Evaporation quantum of liquid is expressed as mass source for vapor in vapor mass conservation equation, while it is dealt with mass sink for itself.

在建立多孔介质各相质量守恒方程时，液体蒸发量相对于蒸汽相而言为质量源，对液相本身而言为质量汇。

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According to conservation of mass, this article establishes a kind of mathematical model for the equation equilibrium of chemical reaction, and also gives its solution both by man and by computer.

本文根据质量守恒定律建立了一种配平化学反应方程序的数学模型，并给出了模型的人工解法和计算机解法。

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Conservation of mass, second Newton's law, and momentum law are introduced into traffic flow to set up traffic continuity equation, Euler's equation, and momentum integral equation.

应用物理学中的质量守恒定律、牛顿第二定律、动量定律等，建立了交通流的连续性方程、欧拉方程和动量方程；

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