车辆行人事故碰撞速度重建仍存在较大不确定性,通过典型的人车事故案例对传统车速重建方法进行验证,并提出一种新的车速重建方法。采集27例具有事故数据记录器(event data recorder,EDR)数据的案例对抛距法计算精度进行验证,分析碰撞速...车辆行人事故碰撞速度重建仍存在较大不确定性,通过典型的人车事故案例对传统车速重建方法进行验证,并提出一种新的车速重建方法。采集27例具有事故数据记录器(event data recorder,EDR)数据的案例对抛距法计算精度进行验证,分析碰撞速度重建的影响因素,并建立碰撞速度与影响因素的线性回归方程。结果表明:抛距法相对误差最大值为36.7%,最小值为1. 5%,平均相对误差为7. 1%; WRR值与碰撞速度具有正相关性,随碰撞速度增加WRR值增加;在相同的碰撞速度下,发动机罩前缘高度较高的车型导致的WRR值更低;WRR值和发动机罩前缘高度是碰撞速度重建的重要参数。指出行人抛距法计算精度不高,建立的基于WRR值和发动机前缘高度的车辆行驶速度计算方法,将成为制动痕迹和行人抛距缺失情况下车速重建方法的重要补充。展开更多
Fenton reaction based on Fe2+-H2O2 system has been widely applied in water remediation, but the obvious drawbacks largely hinder its practical uses. Alternatively, heterogeneous nanomaterials with proper surface modif...Fenton reaction based on Fe2+-H2O2 system has been widely applied in water remediation, but the obvious drawbacks largely hinder its practical uses. Alternatively, heterogeneous nanomaterials with proper surface modification could be used as Fenton-like catalysts. Surface doping of Ti O2 could concentrate the pollutants surrounding the Fe3O4 catalyst, which might benefit the catalytic performance of Fe3O4. Herein, we reported that Ti O2-doped Fe3O4 nanoparticles(NPs) could be used as high-performance Fenton-like catalyst for dye decoloration in near neutral environment, where the doping of Ti O2 on Fe3O4 surface dramatically improved the catalytic activity of Fe3O4 in Fenton-like reaction. Ti O2-doped Fe3O4 NPs catalyzed the decomposition of H2O2 to oxidize methylene blue without external energy supply, resulting in effective decoloration. Ti O2-doped Fe3O4 NPs showed high catalytic activity under various p H values and even in the presence of radical scavenger. More catalysts and H2O2 would facilitate the decoloration. At higher temperature, the decoloration became faster and more effective. The implication to the environmental applications of Ti O2-doped Fe3O4 NPs is discussed.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.21307101 and 21301015)the Science & Technology Department of Sichuan Province(Pillar Program)(Grant No.2013FZ0060)+1 种基金Education Department of Sichuan Province(Grant No.15ZA0392)the Project of Postgraduate Degree Construction,Southwest University for Nationalities(Grant No.2015XWD-S0703)
文摘Fenton reaction based on Fe2+-H2O2 system has been widely applied in water remediation, but the obvious drawbacks largely hinder its practical uses. Alternatively, heterogeneous nanomaterials with proper surface modification could be used as Fenton-like catalysts. Surface doping of Ti O2 could concentrate the pollutants surrounding the Fe3O4 catalyst, which might benefit the catalytic performance of Fe3O4. Herein, we reported that Ti O2-doped Fe3O4 nanoparticles(NPs) could be used as high-performance Fenton-like catalyst for dye decoloration in near neutral environment, where the doping of Ti O2 on Fe3O4 surface dramatically improved the catalytic activity of Fe3O4 in Fenton-like reaction. Ti O2-doped Fe3O4 NPs catalyzed the decomposition of H2O2 to oxidize methylene blue without external energy supply, resulting in effective decoloration. Ti O2-doped Fe3O4 NPs showed high catalytic activity under various p H values and even in the presence of radical scavenger. More catalysts and H2O2 would facilitate the decoloration. At higher temperature, the decoloration became faster and more effective. The implication to the environmental applications of Ti O2-doped Fe3O4 NPs is discussed.
