This article deals with two important issues in digital filter implementation： roundoff noise and limit cycles. A novel class of robust state-space realizations, called normal realizations, is derived and characteriz...This article deals with two important issues in digital filter implementation： roundoff noise and limit cycles. A novel class of robust state-space realizations, called normal realizations, is derived and characterized. It is seen that these realizations are free of limit cycles. Another interesting property of the normal realizations is that they yield a minimal error propagation gain. The optimal realization problem, defined as to find those normal realizations that minimize roundoff noise gain, is formulated and solved analytically. A design example is presented to demonstrate the behavior of the optimal normal realizations and to compare them with several well-known digital filter realizations in terms of minimizing the roundoff noise and the error propagation.展开更多
Plutella xylostella,a major pest of cruciferous vegetables worldwide,has developed resistance to diamide insecticides.Thiotraniliprole,a novel synthetic diamide insecticide,exhibits excellent activity against P.xylost...Plutella xylostella,a major pest of cruciferous vegetables worldwide,has developed resistance to diamide insecticides.Thiotraniliprole,a novel synthetic diamide insecticide,exhibits excellent activity against P.xylostella.In the present study,we aimed to confirm the resistance risk,cross-resistance,and mechanisms of resistance to thiotraniliprole in P.xylostella.After 40 consecutive generations of thiotraniliprole selection,we obtained a thiotraniliprole-resistance P.xylostella strain with a 5141.58-fold resistance ratio(RR)to thiotraniliprole.The overall realized heritability(h^(2))value of resistance was estimated as 0.9 using threshold trait analysis,indicating that the risk of developing resistance to thiotraniliprole is high in P.xylostella.The thiotraniliprole-resistant(TR)strain showed noticeable cross-resistance to chlorantraniliprole(RR=44670.05),cyantraniliprole(RR=7038.58),and tetrachlorantraniliprole(RR=1506.01),but no cross-resistance to tolfenpyrad,indoxacarb,diafenthiuron,or abamectin compared with the susceptible(S)strain.The enzyme assay data showed that the activities of glutathione-S transferase(GST),carboxylesterase(CarE),and the content of cytochrome P450 monooxygenase(P450s)were significantly higher in the TR strain than in the S strain.Sequencing of the full-length PxRyR cDNA revealed the gene site I4790K in the TR strain with a 100%frequency.This mutation in PxRyR likely underlies the high-level cross-resistance between thiotraniliprole and three other diamide insecticides.These findings provide valuable information for optimizing resistance management strategies to delay thiotraniliprole resistance development and ensure sustainable control of P.xylostella.展开更多
采用R ea lizab le k-ε双方程模型和P ISO算法,在正弦型周期变化风谱所形成的大气边界层对数风速廓线下,对绕三维建筑物的流动进行了数值模拟.采用分区网格划分方法,应用自适应网格技术,固体壁面采用标准壁面函数法处理.计算结果显示,...采用R ea lizab le k-ε双方程模型和P ISO算法,在正弦型周期变化风谱所形成的大气边界层对数风速廓线下,对绕三维建筑物的流动进行了数值模拟.采用分区网格划分方法,应用自适应网格技术,固体壁面采用标准壁面函数法处理.计算结果显示,整个流场都随正弦风谱呈周期性波动,各点速度的变化周期相同,只是幅度有所改变.周期的变化对整个流场速度的大小影响较小,但振幅的改变可使速度值发生很大变化.在建筑物周围,受阻挡的气流被挤压而绕流,横剖面后部形成两个旋转方向相反的大尺度涡;纵剖面后部分离后产生与H相同高尺的分离涡,回流区长度在0.15 m左右,且不随周期和振幅而改变,整个流动具有对称性.展开更多
基金the National Nature Science Foundation of China (60774021)
文摘This article deals with two important issues in digital filter implementation： roundoff noise and limit cycles. A novel class of robust state-space realizations, called normal realizations, is derived and characterized. It is seen that these realizations are free of limit cycles. Another interesting property of the normal realizations is that they yield a minimal error propagation gain. The optimal realization problem, defined as to find those normal realizations that minimize roundoff noise gain, is formulated and solved analytically. A design example is presented to demonstrate the behavior of the optimal normal realizations and to compare them with several well-known digital filter realizations in terms of minimizing the roundoff noise and the error propagation.
基金Supported by the Zhejiang Provincial Public Welfare Technology Application Research Program(No:LGN21C140001).
文摘Plutella xylostella,a major pest of cruciferous vegetables worldwide,has developed resistance to diamide insecticides.Thiotraniliprole,a novel synthetic diamide insecticide,exhibits excellent activity against P.xylostella.In the present study,we aimed to confirm the resistance risk,cross-resistance,and mechanisms of resistance to thiotraniliprole in P.xylostella.After 40 consecutive generations of thiotraniliprole selection,we obtained a thiotraniliprole-resistance P.xylostella strain with a 5141.58-fold resistance ratio(RR)to thiotraniliprole.The overall realized heritability(h^(2))value of resistance was estimated as 0.9 using threshold trait analysis,indicating that the risk of developing resistance to thiotraniliprole is high in P.xylostella.The thiotraniliprole-resistant(TR)strain showed noticeable cross-resistance to chlorantraniliprole(RR=44670.05),cyantraniliprole(RR=7038.58),and tetrachlorantraniliprole(RR=1506.01),but no cross-resistance to tolfenpyrad,indoxacarb,diafenthiuron,or abamectin compared with the susceptible(S)strain.The enzyme assay data showed that the activities of glutathione-S transferase(GST),carboxylesterase(CarE),and the content of cytochrome P450 monooxygenase(P450s)were significantly higher in the TR strain than in the S strain.Sequencing of the full-length PxRyR cDNA revealed the gene site I4790K in the TR strain with a 100%frequency.This mutation in PxRyR likely underlies the high-level cross-resistance between thiotraniliprole and three other diamide insecticides.These findings provide valuable information for optimizing resistance management strategies to delay thiotraniliprole resistance development and ensure sustainable control of P.xylostella.
文摘采用R ea lizab le k-ε双方程模型和P ISO算法,在正弦型周期变化风谱所形成的大气边界层对数风速廓线下,对绕三维建筑物的流动进行了数值模拟.采用分区网格划分方法,应用自适应网格技术,固体壁面采用标准壁面函数法处理.计算结果显示,整个流场都随正弦风谱呈周期性波动,各点速度的变化周期相同,只是幅度有所改变.周期的变化对整个流场速度的大小影响较小,但振幅的改变可使速度值发生很大变化.在建筑物周围,受阻挡的气流被挤压而绕流,横剖面后部形成两个旋转方向相反的大尺度涡;纵剖面后部分离后产生与H相同高尺的分离涡,回流区长度在0.15 m左右,且不随周期和振幅而改变,整个流动具有对称性.
