钢渣集料膨胀抑制方法及混合料体积稳定性研究现状

将大宗固体废弃物钢渣进行大规模的再利用具有良好的经济、环境和社会效益。钢渣的体积膨胀风险是限制其大量用作建筑材料的主要原因。因此,对钢渣的体积稳定性进行有效调控是钢渣资源化的关键。针对钢渣集料体积安定性不良的问题,分别从钢渣集料和钢渣沥青混合料的体积稳定性特征方面概述钢渣沥青混凝土体积稳定性调控方法研究进展。研究结果表明：工艺法和熔融调质法都能显著减少熔融钢渣中的活性物质含量,从而降低膨胀风险;对于冷却后的固态钢渣,酸碱中和法和掺合料法对钢渣的体积膨胀抑制效果明显,能将钢渣的体积膨胀率降低70%以上;其中,将矿渣微粉、粉煤灰和硅灰进行三元复掺会产生"超叠加效应",抑制效果明显高于单一掺合料;无机和有机表面改性技术能将钢渣膨胀率降低20%~45%,与其他调控方法相比效果较差,但其处理方式简单且处理周期短,适用于处理f-CaO含量较低的钢渣;粗钢细石沥青混凝土的浸水膨胀率与纯钢渣沥青混凝土相比降低了30%~40%,且钢渣沥青混合料的浸水膨胀率随着钢渣替代比例的升高而增加。因此,在实际应用中,应根据原材料情况严格控制钢渣的替代比例,以保证膨胀特性满足要求。     

城市轨道交通全直流照明系统设计探讨

针对目前LED照明灯具内置整流器存在效率低、谐波含量高、电解电容易损坏的缺点,讨论在城市轨道交通中使用全直流照明系统的可行性。结合城市轨道交通的特点,直流照明系统的电压建议为220V,通过验算末端电压损失,证明更低电压虽然安全性更好,但难以满足轨道交通的实际需求。有两种可行的整流方案,一种是在变电所集中整流,另一种是分散整流,对这两种方案的用房和造价进行对比分析,研究认为基于当前的现状考虑,配电室及应急照明电源室分散整流方案是一种比较好的过渡方案,此方案被接受后,再过渡到变电所内集中整流方案。     

视频监控系统在徐沛铁路的应用

扼要介绍了视频监控系统国内外现状、水平和发展趋势;并结合徐沛铁路实际,重点介绍了视频监控技术的选择、监控系统的构成、道口无线监控方案,以及视频监控应用情况。     

高速铁路正交异性钢桥面板关键结构细节动力系数试验研究

结合高速动车组通过南京大胜关长江大桥时主桥正交异性钢桥面板典型结构细节动应力的测试,研究与铁路桥梁疲劳性能紧密相关的不同车速条件下正交异性钢桥面板典型结构细节的动力系数.结果表明,各结构细节的传统应力极值动力系数离散性偏大,基本上处于1.0～2.0之间,个别甚至小于1.0.因此,综合考虑动车组高速通过时桥梁整体振动与桥面板局部振动叠加、整体动应力与局部动应力叠加对结构细节局部动应力最大、最小值分配比例的影响,针对采用正交异性钢桥面板的高速铁路桥梁,提出结构细节的动力系数应以应力幅动力系数代替传统应力极值动力系数.与应力极值动力系数相比,应力幅动力系数的离散性显著降低,其值基本上集中在1.0～1.6之间,且没有出现小于1.0的情况.     

铁路道口预警安全系统在徐沛铁路中的应用

铁路道口预警安全系统是由中央处理系统、机车移动信息终端、地面无源应答器、道口监控和无线传输网络组成。介绍道口监控和无线网络传输的工作原理,以及在徐沛铁路的具体应用和效果。     

Airline flight scheduling for oligopolistic competition with direct flights and a point to point network

In this research, we consider a flight scheduling problem for oligopolistic competition with direct flights and a point to point network. In this type of market situation, passengers are sensitive to the departure time of a flight rather than the transfer time. The airline needs to carefully consider the departure times of their competitors when determining their own. Therefore, unlike past approaches which have only considered one departure time for a competitor's flight, a flight scheduling framework is developed which takes into consideration possible competitor departure times. The framework includes two dependent stages which are repeatedly solved during the solution process. In addition, an upper bound model is also designed to evaluate the solution quality. Numerical tests are performed using data for Taiwan's outlying island route which is characterized by the above market situation. Satisfactory results are obtained, showing the good performance of the framework. Copyright © 2017 John Wiley & Sons, Ltd.     

Feedback control strategy of a new car-following model based on reducing traffic accident rates

ABSTRACT

To reduce the traffic accident death rate effectively and alleviate the traffic congestion phenomenon, this study proposes a new type of car-following model under the influence of drivers’ time-varying delay response time. Based on Lyapunov function theory, this paper reduces the traffic accident rate problem to the stability issues of the new model. By constructing suitable Lyapunov functions and using the linear matrix inequality method, the stability problem of the new car-following model is studied. The model, under the action of the controller, can effectively restrain traffic congestion. Using the traffic accident rate model proposed by Solomon, compared with the car-following model without the controller, the model under the controller shows a stronger convergence. This also means that the traffic congestion phenomenon has been effectively suppressed while greatly reducing the mortality rate of traffic accidents.     

造纸废水灌溉对沙漠生态林土壤营养成份的影响

以草浆造纸废水灌溉沙漠生态林湿地为题,通过对不同灌溉年限以及不同土壤深度的土壤营养成份(有机质、总氮、总磷)进行研究,结果显示:沙漠土壤在造纸废水灌溉条件下,相同灌溉年限的土壤有机质、总氮、总磷含量均随着土壤深度的增加逐渐降低;相同土壤深度的土壤有机质、总氮、总磷含量均随着灌溉年限的增加逐渐增大.     

高路堤双面直立互锚薄壁挡土墙模型试验研究

高路堤双面直立互锚式薄壁挡土墙是一种新型支挡结构物,作用机理复杂.介绍在实际工程现场进行的高3 m,宽5 m的模型挡土墙试验,通过侧向土压力和侧向位移的检测,研究了该类挡土墙的受力性能及变形,给工程设计、施工提供理论参考.     

胶粘新技术在内燃机电站维修领域应用案例

介绍粘胶新技术在内燃机电站维修领域应用实例,针对铝合金类、电胶木类、铸铁类损坏的零部件,用传统修理工艺难以修复的案例,采用粘接材料实施修复,工艺简单,效果良好.