Application of passive sampling on assessment of concentration distribution and health risk of volatile organic compounds at a high-tech science park

The objectives of this study are to investigate the volatile organic compound (VOC) distribution using passive samplers and to assess the resulting health risks in a high-tech science industrial park. With the advantages of passive sampling techniques, long-term and wide-area samples are collected. The results show TVOC concentrations in summer, fall, winter, and spring are 7.14?±?5.66 ppb, 18.17?±?5.81 ppb, 10.30?±?3.54 ppb, and 14.56?±?4.53 ppb, respectively; those on weekdays and weekends are 14.36?±?6.80 ppb and 9.87?±?4.86 ppb, respectively; and those in industrial and residential zones are 12.97?±?0.39 ppb and 11.13?±?0.68 ppb, respectively. Based on concentration variations, and benzene, toluene, ethylbenzene, and xylene ratios, we can resolve the source origins. Health risks are assessed based on the resulting concentrations. In the case of non-cancer chronic effects, long-term exposure to these concentrations does not support there is a risk of adverse health effects. However, potential cancer risks of exposure to these concentrations may occur, especially to carbon tetrachloride and benzene. By applying this study’s procedures, information on VOC concentration distribution, source identification, and health assessment can be obtained and they are applicable to similar studies.     

单洞双线铁路隧道火灾人员疏散安全性分析

为了分析单洞双线铁路隧道火灾人员疏散安全性，基于单洞双线铁路隧道结构特点，分析不同火灾场景下人员疏散模式，利用火灾动力学模拟软件FDS，建立隧道火灾模型，分别研究火源位于车头和列车中部车厢内时可用安全疏散时间。利用Pathfinder软件，模拟人员折返路线与不同疏散口间距下人员疏散过程，分析必需安全疏散时间及其影响因素。研究结果表明:隧道发生火灾时，人员可用安全疏散时间与火源位置有关，必需安全疏散时间受疏散总人数、疏散口选择、疏散口间距等因素影响很大。在设计隧道疏散系统时，可通过减小疏散口间距和设置明显的疏散设施指示标识，减少人员疏散所用时间。     

生物过滤在饮用水处理中的研究进展

生物过滤作为饮用水强化常规处理方法的一种,集生物降解、物理截留功能于一体,可以提高污染物质去除能力,改善出厂水质,受到学界的广泛关注.概述了生物过滤的工艺特性、滤料选型原则、去除效能及影响因素、生物膜特征,总结了相关数学模型.     

基于需求分析的应急资源结构框架研究

应急资源结构是指在应对公共突发事件中所利用的应急资源的内部联系和一定秩序,构建应急资源结构框架是进行应急资源体系建设的重要基础。本文以2008雪灾和"5.12"汶川大地震的应急管理为案例,分析了在两次自然灾害应急管理中的应急资源需求,对应急资源进行了归类。在此基础上,充分考虑国民经济与社会发展指标体系的现状,构建了层次递阶的应急资源结构框架:第一个层次为应急资源类别,包括应急救援资源、基础设施与服务、专业处置资源和支撑保障资源四大类别;第二个层次为应急资源子类,在每个资源类别下划分若干个应急资源子类;第三个层次为应急资源细目,在每个子类下设计若干应急资源细目。从而形成了以应急救援资源为核心、以基础设施与服务为基础、以专业处置资源为依托、兼顾支撑保障资源的应急资源结构框架。     

Greenhouse gas savings potential of sugar cane bio-energy systems

One of the major justifications for bio-energy systems is their low greenhouse gas (GHG) emissions compared to fossil-energy ones. Transforming a sugar mill into a bio-energy plant would contribute to climate change mitigation via the extraction of renewable electricity and ethanol. This study takes the case of the sugar industry in Thailand and identifies scenario options that offer GHG reduction benefits. Improving efficiency in electricity generation from sugar cane residues e.g. excess bagasse and cane trash is such a beneficial option. Furthermore, extracting ethanol in a so-called bio-refinery, where the co-product stillage is utilized for energy, tends to magnify the potential benefit. The largest savings potential achieved with extracting ethanol from surplus sugar versus current practice in the sugar industry in Thailand amounts to 14 million tonnes CO₂e a year. This cannot be realized in practice until the carbon debt from land conversion is repaid, which takes 4.5–7 years, assuming that the land converted is grassland.     

基于ecopath模型对滆湖生态系统结构与功能的定量分析

根据2010年对江苏滆湖渔业资源和生态环境调查数据,采用Ecopath with Ecosim软件构建了滆湖生态系统的物质平衡ecopath模型,以期为在滆湖进行生态修复提供支持和指导。ecopath分析结果表明：2010年滆湖生态系统包含7个营养级,各功能组的有效营养级范围为1~3691,其营养物质流动主要发生在前4个营养级,占总流量的998%。系统总生产量为1 974.82 t/km2〖DK〗·a,总流量为8 562.544 t/km2〖DK〗·a,联结指数、系统杂食系数、Finn’s循环指数以及Finn’s平均路径长度分别为0219、0189、799和2841;生产量/呼吸量、生产量/生物量分别为2189和3509;平均捕捞营养级为256。食物链以开始于藻类的牧食食物链和开始于碎屑的碎屑食物链为主,系统总能量转换效率为64%。与滆湖1986～1989年的ecopath模型相比较,滆湖生态系统的总流量减小,r 对策者在系统中所占比例增加,K 对策者在系统中所占比例减小,根据Odum对成熟生态系统的描述,滆湖目前正处于退化演变过程中     

土地财政影响住房价格的理论探讨与实证分析

在住房价格不断飙升的背景下,地方政府得益于土地财政收入的迅速增加,引发了土地财政是否推动房价上涨的探讨。基于乘数效应和简化的区域经济增长三部门模型,分析土地财政影响房价的机制;采用我国1999—2010年各省面板数据进行单位根检验、Hausman检验和协整检验,构建土地财政影响住房价格的长期均衡模型。理论与实证分析均发现,存在土地财政推高房价的循环效应,地方政府经济增长对土地财政的依赖程度与住房价格呈正相关关系。     

超长回采工作面微震特征的影响因素研究*

为探讨超长工作面微震特征影响因素,采用微震监测技术研究42108工作面微震事件的空间分布特征及冲刷构造、推进速度、矿压对煤岩体微震事件特征的影响机制。研究结果表明:微震事件集中发生于工作面辅运巷侧,微震事件的空间分布受临近采空区、上覆煤层煤柱影响较大;微震事件能量和空间分布特征与推进速度相关性较差,当推进速度超过5.5 m/d后,微震事件频次、总能量与推进速度呈正相关;过冲刷构造时工作面推进速度降低,微震能量、频次的稳定性较差,易造成大能量积聚,使工作面危险性增大;微震事件集中发生位置与矿压值较大区域相吻合。     

Uncertainty or trust? Political trust,perceived uncertainty and public acceptance of personal carbon trading policy

Environmental Geochemistry and Health - Achieving carbon neutrality has become a global consensus, and plenty of measures and policies have been proposed in various industries to obtain this...     

Steel slag quality control for road construction aggregates and its environmental impact: case study of Vietnamese steel industry—leaching of heavy metals from steel-making slag

Environmental Science and Pollution Research - Steel slag is an industrial by product of steel manufacturing processes and has been widely utilized within civil and construction materials for road...