The nitrate-nitrogen variation rate was one of the important parameters to describe ammonia-nitrogen nitrification status in biological treatment of slightly polluted source water. 硝酸鹽氮變化率是描述微污染水源水生物處理系統氨氮硝化狀況的重要參數。
The rate of change of momentum of a body is proportional to the impressed force and takes place in the direction of that force. 一物體動(dòng)量的變化率與外加力成正比，并與外加力的方向一致。
