In the study of optical properties of low class crystal system, the identification of opticsign has important meaning to unknown crystal and mineral determination.
在低级晶族光学特性的研究中，光性符号的确定对未知晶体及矿物的鉴定有着重要的意义。
2
This is a sign that her optic nerve is functioning.
这是她的视神经开始发挥功能的迹象。
3
Analyzes the diagraph method of a few and main technique index sign of the fiber optic correspondence system primarily and its in actually work of application.