Globally Coupled Chaotic Maps with Constant Force

We investigate the motion of the globally coupled maps （logistic map） with a constant force. It is shown that the constant force can cause multi-synchronization for the globally coupled chaotic maps studied by us.     

高速分幅相机与阳加速器的精密电流同步技术

针对在阳加速器上进行Z箍缩实验时存在的同步精度低的问题,研究了一套同步触发信号取自加速器输出电流的技术。利用加速器工作电流波形与物理实验现象间的固有延迟时间关系来判断同步的时刻,时间关联的精度可到达ns量级。为了防止加速器对测量系统的影响,根据延迟时间长短的不同情况还研究了光电隔离方式和光纤传输方式,解决了在阳加速器平台上的电磁干扰问题,实现了在阳加速器上进行可靠物理实验的精密测量工作;本触发方式配合高速分幅相机的应用,稳定而可靠地以10 ns间隔、3 ns曝光时间拍摄到了Z箍缩的发展过程。     

利用电压异步调节束流能散度

对直线感应加速器加速电压的同步性对束流能散度的影响进行了分析,结果表明：考虑束流负载效应后,束流的不同部分将得到不同的能量增益,前后沿部分相对于平顶部分得到更多的能量增益,从而在一定程度上增加整个束流的能散度,限制了加速器光源尺寸的进一步减小。因此,提出利用调节加速电压异步的方法来调节束流不同部分得到的能量增益,从而在一定程度上降低整个束流脉宽期间的能散度。初步的试验结果也证明,加速电压的异步调节可以明显改变束流整体的的能散度。     

Bistability in Coupled Oscillators Exhibiting Synchronized Dynamics

We report some new results associated with the synchronization behavior of two coupled double-well Duffing oscillators （DDOs）. Some sufficient algebraic criteria for global chaos synchronization of the drive and response DDOs via linear state error feedback control are obtained by means of Lyapunov stability theory. The synchronization is achieved through a bistable state in which a periodic attractor co-exists with a chaotic attractor. Using the linear perturbation analysis, the prevalence of attractors in parameter space and the associated bifurcations are examined. Subcritical and supercritical Hopf bifurcations and abundance of Arnold tongues -- a signature of mode locking phenomenon are found.     

Anti-control and Generalized Synchronization of Chaos for a Kind of n-Dimensional Linear Differential System

This paper introduces the finding of some chaotic attractors in a kind of n-dimensional autonomous hybrid system, which is realized via applying some discontinuous state feedback to a kind of n linear differential system. And a constructive theorem is proposed for generalized synchronization related to the above chaotic hybrid systems. Examples are presented for illustrating the methods.     

Bidirectional Partial Generalized Synchronization in Chaotic and Hyperchaotic Systems via a New Scheme

In this paper, a bidirectional partial generalized (lag, complete, and anticipated) synchronization of a class of continuous-time systems is defined. Then based on the active control idea, a new systematic and concrete scheme is developed to achieve bidirectional partial generalized (lag, complete, and anticipated) synchronization between two chaotic systems or between chaotic and hyperchaotic systems. With the help of symbolic-numerical computation, we choose the modified Chua system, Lorenz system, and the hyperchaotic Tamasevicius-Namajunas-Cenys system to illustrate the proposed scheme. Numerical simulations are used to verify the effectiveness of the proposed scheme. It is interesting that partial chaos synchronization not only can take place between two chaotic systems, but also can take place between chaotic and hyperchaotic systems. The proposed scheme can also be extended to research bidirectional partial generalized (lag, complete, and anticipated) synchronization between other dynamical systems.     

XFEL飞秒同步与定时系统中光纤长度变化的数字化监测(英)

分析了X射线自由电子激光装置对飞秒同步定时系统的技术需求。系统中采用光纤来传输定时/相位信息。而光纤的光长度会随温度的慢漂而改变,因此通过对比实验研究了温度慢漂对光纤长度变化的影响。研制了基于现场可编程门阵列（FPGA）的数字化相位和幅度检测器对光纤长度变化进行数据监测。百米光纤在典型昼夜温差下导致的时间延迟约6 ps。结果显示此数字化相位和幅度检测器可以用于飞秒同步定时系统的长度变化监测和稳定控制系统当中。     

激光器自发辐射噪声对混沌光通信系统的影响

构建了基于外光反馈的混沌光通信系统模型, 通过引入Langevin噪声源, 建立了包含自发辐射噪声特性的主从式速率方程. 利用所得数学模型, 研究了系统中可能存在的两类同步:全混沌同步和普通注入锁模型混沌同步; 分析了两端激光器自发辐射噪声对此二类同步以及系统收发两端混沌信号的影响; 最后,以2.5Gb/s伪随机数字调制下的混沌掩蔽方式为例,介绍了系统的加/解密过程以及噪声对系统解码性能的影响. 关键词： 混沌光通信 外光反馈 光注入 混沌同步 自发辐射噪声     

量子阱激光器混沌相位控制同步以及编码研究

提出外部光注入多量子阱激光器激光混沌相位控制同步，及其混沌相位相移键控外调制ON/ON全光保密通信系统，数值模拟了在相位控制器控制下的激光混沌同步.通过连续ON/ON键控调制相位控制器调制通过相位控制器的激光相位相移，实现激光混沌相位相移键控连续调制，设置接收系统相位控制器，控制通过接收相位控制器的激光相位相移，以实现激光混沌解调.分别数值模拟了该系统调制速率01和05Gbit/s混沌相位相移ON/ON键控通信，进行了混沌ON/ON键控调制速率分析，以及系统参数失配和系统抗噪声扰动的数值分析. 关键词： 混沌 同步 通信 多量子阱激光器