喜鹊筑巢行为对我国电气化铁路运输安全影响的调查研究——以朔黄铁路为例

喜鹊的筑巢与繁殖给铁路运输安全带来了巨大隐患.以朔黄铁路为例,介绍了目前喜鹊筑巢行为的治理方法,并进行了优劣对比,提出了"引导与驱鸟结合"的双重治理措施,以及研发适合电气化铁路的新型数码超声波驱鸟器的方案.     

高速公路隧道入口区段交通流模拟与安全性研究

隧道内外照明差异使交通流状态产生了相应的变化.为模拟高速公路隧道入口交通流运行与安全状态,根据驾驶速度与能见度关系,提出了元胞传输模型的改进原理与方法.通过与实际道路交通流数据的比较,验证了模型的有效性.运用该模型模拟并比较不同条件下交通运行状态.结果表明,改进的元胞传输模型能够揭示隧道入口流量与车速状态.受到隧道能见度的影响,在隧道入口段车速将有明显的降低.随着隧道内能见度的降低,这种影响更为明显.高流量情况下,隧道入口的扰动可能影响后续车辆速度与流量;低流量情况下则影响不大.车速扰动对于道路全段的安全性影响较大,在交通激波的传递过程中,更容易出现交通事故.低密度情况下,隧道内能见度越低,安全性越差.     

成都市新都区城市主干道挥发性有机物分布特征研究

选择新都区的部分城市主干道两侧大气中VOCs(挥发性有机物)含量进行检测,了解新都区城区空气质量,分析车流量、降水、温度等条件对不同道路类型(相对宽阔型、高层峡谷型、交叉口道路)两侧空气中VOCs浓度的影响.车流量是影响VOCs浓度偏高的主要原因,一天不同时段的浓度变化呈双峰型,高浓度出现在早晨和傍晚.大气降水会使VOCs浓度降低,温度对其影响不大,温度的骤降通常伴随降水,使VOCs浓度下降,不同道路类型其下降的幅度存在差异,相对开阔型下降幅度最大.夏季,不同道路类型两侧空气中VOCs浓度的趋势相似,浓度差异大;在冬季三种道路类型两侧空气中VOCs浓度的趋势相同,浓度差异小.     

低速城市道路交通噪声预测中噪声源强计算模式的适用性分析研究

为研究各种源强计算模式对低速城市道路噪声预测的适用性,本文选取了安徽省合肥市运营稳定的1条低速城市道路进行实测.将实测的噪声结果与分别采用3种平均车速计算公式(包括设计车速、JTJ 005-96规范车速、JTG B03-2006规范车速)、3种源强计算模式(包括JTJ 005-96规范源强模式、JTG B03-2006规范源强模式、卓春晖报道的源强模式)预测出的结果进行对比.结果表明,采用道路设计车速、卓春晖报道的源强模式预测的结果与实测值最为相符.     

Vehicle-Induced Lead and Cadmium Contamination of Roadside Soil and Plants in Italy

Lead and cadmium concentrations in spontaneous vegetation and in soil sampled at various distances (0–208 m) from several motorways throughout Italy were measured. Lead and cadmium concentrations appear to be correlated to distance from the motorway and to traffic levels. A comparison with data from a remote and unpolluted site shows that foliar lead concentrations can be up to 40 times higher, and foliar cadmium concentrations up to 3 times higher. Plants behave differently in their accumulation of lead and cadmium; conifers present the highest levels. Also the various receptors and compartments of the roadside ecosystem differ in their accumulation of lead and cadmium; soil and bark have consistently higher concentrations, while the leaves and twigs of trees have consistently lower levels. the data recorded by ad hoc introduced bio-accumulating plants (Lolium multiflorum L.) are consistent with those of the spontaneous vegetation. the concentrations of both lead and cadmium in Lolium vary from June to November, following in part the fluctuation in traffic density.     

Use of contract models to improve environmental outcomes in transport infrastructure construction

The type of contract model may have a significant influence on achieving project objectives, including environmental and climate change goals. This research investigates non-standard contract models impacting greenhouse gas emissions (GHG) in transport infrastructure construction in Australia. The research is based on the analysis of two case studies: an Early Contractor Involvement (ECI) contract and a Design and Construct (D&C) contract with GHG reduction requirements embedded in the contractor selection. Main findings support the use of ECIs for better integrating decisions made during the planning phase with the construction activities, and improve environmental outcomes while achieving financial and time savings.     

新驾驶员反应特性分析

新驾驶员是交通事故的频发人群,并与其驾驶反应特性有关。笔者对96名(男75名,女21名)新驾驶员(驾龄≤3年)的反应时进行测试,与一定样本量(83名)的对照组相应指标作比较,其结果表明:对于简单反应时间,由于信息复杂度低,受试组和对照组未能表现出显著差异;当加大信息复杂度时(3光复合刺激),两组间反应时差异较为显著(p<0.01),即新驾驶员的反应能力较对照组差;应当有针对性地对新驾驶员进行反应时训练以增加其驾车安全性。     

A Simple Model for Urban Background Pollution

A simple urban background pollution model is presented. Contributions from the individual area sources, subdivided into a grid net of a resolution of 2km × 2km, are integrated along the wind direction path assuming linear dispersion with the distance to the receptor point. Horizontal dispersion is accounted for by averaging the calculated concentrations over a certain, wind speed dependent wind direction sector, centred on the average wind direction. Formation of the nitrogen dioxide due to oxidation of nitrogen monoxide by ozone is calculated using a simple chemical model based on assumption of a photochemical equilibrium on the time scale of the pollution transport across the city area. The rate of entrainment of fresh rural ozone is governed by this time scale. The model is suitable for calculations of urban background when the dominating source is the road traffic. For this source the emissions take place at ground level, and a good approximation is to treat the emissions as area sources, but with an initial vertical dispersion determined by the height of the buildings.     

铁岭市线源车流量调查及污染物排放量的估算

通过对辽宁省铁岭市主要交通干线车流量的调查，估算出不同干线污染物的排放量，借以掌握线源污染物排放量，为环境管理提供依据。