Bear in mind that the chief ray is now principalray.
记住，此时主光线就是主点光线。
2
Starting from the ray path equation, object-image relationships are found and used to determine the equivalent focal length and the principal planes of tapered GRIN fiber.
本文从光线轨迹方程出发，推导了锥形梯度折射率纤维的物像关系式，并得出了它的等效焦距和主平面位置。
3
X-ray Crystallography is the principal method by which the detailed 3 - dimensional structures of molecules - especially the molecules of living systems - have been discovered.