In this paper, author obtain sufficient condition for the boundedness of solutions of the second order nonlinear differential systemdxdt=y-φ(x), dydt=-yf(x)-g(x).(E)The result can be applied to the Liénard-type ...In this paper, author obtain sufficient condition for the boundedness of solutions of the second order nonlinear differential systemdxdt=y-φ(x), dydt=-yf(x)-g(x).(E)The result can be applied to the Liénard-type system, which substantially extends and imporves some important results associated with the same problems in the literatures [1—10] et al..展开更多
The electro-optic properties of a poled second-order nonlinear optical maleimide polymer system were reported.This polymer was synthesized by doping disperse red 1 moieties into the maleimide system as the side chains...The electro-optic properties of a poled second-order nonlinear optical maleimide polymer system were reported.This polymer was synthesized by doping disperse red 1 moieties into the maleimide system as the side chains.Its glass transition temperature was measured to be 202 ℃ by Differential Scanning Calorimetry (DSC) technology.After being poled,the measured electro-optic coefficient of PHSD at the wavelength of 1 550 nm is as large as 3.03 pm/v.Except for an initial decay after being poled,PHSD exhibits little electro-optic relaxation in a long term and its electro-optic coefficient remains about 2.46 pm/v after 15 days.展开更多
System identification is an effective way for modeling ship manoeuvring motion and ship manoeuvrability prediction. Support vector machine is proposed to identify the manoeuvring indices in four different response mod...System identification is an effective way for modeling ship manoeuvring motion and ship manoeuvrability prediction. Support vector machine is proposed to identify the manoeuvring indices in four different response models of ship steering motion, including the first order linear, the first order nonlinear, the second order linear and the second order nonlinear models. Predictions of manoeuvres including trained samples by using the identified parameters are compared with the results of free-running model tests. It is discussed that the different four categories are consistent with each other both analytically and numerically. The generalization of the identified model is verified by predicting different untrained manoeuvres. The simulations and comparisons demonstrate the validity of the proposed method.展开更多
Based on the theory of semi-global C 1 solution and the local exact boundary controllability for first-order quasilinear hyperbolic systems,the local exact boundary controllability for a kind of second-order quasiline...Based on the theory of semi-global C 1 solution and the local exact boundary controllability for first-order quasilinear hyperbolic systems,the local exact boundary controllability for a kind of second-order quasilinear hyperbolic systems is obtained by a constructive method.展开更多
A new method to solve the Gauss-Codazzi system is given in which we transform the linearized system to a partial differential equation of second order, and by the method we solve the problem of semi-global isometric e...A new method to solve the Gauss-Codazzi system is given in which we transform the linearized system to a partial differential equation of second order, and by the method we solve the problem of semi-global isometric embedding of surfaces with Gaussian curvature changing sign cleanly.展开更多
文摘In this paper, author obtain sufficient condition for the boundedness of solutions of the second order nonlinear differential systemdxdt=y-φ(x), dydt=-yf(x)-g(x).(E)The result can be applied to the Liénard-type system, which substantially extends and imporves some important results associated with the same problems in the literatures [1—10] et al..
基金This work is partially supported by National Natural ScienceFoundation of China ( Grant No:60377013 ,60507013) WHUT Foundation(XJJ2005175) .
文摘The electro-optic properties of a poled second-order nonlinear optical maleimide polymer system were reported.This polymer was synthesized by doping disperse red 1 moieties into the maleimide system as the side chains.Its glass transition temperature was measured to be 202 ℃ by Differential Scanning Calorimetry (DSC) technology.After being poled,the measured electro-optic coefficient of PHSD at the wavelength of 1 550 nm is as large as 3.03 pm/v.Except for an initial decay after being poled,PHSD exhibits little electro-optic relaxation in a long term and its electro-optic coefficient remains about 2.46 pm/v after 15 days.
基金the Special Research Fund for the Doctoral Program of Higher Education (No. 20050248037)the National Natural Science Foundation of China(No. 50779033)
文摘System identification is an effective way for modeling ship manoeuvring motion and ship manoeuvrability prediction. Support vector machine is proposed to identify the manoeuvring indices in four different response models of ship steering motion, including the first order linear, the first order nonlinear, the second order linear and the second order nonlinear models. Predictions of manoeuvres including trained samples by using the identified parameters are compared with the results of free-running model tests. It is discussed that the different four categories are consistent with each other both analytically and numerically. The generalization of the identified model is verified by predicting different untrained manoeuvres. The simulations and comparisons demonstrate the validity of the proposed method.
基金supported by the Excellent Doctoral Research Foundation for Key Subject of Fudan University (No.EHH1411208)
文摘Based on the theory of semi-global C 1 solution and the local exact boundary controllability for first-order quasilinear hyperbolic systems,the local exact boundary controllability for a kind of second-order quasilinear hyperbolic systems is obtained by a constructive method.
基金supported by the Fundamental Research Funds for the Central Universities(Grant No. ZYGX2010J109)National Natural Science Foundation of China (Grant No. 11101068)the Sichuan Youth Science and Technology Foundation (Grant No. 2011JQ0003)
文摘A new method to solve the Gauss-Codazzi system is given in which we transform the linearized system to a partial differential equation of second order, and by the method we solve the problem of semi-global isometric embedding of surfaces with Gaussian curvature changing sign cleanly.
