The effect of moving bottlenecks on a two-lane traffic flow

In this paper, we study the effect of moving bottlenecks on traffic flow. The full velocity difference （FVD） model is extended to the traffic flow on a two-lane highway, and new lane changing rule is proposed to reproduce the vehicular lane changing behavior. Using this model, we derive the fundamental current-density diagrams for the traffic flow with the effect of moving bottleneck. Moreover, typical time-space diagram for a two-lane highway shows the formation and dissipation of a moving bottleneck. Results demonstrate that the effect of moving bottleneck enlarges with the increase of traffic density, but the effect can be reduced by increasing the maximum velocity of heavy truck. The effects of multiple moving bottlenecks under different conditions are investigated. The effect becomes more remarkable when the coupling effect of multiple moving bottlenecks occurs.     

木质素-聚氨酯水凝胶的合成及其性能

异氰酸根封端的聚氨酯离子聚合物与乙酸木质素交联合成了一种水凝胶。研究了该水凝胶的吸水溶胀率、热稳定性能及以此凝胶包裹的硫酸铵的缓释性能。结果表明:当木质素与聚氨酯离子聚合物的质量比为0.35时,水凝胶在pH=6.86的缓冲溶液中的最大溶胀率为3.14;聚氨酯水凝胶中引入木质素,可以提高凝胶的热稳定性;木质素-聚氨酯水凝胶包裹的硫酸铵表现出明显的缓释特征。     

活性炭负载对甲苯磺酸催化微波合成环己酮乙二醇缩酮

在微波辐射下,以活性炭负载对甲苯磺酸为非均相催化剂,不用溶剂,用环己酮和乙二醇为原料合成环己酮乙二醇缩酮。重点考察了酮醇物质的量比、催化剂用量、微波功率和辐射时间对产品收率的影响。实验结果表明,活性炭负载对甲苯磺酸有着良好的催化活性,当环己酮的加入量为0.2mol,n（环己酮）：n（乙二醇）=1：1.6,催化剂用量为反应物总质量的0.75%,微波功率450W,辐射时间4min时,缩酮收率可达76.7%,且催化剂重复使用6次仍保持较高活性。     

处理含铅废水的现状及研究进展

废水中的铅严重危害环境及人体的健康,如何处理含铅废水引起了很多科研人员的重视。本文综述了近年来处理含铅废水的研究进展,详细介绍了吸附法、膜分离法、离子液体萃取法、化学沉淀法、电解法、电絮凝法、微生物絮凝法和植物修复法等处理含铅废水的现状,分析了各种处理方法的优缺点,并展望了未来深度处理含铅废水的发展趋势。