北京市交通扬尘PM2.5排放清单及空间分布特征

为建立一种自下而上的交通扬尘PM_2.5排放清单方法,对北京市不同区域、不同类型道路的路面积尘负荷进行了采样和实验室分析,对各类路网的道路车流量和车辆类型进行了调查和统计,建立了北京市道路交通扬尘PM_2.5排放清单,并对其空间分布进行了分析. 结果表明:北京市城区快速路、主干道、次干道、支路和胡同的交通扬尘PM_2.5排放因子分别为(0.05±0.03)(0.09±0.05)(0.11±0.05)(0.16±0.14)和(0.27±0.20)g/(km·辆),相应各类型道路的交通扬尘PM_2.5排放强度分别为(7.21±4.66)(5.27±3.03)(3.34±1.49)(2.84±2.49)和(0.54±0.40)kg/(km·d);郊区高速路、国道、省道、县道、乡道和城市道路的交通扬尘PM_2.5排放因子分别为(0.10±0.03)(0.50±0.33)(0.39±0.37)(0.41±0.41)和(0.65±0.31)(0.19±0.08)g/(km·辆),各类型道路交通扬尘的PM_2.5排放强度分别为(3.82±1.31)(10.00±6.58)(3.93±3.74)(1.64±1.63)(0.65±0.31)和(0.74±0.32)kg/(km·d). 北京市道路交通扬尘PM_2.5的年排放量为13 565 t,从空间分布上看,郊区交通扬尘PM_2.5年排放量、单位道路长度排放量以及排放因子均高于市区,而城区单位行政区面积的交通扬尘PM_2.5排放量高于远郊区县. 从交通扬尘PM_2.5排放的空间分布特征看,在继续加强城区交通扬尘控制的同时,应采取措施控制远郊区县公路的扬尘排放. 自下而上的交通扬尘PM_2.5排放清单提高了排放的时空分辨率,能够识别路网中高排放的区域和路段,为交通扬尘总量管理和减排目标考核提供了一种技术手段.      

淮安市区空气质量评价及趋势分析

根据淮安市区2007年实测空气质量日报资料,用空气污染指数法,对淮安市区空气质量进行评价;并用秩相关系数检验法作污染趋势分析。结果表明,2007年淮安市区的空气质量类别为Ⅱ级,空气质量状况为良好,监测点富华服装公司的空气质量最差,监测点淮阴区监测站的空气质量最好;一年中以8月份的空气质量最好,1月份的空气质量最差;污染物SO2及NO2浓度随时间变化趋势明显,而PM10的浓度随时间变化趋势不显著。     

上海市崇明岛公路两侧土壤重金属污染研究

采集了上海市崇明岛陈海、北沿公路两侧土壤和灰尘样品270余个,测定了样品的Pb、Cd、Cu、 Zn和Cr重金属含量。结果表明,陈海和北沿公路两侧土壤重金属Pb、Cd、Cu、 Zn和Cr的平均含量达到277、0279、258、918和776 mg/kg,土壤Cd污染较严重。采集的路面灰尘样品Pb、Cd、Cu、 Zn和Cr的平均含量达到512、049、489、209和970 mg/kg,超过土壤背景值2~4倍,是土壤重金属的主要二次污染源。公路防护林体系较差的北沿公路路侧土壤纵向剖面（垂直于公路走向）重金属含量随距路肩距离增加呈指数下降,土壤重金属重污染区在距路肩15 m范围内。防护林体系较完善的陈海公路距路肩15 m范围内土壤重金属污染较小,土壤重金属重污染区出现在距路肩20~50 m范围内。     

基于双层规划的危险品运输专用车道优化设计

为更有效地设置危险品运输专用车道,在降低运输风险的同时减少专用道对路权的占用,从路网整体出发,以总体出行成本最小、路网运输风险最小和专用道利用率最大为目标,构建双层规划模型;使用NSGA-2算法求解双层规划模型,结合算例网络进行分析,验证模型和算法的有效性。结果表明:模型可综合考虑路网风险和总体出行成本,得到有效的专用道布局方案;在危险品运输交通量较大和采用路径限制政策的情况下,专用道可取得更好的风险控制效果、更低的总体出行成本和更高的专用道利用率。     

Noise Impact and Improvement on Indoors Acoustic Comfort for the Building Adjacent to Heavy Traffic Road

A good acoustic environment is absolutely essential to maintaining a high level satisfaction and moral health among residents. Noise and other boresome sounds come from both in- door and outdoor sources. For the residential buildings adjacent to heavy traffic roads, outdoors traffic noise is the main source that affects indoor acoustic quality and health. Ventilation and outdoor noise prevention become a pair of contradictions for the residents in China nowadays for those buildings adjacent to heavy traffic roads. It is investigated that traffic noise emission is mainly con- stituted by the motors of trucks, buses and motorcycles as well as brake. In this paper, two methods of traffic noise reduction on the indoor sound environment and comfort are carried out to study and compare the residential buildings adjacent to heavy traffic roadway in a city. One is to install noise barriers on the two sides of the roadway, which consist of sound-proof glass and plas- tic materials. The effect of sound-insulation of this method is heavily dependent on the relative distance between the noise bar- rier and indoors. A reduction of sound with an average pressure level of 2–15dB is achieved on the places behind and under the noise barrier. However, for the equivalent of noise barrier height, the noise reduction effect is little. As for the places of higher than the noise barrier, the traffic noise will be even strengthened by 3–7dB. Noise increment can be seen at the points of distance farther than 15m and height more than noise barrier; the noise reduction effect is not satisfactory or even worsened. In addition, not every location is appropriate to install the noise barrier along the heavy traffic roads. The other method of noise reduction for the buildings adjacent to heavy traffic is to install the airproof and soundproof windows, which is the conversion from natural venti- lation to mechanical ventilation. A reduction of sound with an average pressure level of 5dB to 17dB can be achieved compared with common glass windows, if adopting sound proof glass win- dows. These two methods are helpful to isolate high frequency noise but not for low frequency noise. For those frequency noises, installing thick and cotton curtain and porous carpet can only decrease 2.4–4.5dB, which hardly contributes to indoor sound comfort, so further study is demanded to cut down traffic noise, especially to cut down the low frequency noise.     

Road effects on abundance and fitness of Galápagos lava lizards (Microlophus albemarlensis)

Vehicle collisions with wildlife have the potential to negatively impact species everywhere roads divide natural habitats; this is especially true in areas where roads are a recent addition to the landscape (e.g., in the last decade) and/or where expansion of a road network is underway. This study addresses the impact of traffic fatalities on lava lizards, Microlophus albemarlensis, on the island of Santa Cruz, Galápagos. The main road bisecting the island north to south was added to the island beginning in 1974 but not fully paved until 2000. We assessed impacts occurring due to traffic and vehicle speeds on the island. This study adds impacts to lizard populations to those conducted on birds on Santa Cruz, providing a means to create multi-species recommendations. To quantify impacts to lizard populations, we assessed lizards on randomly chosen transects perpendicular to the road. We used Poisson regression to analyze those data and found a 30% increase in lizard abundance per 100 m distance from the road across vegetation zones. We compared incidence of prior tail loss of road-killed lizards and live animals to comment on additional energetic costs of occupying near-road territories. Tail condition could not be assessed in some road-killed lizards; among those that we could assess, 29% showed evidence of prior tail loss. That rate declined to apparent baseline conditions of only 1% beyond 200 m from the road. By traveling the length of the 40-km road, we identified hot spots for fatalities of both lizards and birds to provide necessary information for developing management and remediation strategies. We offer guidance on Best Management Practices, such as testing overpasses, fencing and underpasses, which might reduce vehicle impacts to lizards from drivers on the current road. This information is essential because of a planned increase in the Santa Cruz road network in areas where lava lizards are most abundant.     

道路行车安全性虚拟评价方法研究

针对在道路建成之前很难对设计道路进行有效的安全性评价的问题,在介绍运行车速评价法、速度分布评价法、线形指数评价法和驾驶人工作负荷评价法等国外道路安全评价方法的基础上,提出包括运行车速与设计车速差、相邻路段运行车速差、速度降低因子、横向力系数变化因子以及路段间的加速度值等5个评价因子在内的道路安全评价模型,并确定了相应指标的评价标准.该方法的评价过程包括自行模式和互动模式.自行模式是在驾驶员模糊车速控制模型的基础上预测路段的运行车速,从而进行线形的安全评价;交互模式主要是在虚拟仿真的基础上对道路、隧道、桥梁的交通工程设施、照明等系统进行安全性评价.通过该评价方法可以在道路的设计阶段发现存在的行车安全性问题,通过修改设计或进行安全改善,提高道路的运营安全性.     

道路运输企业安全评价方法及实例分析

为了有效预防道路运输企业的生产安全事故,在建立道路运输企业安全评价指标体系基础上,利用层次分析法基本原理,详细说明了采用层次分析法评价的步骤,并采用指数标度以提高评价精度,在此基础上确定了各指标的权重,采用模糊综合评价方法进行评价.最后针对实际企业进行实证,结果表明,将模糊综合评价方法引入道路运输企业安全评价,克服了现行评价方法不够定量与评价面过广的不足.该评价方法可结合道路运输企业实际,在开展道路运输企业安全管理及绩效考核工作中得到广泛应用.     

石墨炉原子吸收分光光度法测定城市交通干道空气中的铅

用超细玻璃纤维滤膜收集城市交通干道空气中的铅,硝化后使用石墨 炉原子吸收分光光度法测定。本方法具有灵敏度高,精密度和准确度较好等优点。铅平均浓度在10.57-69.67ug/L时,其相对偏差在0.47%-5.7%,标准差在0.185-0.33%之间,CV在0.47%-3.03%之间,标准曲线的相关系数为0.998.     

公路隧道内车辆行驶工况的试验研究

在北京市谭峪沟隧道内汽车行驶工况调查的基础上,采用以二维直方统计为核心的随机工况统计方法,对公路隧道内车辆实际行驶状态作了比较全面的分析,为合理地确定我国公路汽车排放因素,进而确定隧道内空气污染控制方针提供科学依据.