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201.
ApplicationofaerialremotesensinginthestudyonvegetationinGuangzhou,ChinaChenShijie;HeShigan;YangJielin;WangLiangping(Departmen...  相似文献   
202.
北京市轻型汽车尾气排放检测结果分析   总被引:2,自引:0,他引:2  
对北京市566辆在用轻型车排放尾气进行了BASM检测,对不同厂牌的化油器车、化油器改造车和电喷车排放的HC、CO和NO平均浓度进行了比较,结果表明,化油器改造车3种污染物平均浓度比化油器车低50%左右,电喷车3种污染物平均浓度可比化油器车低80%左右。同时对几种车型的劣化规律进行了分析,发现化油器车的劣化关系离散性大,而另外两种技术的车辆的劣化关系呈收敛性,说明化油器车的污染物排放和保养关系密切,电喷车劣化规律明显优于化油器车和化油器改造车。实验结果为I/M实施提供了科学依据。  相似文献   
203.
油田车队综合信息管理系统采用了RFID射频识别、GPS全球卫星定位和GIS地理信息技术,阐述了管理系统的系统硬件与系统软件.应用实践证明,使用该系统实现了车辆的场内和外部信息管理的统一,达到了车辆运行全天候、全方位监控管理的目的.  相似文献   
204.
绿色机动车—燃料电池汽车   总被引:2,自引:0,他引:2  
马紫峰  陆天虹 《上海环境科学》1999,18(12):551-553,557
简要叙述了燃料电池汽车的技术特点,主要有:能量转化效率高,CO2排放量比内燃机汽车低,基本不产生有毒气体,不要充电。在此基础上较详细地介绍了世界各国的燃料电池汽车研究现状,并针对上海市机动车污染严重的现状,提出了发展燃料电池汽车及其相关产业的建议。  相似文献   
205.
Over the past decade, the emission standards and fuel standards in Beijing have been upgraded twice, and the vehicle structure has been improved by accelerating the elimination of 2.95 million old vehicles. Through the formulation and implementation of these policies, the emissions of carbon monoxide (CO), volatile organic compounds (VOCs), nitrogen oxides (NOx), and fine particulate matter (PM2.5) in 2019 were 147.9, 25.3, 43.4, and 0.91 kton in Beijing, respectively. The emission factor method was adopted to better understand the emissions characteristics of primary air pollutants from combustion engine vehicles and to improve pollution control. In combination with the air quality improvement goals and the status of social and economic development during the 14th Five-Year Plan period in Beijing, different vehicle pollution control scenarios were established, and emissions reductions were projected. The results show that the emissions of four air pollutants (CO, VOCs, NOx, and PM2.5) from vehicles in Beijing decreased by an average of 68% in 2019, compared to their levels in 2009. The contribution of NOx emissions from diesel vehicles increased from 35% in 2009 to 56% in 2019, which indicated that clean and energy-saving diesel vehicle fleets should be further improved. Electric vehicle adoption could be an important measure to reduce pollutant emissions. With the further upgrading of vehicle structure and the adoption of electric vehicles, it is expected that the total emissions of the four vehicle pollutants can be reduced by 20%-41% by the end of the 14th Five-Year Plan period.  相似文献   
206.
于雷  乔风翔  刘娟 《交通环保》2005,26(1):7-9,22
车辆行驶里程(VMT)是机动车尾气排放预测模型的重要输入参数之一,VMT值的精确度直接影响了模型的预测精度。文中提出了一种VMT估算模型,该模型引入指数回归模型,结合采样交通流量和路段特征来估测所有路段流量和VMT,并按时间和速度进行了进一步划分,在实际运用中,该模型在现有技术条件下也易于标定。  相似文献   
207.
208.
Objective: This article investigated and compared frequency domain and time domain characteristics of drivers' behaviors before and after the start of distracted driving.

Method: Data from an existing naturalistic driving study were used. Fast Fourier transform (FFT) was applied for the frequency domain analysis to explore drivers' behavior pattern changes between nondistracted (prestarting of visual–manual task) and distracted (poststarting of visual–manual task) driving periods. Average relative spectral power in a low frequency range (0–0.5 Hz) and the standard deviation in a 10-s time window of vehicle control variables (i.e., lane offset, yaw rate, and acceleration) were calculated and further compared. Sensitivity analyses were also applied to examine the reliability of the time and frequency domain analyses.

Results: Results of the mixed model analyses from the time and frequency domain analyses all showed significant degradation in lateral control performance after engaging in visual–manual tasks while driving. Results of the sensitivity analyses suggested that the frequency domain analysis was less sensitive to the frequency bandwidth, whereas the time domain analysis was more sensitive to the time intervals selected for variation calculations. Different time interval selections can result in significantly different standard deviation values, whereas average spectral power analysis on yaw rate in both low and high frequency bandwidths showed consistent results, that higher variation values were observed during distracted driving when compared to nondistracted driving.

Conclusions: This study suggests that driver state detection needs to consider the behavior changes during the prestarting periods, instead of only focusing on periods with physical presence of distraction, such as cell phone use. Lateral control measures can be a better indicator of distraction detection than longitudinal controls. In addition, frequency domain analyses proved to be a more robust and consistent method in assessing driving performance compared to time domain analyses.  相似文献   

209.
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.  相似文献   

210.
我国环境应急监测车的现状与发展趋势   总被引:3,自引:0,他引:3  
根据国家对突发环境事件应急处置的要求,结合我国环境应急监测车的发展现状和存在问题,对环境应急监测车在环境事件应急指挥系统、应急监测仪器和设备、污染物扩散模拟系统、危险化学品应急处置专家库、现场视频无线传输和通讯系统、气象系统、监测车辅助系统、个体防护器材等方面的配置和研发提出建议。  相似文献   
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