China's Central Cities Railway Passenger Transport Connects and Its Distribution Base on O-D network
利用中国286个中心城市的铁路客运数据，基于O-D网络分析其空间集聚、网络结构和分布特征，发现全国铁路客运联系呈“开”字形东倾结构，三大核心集群和六个中心节点，并揭示了距离衰减规律及区域联系短板。
According to China's 286 central cities complete interactivecity-train-citydata, adopts the method of GIS space analysis based on O-D network, through multi research angles from central cities railway passenger transport contacts space agglomeration, arbitrary two central cities railway contacts and its spatial distribution by subdivision train number type, this article analyses China's center cities railway passenger contacts spatial distribution, precisely and clearly describes central cities railway passenger contacts spatial agglomeration, network structures and its distribute characteristics. Research shows that, the national railway passenger contacts distribution appears the shape structure of kai font to east tilt, two vertical lines of Beijing-Shanghai to Shanghai-Shenzhen, Beijing-Guangzhou to BeijingHarbin, two horizontal lines of Longhai-Lanxin, Shanghai-Kunming, them crossing into the nationwide railway passenger contacts mainly framework. China's railway passenger contacts have three core cluster regions, Beijing-Tianjin-Hebei, Yangtze River Delta and Pearl River Delta. Beijing, Shanghai, Guangzhou, Wuhan, Xi'an, Chengdu together constitute nationwide railway passenger contacts center. Within 200km space distance, because each urban agglomerations or economic rations within the economic contacts is closely, degree of traffic integration is higher, the operational train number of central cities is the sharp increase, outside 200km space distance, the spatial attenuating tendency of railway passenger contacts obeys cubic curve rule on the whole. China's central cities railway passenger transport links nearly 1/ 2 is implemented in the 500 km range, and the MU trains and high-speed rail contacts each has operated its 2/3 proportion in this distance space. With the gradual increase of spatial distance, the nationwide railway passenger transport links show different space scales contacts as follows within urban agglomerations or economic rations, province region, neighboring provinces, between regions and up to big regions. Research shows that, between the Yangtze River Delta to Pearl River Delta, the Pearl River Delta to western economy zone, direct passenger contacts are weakly which relative to their superior geographical location, that is a defect for nationwide transportation layout.