"No rules" only means a different mindset which is so much more difficult to master.

“没有规矩”，这种观念掌握起来只能比有规矩的难得多。

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Vibration signals borne by different main bearing clearances are not stationary and time variant. It is difficult to early detect and diagnose by means of traditional methods.

内燃机曲轴轴承所受到的冲击信号是非平稳、时变信号，用传统的诊断方法难以进行故障的早期发现和诊断。

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