弯曲干流型汇合口推移质泥沙运动研究

弯曲干流型汇合口的推移质泥沙运动与单一河道存在显著差别,在汇合口处常常出现河口浅滩或江心洲,影响船舶通行。弯曲干流型汇合口推移质泥沙运动主要受弯道水流特性和支流入汇的影响,而随着上游来流量的变化,汇流比发生改变,两者的影响比重发生变化,主流也相应在一定幅度内摆动。为研究其水流泥沙运动及河床演变给航道以及整个流域带来的影响,通过理论分析和水槽概化模型试验,揭示了弯曲干流型汇合口推移质泥沙运动规律,并结合长江与沱江汇合口为例分析了该河段演变规律和泥沙冲淤机理。

并立与分化——明清时期汉水流域复式城市的形成、类型与启示

明清时期汉水流域的复式城市是该地区较为独特的城市类型,其按照历史成因和形成过程,可分为汇合型与拓展型。拓展型复式城市较为多见,根据城市拓展的动因不同,又可分为行政拓展型和商业拓展型。行政拓展型是出于城市行政管理的需要,在原有治城的附近规划建立新城,形成新旧并立的复式城市。商业拓展型则是出于经济活动的需要,突破了相对封闭、规划严整的治所城市,在治城附近逐渐兴起商业市镇,并最终形成商业镇城与治城并立的复式城市。这些复式城市的形成、发展之轨迹,正是明清时期地方城市发展史的缩影。

Novel IOV worm model and its corresponding hybrid anti-worm strategy in expressway interchange terminal

In order to take precaution and cure against intemet of vehicles （IOV） worm propagation in expressway, the IOV worm propagation and its corresponding anti-worm strategy were studied in expressway interchange terminal. According to omnirange driving in expressway interchange terminal and vehicular mobile communication environment, an IOV worm propagation model is constructed; and then according to the dynamic propagation law and destructiveness of IOV worm in this environment, a novel hybrid anti-worm strategy for confrontation is designed. This worm propagation model can factually simulates the IOV worm propagation in this interchange terminal environment; and this hybrid anti-worm strategy can effectively control IOV worm propagation in the environment, moreover, it can reduce the influence on network resource overhead.