为了消除跟驰模型用于交通排放测算产生的系统误差,提高微观交通仿真模型与交通排放模型融合应用于交通排放测算的准确性,引入衡量加速度变化率的参数急动度(jerk),提出一种考虑jerk分布特征的Wiedemann跟驰模型优化方法。通过对实际轨...为了消除跟驰模型用于交通排放测算产生的系统误差,提高微观交通仿真模型与交通排放模型融合应用于交通排放测算的准确性,引入衡量加速度变化率的参数急动度(jerk),提出一种考虑jerk分布特征的Wiedemann跟驰模型优化方法。通过对实际轨迹数据与车辆跟驰数据的拟合分析,建立各加速度区间下的jerk分布,并增设jerk约束对交通仿真模型生成轨迹进行优化。以北京市出租车轨迹数据和跟驰数据为例,测算结果表明:Wiedemann模型优化后,不同速度区间的车辆比功率(Vehicle Specific Power,VSP)分布误差平均降低1.2%,CO_(2),CO,THC,NOX等4种排放物的排放因子平均误差分别降低了16.9%,118.3%,27.0%,20.5%,表明该优化方法能够有效改善原模型中不真实的加速度,降低排放测算误差。展开更多
A kind of nitrogen-doped carbon(NC) nanomaterials was prepared via calcining the nitrogen-rich organic molecular glycoluril under nitrogen atmosphere. Elemental analysis result indicates the N content of the obtained ...A kind of nitrogen-doped carbon(NC) nanomaterials was prepared via calcining the nitrogen-rich organic molecular glycoluril under nitrogen atmosphere. Elemental analysis result indicates the N content of the obtained NC is 13.9 wt.%. Electrochemical measurement demonstrated that the obtained NC catalyst is an efficient ORR electrocatalyst in alkaline electrolyte. The process of ORR is dominated by a four-electron transfer pathway with the most efficient catalytic activity. In addition, the NC catalyst exhibits excellent stability and good resistance to methanol poisoning. After 10000 s of chronoamperometric durability test, the relative current of NC catalyst retained as high as 95%. This work provides a new strategy for the preparation of cost-effective ORR catalysts with high catalytic performance.展开更多
文摘为了消除跟驰模型用于交通排放测算产生的系统误差,提高微观交通仿真模型与交通排放模型融合应用于交通排放测算的准确性,引入衡量加速度变化率的参数急动度(jerk),提出一种考虑jerk分布特征的Wiedemann跟驰模型优化方法。通过对实际轨迹数据与车辆跟驰数据的拟合分析,建立各加速度区间下的jerk分布,并增设jerk约束对交通仿真模型生成轨迹进行优化。以北京市出租车轨迹数据和跟驰数据为例,测算结果表明:Wiedemann模型优化后,不同速度区间的车辆比功率(Vehicle Specific Power,VSP)分布误差平均降低1.2%,CO_(2),CO,THC,NOX等4种排放物的排放因子平均误差分别降低了16.9%,118.3%,27.0%,20.5%,表明该优化方法能够有效改善原模型中不真实的加速度,降低排放测算误差。
基金Financial support from the National Key R&D Program of China(2017YFA0206800,2017YFA0700100)the NSFC(21573238,21571177,21520102001)+1 种基金Key Research Program of Frontier Science,CAS(QYZDJ-SSW-SLH045)“Strategic Priority Research Program”of the Chinese Academy of Sciences(XDB20000000)。
文摘A kind of nitrogen-doped carbon(NC) nanomaterials was prepared via calcining the nitrogen-rich organic molecular glycoluril under nitrogen atmosphere. Elemental analysis result indicates the N content of the obtained NC is 13.9 wt.%. Electrochemical measurement demonstrated that the obtained NC catalyst is an efficient ORR electrocatalyst in alkaline electrolyte. The process of ORR is dominated by a four-electron transfer pathway with the most efficient catalytic activity. In addition, the NC catalyst exhibits excellent stability and good resistance to methanol poisoning. After 10000 s of chronoamperometric durability test, the relative current of NC catalyst retained as high as 95%. This work provides a new strategy for the preparation of cost-effective ORR catalysts with high catalytic performance.
