Evaluating the Effect of a Mechanical Adjunct to Improve the Installation of Child Restraint Systems to Vehicles

Objectives: We explored if an alternative CRS design that utilized a mechanical adjunct to amplify the force applied to the adult seat belt (intervention CRS) results in more accurate and secure attachment between the CRS and the vehicle compared to similar CRS models that use LATCH or the existing adult seat belt. We conducted three separate studies to address this question and additionally explored: (1) the contribution of prior CRS installation experience (Study 1), (2) the value-added of CRS labeling (Study 2), and (3) paper-based vs. video instructions (Study 3).

Methods: In Studies 1 and 2 we assessed a forward facing combination CRS design (intervention CRS) compared to a commercially available LATCH equipped model (control CRS) and in Study 3 we conducted a similar study using a convertible model of both the intervention and control CRS. Participants installed both CRS in a contemporary minivan and could choose which type of attachment to use for the control CRS (LATCH or seat belt); order of installation was counter-balanced. Evaluators systematically examined installations for accuracy and security.

Results: Study 1: A greater proportion of participants in both the experienced and inexperienced groups was able to securely install the intervention CRS compared to the control CRS: (45% vs. 16%, p =.0001 for experienced) and (37% vs. 6%, p =.003 for inexperienced). No differences between the CRS were observed for accuracy of installation in either user group. Study 2: A greater proportion of participants were able to securely install the enhanced intervention CRS compared to the control CRS: (62% vs. 9%, p =.001). The intervention CRS demonstrated reduced installation accuracy: (30% vs. 61%, p =.001). Study 3: A greater proportion of participants was able to securely install the intervention CRS compared to the control CRS: 79% vs. 66% p =.03, but this effect was smaller than in the previous studies. Participants were less likely to achieve an accurate installation with the intervention CRS compared to the control CRS: 54% vs. 79%, p =.004. Common accuracy errors in each study included twisting or misrouting the seatbelt when installing the intervention CRS.

Conclusions: Our results suggest that novel CRS designs that utilize mechanical advantage to facilitate attachment of the CRS to the vehicle result in a tighter installation compared to LATCH equipped models, but an increase in accuracy errors occurred.     

广东省典型内河港区主要大气污染物排放特征研究

以广东省珠江三角洲地区某内河港区为对象,选取港区内船舶、作业机械、运输车辆的大气污染物排放计算方法,结合保有量、活动水平、燃油品质等基础信息计算了该港区在2013年的大气污染物排放量,并分析了其排放特征.结果表明,在内河港区及周边水域,船舶排放的SO2占比超过80％;其他污染因子方面,船舶排放占比32％～47％,作业机械排放占比36％ ～ 48％,运输车辆排放占比10％ ～32％.在内河港区及其周边水域,船舶及港区作业机械的排放均有突出污染贡献.     

国Ⅰ～国Ⅲ重型柴油车尾气PM_(2.5)及其碳质组分的排放特征

机动车排放是大气PM2.5污染的主要来源之一,而在机动车排放的PM2.5中,约80%以上来自重型柴油车.为了研究重型柴油车尾气PM2.5及其碳质组分的排放特征,本研究基于车载排放测试系统(PEMS),对7辆不同排放阶段的重型柴油车进行了尾气PM2.5采样分析,并进一步分析了PM2.5中的OC和EC组分.结果显示,从国Ⅰ到国Ⅲ阶段,重型柴油车PM2.5排放因子分别为(0.466±0.300)g·km-1、(0.112±0.025)g·km-1和(0.056±0.034)g·km-1,表明随着排放标准的加严,测试车辆的尾气PM2.5排放因子呈现显著的下降趋势.行驶工况对重型柴油车尾气PM2.5及其碳质组分排放存在较大影响,PM2.5排放因子在高速和市区工况下相对较高,而在市郊工况下则较低;OC和EC的比值在市区工况下为(2.86±1.07)∶1,而在市郊和高速工况下为(0.97±0.49)∶1.     

机动车尾气排放VOCs研究进展

机动车尾气排放的挥发性有机物(VOCs)严重危害着人类的健康和大气环境,备受人们关注。本综述对机动车尾气排放VOCs的采样和分析等监测技术研究进展进行了综合和概括;对国内外机动车尾气排放VOCs的研究进行了分类和归纳。对国内研究存在的问题进行了总结,并对未来相关研究进行了展望。目前,国内机动车排放VOCs源成分谱、采样分析方法,以及其排放特征都需要进一步深入研究。     

火场环境下无人机热损伤试验研究

无人机(UAV)逐步运用于火场搜救,但同时会因为火场高温而受损,为提高UAV在火场救援中的工作效率,设计一种UAV动态测试平台,开展UAV火场飞行试验;分析火场环境下UAV的热损伤情况,探究UAV在火场中的机身温度变化特征和UAV火场飞行安全距离。结果表明:火场热辐射和热对流是造成UAV热损伤的主要形式;旋翼产生的气流场对UAV机身有较为明显的降温效应,在试验工况下最高有25.6℃的降温作用;UAV与火焰的相对距离减少会增加机身的热损伤,在距离0.8 m处开始发生不可逆热损坏,试验工况下UAV火场飞行的安全距离为0.8 m。     

基于多信息检测的车辆智能防撞预警技术研究

运用多源信息检测技术对驾驶状态进行综合检测,利用架设在车辆外部的摄像机获取本车与前方车辆之间的相对距离、相对速度信息,利用架设在车辆内部的摄像机获取驾驶人状态信息,通过综合判断降低车辆防撞检测的漏警率、误警率以及冗余报警率;构建车辆行驶安全判定规则,对行车实时危险和潜在危险进行检测、分析与判断,获取可靠的防撞警示提醒;使反应时间、相对距离、相对速度3个方面都能得到优化控制,从而避免车辆碰撞事故;同时也为提高车速、增加道路通行能力、实现自动驾驶等奠定良好的基础。     

广州市氮氧化物控制的费用效果分析初探

近年来,广州市氮氧化物(NO_x污染日益加重,主要原因是机动车保有量的快速增加和城市交通改善的严重滞后。控制机动车排放造成的污染己成为亟待解决的问题。费用效果分析是进行控制方案选择的重要依据。笔者对广州市NO_x控制的不同方案进行了初步的费用效 果分析。结果表明,在用车改造加装真空延时阀对NO_x的削减费效性最好,其次是在用车I/M计划的费效性较好,而采用严格新标准的削减 潜力最大。      

应用模式模拟济南市机动车污染的空间分布

以济南市机动车污染排放实际情况为基础,结合具体的地理、气象等特点,采用ISCST3模式模拟计算了济南市196 km2范围内年均CO 和NOx浓度空间分布,确定出济南市机动车污染较为严重,需要重点控制机动车污染的区域。      

南京市机动车排气监测与评价

通过对南京市机动车排气污染物的年检监测,表明南京市的汽油车、柴油车、摩托车排气合格率总体呈上升趋势,2002年全市机动车排气监测总合格率为99.9%,比1993年上升了8.6个百分点;汽车尾气达标率也呈上升趋势,2002年达83.8%,比1993年上升了2.6个百分点。对机动车排气路检结果表明,CO超标的车辆占84.4%,CO、HC两项指标都超标的车辆占31.1%。对各类汽油助力车排气监测结果表明,二冲程汽油助力车尾气中CO、HC排放量要高于四冲程汽油助力车的排放量。对各类正三轮摩托车排气抽检结果表明,大部分四冲程正三轮摩托车尾气排放污染物能达标,且排气管无碳烟;二冲程正三轮摩托车尾气中HC值偏高,排气管碳烟明显。     

关于机动车尾气检测方法及污染防治措施研究

机动车尾气成分中包含着许多种类的化合物,而绝大多数化合物不仅威胁人体健康而且极易造成空气污染。现阶段,我国机动车尾气排放特征为排放量大、短期、局部污染极为严重与集中排放等,对此我国应提高对机动车尾气检测问题的重视程度,并采取相应的措施防治机动车尾气排放。基于此,文章简要分析机动车尾气的有关检测方法及其防治路径。