一种简单的基于蔡氏电路的数字加密通信实验

介绍一种简单的基于蔡氏电路的对数字信号进行加密传输以及解密的实验方法,以及该实验作为一个新的与前沿科学相结合的普通物理实验的优点.     

Reconstruction of dynamic structures of experimental setups based on measurable experimental data only

Nowadays, massive amounts of data have been accumulated in various and wide fields, it has become today one of the central issues in interdisciplinary fields to analyze existing data and extract as much useful information as possible from data. It is often that the output data of systems are measurable while dynamic structures producing these data are hidden,and thus studies to reveal system structures by analyzing available data, i.e., reconstructions of systems become one of the most important tasks of information extractions. In the past, most of the works in this respect were based on theoretical analyses and numerical verifications. Direct analyses of experimental data are very rare. In physical science, most of the analyses of experimental setups were based on the first principles of physics laws, i.e., so-called top-down analyses. In this paper, we conducted an experiment of "Boer resonant instrument for forced vibration"(BRIFV) and inferred the dynamic structure of the experimental set purely from the analysis of the measurable experimental data, i.e., by applying the bottomup strategy. Dynamics of the experimental set is strongly nonlinear and chaotic, and it's subjects to inevitable noises. We proposed to use high-order correlation computations to treat nonlinear dynamics; use two-time correlations to treat noise effects. By applying these approaches, we have successfully reconstructed the structure of the experimental setup, and the dynamic system reconstructed with the measured data reproduces good experimental results in a wide range of parameters.     

手机短信网络的生长过程研究

模拟了短信网络的生长过程并研究其拓扑结构.发现短信网络在生长过程中，度分布、节点的度与其加入网络时间的关系、平均度随时间的变化等方面与先前的模型有所不符.根据短信网络的数据分析，提出了短信网络的生长机制——局部优先连接机制.结果表明，模拟以短信网络为代表的实际网络时，局部优先连接模型优于其他网络模型. 关键词： 复杂网络 短信网络 局部优先连接     

运动后人体心肺节律同步关系及信号的耦合方向

研究运动后青年心肺系统的耦合关系.通过提取在校学生运动后的心跳和呼吸信号,采用经验模态分解的方法对信号进行滤波,分析了心肺信号的相同步行为和心肺节律间耦合作用的相对强弱关系.结果表明,人体在运动后仍然存在心肺系统节律同步现象.这种同步比例不仅因人而异,而且因时而异.由传递熵的计算结果得知,呼吸对于心跳的耦合作用相对较大.     

基于时空混沌的CPSK多用户扩频通信

传统的混沌扩频（CDSS）是利用混沌序列量化、编码后产生的0、1序列作为扩频码,来实现频谱展宽。另外,由于混沌序列本身的宽频特性,一些传统的混沌数字调制技术也可被用于扩频通信系统的设计。在单向耦合映像格子（OCML）时空混沌模型同步的基础上,直接利用混沌相位键控（CPSK）调制技术构建了一个多用户扩频通信系统。该模型为每个用户分配一个OCML时空混沌模型,为了更好地利用时空混沌系统的时间与空间混沌特性,其采用＂跳格序列＂作为扩频调制序列对用户信息进行调制。通过与传统混沌直接序列扩频（CDSS）系统的仿真比较发现,所设计的CPSK调制多用户扩频通信系统拥有比后者更好的误码性能及安全性能。     

液晶物性实验介绍

介绍了在大学物理实验教学中新开设的研究液晶的旋光特性和电光效应(光开关、液晶光栅)的实验,以及对实验结果的分析．