| 释义 |
Principal section
| (Crystallog.) | a plane passing through the optical axis of a crystal. |
See also: Principal
principal section
principal section[′prin·sə·pəl ′sek·shən] (mathematics) A normal section at a given point on a surface whose curvature has a maximum or minimum value. (optics) A plane in a crystal that contains the crystal's optic axis and the ray of light under consideration. Also known as principal plane. |