通过对基于稳定域边界的主导不稳定平衡点法(Boundary of stabiliIy based controlling unstable equilibrium point method,BCU)的前提条件的分析,得到了当故障清除后的电力系统不完全稳定时,应用该方法的一个必要条件:相关的广义梯度...通过对基于稳定域边界的主导不稳定平衡点法(Boundary of stabiliIy based controlling unstable equilibrium point method,BCU)的前提条件的分析,得到了当故障清除后的电力系统不完全稳定时,应用该方法的一个必要条件:相关的广义梯度系统不完全稳定。并证明了使该条件得到满足的一个充分条件:广义梯度系统无源点。在稳定性分析中,可以通过检验该条件来间接地检验电力系统是否满足BCU法的前提条件。对一个4机系统和IEEE 50机测试系统的计算验证了上述的结果。展开更多
In this article, the authors study some limit properties for sequences of pairwise NQD random variables, which are not necessarily identically distributed. They obtain Baum and Katz complete convergence and the strong...In this article, the authors study some limit properties for sequences of pairwise NQD random variables, which are not necessarily identically distributed. They obtain Baum and Katz complete convergence and the strong stability of Jamison＇s weighted sums for pairwise NQD random variables, which may have different distributions. Some wellknown results are improved and extended.展开更多
The existence, uniqueness, globally exponential stability andspeed of exponential convergence for a class of cellular neural networks are investigated. The existence of a unique equilibrium is proved under very concis...The existence, uniqueness, globally exponential stability andspeed of exponential convergence for a class of cellular neural networks are investigated. The existence of a unique equilibrium is proved under very concise conditions, and theorems for estimating the global convergence speed approaching the equilibrium and criteria for its globally exponential stability are derived, Considering synapse time delay, by constructing appropriate Lyapunov functional, the existence of a unique equilibrium and its global stability for the delayed network are also proved. The results, which do not require the cloning template to be symmetric, are easy to use in network design.展开更多
Shortcut nitrification-denitrification(SCND)is widely concerned because of its low energy consumption and high nitrogen removal efficiency.However,the current difficulty lies in the stable maintenance of SCND performa...Shortcut nitrification-denitrification(SCND)is widely concerned because of its low energy consumption and high nitrogen removal efficiency.However,the current difficulty lies in the stable maintenance of SCND performance,which leads to the challenge of large-scale application of this new denitrification technology.In this study,the nitrogen removal pathway from complete nitrification-denitrification(CND)to SCND was rapidly realized under high free ammonia(FA),high pH and low dissolved oxygen(DO)conditions.The variations of specific oxygen uptake rate(SOUR)of activated sludge in both processes were investigated by an online SOUR monitoring device.Different curves of SOUR from CND to SCND process were observed,and the ammonia peak obtained based on SOUR monitoring could be used to control aeration time accurately in SCND process.Accordingly,the SOUR ratio of ammonia oxidizing bacteria(AOB)to nitrite oxidizing bacteria(NOB)(SOURAOB/SOURNOB)was increased from 1.40 to 2.93.16S rRNA Miseq high throughput sequencing revealed the dynamics of AOB and NOB,and the ratio of relative abundance(AOB/NOB)was increased from 1.03 to 3.12.Besides,SOURAOB/SOURNOB displayed significant correlations to ammonia removal rate(P<0.05),ammonia oxidation rate/nitrite oxidation rate(P<0.05),nitrite accumulation rate(P<0.05)and the relative abundance of AOB/NOB(P<0.05).Thus,a strategy for evaluation the SCND process stability based on online SOUR monitoring is proposed,which provides a theoretical basis for optimizing the SCND performance.展开更多
文摘通过对基于稳定域边界的主导不稳定平衡点法(Boundary of stabiliIy based controlling unstable equilibrium point method,BCU)的前提条件的分析,得到了当故障清除后的电力系统不完全稳定时,应用该方法的一个必要条件:相关的广义梯度系统不完全稳定。并证明了使该条件得到满足的一个充分条件:广义梯度系统无源点。在稳定性分析中,可以通过检验该条件来间接地检验电力系统是否满足BCU法的前提条件。对一个4机系统和IEEE 50机测试系统的计算验证了上述的结果。
基金the National Natural Science Foundation of China(10671149)
文摘In this article, the authors study some limit properties for sequences of pairwise NQD random variables, which are not necessarily identically distributed. They obtain Baum and Katz complete convergence and the strong stability of Jamison＇s weighted sums for pairwise NQD random variables, which may have different distributions. Some wellknown results are improved and extended.
基金This work was supported by the National Natural Science Foundation of China ( Grant No. 69871005) .
文摘The existence, uniqueness, globally exponential stability andspeed of exponential convergence for a class of cellular neural networks are investigated. The existence of a unique equilibrium is proved under very concise conditions, and theorems for estimating the global convergence speed approaching the equilibrium and criteria for its globally exponential stability are derived, Considering synapse time delay, by constructing appropriate Lyapunov functional, the existence of a unique equilibrium and its global stability for the delayed network are also proved. The results, which do not require the cloning template to be symmetric, are easy to use in network design.
基金This research was supported by Sichuan Key Point Research and Invention Program(Nos.2019YFS0502,2020YFS0026)Instrument Developing Project of the Chinese Academy of Sciences(No.YJKYYQ20180002)Project funded by China Postdoctoral Science Foundation(No.2020M673293).
文摘Shortcut nitrification-denitrification(SCND)is widely concerned because of its low energy consumption and high nitrogen removal efficiency.However,the current difficulty lies in the stable maintenance of SCND performance,which leads to the challenge of large-scale application of this new denitrification technology.In this study,the nitrogen removal pathway from complete nitrification-denitrification(CND)to SCND was rapidly realized under high free ammonia(FA),high pH and low dissolved oxygen(DO)conditions.The variations of specific oxygen uptake rate(SOUR)of activated sludge in both processes were investigated by an online SOUR monitoring device.Different curves of SOUR from CND to SCND process were observed,and the ammonia peak obtained based on SOUR monitoring could be used to control aeration time accurately in SCND process.Accordingly,the SOUR ratio of ammonia oxidizing bacteria(AOB)to nitrite oxidizing bacteria(NOB)(SOURAOB/SOURNOB)was increased from 1.40 to 2.93.16S rRNA Miseq high throughput sequencing revealed the dynamics of AOB and NOB,and the ratio of relative abundance(AOB/NOB)was increased from 1.03 to 3.12.Besides,SOURAOB/SOURNOB displayed significant correlations to ammonia removal rate(P<0.05),ammonia oxidation rate/nitrite oxidation rate(P<0.05),nitrite accumulation rate(P<0.05)and the relative abundance of AOB/NOB(P<0.05).Thus,a strategy for evaluation the SCND process stability based on online SOUR monitoring is proposed,which provides a theoretical basis for optimizing the SCND performance.
