M-xylene bicyclic peroxy radical(M-BPR)is an important atmospheric intermediate formed by the oxidation of m-xylene,which plays an important role in the new particle formation and growth of secondary organic aerosol.I...M-xylene bicyclic peroxy radical(M-BPR)is an important atmospheric intermediate formed by the oxidation of m-xylene,which plays an important role in the new particle formation and growth of secondary organic aerosol.In this work,the reaction mechanism,thermodynamic analysis,and kinetics of the reaction between M-BPR and HO_(2)were investigated at the CCSD(T)/cc-pVDZ//B3LYP/6-311G(d,p)level of theory coupled with transition state theory.The calculated results indicate that the title reaction can occur on both singlet and triplet potential energy surfaces,and the formation of hydroperoxides and 3O_(2)via triplet state is the main reaction channel,while the other four singlet product channels are negligible due to the higher barrier heights.Additionally,the reaction rate constants are estimated by using the transition state theory over the temperature range of 258 K to 378 K,and reaction rate constants arc found to be negatively correlated with temperature.At 298 K,the total rate constant for the title reaction is 1.86×10^(-11)cm^(3)·molecule^(-1)·s^(-1).The calculated rate constants over the studied temperature range were used to fit the data and the three-parameter Arrhenius ex-studied is obtainted to be k(T)=4.22×10^(-15)·(T/300)^(1.44)·exp(2505/T).展开更多
FxLMS(Filtered-x Least Mean Square)算法在主动振动控制系统中有着广泛的应用,在实际系统中由于参考输入信号会混入诸如测量噪声、冲击噪声、野值等与参考信号不相关的干扰信号,这会导致系统更新稳定性性能变坏,甚至发散。针对这个问...FxLMS(Filtered-x Least Mean Square)算法在主动振动控制系统中有着广泛的应用,在实际系统中由于参考输入信号会混入诸如测量噪声、冲击噪声、野值等与参考信号不相关的干扰信号,这会导致系统更新稳定性性能变坏,甚至发散。针对这个问题,提出一种改进的FxLMS算法。新的算法利用跟踪微分滤波器和非线性变换函数分别对参考输入信号和反馈误差信号进行处理。同时,以滤波器更新向量的差值最小为优化条件推导出新的更新公式。通过在主动振动控制系统中与已有算法进行仿真比较,仿真结果证明在处于噪声干扰的情况下新的算法体现出更好的更新稳定性。展开更多
基金the Anhui University of Traditional Chinese Medicine High Level Talent Support Program Project(No.2021rcybO1)the National Natural Science Foundation of China(No.42075113,No.91544228)Scientific Research Program of Higher Education Institutions in Anhui Province(2023AH050836).
文摘M-xylene bicyclic peroxy radical(M-BPR)is an important atmospheric intermediate formed by the oxidation of m-xylene,which plays an important role in the new particle formation and growth of secondary organic aerosol.In this work,the reaction mechanism,thermodynamic analysis,and kinetics of the reaction between M-BPR and HO_(2)were investigated at the CCSD(T)/cc-pVDZ//B3LYP/6-311G(d,p)level of theory coupled with transition state theory.The calculated results indicate that the title reaction can occur on both singlet and triplet potential energy surfaces,and the formation of hydroperoxides and 3O_(2)via triplet state is the main reaction channel,while the other four singlet product channels are negligible due to the higher barrier heights.Additionally,the reaction rate constants are estimated by using the transition state theory over the temperature range of 258 K to 378 K,and reaction rate constants arc found to be negatively correlated with temperature.At 298 K,the total rate constant for the title reaction is 1.86×10^(-11)cm^(3)·molecule^(-1)·s^(-1).The calculated rate constants over the studied temperature range were used to fit the data and the three-parameter Arrhenius ex-studied is obtainted to be k(T)=4.22×10^(-15)·(T/300)^(1.44)·exp(2505/T).
文摘FxLMS(Filtered-x Least Mean Square)算法在主动振动控制系统中有着广泛的应用,在实际系统中由于参考输入信号会混入诸如测量噪声、冲击噪声、野值等与参考信号不相关的干扰信号,这会导致系统更新稳定性性能变坏,甚至发散。针对这个问题,提出一种改进的FxLMS算法。新的算法利用跟踪微分滤波器和非线性变换函数分别对参考输入信号和反馈误差信号进行处理。同时,以滤波器更新向量的差值最小为优化条件推导出新的更新公式。通过在主动振动控制系统中与已有算法进行仿真比较,仿真结果证明在处于噪声干扰的情况下新的算法体现出更好的更新稳定性。
