车载液晶显示器环境试验技术分析

与普通的家用显示器相比,车载液晶显示器应能耐受更严酷的环境条件,本文参照GJB150和Gb2423的试验项目和试验应力,提出了车载液晶显示器环境试验方案。并在试验的基础上对出现的故障进行改进,以提高车载液晶显示器的环境适应性。     

Control strategies for vehicular NOx emissions in Guangzhou, China

Guangzhou is a city in southern China that has experienced very rapid economic development in recent years. The city's air has very high concentrations of various pollutants, including sulphur dioxide (SO₂), oxides of nitrogen (NOx), ozone (O₃) and particulate. This paper reviews the changes in air quality in the city over the past 15 years, and notes that a serious vehicular-related emissions problem has been superimposed on the traditional coal-burning problem evident in most Chinese cities. As NOx concentrations have increased, oxidants and photochemical smog now interact with the traditional SO₂ and particulate pollutants, leading to increased health risks and other environmental concerns.
Any responsible NOx control strategy for the city must include vehicle emission control measures. This paper reviews control strategies designed to abate vehicle emissions to fulfill the city's air quality improvement target in 2010. A cost-effectiveness analysis suggests that, while NOx emission control is expensive, vehicular emission standards could achieve a relatively sizable emissions reduction at reasonable cost. To achieve the 2010 air quality target of NOx, advanced implementation of EURO3 standards is recommended, substituting for the EURO2 currently envisioned in the national regulations. Related technical options, including fuel quality improvements and inspection/maintenance (I/M) upgrades (ASM or IM240), are assessed as well.     

柴油车尾气残余物有机污染特征及其环境危害

利用大型烃分析仪(GHM)对小型柴油车尾气排气管内的黑色残余物进行了定量和定性分析,讨论了残余物质中所含各种类型有机污染物的数量和组成特征。研究结果表明,柴油机在燃烧过程中存在着不完全燃烧现象,尾气黑色残余物中含有129.17mg/g的有机污染物,它们大多为可造成严重环境污染的高熔点、强毒性的重质极性有机污染物。     

Forfeiture programs in California: why so few?

PROBLEM: It is estimated that at least 75% of suspended or revoked drivers continue to drive illegally. In states like California, there are also a substantial and growing number of people who drive without ever having been licensed. Some states, such as Ohio and California, have enacted vehicle impoundment and forfeiture programs as sanctions to reduce these offenses. Published evaluations indicate that vehicle impoundment laws reduce recidivism and crash rates. However, vehicle forfeiture programs have been less successful, mostly because of low levels of enforcement. METHOD: Police officers and district attorneys from 17 jurisdictions were interviewed by phone or in person to determine current enforcement levels and impediments to more aggressive application of statutory authority. RESULTS AND DISCUSSION: The survey found that most California jurisdictions are enforcing vehicle impoundments for first-time offenders. However, very few jurisdictions were enforcing the vehicle forfeiture law for repeat offenders. Among the reasons for not enforcing the vehicle forfeiture law was a perception that it was too time-consuming and/or not a priority among prosecutors. However, a number of authorities indicated that the simple vehicle impoundment procedure is often functionally equivalent to forfeiture because many drivers fail to retrieve the vehicle at the end of the impoundment period. IMPACT ON INDUSTRY: Vehicle impoundment programs are effective mechanisms in deterring illicit driving, and states should be encouraged to initiate vehicle impoundment laws. States could achieve even greater safety benefits if vehicle forfeiture sanctions were extensively used for repeat offenders. However, based on California's experience, the incremental benefits of vehicle forfeiture (over vehicle impoundment) may not be very great.     

Using a driving simulator to identify older drivers at inflated risk of motor vehicle crashes

PROBLEM: To develop appropriate assessment criteria to measure the performance of older drivers using an interactive PC-based driving simulator, and to determine which measures were associated with the occurrence of motor-vehicle crash. METHOD: One hundred and twenty-nine older drivers residing in a metropolitan city volunteered to participate in this retrospective cohort study. Using the driving simulator, appropriate driving tasks were devised to test the older drivers, whose performances were assessed by 10 reliable assessment criteria. Logistic regression analysis was then undertaken to determine those criteria that influence the self-reported crash outcome. RESULTS: As expected, driving skill of older drivers was found to decline with age. Over 60% of the sample participants reported having at least one motor-vehicle crash during the past year. Adjusting for age in a logistic regression analysis, the cognitive abilities associated with the crash occurrence were working memory, decision making under pressure of time, and confidence in driving at high speed. SUMMARY: The findings of this retrospective study indicated those individuals at inflated risk of vehicle crashes could be identified using the PC-based interactive driving simulator. Prospective studies need to be undertaken to determine whether the driving simulator can predict future crash events. IMPACT ON INDUSTRY: This study demonstrated an economical driving simulator approach to screen out problematic or unsafe older drivers before a more detailed but expensive road test is considered.     

珠江三角洲典型城市机动车尾气排放的影响因素分析

机动车技术水平和道路路况是影响机动车尾气排放的两大因素。本文以中山、佛山和广州三个城市为代表城市,首先采用问卷调查和实时采集交通流视频的方式收集三个城市的机动车技术水平信息和道路路况,并分析了上述三个城市的燃油类型和累计行驶里程和交通流的分布特征。分析结果衰明,备城市的机动车技术水平特征及差距,其中广州的出租车、公交车已规模推广环保型燃料,各类车型燃料使用比例不同使得尾气成分有一定差异;广州公交车累计行驶里程和年均行驶里程分布较靠后,公交系统的使用率较高;出租车年均行驶里程低于佛山、中山。在交通流分布上,广州总交通量大于中山;广州各级道路交通量呈梯度递减分布,小时交通量差距较大;中山仅国道承担较大范围的运输,其他各级道路分布形状统一,非工作类出行比例低。     

利用SPAMS研究长沙市秋季PM2.5化学组成及来源

2019年10月12日—11月25日,使用单颗粒气溶胶飞行时间质谱仪(SPAMS)在位于长沙市的湖南省生态环境厅点位进行了为期45 d的定点监测。结果表明,监测期间长沙市总体空气质量小时级别优、良天气占比为80.3%。长沙市首要污染物为PM_(2.5),其主要来源为机动车尾气源,二次无机源次之,工业工艺源排在第三位,占比分别为27.4%,21.5%和17.4%。整体来看,监测期间PM_(2.5)质量浓度的升高大多伴随着以上3种污染源颗粒物的同步升高。机动车尾气源具有明显的早高峰,工业工艺源、生物质燃烧源和餐饮源夜间占比增加。在偏东方向气团主导下,工业工艺源和燃煤源贡献最大;在东北方向气团主导下,PM_(2.5)质量浓度最高,且机动车尾气源占比最高。     

广州市机动车排放污染三维仿真模拟研究

基于三维的对流一扩散方程,采用50 m× 50 m× 20 m的高分辨率网格对广州市机动车排放污染扩散的宏观分布状况进行了数值模拟研究,应用有限体积法数值求解上述方程.模拟过程综合考虑了广州市的路网结构、交通流和路网线源排放强度等因素,进行了均匀风速的简单气象条件试算.结果表明,机动车排放污染物浓度随交通流量而变化,随高度增加而下降,上风向污染物浓度大于下风向,模拟结果与实际污染情况具有较好的一致性.     

双排气管车辆排气取样检测研究

双排气管汽油车进行尾气检测时，环保监管部门的监管要求与环保尾气检测机构的实际操作常存在分歧。对于双排气管汽油车究竟插入几个取样探头测试，才能准确、科学地检测出尾气中的含量浓度，从而对尾气检测结果做出公正准确的判断，从检测标准要求、比对实验方法验证、排气管构造图解析3个方面对该问题进行了讨论。     

佛山市交通CO2排放及低碳出行对策

以佛山市2012年数据为基础,结合COPERT模型,分析了车型种类、排气量、燃油类型、排放水平等对CO2排放因子的影响规律,探讨了不同车型组成与排放水平下的CO2排放分担率,讨论并评估了佛山市的低碳交通出行对策。结果表明:排放水平对CO2排放因子的影响不明显,除重型客车与公交车,燃油类型对CO2排放因子的影响亦不明显,各车型的CO2排放因子随着排气量的增加而增加;当佛山市机动车平均行驶速度提高至55 km/h时,每辆车CO2综合排放因子可达最小值125.73 g/km;轻型客车和摩托车的CO2排放量最大,分别为1469 493 t/a和394 174.3 t/a,分担率分别为52.1%和14.0%;不同排放水平的载客车CO2排放分担率从大到小排序依次为:国I国0国Ⅱ国Ⅲ国Ⅳ,分别为34.7%、22.0%、21.2%、17.5%及4.6%。