各位老师，with怎么理解？

Physical Principles of Gas Flow and Resistance

Gas flows from a region of high pressure to one of lower pressure. The rate at which it does so is a function of the pressure difference and the resistance to gas flow, analogous to the flow of an electrical current (Fig. 3.1). The precise relationship between pressure difference and flow rate depends on the nature of the flow, which may be laminar, turbulent or a mixture of the two. It is useful to consider laminar and turbulent flow as two separate entities, but mixed patterns of flow usually occur in the respiratory tract.With a number of important caveats, similar basic considerations apply to the flow of liquids through tubes, which is considered in Chapter 6.

一、气流和阻力的物理学原理

气体从高压区流向低压区。与电流类似，气体流速是压力差和气流阻力的函数（图3.1）。压力差与气流速的精确关系取决于气流性质（层流、湍流、或是两者的混合）。虽将层流和湍流视为两种独立的气流形式有助于理解，但呼吸道内通常是层流和湍流的混合。除了一些重要的注意事项，类似的基本考虑也适用于管道内流动的液体（见第6章）。

各位老师，with怎么理解？我上面理解的对吗？谢谢

with : 缩写自古英语wither,相对，相反，来自PIE*wi-tero,更加分开，*wi,分开，词源同widow,wide,*tero,比较级后缀，词源同alternate,interior.词义由相反过渡到再一次，和，与。词义演变比较again.