This paper focuses on the influence of the disturbance rejection rate(DRR)and parasitic loop parameters on the stability domain of the roll-pitch seeker's guidance system.The DRR models of the roll-pitch seeker ca...This paper focuses on the influence of the disturbance rejection rate(DRR)and parasitic loop parameters on the stability domain of the roll-pitch seeker's guidance system.The DRR models of the roll-pitch seeker caused by different types of disturbance torques and the scale deviation of different sensors are established.The optimal DRR model of the roll-pitch seeker,which contains the scale deviation model,is proposed by formula derivation.The model of the roll-pitch seeker's guidance system is established and equivalently simplified by the dimensionless method.The Lyapunov stability criterion for stability analysis of the guidance system is given by means of the passivity theorem and related definitions and lemmas.A simplified model of the roll-pitch seeker's guidance system,which is suitable for the Lyapunov stability criterion,is established by formula derivation and equivalent transformation.Three conditions that satisfy the Lyapunov stability criterion are obtained.Mathematical simulation with Nyquist plots is used to analyze the influence of different DRR parameters on the stability domain of the roll-pitch seeker's guidance system.Simulation results of this paper can provide reference for the stability analysis of systems related to the roll-pitch seeker.展开更多
A laboratory-scale investigation was performed to study arsenic(As(V))removal by negatively charged GE-HL nanofiltration(NF)membrane in simulated drinking water.Effects of As(V)concentration(0–200μg·L–1),pH,an...A laboratory-scale investigation was performed to study arsenic(As(V))removal by negatively charged GE-HL nanofiltration(NF)membrane in simulated drinking water.Effects of As(V)concentration(0–200μg·L–1),pH,and co-ions and counter-ions were investigated.The NF membrane presented good stability,and the rejection rates exceeded 90%.The rejection rates of As(V)decreased with the increase of As(V)concentration,while it increased with the increase of pH(reached 96%at pH 6.75).Moreover,a negative relationship was observed between the co-existing ions of Cl^(–),Na^(+),SO_(4)^(2–),and Ca^(2+)and the removal of As(V),in which bivalent ions presented more significant effects than monovalent ions.展开更多
基金supported by the Defense Science and Technology Key Laboratory Fund of Luoyang Electro-optical Equipment Institute,Aviation Industry Corporation of China(6142504200108)。
文摘This paper focuses on the influence of the disturbance rejection rate(DRR)and parasitic loop parameters on the stability domain of the roll-pitch seeker's guidance system.The DRR models of the roll-pitch seeker caused by different types of disturbance torques and the scale deviation of different sensors are established.The optimal DRR model of the roll-pitch seeker,which contains the scale deviation model,is proposed by formula derivation.The model of the roll-pitch seeker's guidance system is established and equivalently simplified by the dimensionless method.The Lyapunov stability criterion for stability analysis of the guidance system is given by means of the passivity theorem and related definitions and lemmas.A simplified model of the roll-pitch seeker's guidance system,which is suitable for the Lyapunov stability criterion,is established by formula derivation and equivalent transformation.Three conditions that satisfy the Lyapunov stability criterion are obtained.Mathematical simulation with Nyquist plots is used to analyze the influence of different DRR parameters on the stability domain of the roll-pitch seeker's guidance system.Simulation results of this paper can provide reference for the stability analysis of systems related to the roll-pitch seeker.
基金the Alcoa fund and Beijing Municipal Science and Technology Commission(Z0006345000091)。
文摘A laboratory-scale investigation was performed to study arsenic(As(V))removal by negatively charged GE-HL nanofiltration(NF)membrane in simulated drinking water.Effects of As(V)concentration(0–200μg·L–1),pH,and co-ions and counter-ions were investigated.The NF membrane presented good stability,and the rejection rates exceeded 90%.The rejection rates of As(V)decreased with the increase of As(V)concentration,while it increased with the increase of pH(reached 96%at pH 6.75).Moreover,a negative relationship was observed between the co-existing ions of Cl^(–),Na^(+),SO_(4)^(2–),and Ca^(2+)and the removal of As(V),in which bivalent ions presented more significant effects than monovalent ions.
