京沪铁路小汶河大桥应急加固技术

介绍了京沪铁路小汶河大桥第6孔拱圈险情,科学采取了拱圈加固方案。首次将八三式铁路轻型军用墩应用于拱桥的应急加固支撑,创新了变截面墩身结构形式。在既有线限速行车条件下,快速将拱圈加固支撑完毕,保证了既有线行车安全,为今后拱桥的应急加固积累了丰富的经验。     

轻型集装箱跨运车的开发及应用

通过整机轻型化、平顺性、防偏载等关键技术研究开发出的轻型集装箱跨运车具有显著的新颖性。该机的作业效率高于拖挂车的水平运输方案,可应用于专业集装箱码头、货场和中转站等场所。     

SRC工况下轻型车排气温度特征分析

利用自动驾驶仪控制汽车在底盘测功机上按照S RC工况运行了4个循环,采集了车辆的排气温度,分析排气温度与工况的关系及其分布特征。研究表明：在S RC工况下,排气温度主要分布在650～800℃;在每个小循环下的温度变化曲线呈现出一个左峰高于右峰的“M”形状;重复运行S RC工况时,排气温度一致性非常好;低于60 km／h和高于110 km／h速度区间内平均温度稳定,60～110 km／h区间内平均温度随车速升高逐渐升高;长时间加速工况下,排气温度会急剧升高。     

国产轻型汽油车蒸发排放现状与分析

本文简述了汽油车污染物的来源及控制汽车车蒸发排放的必要性，比较分析了常用的两种蒸发排放测量方法，基于大量测量结果说明了国产轻型车蒸发排放现状，试验分析了蒸发排放影响因素。     

桃威铁路老清河大桥抢通技术

因遭遇强降雨,造成老清河大桥2号桥墩倾斜、4号墩基础冲刷严重,线路轨向最大偏差68mm,致使桃威铁路行车中断。分析了水害原因,制订了临时抢通技术方案：先进行2号墩、4号墩基础抛石加固,然后在2号墩两侧搭设临时钢墩进行加固,对既有桥墩部分卸载,满足临时通车要求后,再拆除导致河流改道的拦水坝。重点阐述了八三式铁路轻型军用墩拼架过程中采取的单元化预拼、墩外拼组顶推横移就位技术。该技术的科学应用大大降低了施工难度、规避了施工风险、提高了抢架效率,缩短了抢架进程,为今后铁路桥梁水害应急处理积累了经验。     

轻型汽车排放生产一致性检查判定方法试验研究

利用轻型汽车排放标准GB18352.3-2005中的国Ⅲ、国Ⅳ两个阶段Ⅰ型试验排放限值的变化及使用满意统计量和不满意统计量的判定方法,对排放生产一致性检查判定的影响进行分析.可以得出,对于同一组实验数据,按照国Ⅳ排放限值进行排放生产一致性检查判定比按照国Ⅲ放限值严格;采用满意统计量判定比采用不满意统计量判定严格.有助于轻型汽车生产企业确定排放生产一致性检查的控制方案.     

Isocyanic acid and ammonia in vehicle emissions

Vehicles are considered to be an important source of ammonia (NH₃) and isocyanic acid (HNCO). HNCO and NH₃ have been shown to be toxic compounds. Moreover, NH₃ is also a precursor in the formation of atmospheric secondary aerosols. For that reason, real-time vehicular emissions from a series of Euro 5 and Euro 6 light-duty vehicles, including spark ignition (gasoline and flex-fuel), compression ignition (diesel) and a plug-in electric hybrid, were investigated at 23 and −7 °C over the new World harmonized Light-duty vehicle Test Cycle (WLTC) in the Vehicle Emission Laboratory at the European Commission Joint Research Centre Ispra, Italy. The median HNCO emissions obtained for the studied fleet over the WLTC were 1.4 mg km⁻¹ at 23 °C and 6 mg km⁻¹ at −7 °C. The fleet median NH₃ emission factors were 10 mg km⁻¹ and 21 mg km⁻¹ at 23 and −7 °C, respectively. The obtained results show that even though three-way catalyst (TWC), selective catalytic reduction (SCR), and NOx storage catalyst (NSC) are effective systems to reduce NOx vehicular emissions, they also lead to considerable emissions of the byproducts NH₃ and/or HNCO. It is also shown that diesel light-duty vehicles equipped with SCR can present NH₃ emission factors as high as gasoline light-duty vehicles at both, 23 and −7 °C over the WLTC. Therefore, with the introduction in the market of this DeNOx technology, vehicular NH₃ emissions will increase further.