sigmafield strictly prior to τ

例句：

1. 1.The sigmafield is a critical factor in determining the strength of an electric field.
   电场强度是决定电场强度的关键因素。
2. 2.The sigmafield is measured using specialized equipment.
   电场强度的测量使用专门的设备进行。
3. 3. The sigmafield is responsible for the distribution of charge within the material.
   电场强度负责材料内部电荷的分布。