Adaptive function projective synchronization of uncertain complex dynamical networks with disturbance

We investigate the problem of function projective synchronization (FPS) in drive-response dynamical networks with non-identical nodes. An adaptive controller is proposed for the FPS of complex dynamical networks with uncertain parameters and disturbance. Not only are the unknown parameters of the networks estimated by the adaptive laws obtained from the Lyapunov stability theory and Taylor expansions, but the unknown bounded disturbances are also simultaneously conquered by the proposed control. Finally, a numerical simulation is provided to illustrate the feasibility and effectiveness of the obtained result.     

A new hyperchaotic system and its linear feedback control

This paper reports a new hyperchaotic system by adding an additional state variable into a three-dimensional chaotic dynamical system, studies some of its basic dynamical properties, such as the hyperchaotic attractor, Lyapunov exponents, bifurcation diagram and the hyperchaotic attractor evolving into periodic, quasi-periodic dynamical behaviours by varying parameter k. Furthermore, effective linear feedback control method is used to suppress hyperchaos to unstable equilibrium, periodic orbits and quasi-periodic orbits. Numerical simulations are presented to show these results.     

The analysis of complex behaviours of a novel three dimensional autonomous system

This paper introduces a new three dimensional autonomous system with five equilibrium points.It demonstrates complex chaotic behaviours within a wide range of parameters,which are described by phase portraits,Lyapunov exponents,frequency spectrum,etc.Analysis of the bifurcation and Poincar’e map is used to reveal mechanisms of generating these complicated phenomena.The corresponding electronic circuits are designed,exhibiting experimental chaotic attractors in accord with numerical simulations.Since frequency spectrum analysis shows a broad frequency bandwidth,this system has perspective of potential applications in such engineering fields as secure communication.     

有机磷农药甲基对硫磷的太赫兹(THz)光谱研究

运用太赫兹时域光谱技术(THz-TDS)与理论模拟相结合的方法研究了有机磷农药甲基对硫磷在THz波段的光谱特性.在室温氮气环境中得到了样品在0.2～2.0 THz波段的吸收谱和折射率谱.表明其特征吸收峰分别位于0.65,1.33,1.81和1.91 THz处,其平均折射率为1.39.同时运用密度泛函理论(DFT)计算了甲基对硫磷分子的结构及其在太赫兹波段的振动频率,计算结果与实验数据吻合较好.研究结果表明,实验光谱的特征吸收峰是由分子的集体振动及扭转形成,不同的吸收峰位对应分子不同的振转模式.     

Spectrum Analysis and Circuit Implementation of a New 3D Chaotic System with Novel Chaotic Attractors

The new autonomous system with only three equilibrium points is introduced. This system does not belong to the generalized Lorenz systems. The novel attractors are observed over a large range of parameters, which have rarely been reported in previous work. As an important component in chaotic signal generators, a physical circuit has been designed. The experimental results are in agreement with numerical simulations. More significantly, spectral analysis shows that the system has an extremely broad frequency spectral bandwidth in 0-131.6 Hz, without investigating any possible electronic techniques, which is more desirable for secure communications.     

Projective synchronisation with non-delayed and delayed coupling in complex networks consisting of identical nodes and different nodes

This paper first investigates the projective synchronisation problem with non-delayed and delayed coupling between drive-response dynamical networks consisting of identical nodes and different nodes.Based on Lyapunov stability theory,several nonlinear controllers are applied to achieve the projective synchronisation between the drive-response dynamical networks;simultaneously the topological structure of the drive dynamical complex networks can be exactly identified.Moreover,numerical examples are presented to verify the feasibility and effectiveness of the theorems.     

Adaptive control and synchronization of an uncertain new hyperchaotic Lorenz system

This paper is involved with the adaptive control and synchronization problems for an uncertain new hyperchaotic Lorenz system. Based on the Lyapunov stability theory, the adaptive control law is derived such that the trajectory of hyperchaotic Lorenz system with unknown parameters can be globally stabilized to an unstable equilibrium point of the uncontrolled system. Furthermore, an adaptive control approach is presented to the synchronizations between two identical hyperchaotic systems, particularly between two different uncertain hyperchaotic systems. Numerical simulations show the effectiveness of the presented method.     

储氢材料新合成方法的研究--Ⅲ.置换-扩散法合成Mg2Ni0.75Cu0.25

本文用置换-扩散法合成了三元储氢合金材料Mg_2Ni_(0.75)Cu_(0.25),并对合成的样品进行了吸、放氢性能测试。结果表明,它与氢的反应是可逆的,氢化产物的热分解温度较Mg_2NiH_4有明显的降低。本法合成的样品与冶炼法合成的样品相比较,具有易于活化,吸、放氢速度明显加快等优点。     

Mg_2Ni_(0.75)Cu_(0.25)-Mg_(1.76)体系的合成及氢化过程的初步研究

Leilly、Rudmen和本研究组分别对Mg_2Ni-xMg,Mg_2Cu-xMg体系进行了研究,巳发现Mg_2Ni或Mg_2Cu的存在对镁的氢化,释氢过程有催化作用,并描述了二元合金Mg_2Ni,Mg_2Cu对Mg的吸、放氢过程的催化氢化、脱氢模型。但有关三元合金对纯镁的吸、放氢催化性能研究,至今未见报道。我们合成了在基质镁粒表面包覆Mg_2Ni_(0.75) Cu_(0.25)的新型材料,并研究此三元合金表面对所包覆的Mg核与H_2之间反应的影响。