悬索桥钢箱梁桥面正交异性板局部承压试验与理论分析

正交异性板局部承载力对钢箱梁结构非常关键,我国桥梁设计规范也没有相关规定。以广州珠江黄埔大桥悬索桥钢箱梁局部承压试验为例,介绍了钢箱梁桥面正交异性板局部承压试验的内容、方法和实际加载方案等,通过对实测结果与理论计算值进行对比研究,进而对正交异性板承载力计算理论进行分析。     

一种浮标自由上浮模型试验换算方法

对浮标自由上浮模型试验过程中的受力进行分析,提出一种预报浮标实尺在水下自由上浮过程中最大稳定速度的方法,预报结果与CFD模拟的结果相近.     

基于正交法的磁性Fe3O4纳米颗粒制备工艺选择

采用化学共沉淀法以FeCl3·6H2O,FeCl2·4H2O为原料,氨水为沉淀剂,进行了9组正交试验,探索制备Fe3O4纳米颗粒磁性能的影响因素,利用振动样品磁强计（VSM）和透射电镜（TEM）对磁粉进行表征,利用正交表极差分析找出了最佳制备工艺条件：即A2B1C3D2,去离子水用量为200 mL（Fe3＋为0.1 mol/L）;表面活性剂用量为1 mL;氨水30 mL;[Fe3＋]/[Fe2＋]=1.75时Fe3O4颗粒饱和磁化强度为62.70 emu/g.     

外倾式部分斜拉桥重庆嘉悦大桥锚固结构试验及受力分析

介绍了重庆嘉悦大桥的主梁结构特点,以及该桥的主梁节段空间应力仿真分析结果,并介绍了为验证计算结果所做的主梁一节段1∶3缩尺模型试验的研究情况。从理论和实践上探讨了PC主梁部分斜拉桥采用特殊索梁锚固结构的可行性,以及锚固结构在超大索力作用下的安全性,得到了一些对设计、施工有益的结论和建议。     

等惯性两区段分散输水系统在40 m级单级巨型船闸中的应用*

输水系统是船闸实现其功能的关键设施,其设计直接影响船闸工程的安全与效率。等惯性四区段出水分散输水系统是目前国内外高水头大型船闸常用的输水系统形式,但其结构复杂、建设难度大,且由于设置第二分流口而带来自身空化等问题。为解决上述问题,结合我国内河船闸特点,通过国内外工程资料分析、理论与计算分析、物理模型试验等手段,提出并验证了“闸墙长廊道+闸室中心立体分流+闸底两区段四纵支廊道出水+侧支孔+明沟消能”的等惯性两区段输水系统形式在40 m级单级巨型船闸中的适用性,为高水头大型船闸建设提供参考和依据。     

基于NSCT变换的红外与可见光图像融合方法

针对小波变换不能很好地表达图像边缘信息，NSCT变换对图像细节信息表达缺失的问题，本文提出了一种改进的基于NSCT变换的图像融合方法．首先将经过预处理和配准后的红外图像和可见光图像进行NSCT变换，得到各个源图像的低频和高频系数，然后对分解后的低频系数采用小波变换的融合规则进行融合处理，高频系数则采用基于特征的区域能量的融合规则进行融合处理，最后对融合后的系数进行NSCT反变换得到融合图像．仿真实验表明，采用改进的NSCT融合方法对红外与可见光图像的融合有良好的效果，图像更清晰，信息更全面．     

某出口米轨动车组(Tc车)车体设计及试验对比研究

介绍了使用大型通用计算机辅助工程软件ANSYS和有限元方法,对某出口米轨动车组(Tc车)进行了分析计算的过程,并通过实际物理样机试验数据与计算数据的比对,分析车身强度的可靠性。     

Commuters’ behavior towards upgraded bus services in Greater Beirut: Implications for greenhouse gas emissions,social welfare and transport policy

Climate change is one of the most critical environmental challenges faced in the world today. The transportation sector alone contributes to 22% of carbon emissions, of which 80% are contributed by road transportation. In this paper we investigate the potential private car greenhouse gas (GHG) emissions reduction and social welfare gains resulting from upgrading the bus service in the Greater Beirut Area. To this end, a stated preference (SP) survey on mode switching from private car to bus was conducted in this area and analyzed by means of a mixed logit model. We then used the model outputs to simulate aggregate switching behavior in the study area and the attendant welfare and environmental gains and private car GHG emissions reductions under various alternative scenarios of bus service upgrade. We recommend a bundle of realistic bus service improvements in the short term that will result in a reasonable shift to buses and measurable reduction in private car emissions. We argue that such improvements will need to be comprehensive in scope and include both improvements in bus level of service attributes (access/egress time, headway, in-vehicle travel time, and number of transfers) and the provision of amenities, including air-conditioning and Wi-Fi. Moreover, such a service needs to be cheaply priced to achieve reasonably high levels of switching behavior. With a comprehensively overhauled bus service, one would expect that bus ridership would increase for commuting purposes at first, and once the habit for it is formed, for travel purposes other than commuting, hence dramatically broadening the scope of private car GHG emissions reduction. This said, this study demonstrates the limits of focused sectorial policies in targeting and reducing private car GHG emissions, and highlights the need for combining behavioral interventions with other measures, most notably technological innovations, in order for the contribution of this sector to GHG emissions mitigation to be sizable.     

Expanding scope of hybrid choice models allowing for mixture of social influences and latent attitudes: Application to intended purchase of electric cars

Recently, policy makers’ expectations about the role of electric cars in reducing emissions have risen substantially. In parallel, academic research on purchase intentions has dramatically increased. Originally, most studies have focused on utility attributes and price. More recently, several hybrid choice models have been estimated to include the impact of attitudes on choice probabilities. In addition, a few studies have caught the attention to social influence. In contributing to this line of research, this paper reports the results of an expanded hybrid choice, which simultaneously estimated all these different effects in a single integrated model of purchase intention. Results indicate that the model performs well. Costs considerations contribute most to the utility of electric cars. Social influence is less important, but there is also evidence that people tend to take it into consideration when there are positive public opinions about electric cars and the market share becomes almost half of friends of their social network. The intention to purchase an electric car is also influenced by attitudes about environmental concerns and technology acceptance.     

盾构直接切除大直径桩基的试验与工程实践

为研究盾构直接切削大直径桩基的可行性、评价滚刀和切刀的切桩性能、获取盾构切桩的关键掘进控制参数，进行盾构直接切削大直径桩基的模型试验。研究结果表明： 1)盾构切除大直径桩基宜采用“低推进速度，高转速”的磨桩方式，刀盘推进速度建议取3~5 mm/min，刀盘转速建议取1.0~1.2 r/min； 2)滚刀对混凝土的切削效果较好，切刀对钢筋的切削效果较好； 3)混凝土强度越高，滚刀对钢筋的切割效应越好； 4)滚刀切桩时，刀盘轴向振动作用明显，在低推进速度和低转速下，其刀盘的振动小于切刀切桩时刀盘的振动; 5)切刀切桩时，刀盘环向振动强烈，在高推进速度下刀盘易卡顿，提高转速可减少刀盘卡顿。