混沌系统的变量变化率反馈控制方法研究

设计了一种控制连续非线性系统中混沌的新方法———变量变化率脉冲反馈 (VRPF)方法 .介绍了VRPF方法的控制原理以及反馈系数和脉冲间隔的选择技巧 .将此方法应用到BZ反应 3D模型系统混沌的控制中 ,计算机仿真模拟显示 ,通过恰当地选择反馈系数和脉冲间隔 ,可以将系统稳定在 1p、2p、3p、4p、…、2 n× 3mp (n、m为整数 )这样不同的周期轨道 ,从而使系统的功率谱也由混沌态时的连续谱转变为具有分立单峰的分立谱 .此外 ,仿真模拟还发现VRPF方法具有极宽的控制域     

电磁场中空间思维的构建

利用电子线路实验实现了用变量脉冲扰动法控制离散混沌 .该方法只用单一输出信号作为反馈信号 ,每隔一定的脉冲间隔将其加到系统的某些变量中去 ,适当调节脉冲间隔和反馈系数 ,可得到多个稳定的周期轨道 .该方法不仅适用于一维和二维离散系统 ,也适用于三维或更高维的离散系统 .     

变量脉冲扰动法控制离散混沌系统的实验

利用电子线路实验实现了用变量脉冲扰动法控制离散混沌．该方法只用单一输出信号作为反馈信号，每隔一定的脉冲间隔将其加到系统的某些变量中去，适当调节脉冲间隔和反馈系数，可得到多个稳定的周期轨道．该方法不仅适用于一维和二维离散系统，也适用于三维或更高维的离散系统．     

状态反馈控制声光双稳系统的倍周期分岔和混沌

设计了一种动力学状态反馈(DSF)方法控制非线性混沌系统.介绍了DSF方法的控制原理,并用此方法控制声光双稳(AOB)系统的混沌,以此验证其有效性.仿真模拟显示,通过选择恰当的控制参数,有效地实现了声光双稳(AOB)系统中倍周期分岔的延迟控制和混沌吸引子中原不稳定周期轨道的稳定控制,同时,还可以将系统控制在2np、3mp 和2np×3mp这样其它任意所需的周期轨道上.     

用系统变量比例脉冲方法控制超混沌的电路实验研究

利用电子线路实验实现了用正比于系统变量周期脉冲扰动法(PP-SV)控制超混沌,只用单一输出信号作为反馈信号,改变原来只对系统变量进行自身替换的方式,将反馈信号加到系统的其他变量上.将这种改进的方式用于一个超混沌电路中,得到了很好的控制效果.数值模拟结果与实验结果基本符合. 关键词： 超混沌 电路实验 脉冲扰动 反馈控制     

非线性反馈控制单模激光Haken-Lorenz混沌系统

提出一种变量非线性反馈（VNF）方法控制混沌系统.介绍了该方法的控制原理以及反馈系数的选取原则,以单模激光Haken-Lorenz系统为例对非线性反馈控制方法进行了理论研究.仿真结果显示,通过恰当的选择反馈系数k,使系统的最大李雅普诺夫（Lyapunov）指数由正值转变为负值,相图中系统的轨迹由混沌吸引子转变为周期数为2n×3mp(n、m为整数)的周期轨道.通过与线性反馈控制结果对比发现,非线性反馈控制方法简便有效,控制速度快.     

状态反馈和参数调整控制离散非线性系统的倍周期分岔和混沌

利用系统的状态反馈和参数调节的方法，有效地实现了离散非线性动力系统的倍周期分岔的延迟控制和混沌吸引子中不稳定周期轨道的控制.同时，通过选择合适的调控参数，可以将系统从一个2n周期轨道控制到2m(m关键词： 状态反馈 参量调节 混沌控制 分岔控制     

用周期拍方法控制非线性耗散系统和保守系统的混沌

通过分析无反馈周期拍方法控制耗散系统的动力学特性,找出了控制耗散系统混沌轨道的必要条件,并且对周期拍方法进行推广,在加上作为微扰的反馈项后,实现对2维Hamiltonian系统混沌轨道的控制.对于标准映象,系统的整体混沌轨道被稳定在目标周期轨道上,并且在有较弱外噪声的情况下具有鲁棒性.在3维连续流的情况下,与局限于Poincar e^-截面的脉冲控制方法进行比较,确定了两种控制方法各自的适用范围,结论是,为了稳定控制保守系统的混沌轨道,外加控制项必为耗散的. 关键词： 混沌控制 保守系统     

一种基于间歇性正比于系统参量的脉冲微扰控制混沌方法

提出了用间歇性正比于系统参量的脉冲微扰控制混沌方法.用此法分别研究了一维和二维离散混沌系统的控制,获得了稳定的2ⁿP,2ⁿ*3^mP序列和128P,192P的高周期轨道.分析表明,对于一维逻辑斯谛映象的混沌控制,间歇性正比于系统参量的脉冲微扰法与间歇性正比于系统变量的反馈控制法是等效的. 关键词：     

耦合双稳映象格子模型的时空混沌控制

变量反馈技术实现了耦合双稳映象格子模型的时空混沌控制.数值实验结果表明,利用不同的反馈技术和不同的反馈强度,可以将双稳映象系统的混沌及耦合双稳映象格子模型的时空混沌控制到不动点或周期轨道.变量反馈控制法除了局域双稳映象系统的定态点外,不需要先获取耦合双稳映象格子时空系统的动力学信息,它对抑制耦合双稳映象系统中的湍流具有一定的指导作用.     

Attosecond time-resolved autoionization of argon

Autoionization of argon atoms was studied experimentally by transient absorption spectroscopy with isolated attosecond pulses. The peak position, intensity, linewidth, and shape of the 3s3p?np 1P Fano resonance series (26.6-29.2 eV) were modified by intense few-cycle near infrared laser pulses, while the delay between the attosecond pulse and the laser pulse was changed by a few femtoseconds. Numerical simulations revealed that the experimentally observed splitting of the 3s3p?4p 1P line is caused by the coupling between two short-lived highly excited states in the strong laser field.     

Theoretical and experimental studies of parameter estimation based on chaos feedback synchronization

In this paper, we perform theoretical and experimental studies of parameter estimation based on chaos feedback synchronization. The Chua chaotic system is applied as the original system, and its time series of a single variable is applied as a feedback variable to drive a simulative system. The simplex method is employed to minimize the synchronization error in the simulative system to iteratively approach the original system parameters. Furthermore, the effects of feedback function, feedback weight, and noise are investigated. The parameter estimation method based on feedback synchronization shows its robustness to noise perturbation. Finally, the circuit experiment of parameter estimation is implemented in order to examine its practical applicability. The original Chua circuit parameters can be well approached from its recorded time series of a single variable. The results show the parameter estimation method based on feedback synchronization may be capable of estimating real system parameters from a chaotic time series.     

分子间多量子相干横向弛豫时间(和自扩散系数)测量的参数优化和数据处理方法

针对测量横向弛豫时间T₂的CPMG脉冲序列和我们所设计的可同时测量高极化单组份单 峰核自旋体系n阶分子间多量子相干横向弛豫时间T_2,n和自扩散系数D_n的改进的CRAZED脉冲序列,分析了影响测量T₂、T_2,n（或D_n）的各种因素,并着重从技术方面讨论了准确测量T_2,n和D_n的实验参数优化和实验数据处理方法.     

Calculations of Rydberg energy levels for Ni ⅩⅧ using the weakest bound electron potential model theory

Martin expression about the quantum defect of single-valence atoms is extended to many-valence atoms by identifying the weakest bound electron (WBE) under the weakest bound electron potential model(WBEPM) theory. Six Rydberg series energy levels of 2p6np2P°1/2 (n ≥ 3), 2p6np2P°3/2 (n ≥ 3), 2p6nd2D3/2(n ≥ 3), 2p6nd2D5/2 (n ≥ 3), 2p6nf2F°5/2 (n≥4), and 2p6nf2F°7/2 (n ≥ 4) for Ni ⅩⅧ are calculated by this method. The calculated results are in good agreement with the experimental results.     

The design and artificial realization of a controller of pulse coupling feedback

In this paper a controller of pulse coupling feedback (PCF) is designed to control chaotic systems. Control principles and the technique to select the feedback coefficients are introduced. This controller is theoretically studied with a three dimensional (3D) chaotic system. The artificial simulation results show that the chaotic system can be stabilized to different periodic orbits by using the PCF method, and the number of the periodic orbits are 2ⁿ× 3^mp (n and m are integers). Therefore, this control method is effective and practical.     

Raman regime energy dependence of alignment and orientation of KrII states populated by resonant Auger effect

The energy dependencies of alignment parameters A20 for KrII 4p(4)5p states after the Auger decay of the KrI 3d(9)np resonances were investigated theoretically and experimentally for the first time in the Raman regime with the bandwidth of the exciting radiation (deltaE(FWHM)=20 meV) smaller than the natural width of the resonances (Gamma approximately 80 meV). The observed energy dependence is due to the in-terference between the different resonance channels and the direct photoionization channel. A strong energy dependence for both the orientation parameter O10 and the photoelectron angular distribution parameter beta(el) is also predicted.     

脉冲激光作用下气溶胶导致大气击穿研究

 利用锁模Nd:YAG激光及其倍频激光照射漂浮在大气中的Al₂O₂、ZnO、ZrO₂、18号玻璃粉等气溶胶粒子，在不同光学参数下对光致大气击穿阈值进行了测量。测量结果表明：空气中含较大粒子(d >30 μm)的光致击穿阈值比含较小粒子(d <1μm)的空气击穿阈值低2~3个数量级；含杂空气的击穿阈值随入射激光束直径的增大而下降，随气溶胶粒子直径的增大而减小，且随气溶胶成份的不同而不同；光致击穿阈值随波长的减小而增大。     

USING RANDOM PROPORTIONAL PULSE FEEDBACK OF SYSTEM VARIABLES TO CONTROL CHAOS AND HYPERCHAOS

A method that allows one to control chaotic and hyperchaotic systems by a random proportional pulse feedback of system variables is proposed. This method is illustrated with the Rossler chaotic and the complex Lorenz-Harken hyperchaotic systems, and a better control result is obtained. The advantage of this method is that just one perturbed system variable is enough to obtain a stabilized periodic orbit.