平面交叉口电动自行车交通冲突模型研究

为研究电动自行车在交叉口的安全特性,减少交通管理中的安全隐患,在运用TCT技术分析电动自行车交通特性的基础上,通过实地调研7个典型的四相位信号控制平面十字形交叉口,利用SPSS软件分别选取线性、多项式及指数函数对电动自行车的交通冲突调查数据进行拟合,构建了电动自行车的交叉口交通冲突模型。最后,结合所获得的交通冲突模型的各项参数,运用欧几里德贴进度评价方法,建立了交通冲突强度的评价模型,该模型可用于评估交叉口路段电动自行车的运行安全性。结果表明,散点化的比较方法不仅可以对同一交叉口的不同进(出)口道的电动自行车交通冲突强度进行分析,还能对不同交叉口同一冲突类型的安全状况进行对比评价。     

Orthopedic injury in electric bicycle-related collisions

Objective: Although electric bicycle-related injuries have become the most common reason for hospitalization due to a road crash in China, no study has comprehensively investigated electric bicycle collisions and their impact on orthopedic injuries; such a study may provide evidence to support a new road safety policy.

Methods: A retrospective review of orthopedic injuries from electric bicycle collisions was performed in an urban trauma center. We collected variables including age, gender, location of fracture, presence of open or closed fractures, concomitant vascular, and neurologic injuries.

Results: A total of 2,044 cases were involved in electric bicycle collisions. The orthopedic injury victims were predominantly male and middle aged. The most common orthopedic injury was a femur fracture. Open fractures frequently involved the forearm and tibia/fibula. Male patients were more likely to suffer from multiple fractures and associated injuries than female patients. Fewer patients age 60 years old or older wore helmets at the time of the accident compared to those in other age groups.

Conclusions: Orthopedic injuries from electric bicycle-related accidents cause patients substantial suffering that could lead to serious social consequences. Helmet use and protective clothing or similar safety gear, especially for electric bicycle users, should be required to provide greater protection.     

Impact of improving vehicle front design on the burden of pedestrian injuries in Germany,the United States,and India

Objective: European car design regulations and New Car Assessment Program (NCAP) ratings have led to reductions in pedestrian injuries. The aim of this study was to evaluate the impact of improving vehicle front design on mortality and morbidity due to pedestrian injuries in a European country (Germany) and 2 countries (the United States and India) that do not have pedestrian-focused NCAP testing or design regulations.

Methods: We used data from the International Road Traffic and Accident Database and the Global Burden of Disease project to estimate baseline pedestrian deaths and nonfatal injuries in each country in 2013. The effect of improved passenger car star ratings on probability of pedestrian injury was based on recent evaluations of pedestrian crash data from Germany. The effect of improved heavy motor vehicle (HMV) front end design on pedestrian injuries was based on estimates reported by simulation studies. We used burden of disease methods to estimate population health loss by combining the burden of morbidity and mortality in disability-adjusted life years (DALYs) lost.

Results: Extrapolating from evaluations in Germany suggests that improving front end design of cars can potentially reduce the burden of pedestrian injuries due to cars by up to 24% in the United States and 41% in India. In Germany, where cars comply with the United Nations regulation on pedestrian safety, additional improvements would have led to a 1% reduction. Similarly, improved HMV design would reduce DALYs lost by pedestrian victims hit by HMVs by 20% in each country. Overall, improved vehicle design would reduce DALYs lost to road traffic injuries (RTIs) by 0.8% in Germany, 4.1% in the United States, and 6.7% in India.

Conclusions: Recent evaluations show a strong correlation between Euro NCAP pedestrian scores and real-life pedestrian injuries, suggesting that improved car front end design in Europe has led to substantial reductions in pedestrian injuries. Although the United States has fewer pedestrian crashes, it would nevertheless benefit substantially by adopting similar regulations and instituting pedestrian NCAP testing. The maximum benefit would be realized in low- and middle-income countries like India that have a high proportion of pedestrian crashes. Though crash avoidance technologies are being developed to protect pedestrians, supplemental protection through design regulations may significantly improve injury countermeasures for vulnerable road users.     

电场强化博落回修复铀镉复合污染土壤机理

采用盆栽试验,研究了在0.3V/cm的外加直流电场作用下,博落回的生物量、富集铀（U）的性能和抗氧化酶活性,以及其根际土壤中有机酸含量、U和镉（Cd）的结合形态、植物根部U的价态、微生物群落结构的变化等.结果表明,施加直流电场后,博落回总生物量升高了15.33%~29.88%,其中电场+铀污染（DC+U）和电场+镉污染（DC+Cd）处理组的博落回对U和Cd的富集系数提高了90.84%和93.33%;土壤中草酸、酒石酸、琥珀酸、苹果酸和乳酸含量分别增加了18.36%~45.31%、58.62%~503.22%、15.71%~118.99%、12.34%~123.27%和25.97%~36.05%;过氧化物酶（POD）和谷胱甘肽过氧化物酶（GSH-PX）的活性分别提高了13.63%~34.82%和9.70%~28.64%;根际土壤中植物可利用态U、Cd所占比例显著增大;博落回根部的大部分U由稳定的U（IV）变成了更容易从地下部分向地上部分转移的U（VI）;酸杆菌门（Acidobacteria）等细菌菌门和子囊菌门（Ascomycota）等真菌菌门比例升高,这些微生物通过提高酶活性增强了博落回对U、Cd的耐受性和富集作用.     

杂散电流下新型阻锈剂对混凝土中氯离子扩散的影响

目的探寻混凝土在杂散电流和氯离子耦合作用下的腐蚀规律,研究新型阻锈剂的阻锈性能。方法运用电通量法和RCM法,对20 V杂散电流作用下,混凝土的抗氯离子渗透性能进行表征,设置空白组对照实验,对添加阻锈剂后,混凝土的抗氯离子渗透性能进行效果评价。结果在杂散电流和氯离子的共同作用下,混凝土结构腐蚀的倾向将变大,并且会加速腐蚀反应的进行。混凝土结构在通电48 h后,其电通量高达5778.67 C。与空白组相比,添加阻锈剂混凝土试块的氯离子扩散系数下降45.62%。结论添加4%阻锈剂的混凝土试块有着较好的抵抗氯离子渗透的能力。     

棉布厚度对辐射式电暖器引燃能力影响研究

实验研究了棉布厚度对辐射式电暖器的引燃能力影响情况。实验用电暖器上加热管向外辐射热通量占电器功率之间的比例(辐射率η值)为65%。辐射式电暖器可以使棉布发生阴燃燃烧,当单面工作功率为400 W的电暖器紧贴棉布且全过程全覆盖的前提下棉布阴燃的临界厚度在0.18 mm～0.48 mm之间,当棉布厚度超过0.48 mm时将发生阴燃,但薄棉布通常难以直接发生有焰燃烧。对于用棉布开始阴燃时间表征的电暖器引燃能力,随着棉布厚度的增大,电暖器对棉布的引燃能力将减弱。     

Ventilation mode changes our safety in buses: Study on “air-rain” flow against chemical and arson attack in public transport vehicles

Objectives: Public transport vehicles (PTVs) play a decisive role in development of the urban economy. However, the safety of PTVs is threatened by the man-released chemical or arson attack. It was found that indoor air safety can be greatly improved by employing air-rain ventilation instead of the common ventilation in a PTV.

Methods: Numerical simulations and experiments have been done to prove the effectiveness of the air-rain flow against chemical attack or arson in PTVs.

Results: The research shows that, during a chemical attack, an air-rain flow of 0.1 m/s can constrain the spread of a chemical agent in a very limited zone near its source, which is far away from the passengers’ breathing area in the PTV. During an arson attack, at an air-rain flow of 0.3 m/s, most of the area in the PTV maintains a low temperature for at least 60?s during a fire, which is long enough for passenger evacuation.

Conclusion: Compared to common ventilation, the key characteristic of air-rain ventilation is its resistance to the blending effect of the air. Because of this, the spread of chemical agents, hot gas/combustion products during a fire, and fuel aerosol is constrained to a limited area in a PTV. Passengers are then protected from chemical attack, explosion of fuel aerosols, and high temperatures and smoke. Thus, we can say that this new ventilation mode increases passenger safety in buses.     

Occupational exposure to electric and magnetic fields during tasks at ground or floor level at 110 kV substations in Finland

The aim was to investigate occupational exposure to electric and magnetic fields during tasks at ground or floor level at 110?kV substations in Finland and to compare the measured values to Directive 2013/35/EU. Altogether, 347 electric field measurements and 100 magnetic field measurements were performed. The average value of all electric fields was 2.3?kV/m (maximum 6.4?kV/m) and that of magnetic fields was 5.8?µT (maximum 51.0?µT). It can be concluded that the electric and magnetic field exposure at ground or floor level is typically below the low action levels of Directive 2013/35/EU. The transposition of the directive will not create new needs to modify the work practice of the evaluated tasks, which can continue to be performed as before. However, for workers with medical implants, the exposure may be high enough to cause interference.     

除尘器灰斗电加热器供配电节能降耗方案优化

对目前广泛使用的除尘器灰斗电加热器的供配电系统进行了分析,提出了电控设备投资更省、供配电系统运行更节能经济的优化方案,并通过工程实例进行了分析验证。