Kinetic analysis of self-condensing vinyl polymerization with unequal reactivities

The distribution function of the hyperbranched polymers formed from the self-condensing vinyl polymerization with unequal reactivities was derived and the differential equations for the second moments are established, based on the variable of the conversion of B^＊ groups. The various average degrees of branching can be designed by suitable values of reactivities ratio （r） and the conversion of A group （x）. In order to reach the maximum degree of branching at a specified x, r needed is dependant on the value of x. The higher the x, the less the r needed is for the maximum value of degree of branching. At the end of the reaction, the maximum degree of branching reaches 0.5 with r=2.59.     

自然数八度周期律暨丢番图四定理

在发现自然数八度周期律的基础上,明确而系统地制定了丢番图四定理,从而准确、彻底、全面地解决了数论中任意正整数究竟能够分解成几个平方数之和的这一古老问题。     

论高等教育的社会评估

分析我国当前高等教育评估的发展概况和特点;指出我国当前高等教育评估的必要性和面临的困难;提出保障高等教育社会评估的两点建议。     

浅谈莫扎特对歌剧改革的贡献

莫扎特在歌剧创作上体现了格鲁克的改革意图,并且他的成就又超过了格鲁克。他的作品总结了歌剧在二百年间的发展。     

古交市火山汾河大桥设计

火山汾河大桥跨越汾河、连接古交市区和正在开发的火山新区,采用7×30m预应力先简支后连续箱梁结构。介绍了该桥的设计和计算特点。     

A policy-based billing management architecture for the next generation IP-based network

IP billing is not only a basic functionality to operate IP sen＇ices, but also it is fundamental to offer customers with a stable and QoS-enabled network environment. As IP-based network has been widely agreed to be the core network of NGN, and existing IP billing system is too simple to fulfill the emerging requirements, the next generation IP billing has become an interesting topic in recent years. Policy-based management brings flexibility and scalability to systems by describing management logic and functions through policies, and thus reduces the complexity of the management of large-scale systems. Working on existing efforts, this paper proposed an improved IETF policy framework based upon which a policy-based billing management architecture for the next generation IP-based network was presented. Then a prototype with some basic functionalities was developed. The results of the experiment validated the expected improvements specified in this paper.     

评价电路本质安全性能计算方法的修正

重新建立了电阻性本质安全电路电弧放电能量的计算公式 ,证明在评价电路的安全性能时 ,理论上将电阻性电路当作电感性电路的特例处理 ,存在着最大可达 1 2 .5 %的误差 实验发现当电路从电感性过渡到电阻性时 ,电弧放电开始瞬间电弧电流将突然下降 还发现对电感性电路 ,放电电流线性衰减模型仅适用于电感量为 1mH左右时的情况 最后对评价电路本质安全性能的计算方法进行了修正 图 8,参 6     

Probabilistic D-Clustering

We present a new iterative method for probabilistic clustering of data. Given clusters, their centers and the distances of data points from these centers, the probability of cluster membership at any point is assumed inversely proportional to the distance from (the center of) the cluster in question. This assumption is our working principle. The method is a generalization, to several centers, of theWeiszfeld method for solving the Fermat–Weber location problem. At each iteration, the distances (Euclidean, Mahalanobis, etc.) from the cluster centers are computed for all data points, and the centers are updated as convex combinations of these points, with weights determined by the above principle. Computations stop when the centers stop moving.