spin-momentum vector

例句：

1. 1. In quantum mechanics, the spin-momentum vector is crucial in determining the behavior of particles.
   在量子力学中，自旋动量矢量对于粒子行为至关重要。
2. 2. The spin-momentum vector of a particle can be used to calculate its energy levels.
   一个粒子的自旋动量矢量可以用来计算其能量级。
3. 3. The spin-momentum vector is a fundamental concept in quantum mechanics that describes the relationship between the spin and momentum of a particle.
   自旋动量矢量是量子力学中的一个基本概念，它描述了粒子的自旋和动量之间的关系。