quantum constant

例句：

1. 1. The quantum constant is a fundamental concept in quantum mechanics.
   量子常数是量子力学中的一个基本概念。
2. 2. The constant of elasticity is a key parameter in the study of materials behavior.
   弹性常数是研究材料行为的一个关键参数。
3. 3. The constant of friction between two surfaces is a measure of how easily they can slide over each other.
   两个表面之间的摩擦系数是一个衡量它们是否容易相互滑动的指标。