Resource Search in Unstructured Peer-to-Peer System Based on Multiple-Tree Overlay Structure

We propose a multiple-tree overlay structure for resource discovery in unstructured P2P systems. Peers that have similar interests or hold similar type of resources will be grouped into a tree-like cluster. We exploit the heterogeneity of peers in each cluster by connecting peers with more capacities closer to the root of the tree. The capacity of a peer can be defined in different ways （e.g. higher network bandwidth, larger disk space, more data items of a certain type etc.） according to different needs of users or applications.     

On the verge of <Emphasis Type="Italic">Umdeutung</Emphasis> in Minnesota: Van Vleck and the correspondence principle. Part one

In October 1924, The Physical Review, a relatively minor journal at the time, published a remarkable two-part paper by John H. Van Vleck, working in virtual isolation at the University of Minnesota. Using Bohr’s correspondence principle and Einstein’s quantum theory of radiation along with advanced techniques from classical mechanics, Van Vleck showed that quantum formulae for emission, absorption, and dispersion of radiation merge with their classical counterparts in the limit of high quantum numbers. For modern readers Van Vleck’s paper is much easier to follow than the famous paper by Kramers and Heisenberg on dispersion theory, which covers similar terrain and is widely credited to have led directly to Heisenberg’s Umdeutung paper. This makes Van Vleck’s paper extremely valuable for the reconstruction of the genesis of matrix mechanics. It also makes it tempting to ask why Van Vleck did not take the next step and develop matrix mechanics himself. This paper was written as part of a joint project in the history of quantum physics of the Max Planck Institut für Wissenschaftsgeschichte and the Fritz-Haber-Institut in Berlin.     

The Response of Debris-Flow Events to Solar Proton Flares （Ⅰ）

By analyzing the observation data from Dongchuan Debris Flow Observation and Research Station and historical data from year 1965 to 1990 gotten from National Astronomical Ob-servatories/Yunnan Observatory,the responding of debris flow in Jiangjia Ravine to Solar Proton Flare is studied. The following conclusion can be drawn. Solar Proton Flare,as one of most im-portant astronomical factors,affects the activity of debris flow in Yunnan. Generally,from 1965 to1990,the more active Solar Pro-ton Flare is,the greater the probability of high frequency and large runoff of debris flow is. On the contrary,the less active Solar Pro-ton Flare is,the greater the probability of low frequency,small runoff,and low sediment transport of debris flow is.     

谈谈多媒体英语教学

文章介绍综合利用软件，创造良好的多媒体英语教学环境的方法和多媒体在英语课堂上的使用，以及多媒体英语教学需要注意的问题。     

Bang bang control of unified chaotic system

The unified chaotic system contains the Lorenz system and the Chen system as two dual systems at the two extremes of its parameter spectrum. This paper presents the design of bang bang controller for unified system and multitude of numerical experiments under various control parameters. Numerical experiments meet the theoretic proof perfectly and convincingly demonstrated the controller can be effectively used for unified systems with uncertainty of the equilibrium points. The method enriches the applications of chaotic control. Foundation item: Supported by the National Natural Science Foundation of China(50209012) Biography: Deng Xiao-ming (1980-), male, Master candidate, research direction: chaos control.     

筒型基础系缆平台沉／拔过程侧摩阻力原型测试

介绍了1999年首次安装在渤海锦州9－3地区多筒基础平台安装施工过程中的侧摩阻力原型测试研究，描述了简型基础上沉和上拔过程中筒壁侧摩阻力的测试系统和测试方法，给出了主要测试结果并与现行规范进行了对比分析，这项成果对筒型基础平台的设计和施工具有直接的参考意义。     

PuCO气态分子的热力学稳定性

在相对论有效原子实势近似下 ,用密度泛函B3LYP方法研究得到PuCO气态分子的热力学函数 ,根据热力学原理 ,计算得到PuCO气态分子在不同温度下的标准生成自由能变 ,据此说明PuCO气态分子不具有热力学稳定性     

论网络教育对传统教育的影响

本主要论述了网络教育的时代性、网络教育的特点和目前存在不足，以及网络教育的未来发展趋势。本最后得出结论认为：网络教育作为一种辅助方式，对传统方式影响很大，但仍不能动摇其主导地位。     

理想与现实——清末贵州社会变革之再思考

贵州辛亥革命结束了清朝封建帝制在贵州的统治，但是，革命很快归于失败，革命的结局与革命的理想大相径庭，这一切，根源于贵州近代资本主义经济及民族资产阶级力量较之全国说来更加的落后和弱小，在客观物质力量的成长还未壮大到足以冲破封建势力的束缚的时候，一种渐进的和平改革道路也许是当时最好的选择，而激进的，理想主义的行动酿就的只能是一杯难以下咽的苦酒。     

发酵监控系统上位计算机软件编程研究

提出了利用上位机参与实时控制,综合分析在线参数、离线参数和间接参数,辅助发酵过程工艺研究和优化控制,并给出了上位机软件包的部分源程序及框图。该软件包对发酵工艺人员进一步了解菌种的遗传特性、细胞代谢调节和反应器工程特性方面有较大帮助。