基于Logistic的不同车型碰撞行人事故严重程度致因分析

为定量分析不同车型碰撞行人事故严重程度影响因素,以美国北卡罗来纳州2007-2016年人车碰撞事故数据为样本,将其分为小轿车、SUV、货车碰撞行人事故3类,以事故严重程度为因变量,交通参与者属性、道路、环境条件和事故特征为候选自变量,分别建立累计logistic模型进行对比分析,探究人、车、路和环境因素对人车碰撞事故严...     

汽车环境风洞降雨模拟影响因素研究

目的 研究自然界降雨量与汽车环境风洞模拟降雨量之间的关系,得到中国气象条件的雨量设定经验公式,为汽车环境风洞模拟降雨量的设定提供理论依据。方法 理论分析自然界气象降雨和汽车环境风洞模拟降雨的特点和差异,研究影响汽车环境风洞模拟降雨量的因素。结果 在无风条件下,影响汽车环境风洞降雨量的因素有气象降雨量、前挡风玻璃倾角、雨滴直径和车速等。按照车速将降雨分为汽车停止和汽车行驶2种模式,提出结合中国气象条件的汽车环境风洞模拟降雨量的经验公式。结论 在相同降雨等级下,汽车停止状态下的汽车环境风洞降雨量一般大于车辆行驶状态。在气象降雨量等级为短时中雨时,行驶汽车的雨量设定值与车速呈指数增长关系。     

军绿有机涂层破损腐蚀行为研究

目的研究不同破损程度下军绿有机涂层的腐蚀行为,确定破损率对其防护性能变化的影响。方法通过人工制作不同的破损率,并利用电化学阻抗谱技术,研究不同破损程度下军绿有机涂层的电化学特征。结果根据不同破损程度下的军绿有机涂层的电化学特征,确定了涂层从完好到失效的四个阶段,初始完好阶段(破损率K≤0.0004%)、破损增大阶段(0.0016%K≤0.04%)、破损过大阶段(0.16%K≤1%)和失效阶段(4%K≤16%)。结论破损率K为0.04%的点是该涂层防护性能急转直下的转折点,因此破损率K大于0.04%时,应及时对车辆表面涂层进行修补和防护。     

车载电子电器设备的温度变化试验

ISO16750《道路车辆电气及电子设备的环境条件和试验》系列国家标准转化已进入报批阶段。系列标准的第4部分《气候负荷》引用IEC 60068-2-14规定的试验N：温度变化（GB/T2423.22）中的试验Na：规定转换时间的温度快速变化和试验Nb：按规定温度变化速率的温度变化试验。2009年1月,IEC对60068-2-14进行了技术性改版。将IEC 60068-2-33《温度变化导则》（GB/T2424.13）的内容并入;对试验及温度变化容差的描述和要求、编辑和插图都做了修改和修订。等同采标的GB/T2423.22的改版修订工作已在进行,估计2010年稍晚就可以发布。这里就当前国际标准和将发布等同国标的试验方法对车载电子电器设备的温度变化试验进行描述,同时对试验要素和及其应用要素作一些介绍。ISO16750《道路车辆电气及电子设备的环境条件和试验》系列国家标准转化已进入报批阶段。系列标准的第4部分《气候负荷》引用IEC 60068-2-14规定的试验N：温度变化（GB/T2423.22）中的试验Na：规定转换时间的温度快速变化和试验Nb：按规定温度变化速率的温度变化试验。2009年1月,IEC对60068-2-14进行了技术性改版。将IEC 60068-2-33《温度变化导则》（GB/T2424.13）的内容并入;对试验及温度变化容差的描述和要求、编辑和插图都做了修改和修订。等同采标的GB/T2423.22的改版修订工作已在进行,估计2010年稍晚就可以发布。这里就当前国际标准和将发布等同国标的试验方法对车载电子电器设备的温度变化试验进行描述,同时对试验要素和及其应用要素作一些介绍。     

汽油车非常规污染物排放特性研究

选择3种不同排量的典型汽油车,基于国Ⅲ标准的轻型车排放测试循环,用SKC采样泵和2, 4-DNPH、Tenax TA采样管采集尾气中的非常规污染物,利用高效液相色谱仪和热脱附气相色谱质谱联用仪分析汽油车排放中醛酮类化合物和挥发性有机物的组成及含量,同时利用电子低压冲击仪研究了其颗粒物排放的粒径和质量浓度分布特征.结果表明,不同汽油车之间非常规污染物的比排放值有较大差异,3辆汽油车总醛酮比排放量分别为36.44、 16.71、 10.43 mg/km,TVOC分别为155.39、 103.75、 42.29 mg/km.排放的醛酮化合物中甲醛、乙醛、丙烯醛、丙酮和环己酮的检出含量较高,占总醛酮量的77.9%～89.7%,且绝大部分为有毒有害物质;废气中挥发性有机物绝大部分为芳香烃和烷烃,分别占总数的31.6%～39.2%和23.1%～27.9%,其中又以芳香烃类化合物甲苯、二甲苯和苯的检出含量最高,平均占TVOC的16.68%、 16.87%和5.23%;其颗粒物排放以超细颗粒物（<100nm）为主,高速工况下排放的颗粒物明显多于低速和中速工况.     

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.     

Effects of Tracking by Armored Vehicles on Townsend's Ground Squirrels in the Orchard Training Area, Idaho, USA

Spermophilus townsendii ) prey. These changes could occur directly or as a result of changes in the vegetation available as food and cover for the ground squirrels. We assessed the effects of long-term tracking by armored vehicles by comparing 9-ha areas in sagebrush (Artemisia tridentata) -dominated shrubsteppe and bluegrass (Poa secunda) -dominated grasslands subjected to low-intensity tracking for ∼50 years with others that had not been tracked. We did not detect any effect on ground squirrel population dynamics associated with long-term tracking. Although densities of adults and juveniles tended to be higher in the areas exposed to such tracking, we attribute this difference to other factors that varied spatially. To determine short-term (two-year) effects, we experimentally tracked two sagebrush and two grassland sites with an M-1 tank after animals had begun their inactive season. In the following two active seasons we monitored squirrel demography and behavior and vegetative characteristics on the experimentally tracked sites and compared the results with control sites. Although we experimentally tracked ∼33% of the surface of each of four sites where ground squirrel densities were assessed, the tracking had a detectable effect only on some herbaceous perennials and did not influence ground squirrel densities or behavior significantly during the subsequent two active seasons. We conclude that tracking after the start of the inactive season is likely to influence ground squirrel demography or behavior only if vegetation cover is substantially changed by decreasing coverage of preferred food plants or increasing the coverage of annual grasses and forbs that are succulent for only a short time each year.     

一种在线监测机动车尾气超标排放的有效方法

分析机动车尾气污染现状和国内外有效的监测治理方法,对利用汽车OBD尾气监控系统判别车辆尾气超标的方法进行了探讨,并对移动污染源(机动车)的动态监测和管理提出见解,认为运用这个方法可以减少机动车尾气污染和降低排放总量。     

Validity of police-reported alcohol involvement in fatal motor carrier crashes in the United States between 1982 and 2005

Objective

To examine the validity of police-reported alcohol data for drivers involved in fatal motor carrier crashes.

Material and Methods

We determined the availability of blood alcohol concentration (BAC) and police-reported alcohol data on 157,702 drivers involved in fatal motor carrier crashes between 1982 - 2005 using Fatality Analysis and Reporting System (FARS) data. Drivers were categorized as motor carrier drivers if they operated a vehicle with a gross vehicle weight rating of greater than 26,000 pounds. Otherwise, they were classified as non motor carrier drivers. The sensitivity and specificity of police-reported alcohol involvement were estimated for both driver types.

Results

Of the 157,702 drivers, 18% had no alcohol information, 15% had BAC results, 42% had police-reported alcohol data, and 25% had both. Alcohol information varied significantly by driver, crash, and vehicle characteristics. For example, motor carrier drivers were significantly more likely (51%) to have BAC testing results compared to non motor carrier drivers (31%) (p < 0.001). The sensitivity of police-reported alcohol involvement for a BAC level ≥ 0.08 was 83% (95% CI 79%, 86%) for motor carrier drivers and 90% (95% CI 89%, 90%) for non motor carrier drivers. The specificity rates were 96% (95% CI 95%, 96%) and 91% (95% CI 90%, 91%), respectively.

Conclusions

The sensitivity and specificity of police-reported alcohol involvement are reasonably high for drivers involved in fatal motor carrier crashes. Further research is needed to determine the extent to which the accuracy of police-reported alcohol involvement may be overestimated because of verification bias.

Impact on the Industry

Based on the results of this study, the federal government should continue to work with states to strengthen their strategies to increase chemical testing of all drivers involved in fatal crashes.     

洪水作用下汽车的起动流速研究

针对洪水作用下汽车的起动条件开展了一系列的研究:首先分析部分淹没状态下汽车的受力情况,结合滑动平衡的临界起动条件建立相关方程,导出了洪水中汽车起动流速公式;然后在室内水槽中对三款模型车进行了一系列的起动试验。试验结果表明:对于同一款模型车,平行于水流方向放置时,起动流速与水深的相关性较好;并且水深越大,起动流速越小。接着运用试验资料率定了起动流速公式中的相关参数。最后采用模型相似率及率定后的计算公式估算了原型车辆在不同水深下的起动流速,两种方法所得的结果较为接近,故预测结果较为可靠。