Synchronization mechanism of clapping rhythms in mutual interacting individuals

In recent years, clapping synchronization between individuals has been widely studied as one of the typical synchronization phenomena. In this paper, we aim to reveal the synchronization mechanism of clapping interactions by observing two individuals’ clapping rhythms in a series of experiments. We find that the two synchronizing clapping rhythm series exhibit long-range cross-correlations(LRCCs);that is, the interaction of clapping rhythms can be seen as a strong-anticipation process. Previous studies have demonstrated that the interactions in local timescales or global matching in statistical structures of fluctuation in long timescales can be sources of the strong-anticipation process. However, the origin of the strong anticipation process often appears elusive in many complex systems. Here, we find that the clapping synchronization process may result from the local interaction between two clapping individuals and may result from the more global coordination between two clapping individuals. We introduce two stochastic models for mutually interacting clapping individuals that generate the LRCCs and prove theoretically that the generation of clapping synchronization process needs to consider both local interaction and global matching. This study provides a statistical framework for studying the internal synchronization mechanism of other complex systems. Our theoretical model can also be applied to study the dynamics of other complex systems with the LRCCs, including finance, transportation, and climate.     

手机短信息传播过程和短信息寿命研究

比较了短信息在无标度网络、小世界网络和实际的短信息网络三种网络中的传播过程,寻找影响短信息传播的因素.研究发现,网络拓扑结构和手机用户的转发短信行为均会影响短信息传播过程.在无标度网络中短信息传播速率快于小世界网络和实际的短信息网络,而无标度网络的短信息寿命较小世界网络和实际的短信息网络短;网络中手机用户的转发短信息行为明显影响短信息的传播过程.同时还发现短信息寿命与网络直径有关. 关键词： 复杂网络 短信息 信息传播 人类行为     

利用周期信号驱动Chua电路实现相同步

我们在实验上和理论上对周期信号驱动的混沌电路的相同步问题进行了研究。我们选择三类周期信号作为驱动信号，包括Chua电路产生的周期信号，正弦信号和脉冲信号。改变驱动信号的频率、振幅和脉冲信号的占空比，在周期信号和混沌信号存在小的频率失配的条件下，驱动信号的振幅在适当的变化范围内，以及脉冲信号的占空比在适当的变化范围内，都可以获得相同步。甚至当占空比小到3%的情况下，仍然可以得到相同步。特别是这类脉冲信号的控制在实际中是有意义的。     

Experimental observation of partial amplitude death in coupled chaotic oscillators

The dynamics of coupled Lorenz circuits is investigated experimentally. The partial amplitude death reported in {\em Phys. Rev.} E {\bf 72}, 057201 (2005) is verified by physical experiments with electronic circuits. With the increase of coupling constant, the coupled circuits undergo the transition from the breakdown of both the reflection symmetry and the translational symmetry to the partial amplitude death. Its stability is also confirmed by analysing the effects of noise.     

不同晶面银纳米晶高温熔化的各向异性

采用嵌入原子势, 使用分子动力学方法, 模拟研究了银纳米晶高温弛豫过程中的热稳定性和熔化机制, 并引入均方位移和稳定寿命来分析它的结构和形状的演化过程. 结果表明: 对于沿相互垂直{110}, {211}和{111}面切割形成的近正方体截面纳米晶, 高温弛豫熔化存在明显的各向异性行为; (112) 面热稳定性最低, 最易熔化, 其次是(110) 面, 热稳定性最高的是(111) 面, 最难熔化; 三个不同晶面的最外层和次外层原子的稳定寿命极短, 且三个不同晶面之间相差很小, 没有明显差异; 对于具有相同晶面指数的晶面, 第三层及其以内的稳定寿命较长, 且依次微量增长, 但不同晶面第三层及其以内的寿命相差明显.     

银纳米杆高温熔化断裂弛豫性能的原子级模拟研究

采用分子动力学模拟方法,研究了不同长度银纳米杆在不同温度弛豫过程中的结构演变过程.结果表明:银纳米杆存在一与杆长相关的临界熔断温度,该临界熔断温度随杆长增加而显著降低.当温度大于熔点而小于临界熔断温度时,体系形成一个高度无序的球形团簇,而温度大于临界熔断温度时,体系则熔断成两个球形团簇.并给出了银纳米杆的产生该熔断现象的机理. 关键词： 纳米杆 分子动力学 弛豫 熔化     

表面波等离子体源的发展现状

对微波放电产生的平板型表面波等离子体源进行了系统介绍,分析了表面波等离子体的工作原理, 探讨了维持表面波等离子体放电的能量吸收机制,介绍了由单模谐振腔阵列、 亚波长衍射光栅及开槽天线阵列组成的新型波模转换器.表面波等离子体的产生机理、实现途径、 参数特性和数值仿真等方面的研究进展及其所取得的成果,有利于促进新型表面波等离子体源走向产业化应用, 并促使微电子产业的功效取得新的突破.     

Experimental observation of a multirhythmic pattern in chains of Rossler circuits

<正>The influence of parameter mismatches on multirhythmic patterns in chains of coupled Rossler circuits are explored experimentally.The parameter mismatches in coupled chaotic oscillators are found to help form a kind of multirhythmic pattern as reported in chains of biological coupled oscillators[Phys.Rev.Lett.92 228102].Moreover,a new type of multirhythmic pattern based on the envelope of time series is observed.     

[111]晶向银纳米杆结构稳定性的分子动力学研究

采用三维分子动力学模拟方法和Finnis-Sinclair型多体势,以[111]晶向银纳米杆为研究对象,模拟研究不同尺寸纳米杆在不同温度弛豫过程中的动态平衡变化过程,分析研究弛豫后银纳米杆的稳态结构变化、平均势能的变化及其在不同时刻结构的演变过程.结果表明,温度对银纳米杆结构稳定性将产生重大影响,银纳米杆存在一临界失稳温度,当温度小于临界失稳温度时,体系保持完好线状晶态,当温度大于临界失稳温度小于熔点时,体系坍塌熔化后发生重结晶,体系形成由(111)和(100)面围成的多面体;随银纳米杆截面尺寸增大,其临界失稳温度、熔点均增大,当截面尺寸大于2 nm时,临界失稳温度趋近于熔点,失稳现象只在一很窄温度区域内存在.