non-stationary random process

例句：

1. 1. The weather is non-stationary, so we need to be prepared for sudden changes.
   天气不稳定，我们需要为突然的变化做好准备。
2. 2. The system's performance is non-stationary, which means it can change over time.
   该系统的性能是非静态的，这意味着它可以随时间变化。
3. 3. The stock price is non-stationary, indicating that it has not reached a stable equilibrium yet.
   股票价格是非静态的，表明它还没有达到稳定平衡。