一个新的超混沌系统及其电路实现

通过对一个光滑三维二次混沌系统上引入一个新的状态反馈控制器,构造出一个新的四维超混沌系统。详细地分析了该系统平衡点的性质、超混沌吸引子相图、Lyapunov指数和分岔图等基本动力学特性。数值模拟结果表明,新的四维系统能随着参数变化呈现出周期态、拟周期态、混沌态和超混沌态等丰富的动力学行为。最后设计了硬件电路实验,也很好的证实了相关结果。     

三阶非自治铁磁混沌电路的分析及控制

本文对一个LC串并联三阶非自治铁磁混沌电路的混沌动力学行为进行了理论研究和计算机仿真分析。得出几点重要结论：(1)此电路仅含一个由磁通链控制的非线性电感元件，可以作为一个四阶自治扭扩系统来分析。(2)通过计算机仿真验证，证实了该电路确实存在混沌动力学行为。(3)凡是能用本文提出三阶非线性非自治微分方程描述的工程物理系统都具有混沌性质。(4)提出了调整线性参数控制混沌法。     

超混沌五阶自治电路的建模与仿真

提出了一个五阶自治混沌电路，基于电路建模与数值计算仿真对其混沌动力学性态和频谱分布特征进行了较详尽的研究。研究结果表明该电路在某些元件参数范围内，能够产生具有两个正性Lyapunov指数的超混沌信号，呈现出复杂的混沌动力学行为，将其用于保密通信，密文的抗破译强度会有较大的提高。     

4阶Colpitts MOS管混沌电路设计

仅增加一个线性电容并联于单电感两端,使3阶Colpitts MOS管电路成为4阶混沌电路。该电容与电感形成选频谐振子电路,便于产生混沌信号,可扩展存在混沌的参数取值范围。结合新电路归一化状态方程,分别计算电感电流和三只电容端压的4个李指数,探讨关键参数对该混沌电路的影响。对比MATLAB仿真数据与实测单MOS管电路的输出,一致性地显示4阶混沌特有的混沌吸引子已经实现。     

基于限幅特性非线性三阶自治电路的混沌遮掩保密通信

设计了一种限幅特性非线性三阶自治混沌保密通信电路系统.该系统利用串联同步三阶自治混沌电路进行信号混沌遮掩保密通信.有用信号隐藏在混沌参数中,混沌复合信号作为传送信号,在发送端和接收端之间传送.利用接收端响应系统与发送端驱动系统达到同步,可无失真地将有用信息信号检出.该方法设计简单,易于实现,并且同步速度快,实现了高质量的信息保密传送,具有很好的可行性.     

基于蔡氏电路的数字混沌序列的性能研究

首先指出了传统的混沌伪随机序列的缺陷,并从理论上进行了分析,进而提出一种采用A/D转换方式对模拟的蔡氏混沌电路进行数字化,相应处理后,生成真正意义上的数字混沌序列的方法。通过对所得到的序列进行理论与随机性能分析可知：提出的混沌序列产生方法简单,序列的随机性能良好,适合应用于数据加密领域,是一类具有很好应用前景的混沌序列产生方法。     

菌紫质LB膜的三阶非线性光学性能的研究

在ITO导电玻璃上,制作38层Z型细菌视紫红质(bR)的LB膜;控制平均转移比在0.93以上。测量了这个LB膜的紫外-可见吸收谱。利用Z扫描技术在输出飞秒激光,波长为400nm和800nm处对菌紫质LB膜的三阶非线性光学性能进行了研究。在800nm处,它的三阶非线性光学极化率为10-9esu,而在400nm处为10-8esu。这表明菌紫质LB膜在非线性光学器件方面具有潜在的应用前景。     

类Henon吸引子动力学演化研究

给Henon吸引子系统引入正弦因子，提出了类Henon吸引子的一种模型，研究其在相位控制参数下的混沌演化行为。     

蔡氏混沌非线性电路及其频率特性研究

混沌电路是一种非线性电路，具有宽频谱特性，但在实际通信应用中，通信信道的带宽有一定限制，如何调节混沌电路的频谱范围成为混沌电路实际应用的一个问题。本文以蔡氏混沌电路为例，利用MATLAB软件分析蔡氏混沌电路产生的混沌信号及其频率特性。通过对蔡氏混沌电路中元器件R、L和C参数的调整，可以获得具有期望频谱范围的混沌信号。     

基于饱和非线性模块的多涡卷混沌电路

针对分立元件构造的多涡卷混沌电路存在电源电压高、耗能多、频谱范围窄、电路体积大的问题,采用跨导电容结构,设计了一种将非线性模块、跨导器、电压反相器集成于一体的多涡卷混沌电路。非线性模块呈现饱和特性,通过调节电流源和MOS管宽长比来改变其特性曲线的转折点、饱和值、斜率,方便地构造出分段线性函数电路。设计了网格多涡卷Jerk系统和单方向多涡卷Chua系统,采用非线性模块分别搭建了Jerk系统中的阶梯波函数电路和Chua系统中的三角波函数电路。Pspice仿真结果证明了搭建的非线性模块和混沌电路设计、电路功能的正确性。     

Integrated Circuit Implementation of a Compact Discrete-Time Chaos Generator

A discrete-time chaos generator implemented with two nonlinear circuit cells has been fabricated in a 0.6 μm CMOS technology. Each cell is creating a function (map) which allows a chaos signal to be generated. Measurements of the chip were performed with a supply voltage of 5 V, up to a frequency of 2.5 MHz. A bifurcation diagram of the circuit and the Lyapunov exponent calculation are presented. The size of the generator layout (without the switches) is 32 × 19 μ m which makes it suitable for applications where many chaos signal generators are required on a single chip. Dan Juncu received the B.S. and M.Sc. degrees in Electrical and Electronics Engineering from the Technical University, Iasi, Romania in 1997 and 1998, respectively, and the Ph.D. degree in Electronics from UMIST, Manchester, UK in 2003. For his Ph.D. he did research on sensor interfaces for gas sensing devices; after that, he worked on RF IC on a new SiGe technology. In 2004 he joined Cambridge Consultants, Cambridge, UK. His current interests are in the area of switched capacitor filtering and computation, and sensor interfacing. Mandana Rafiei-Naeini received the B.Sc. degree in Electrical Engineering (majoring in Electronics) from Islamic Azad University of Tehran, Iran, in 2001 and the M.Sc. degree with distinction in Electronic Instrumentation Systems from University of Manchester in 2004. She is currently studying towards her Ph.D. degree in the School of Electrical and Electronic Engineering at The University of Manchester, working on clinical electrical impedance tomography systems for brain function imaging. She is a student member of IEE and IEEE. Piotr Dudek received his mgr in ż degree in electronic engineering from the Technical University of Gdańsk, Poland in 1997 and the M.Sc. and Ph.D. degrees from the University of Manchester Institute of Science and Technology (UMIST), Manchester, UK, in 1996 and 2000, respectively. He worked as a Research Associate at UMIST until 2002. Currently, he is a Lecturer in Integrated Circuit Engineering at The University of Manchester. His research interests are in analogue and mixed-mode VLSI circuits, smart sensors, machine vision, massively parallel processors, cellular arrays, bio-inspired engineering and spiking neural networks.