作故

由于气体激光器常用作光源，故必须将其光束耦合到薄膜波导中去。

Because gas lasers were often used as the light source , their beam had to be coupled into the thin-film wave guides .

二帝书院纯作教学用途，故结构简单实用。

Built purely for the use as a study hall , its architecture is simple and functional .

采用本方法不仅能提高国产热偶规管的热稳定性，而且还不需要对原来所配的真空计作任何改动，故极易推广普及。

Realizing this method will not only improve the heat stability of the native thermocouple gauge tubes but also can use the same vacuum gauges as usual without any change .

所研制的控制装置结构简单，不需对机床作任何改装，故有可能成为普通车床及数控车床上具有抑制颤振能力的一个功能部件。

Simple in construction and directly installed on the toolholder without any modification of machine tool , the device developed may serve as a functional component capable of suppressing chatter in ordinary and numerical control machine tools .