The evolving concept of air pollution: a small‐world network or scale‐free network?
The evolving concept of air pollution: a small‐world network or scale‐free network?
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DOI：
10.1002/asl.659
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发表时间：
2016-05
影响因子：
3
通讯作者：
Linan Sun;Zuhan Liu;Jiayao Wang;Lili Wang;Xuecai Bao;Zhaoming Wu;Bogachkova L. Yu.
中科院分区：
文献类型：
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作者：
Linan Sun;Zuhan Liu;Jiayao Wang;Lili Wang;Xuecai Bao;Zhaoming Wu;Bogachkova L. Yu.
为了分析大气污染的动态，采用粗粒化过程的均匀分区，将兰州市日空气污染指数序列转化为由R、R、e、d、d五个字符组成的字符序列。污染波动网络的节点是按时间序列在网络拓扑中连接的125个三符号串（即3天内的125个波动模式）。该网络包含有关网络拓扑中污染波动模式之间的相互联系和相互作用的综合信息。通过对度和度分布的动态统计量的计算，发现其分布遵循三级幂律分布，具有层次结构和小世界效应的无标度特征。因此，污染波动网络不仅是一个具有层次的无标度网络，而且是一个小世界网络。节点的程度越高，出现污染波动模式的概率越大。污染波动网络的主节点一般包含符号R和R，表明污染波动的特征以上升为主。
To analyze the dynamics of air pollution, a homogenous partition of the coarse graining process is employed to transform the daily air pollution index series in Lanzhou into a character series consisting of five characters (R, r, e, d and D). The nodes of the pollution fluctuation network are 125 three‐symbol strings (i.e. 125 fluctuation patterns in a duration of 3 days) linked in the network's topology by a time sequence. The network contains integrated information about the interconnections and interactions among the fluctuation patterns of pollution in the network topology. After calculating the dynamical statistics of degree and degree distribution, we find that the distribution follows a three‐stage power‐law distribution characterized by a scale‐free property with hierarchy structure and small‐world effect. Therefore, the pollution fluctuation network is not only a scale‐free network with hierarchy but also a small‐world network. The higher the degree of the node is, the greater the probability that the pollution fluctuation modes will occur. The main nodes of pollution fluctuation networks generally contain the symbols R and r, which demonstrates that the feature of pollution fluctuation is mainly ascending.