Impulsive control of chaotic systems with exogenous perturbations

The impulsive control of chaotic systems, which are subjected to unbounded exogenous perturbations, is considered. By using the theory of impulsive differential equation together with the fuzzy control technique, the authors propose an impulsive robust chaos controlling criterion expressed as linear matrix inequalities (LMIs). Based on the proposed control criterion, the procedure for designing impulsive controllers of common (perturbed) chaotic systems is provided. Finally, a numerical example is given to demonstrate the obtained theoretical result.     

R值测量中强子事例选择的改进

强子事例的选择和强子探测效率是在BEPC/BES上进行R值测量的两项主要误差来源. 过去实验只选取等于或者大于2叉的强子事例, 因而0叉和1叉事例的丢失将导致强子事例数和强子探测效率的较大误差. 试图提出在R值测量中选取包含1叉强子事例在内的样本, 这将有助于更合理地调节强子事例产生器LUARLW的参数, 减小强子探测效率和R值测量的系统误差.     

耦合映像格子中时空混沌的状态反馈控制

利用状态反馈的方法，实现了耦合映像格子中时空混沌的稳定控制.反馈方式可以是没有延迟的，也可以是有延迟的；控制方式可以是连续的，也可以是脉冲的.数值模拟结果证明了状态反馈方法的有效性. 关键词： 耦合映像格子 时空混沌 状态反馈控制     

一种控制掺铒光纤激光器超混沌的方法——非线性延时反馈参数调制法

提出一种非线性延时反馈参数调制法来控制混沌/超混沌，给出了利用这种方法控制处于超混沌状态的双环掺铒光纤激光器的方案.数值模拟表明，只要延时时间和反馈强度合适就可以把双环掺铒光纤激光器从超混沌状态成功地控制到不同的周期状态. 关键词： 掺铒光纤激光器 超混沌 非线性延时反馈参数调制 混沌控制     

Atom waveguide and 1D optical lattice using a two-color evanescent light field around an optical micro/nano-fiber

We propose a two-color scheme of atom waveguides and one-dimensional （1D） optical lattices using evanescent wave fields of different transverse modes around an optical micro/nano-fiber. The atom guide potential can be produced when the optical fiber carries a red-detuned light with TE01 mode and a blue-detuned light with HEll mode, and the 1D optical lattice potential can be produced when the red-detuned light is transformed to the superposition of the TE01 mode and HE11 mode. The two trapping potentials can be transformed to each other for accurately controlling mode transformation for the red-detuned light. This might provide a new approach to realize flexible transition between the guiding and trapping states of atoms.     

线性偏振激光在相对论等离子体中的调制不稳定性

从相对论等离体中电磁波的非线性色散方程出发,利用Karpman方法获得了线性偏振波模所满足的非线性控制方程,在非线性色散方程和非线性控制方程的基础上对线性偏振激光在相对论等离体中传播的调制不稳定性进行分析,给出了调制不稳定的时间增长率与扰动态波数之间的函数关系。     

Exploring the state of science stereotypes: Systematic review and meta-analysis of the Draw-A-Scientist Checklist

This systematic review and meta-analysis examined recent articles that have used the 1995 Draw-A-Scientist Checklist (DAST-C). This study was focused on the current state of students' stereotypes of scientists and the appropriateness of the DAST-C as a tool to assess these perceptions. Articles included in the review were published between 2003 and 2018, resulting in n = 30 studies. Mean results across studies are presented to describe current stereotypes of scientists, and the current format of the DAST-C is evaluated. Findings suggest that students' perceptions of scientists have largely remained consistent across time: scientists are still perceived as Caucasian, middle-aged or elderly males who wear lab coats and work indoors. However, while the DAST-C is a generally appropriate measure to assess students' perceptions of scientists, recommended revisions to the DAST-C could assist in capturing more modern scientist stereotypes and culturally bound perceptions of scientists.     

Volume of Domains in Symmetric Spaces

The authors derive a formula for the volume of a compact domain in a symmetric space from normal sections through a special submanifold in the symmetric space.This formula generalizes the volume of classical domains as tubes or domains given as motions along the submanifold.Finally,some stereological considerations regarding this formula are provided.     

基于遗传算法的项目经理评价

本文根据自然进化规则，把项目经理视为评价系统，项目经理所要满足的要求视为系统环境，用遗传算法的方法评价项目经理，力求提出一种比较客观科学的、且可以定量分析的项目经理的评价方法。     

量子Turbo码

量子纠错编码技术在量子通信和量子计算领域起着非常重要的作用.构造量子纠错编码的主要方法是借鉴经典纠错编码技术,目前几乎所有经典纠错编码方案都已经被移植到量子领域中来,然而在经典编码领域纠错性能最杰出的Turbo码却至今没有量子对应.提出了一种利用量子寄存器网络构造量子递归系统卷积码的简单实现方案,同时利用量子SWAP门设计了一种高效的量子交织器门组网络方案.最后仿照经典Turbo码的设计原理提出串行级联的量子Turbo码,同时提出了可行的译码方法.量子Turbo码不仅丰富了量子纠错码研究的领域,同时为解释 关键词： 量子递归系统卷积码 量子Turbo码 量子纠错编码 量子信息