特征物理量完成某一物理过程所必须同时满足的两个条件,我们把这 Critical state refers to the transition from a physical phenomenon or state to another physical phenomenon or state, correspondingly, we refer to the critical state of the problem as a critical problem, such problems are the college entrance examination and a variety of Type examination focus and difficult if the physical process involves two critical states, we call the double-critical problem in the double-critical problem generally there are at least two critical conditions: If these two critical conditions are a characteristic physical quantity To complete a physical process must meet both conditions, we take this