This paper discuss how to measure and calculate when a parallel light doesn't incide grating vertically in measuring grating constant and how to adjust a parallel light to incide grating vertically.

本文讨论光栅常数测量中，平行光不垂直入射光栅时如何对测量值的影响及如何调节平行光垂直入射光栅。

youdao

To co-incide with the summit it released two reports that flesh out its thinking on a range of regulatory issues.

ECONOMIST: A new chapter for the world economy, maybe