需要物理封闭或障碍，产生超压。

Physical confinement or obstacles required to produce overpressure.

youdao

如果物理学家发现封闭的时间型曲线确实存在，我们将不得不彻底重新思考理解时间的方式。

If physicists discover that closed timelike curves really can exist, we will have to dramatically rethink the way we understand time.

youdao

本文先指出了非接触法测流量的优越性，再基于各种物理原理，叙述了封闭管道流量的几种非接触测量方法与特点。

The advantages. methods and their properties of the non-contact flow measurement for closed pipelines on the basis of some physical principles are described in this paper.

youdao