Emission factors and particulate matter size distribution of polycyclic aromatic hydrocarbons from residential coal combustions in rural Northern China

Coal consumption is one important contributor to energy production, and is regarded as one of the most important sources of air pollutants that have considerable impacts on human health and climate change. Emissions of polycyclic aromatic hydrocarbons (PAHs) from coal combustion were studied in a typical stove. Emission factors (EFs) of 16 EPA priority PAHs from tested coals ranged from 6.25 ± 1.16 mg kg^?1 (anthracite) to 253 ± 170 mg kg^?1 (bituminous), with NAP and PHE dominated in gaseous and particulate phases, respectively. Size distributions of particulate phase PAHs from tested coals showed that they were mostly associated with particulate matter (PM) with size either between 0.7 and 2.1 μm or less than 0.4 μm (PM_0.4). In the latter category, not only were more PAHs present in PM_0.4, but also contained higher fractions of high molecular weight PAHs. Generally, there were more than 89% of total particulate phase PAHs associated with PM_2.5. Gas-particle partitioning of freshly emitted PAHs from residential coal combustions were thought to be mainly controlled by absorption rather than adsorption, which is similar to those from other sources. Besides, the influence of fuel properties and combustion conditions was further investigated by using stepwise regression analysis, which indicated that almost 57 ± 10% of total variations in PAH EFs can be accounted for by moisture and volatile matter content of coal in residential combustion.     

火灾演化、整体火安全和火灾蔓延

本在介绍了自然火灾演化过程及关荷载如何确定后,对建筑整体火安全概念进行了讨论,包括火灾时居民和消防人员的安全性、自然抗火时间、结构火安全设计和财产损失。对结构破坏后的火蔓延计算及标准热荷载的应用也进行了讨论和介绍。     

综采工作面粉尘运移和粉尘浓度三维分布的数值模拟研究

分析了综采工作面流场及粉尘分布的特点 ,视工作面含尘风流为气 粒两相流 ,建立了描述综采工作面风流中粉尘运动和浓度分布的数学模型。采用计算流体力学的有限容积法求解 ,编制了模拟计算综采工作面三维空间内风速和粉尘浓度分布的计算机程序     

三级生物接触氧化除油生化池的生物膜特性

将生物接触氧化技术用于油田稠油污水的处理,在三级串联运行的生物接触氧化池中,生物膜特性主要由生物膜上原油成分决定。在沿水流方向上,生物膜上易降解原油组分含量降低,难降解组分含量上升,第一级生化池中的生物膜厚度和优势菌种数量明显超过第二级和第三级,藻类主要生长在一级生化池的后部和二、三级生化池中的生物膜上,原生动物出现在二级和三级生化池生物膜上,而后生动物只出现在三级生化池生物膜上。     

Preliminary Strategic Environmental Assessment of the Great Western Development Strategy: Safeguarding Ecological Security for a New Western China

The Great Western Development Strategy (GWDS) is a long term national campaign aimed at boosting development of the western area of China and narrowing the economic gap between the western and the eastern parts of China. The Strategic Environmental Assessment (SEA) procedure was employed to assess the environmental challenges brought about by the western development plans. These plans include five key developmental domains (KDDs): water resource exploitation and use, land utilization, energy generation, tourism development, and ecological restoration and conservation. A combination of methods involving matrix assessment, incorporation of expert judgment and trend analysis was employed to analyze and predict the environmental impacts upon eight selected environmental indicators: water resource availability, soil erosion, soil salinization, forest destruction, land desertification, biological diversity, water quality and air quality. Based on the overall results of the assessment, countermeasures for environmental challenges that emerged were raised as key recommendations to ensure ecological security during the implementation of the GWDS. This paper is intended to introduce a consensus-based process for evaluating the complex, long term pressures on the ecological security of large areas, such as western China, that focuses on the use of combined methods applied at the strategic level.     

Evaluation of best management practice products in preventing discharge of metals: a laboratory evaluation

Heavy metal accumulation in soil poses serious environmental and health risks, as metals are carried with eroded soils. In this study, 17 different soil erosion and sediment control products were investigated for their effectiveness in controlling transport of particulate heavy metals (Cu, Zn, Pb, Cd). Among the treatments investigated, wood mulch and tackifiers were found to be the most effective in reducing total suspended solids (TSS) and total heavy metal losses. They reduced TSS to an undetectable level during short-term simulation tests. Paper mulch was the only treatment that had no significant reduction in both total metal loss and TSS. Fiber rolls, silt fences, and gravel bags were effective in reducing sediment loss. Although the netting/blanket treatments were not effective in reducing total metal discharge, they significantly reduced sediment loss compared with the control.     

Winter Soil Respiration from Different Vegetation Patches in the Yellow River Delta, China

Vegetation type and density exhibited a considerable patchy distribution at very local scales in the Yellow River Delta, due to the spatial variation of soil salinity and water scarcity. We proposed that soil respiration is affected by the spatial variations in vegetation type and soil chemical properties and tested this hypothesis in three different vegetation patches (Phragmites australis, Suaeda heteroptera and bare soil) in winter (from November 2010 to April 2011). At diurnal scale, soil respiration all displayed single-peak curves and asymmetric patterns in the three vegetation patches; At seasonal scale, soil respiration all declined steadily until February, and then increased to a peak in next April. But, the magnitude of soil respiration showed significant differences among the three sites. Mean soil respiration rates in winter were 0.60, 0.45 and 0.17 μmol CO(2) m(-2) s(-1) for the Phragmites australis, Suaeda heteroptera and bare soil, respectively. The combined effect of soil temperature and soil moisture accounted for 58-68 % of the seasonal variation of winter soil respiration. The mean soil respiration revealed positive and linear correlations with total N, total N and SOC storages at 0-20 cm depth, and plant biomass among the three sites. We conclude that the patchy distribution of plant biomass and soil chemical properties (total C, total N and SOC) may affect decomposition rate of soil organic matter in winter, thereby leading to spatial variations in soil respiration.     

环境公害的本土化解读与法律应对——以四川藏区矿产资源开发公害为对象

以四川藏区矿产资源的开发利用为研究对象,一方面,从环境公害本土化的视角解读四川藏区的资源开发公害问题;另一方面,从法律的价值和应对的视角对资源开发公害问题进行法律规制,以期对四川藏区生态环境的保护有所裨益。     

企业环境管理会计核算框架与方法研究

企业环境管理会计从环境的角度,将企业的环境影响纳入到环境会计的核算范围之内,构建一些实物型或价值型的环境业绩指标,表达企业对环境造成的影响或损害。本文立足于国际环境会计应用案例,结合财务会计特征和我国目前的环境数据基础,研究提出了中国企业环境管理会计的基本内涵和方法框架,并就如何加强企业环境管理会计的应用进行了讨论。     

机载设备电压尖峰试验测试标准分析

RTCA/DO-160F、GJB151A/152A-97和GJB181-86都涉及了电压尖峰（或电源线尖峰信号传导敏感度）试验项目。在对设备电源部分性能的考核中,电压尖峰（或电源线尖峰信号传导敏感度）试验是重点验证项目。比较分析这三个标准对该项目在测试条件、测试对象和测试方法上的差异,对于机载设备的电压尖峰（或电源线尖峰信号传导敏感度）试验,由于这三个标准的使用范围和适用对象不同,其要求也不尽相同。RTCA/DO-160F根据设备使用场合的保护等级不同而将设备进行分类,要求较为灵活;GJB151A/152A-97则主要是针对机载设备的使用平台提出要求,是军用机载设备基础性的要求;而GJB181-86则主要适用于飞机供电系统与用电设备之间的协调,针对性强,要求较高。