如何提高桥面铺装和桥面防水的施工质量

建造公路和城市道路,尤其是高速公路和城市快速道路,动辄几亿、几十亿元的投资,其中桥梁占总造价的10％～30％左右．要求设计使用年限比较长,至少要满足50年以上．有些长达100年以上。因此桥梁的安全性和耐久性是非常重要的。经查发现．桥面铺装层与防水层出现质量问题严重影响到桥梁的耐久性。     

佛开扩建工程九江大桥方案比选

介绍了佛开高速公路扩建工程九江大桥桥型方案设计情况,就经济性、美观性、创新性及施工方法等综合指标,对主桥、引桥桥型方案进行了论证、分析和比较。尤其是突破大跨径连续刚构桥主墩多采用双片薄壁墩的传统做法,提出160 m跨单薄壁墩连续刚构方案,减小了墩身刚度,增大了矮墩桥梁做连续刚构的可行性。     

Microstructure evolution during remelting of high solid fraction ZL101 alloy

This work deals with the reheating process for semi-solid thixoforming of ZL101 (AlSi7Mg) alloy. The semi-solid state can decrease the viscosity and the resistance while sheared because of the evolutional behavior, which is characterized by a solid-like behavior at rest and a liquid flow during shearing. The microstructure evolution of ZL101 alloy at different temperatures from 540 to 580 °C has been studied. Results show that the eutectic temperature can affect the transformation speed of semi-solid structure. Semi-solid microstructures with high solid fraction can be obtained by controlling the reheating time in less than 20min, while at the temperature lower than the eutectic temperature it needs more than one hour. Another character of semi-solid ZL101 alloy is the segregation of microstructures in semi-solid state, in which the liquid phase between the solid phases can flow freely and lead to the shrinkage of the sample during the heating process. As the holding time goes on, more shrinkage holes appear and change the surface of the specimen. These shrinkage holes are replenished by the liquid phase during compression deformation, resulting in the segregation of the components.     

The β-amyloid protein induces S100 β expression in rat hippocampus through a mechanism that involves IL-1

Objective To explore the effect of β-amyloid protein （Aβ） on S100β expression in rat hippocampus and its mechanisms. Methods At 7 days after bilateral stereotaxls injection of different dose of fibrillar Aβ25--35 and interluekin-1 receptor antagonist （IL-1ra） into the rat CA1 region, the learning and memory abilities of rats were tested with passive avoidance task. Amyloid deposition was detected by using Congo red staining technique. Nlssl staining and immunohlstochemical techniques were used to analyze the number of neurons, and GFAP and the S100β expression in hippocampal CA1 region , respectively. Results After fibrillar Aβ injection, the step-through latency of rats was significantly shortened compared to that of the control group. The GFAP positive astrocytes were found surrounding amyloid deposition. Neuronal loss occurred in the pyramidal cell layer of CA1 region. The number of S100β positive cells in Aβ-treated group was significantly increased compared with that in the control group. After IL-1ra injection, the number of S100β positive cells was significantly decreased. Conclusion Intrahippocampal injection of Aβ25 - 35 could cause similar pathologic changes of Alzheimer＇s disease. Aβ 25- 35 was capable of up-regulating S100β expression in a dose-dependent manner. The injection of IL-1ra could attenuate the effect of Alton S100β expression.     

基于极值优化的综合运输路网连续网络设计双层规划模型

本文提出了综合交通运输系统路网连续投资配置的双层规划模型,其中上层规划者在投资预算及其他约束条件下,考虑环境污染、土地占用及能源消耗等外部成本,对线路及综合交通运输枢纽做出连续的投资配置,以实现系统最优;下层网络用户在上层规划者的投资配置下,其路径选择满足确定用户平衡原则。最后,基于极值优化设计了求解该模型的算法,并给出了具体算例对算法进行验证。计算结果表明：所建立的模型符合实际情况,且采用的启发式算法也较有效。     

交叉口配时方案实时优化与仿真系统研究

为了充分利用交叉口的时空资源,缓减拥挤,根据单交叉口的实时检测器数据,基于优化模型和仿真模型,以均衡交叉口的交通压力目标,开发了一款交叉口配时方案实时优化与仿真系统,来对配时方案中的周期、绿信比、相序进行动态优化.实测结果表明,与传统定时信号控制方式相比,优化后的交通信号配时控制效果更好,车辆平均延误时间更少.     

既有隧道非开挖改扩建方法综述

目前国内工程界较着重于新建工程,对于老旧隧道的维修或隧道因流量需求增加,须予拆除、扩挖的情况,其准备和考虑的并不充分。通过对国内外主要的隧道非开挖改扩建施工方法的介绍与归纳,为国内类似工程施工提供相关参考。     

斜拉桥地震响应非线性时程分析

基于有限单元法,推导出多自由度结构体系在地震作用下的增量形式的运动方程,建立了大跨度斜拉桥的地震激励模型.考虑结构的几何非线性,采用增量动力平衡迭代格式的Newmark-β法进行非线性时程分析,并以某主跨360 m的斜拉桥为例进行了线性、非线性动力分析,验证了方法的可行性,同时表明大跨度斜拉桥的几何非线性影响因素不容忽视.     

双向连续弯箱梁匝道桥同步顶升精度控制和支座更换关键技术

结合对连续弯箱梁双向匝道桥（曲线梁桥）在营运中侧向移位进行同步顶升和支座更换的实施过程,探讨了连续弯箱梁结构的同步硕升安全控制指标;提出同步顶升应以位移控制为主的控制方法以及同步顶升的精度控制要求;总结了连续多跨曲线梁匝道桥同步顶升精度控制、支座更换的施工工艺要点和关键技术。     

现代轿车电动玻璃升降器研究与探讨

玻璃升降器由简单的丝杆式,单臂式而发展为电动式,电动式玻璃升降器又有双导轨和单导轨两种结构形式,以富康轿车为例介绍了这两种电动式玻璃升降器各自的特点,主要组成结构及工作原理,并对其技术参数进行了分析,同时对防夹电动玻璃升降器和未来智能型电动玻璃升降器也作了简单的介绍。