碳纤维布改善混凝土梁抗弯性能的试验研究

通过试验研究了碳纤维布加固混凝土梁对其力学性能的影响，研究了粘贴碳纤维布后，梁的抗弯承载力、裂缝形态、挠度、延性等性能以及破坏形态的变化情况，并且总结了影响碳纤维布加固效果的各种因素，为碳纤维布加固补强建筑结构的施工与检验提供方法、依据和经验．     

碳纤维布抗震加固砌体墙片研究

通过2片碳纤维布加固砌体墙体在周期反复荷载作用下受力性能的试验,利用对比的方法,把加固试件的极限荷载和极限位移与未加固对比试件的极限荷载和极限位移进行比较,表明了用双面粘贴碳纤维布来增强砌体墙片抗震能力这种加固方法的有效性,发现了加固墙体的裂纹总出现在底部灰缝处的破坏特征,分析了碳纤维布不同粘贴方式对砌体墙片抗震加固效果的影响。在此基础上,得出了碳纤维布加固砌体墙体确实能大大提高墙体的延性、耗能能力和抗剪承载力的结论。提出了碳纤维加固是一种有效且可靠的方法,可供施工参考。     

桥梁横向地震碰撞响应研究进展

在强震作用下，桥梁上、下部结构由于动力特性的不同而发生不同相振动，从而引起梁体与挡块间的非线性碰撞。汶川大地震中，大量公路桥梁遭到严重破坏，横向抗震挡块破坏尤其严重，其中部分是由于横向碰撞而引起。针对这种碰撞现象，对正交简支梁桥、连续梁桥、斜交桥及高速铁路桥梁的横向碰撞反应进行了回顾和总结，并介绍了横桥向防撞措施及震后加固技术的研究现状，同时指出目前我国在这方面亟需解决的问题和进一步研究的方向。     

燃煤机组退役与技术升级的减排及经济效益研究——基于鲁棒电源规划的方法

火电行业是中国推行节能减排战略所重点关注的行业之一。为了降低高污染燃煤机组对环境的不利影响，中国近年来出台了一系列的能源政策，鼓励淘汰高污染的燃煤机组或者对其进行超低排放改造的技术升级。本文研究了燃煤机组主动退役及超低排放改造升级的环境及经济的双重效益。基于电源投资规划鲁棒优化的方法，考虑了受不确定的环保税、超低排放机组上网电价的补贴及电能需求影响下的发电机组最优配置问题，构建了含两阶段决策的三层鲁棒优化模型。该模型是一类具有多个不确定场景耦合特征的大规模优化问题。为了求解的便利，采用列与约束生成（column and constraint generation，CCG）算法进行求解。算例分析结果显示，当考虑了燃煤机组主动退役及超低排放改造升级的决策时，本文构建模型所提供的最优电源结构方案能够有效地降低各类污染物的排放，同时提升发电企业的经济性。     

砌体结构体外预应力抗震加固计算方法研究

利用砌体剪 压复合受力的相关性所带来的抗剪潜力,提出了采用体外预应力法对砌体结构进行抗震加固。通过整体张拉通长设于砌体墙外部两侧全高范围内的预应力筋对墙体施压,改善了结构自身内在的抗震性能。据库仑强度理论,以典型的四层砌体教学楼结构为例,讨论了该种抗震加固设计的简化计算方法。同时,考虑到结构各楼层各位置墙体受压状况的不同,提出了采用“预应力分级键”对预应力筋进行分级张拉的策略,实现了按照各墙体所需来施加对应大小的压应力,从而将原结构的有利因素充分调动起来为抗震加固服务,必要时还需设置柔性斜拉杆。     

A Benefit-Cost Analysis of Retrofitting Diesel Vehicles with Particulate Filters in the Mexico City Metropolitan Area

In the Mexico City metropolitan area, poor air quality is a public health concern. Diesel vehicles contribute significantly to the emissions that are most harmful to health. Harmful diesel emissions can be reduced by retrofitting vehicles with one of several technologies, including diesel particulate filters. We quantified the social costs and benefits, including health benefits, of retrofitting diesel vehicles in Mexico City with catalyzed diesel particulate filters, actively regenerating diesel particulate filters, or diesel oxidation catalysts, either immediately or in 2010, when capital costs are expected to be lower. Retrofit with either type of diesel particulate filter or an oxidation catalyst is expected to provide net benefits to society beginning immediately and in 2010. At current prices, retrofit with an oxidation catalyst provides greatest net benefits. However, as capital costs decrease, retrofit with diesel particulate filters is expected to provide greater net benefits. In both scenarios, retrofit of older, dirtier vehicles that circulate only within the city provides greatest benefits, and retrofit with oxidation catalysts provides greater health benefits per dollar spent than retrofit with particulate filters. Uncertainty about the magnitude of net benefits of a retrofit program is significant. Results are most sensitive to values used to calculate benefits, such as the concentration-response coefficient, intake fraction (a measure of exposure), and the monetary value of health benefits.