nonstationary state

例句：

1. 1. The system is in a nonstationary state because of the sudden change in temperature.
   由于温度的突然变化，系统处于非稳定状态。
2. 2.The researchers found that the nonstationary state could be caused by various factors.
   研究人员发现，非稳定状态可能由各种因素引起。
3. 3.In this case, the nonstationary state can lead to significant changes in the system's behavior.
   在这种情况下，非稳定状态可能导致系统行为的显著变化。