To conduct periodical butchering and yielding tests to ensure the effectiveness of the control system in Butchery.
定期对半成品肉食进行检查确保半成品肉食系统工作正常。
2
Photonic crystals are the periodical arrays of materials with the different refractive indices which can control the light propagation.
光子晶体是由介电常数不同的材料周期性分布而成，可以用来控制光的传输。
3
On the basis of author's practical experience in many years in foreign periodical acquisition, the paper puts forward methods of improving the quality control of foreign periodical acquisition.