Poisson's ratio

例句：

1. 1. The material has a Poisson's ratio of 0.25, which means it tends to shrink when stretched.
   这种材料的泊松比为0.25，意味着它拉伸时会收缩。
2. 2. The engineer calculated the Poisson's ratio for the beam using the formula.
   工程师使用公式计算了梁的泊松比。
3. 3. The Poisson's ratio is an important factor in determining the stability of structures.
   泊松比是决定结构稳定性的一个重要因素。