On the tasis of study in the mathematical model of 3-dimensional ruled surface (RS),this paper introduces a new concept of distance paramcter (DP) and also puts forward that themethod of modeling a RS depends on not o...On the tasis of study in the mathematical model of 3-dimensional ruled surface (RS),this paper introduces a new concept of distance paramcter (DP) and also puts forward that themethod of modeling a RS depends on not only two boundary curves but also DP. According toabove theory, the formulas to calculate corresponding point coordinates to any kind of top and bot-tom profile of a workpiece and formulas to calcuate the maximum inclination angle of ruling linehave been obtained. Then a different top and bottom RS mathining method including profile withline-are combination as well as parametric curves has been achieved by 4-axes simultancous con-trol programming proposed.展开更多
采用两段曝气生物滤池进行了实际生活污水的试验研究,控制 A 段水力负荷在 22.01m3/(m2?d),气水比为 6:1,研究了 B 段气水比分别为 3:1、2:1 和 1:1 时,反应器的运行情况.结果表明,两段曝气生物滤池处理生活污水的出水稳定,当 B 段反应...采用两段曝气生物滤池进行了实际生活污水的试验研究,控制 A 段水力负荷在 22.01m3/(m2?d),气水比为 6:1,研究了 B 段气水比分别为 3:1、2:1 和 1:1 时,反应器的运行情况.结果表明,两段曝气生物滤池处理生活污水的出水稳定,当 B 段反应器的气水比为 2:1 时,去除效果最佳.B段具有明显的同步硝化反硝化特征,当气水比较低时主要进行短程的同步硝化反硝化.对B段反应器0.9m高度处的生物膜进行了静态试验,结果表明,生物膜的比硝化速率为 1.458mg NH3-N/(gMLSS?h);当 DO 和 pH 值等影响因子适宜的情况下,有机碳源的存在不影响硝化作用的进行;反硝化过程中,对亚硝酸进行反硝化的速率比对硝酸盐进行反硝化的速率高 1.15 倍,缩短了反硝化所需时间.展开更多
In aerobic wastewater treatment process, low dissolved oxygen (DO) concentration was generally thought to be harmful to aerobic microorganisms, especially to nitrifying microbes. In fact, ammonium could be well conver...In aerobic wastewater treatment process, low dissolved oxygen (DO) concentration was generally thought to be harmful to aerobic microorganisms, especially to nitrifying microbes. In fact, ammonium could be well converted under low DO and low DO condition could obviously lead to energy saving. In recent years, some new phenomena were found in nitrogen removal reactors operated at low DO concentration, such as sludge granulation;short-cut nitrification -denitrification; simultaneous nitrification-denitrification and denitrification by autotrophic nitrifier. These phenomena were valuable because they could give new method or some convenience to nitrogen removal process. Fig 1, Tab 1, Ref展开更多
文摘On the tasis of study in the mathematical model of 3-dimensional ruled surface (RS),this paper introduces a new concept of distance paramcter (DP) and also puts forward that themethod of modeling a RS depends on not only two boundary curves but also DP. According toabove theory, the formulas to calculate corresponding point coordinates to any kind of top and bot-tom profile of a workpiece and formulas to calcuate the maximum inclination angle of ruling linehave been obtained. Then a different top and bottom RS mathining method including profile withline-are combination as well as parametric curves has been achieved by 4-axes simultancous con-trol programming proposed.
文摘In aerobic wastewater treatment process, low dissolved oxygen (DO) concentration was generally thought to be harmful to aerobic microorganisms, especially to nitrifying microbes. In fact, ammonium could be well converted under low DO and low DO condition could obviously lead to energy saving. In recent years, some new phenomena were found in nitrogen removal reactors operated at low DO concentration, such as sludge granulation;short-cut nitrification -denitrification; simultaneous nitrification-denitrification and denitrification by autotrophic nitrifier. These phenomena were valuable because they could give new method or some convenience to nitrogen removal process. Fig 1, Tab 1, Ref