共查询到20条相似文献,搜索用时 343 毫秒
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利用非对称非线性函数耦合混沌同步方法,讨论了Chen吸引子的混沌同步问题,数值模拟分析初始值和耦合强度因子的选择对于实现混沌同步的影响. 将非对称非线性函数耦合同步方法进一步推广发展到完全连接网络和由星形子网络构成的复杂大网络混沌同步的研究中. 提供了确定网络中神经元之间混沌同步状态稳定性的误差发展方程,并讨论各个耦合强度因子对网络同步稳定性过程的影响,给出了相应的稳定性范围. 通过数值模拟证明利用非线性函数作为耦合函数,实现完全连接网络、星形子网络构成大网络的混沌同步是有效的. 可以预测在网络的混沌同步
关键词:
非线性耦合函数
Chen吸引子
混沌同步
网络 相似文献
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以一类含非黏滞阻尼的Duffing单边碰撞系统为研究对象, 运用复合胞坐标系方法, 分析了该系统的全局分岔特性. 对于非黏滞阻尼模型而言, 它与物体运动速度的时间历程相关, 能更真实地反映出结构材料的能量耗散现象. 研究发现, 随着阻尼系数、松弛参数及恢复系数的变化, 系统发生两类激变现象: 一种是混沌吸引子与其吸引域内的混沌鞍发生碰撞而产生的内部激变, 另一种是混沌吸引子与吸引域边界上的周期鞍(混沌鞍)发生碰撞而产生的常规边界激变(混沌边界激变), 这两类激变都使得混沌吸引子的形状发生突然改变.
关键词:
非黏滞阻尼
Duffing碰撞振动系统
激变
复合胞坐标系方法 相似文献
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采用旋转波近似,讨论一维Klein-Gordon双原子链中的能隙呼吸子. 在驻波边界条件下数值求解一维Klein-Gordon双原子链晶格振动的运动方程组,得到不同耦合系数、不同非线性系数以及不同原子质量比情况下的以重原子为中心的对称模能隙呼吸子. 随着耦合系数的增大,原子之间的耦合作用增强,呼吸子的空间扩展范围增大;非线性作用越大,能隙呼吸子局域化越强;随着原子质量差的增大,呼吸子在空间越来越局域.
关键词:
能隙呼吸子
一维Klein-Gordon双原子链
耦合系数
非线性 相似文献
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本文从描述驻波激光场与囚禁离子相互作用的非线性Jaynes-Cummings模型出发,引入一种新的量子态,即非线性增光子热态.采用理论分析和数值计算相结合的方法,研究了Lamb-Dicke参数,温度和激光场的初相位等参数对这种量子态的非经典效应的影响.结果表明:非线性增光子热态的Mandel Q因子随温度的变化存在一个极小值.Lamb-Dicke参数越大,非线性增光子热态的非经典效应就越强.此外驻波场的初相位也对该态的非经典效应有明显的影响. 相似文献
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《物理学报》2021,(13)
单层二硫化钼(MoS_2)是有广泛应用前景的二维纳米材料,但其力学性质还没有被深入研究,特别是其热弹耦合力学行为迄今还没有被关注到.本文首次提出了考虑热应力影响的单层MoS_2的非线性板理论,并对比研究了其与石墨烯的热弹耦合力学性质.对于不可移动边界,结果显示:1)有限温度产生的热应力降低了MoS_2的刚度,但提高了石墨烯的刚度; 2)在相同几何尺寸和温度条件下,变形较小时MoS_2的刚度大于石墨烯,但伴随变形的增大,MoS_2的刚度将小于石墨烯.研究结果表明,边界预加轴向外力和环境温度可以调节单层二维纳米结构力学性质.本文建立的热弹耦合板模型,可以推广至其他单层二维纳米结构. 相似文献
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Fang-Fang Chen 《Physica A》2009,388(6):984-990
In this paper, the dynamical behaviors of cellular automata rule 119 are studied from the viewpoint of symbolic dynamics in the bi-infinite symbolic sequence space Σ2. It is shown that there exists one Bernoulli-measure global attractor of rule 119, which is also the nonwandering set of the rule. Moreover, it is demonstrated that rule 119 is topologically mixing on the global attractor and possesses the positive topological entropy. Therefore, rule 119 is chaotic in the sense of both Li-Yorke and Devaney on the global attractor. It is interesting that rule 119, a member of Wolfram’s class II which was said to be simple as periodic before, actually possesses a chaotic global attractor in Σ2. Finally, it is noted that the method presented in this work is also applicable to studying the dynamics of other rules, especially the 112 Bernoulli-shift rules therein. 相似文献
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For a dynamical system described by a set of autonomous differential equations, an attractor can be either a point, or a periodic orbit, or even a strange attractor. Recently a new chaotic system with only one parameter has been presented where besides a point attractor and a chaotic attractor, it also has a coexisting attractor limit cycle which makes evident the complexity of such a system. We study using analytic tools the dynamics of such system. We describe its global dynamics near the infinity, and prove that it has no Darboux first integrals. 相似文献
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Jaume Llibre 《Physica D: Nonlinear Phenomena》2009,238(3):241-252
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A crisis is a global bifurcation in which a chaotic attractor has a discontinuous change in size or suddenly disappears as a scalar parameter of the system is varied. In this Letter, we describe a global bifurcation in three dimensions which can result in a crisis. This bifurcation does not involve a tangency and cannot occur in maps of dimension smaller than 3. We present evidence of unstable dimension variability as a result of the crisis. We then derive a new scaling law describing the density of the new portion of the attractor formed in the crisis. We illustrate this new type of bifurcation with a specific example of a three-dimensional chaotic attractor undergoing a crisis. 相似文献
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通过对改进恒Lyapunov指数谱混沌系统进行进一步演变,并引入新的绝对值项,发现了一种新的混沌吸引子.首先,通过相图、Poincar映射、Lyapunov指数以及功率谱,证明该混沌吸引子的存在性.接着,分析研究了这种新型混沌吸引子的基本动力学行为.Lyapunov指数谱、分岔图和状态变量幅值演变的数值仿真说明,该系统存在全局线性调幅参数,在该参数的调整下,系统输出三维信号的幅度皆能得到线性调整,而系统保持相同的混沌吸引子与Lyapunov指数谱.最后,通过构建电路实现了该混沌系统,观察到相应的混沌吸引子,也验证了全局线性调幅参数的调幅作用,数值仿真与电路实现有很好的一致性. 相似文献
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A dyadic shell model for the Navier-Stokes equations is studied in the context of turbulence. The model is an infinite nonlinearly coupled system of ODEs. It is proved that the unique fixed point is a global attractor, which converges to the global attractor of the inviscid system as viscosity goes to zero. This implies that the average dissipation rate for the viscous system converges to the anomalous dissipation rate for the inviscid system (which is positive) as viscosity goes to zero. This phenomenon is called the dissipation anomaly predicted by Kolmogorov’s theory for the actual Navier-Stokes equations. 相似文献
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A chaotic synchronized system of two coupled skew tent maps is discussed in this paper. The locally and globally riddled basins of the chaotic synchronized attractor are studied. It is found that there is a novel phenomenon in the local-global riddling bifurcation of the attractive basin of the chaotic synchronized attractor in some specific coupling intervals. The coupling parameter corresponding to the locally riddled basin has a single value which is embedded in the coupling parameter interval corresponding to the globally riddled basin, just like a breakpoint. Also, there is no relation between this phenomenon and the form of the chaotic synchronized attractor. This phenomenon is found analytically. We also try to explain it in a physical sense. It may be that the chaotic synchronized attractor is in the critical state, as it is infinitely close to the boundary of its attractive basin. We conjecture that this isolated critical value phenomenon will be common in a system with a chaotic attractor in the critical state, in spite of the system being discrete or differential. 相似文献
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《Physica D: Nonlinear Phenomena》2001,148(3-4):201-220
We consider the solutions lying on the global attractor of the two-dimensional Navier–Stokes equations with periodic boundary conditions and analytic forcing. We show that in this case the value of a solution at a finite number of nodes determines elements of the attractor uniquely, proving a conjecture due to Foias and Temam. Our results also hold for the complex Ginzburg–Landau equation, the Kuramoto–Sivashinsky equation, and reaction–diffusion equations with analytic nonlinearities. 相似文献
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应用广义胞映射方法研究了参激和外激共同作用的Duffing-van der Pol振子的随机分岔.以 系统参数通过某一临界值时,如果系统的随机吸引子或随机鞍的形态发生突然变化,则认为 系统发生随机分岔为定义,分析了参激强度和外激强度的变化对于随机分岔的影响.揭示了 随机分岔的发生主要是由于系统的随机吸引子与系统的随机鞍碰撞产生的.分析表明,广义 胞映射方法是分析随机分岔的有力工具,这种全局分析方法可以清晰地给出随机分岔的发生 和发展.
关键词:
随机分岔
全局分析
广义胞映射方法
随机吸引子
随机鞍 相似文献