Presented the denitrogenation mechanism and process characteristics of membrane biological reactor(MBR) and experimental procedure using MBR to treat nitrogenous fertilizer wastewater,and analyzed the experimental results,providing a new technical line for wastewater treatment for nitrogenous fertilizer industry.

The characteristics and nitriding technology of the powder metallurgy materials used for huls in CA S5 20 transmission were investigated.

Through analysis of properties of the moulds used in aluminium alloy forging products after nitriding process, the significance of moulds nitriding process in massive, medium or small type and high - precision aluminium alloy die forging products is discussed.

This article take the H13 compression casting mold as an example,from annealing 、quenching briefly introduced the tempering to the nitridingthe enhancement pressure casts a mold the life heat treatment craft.