An open system, as the name describes, allows mass and energy to freely flow through the boundary.

开系，顾名思义，允许质量和能量自由地,流过它的边界。

麻省理工公开课 - 热力学与动力学课程节选

Mass and energy flow through boundary.

质量和能量流过边界“

麻省理工公开课 - 热力学与动力学课程节选

Mass and energy -- I'm an open system, right?

质量和能量--我是个开系，对吧？

麻省理工公开课 - 热力学与动力学课程节选