Potential of secondary aerosol formation from Chinese gasoline engine exhaust

Light-duty gasoline vehicles have drawn public attention in China due to their significant primary emissions of particulate matter and volatile organic compounds(VOCs). However,little information on secondary aerosol formation from exhaust for Chinese vehicles and fuel conditions is available. In this study, chamber experiments were conducted to quantify the potential of secondary aerosol formation from the exhaust of a port fuel injection gasoline engine. The engine and fuel used are common in the Chinese market, and the fuel satisfies the China V gasoline fuel standard. Substantial secondary aerosol formation was observed during a 4–5 hr simulation, which was estimated to represent more than 10 days of equivalent atmospheric photo-oxidation in Beijing. As a consequence, the extreme case secondary organic aerosol(SOA) production was 426 ± 85 mg/kg-fuel, with high levels of precursors and OH exposure. The low hygroscopicity of the aerosols formed inside the chamber suggests that SOA was the dominant chemical composition. Fourteen percent of SOA measured in the chamber experiments could be explained through the oxidation of speciated single-ring aromatics. Unspeciated precursors, such as intermediate-volatility organic compounds and semi-volatile organic compounds, might be significant for SOA formation from gasoline VOCs. We concluded that reductions of emissions of aerosol precursor gases from vehicles are essential to mediate pollution in China.     

基于GIS空间插值方法的长湖水质评价

通过对各插值方法选择后取反距离加权法与克立格法对长湖的污染现状进行分析,结果表明大部分水域水质处于Ⅴ类和劣Ⅴ类,只有主要出水口习家口和刘岺闸附近的部分水域的水质可以达到Ⅳ类水质标准.同时发现反距离加权法与克立格法均具有较高的精度,但克立格法优于反距离加权法,这两种方法评价湖泊水质都能取得比较好的效果.     

基于面积统计的震后烈度评估

选取了较为典型的历史震例,并将这些震例的等震线图数字化.利用这些等震线图数据,直接统计出地震参数和震后不同烈度面积之间的关系,并将该关系和烈度衰减几何模型结合起来,反演震后烈度的具体分布形状,以进行震后烈度分布的预测.     

Experimental study on filtration and continuous regeneration of a particulate filter system for heavy-duty diesel engines

This study investigated the filtration and continuous regeneration of a particulate filter system on an engine test bench, consisting of a diesel oxidation catalyst（DOC） and a catalyzed diesel particulate filter（CDPF）. Both the DOC and the CDPF led to a high conversion of NO to NO2 for continuous regeneration. The filtration efficiency on solid particle number（SPN） was close to100%. The post-CDPF particles were mainly in accumulation mode. The downstream SPN was sensitively influenced by the variation of the soot loading. This phenomenon provides a method for determining the balance point temperature by measuring the trend of SPN concentration.     

基于模糊推理的FRAM事故定量分析方法研究

为有效克服FRAM事故分析中无法进行定量分析的缺陷,提出结合模糊推理技术的Fuzzy FRAM模型。此改进模型基于FRAM识别系统运行状态;依据功能输出要素的时间/精度属性利用Matlab构建2阶模糊推理系统量化功能输出质量;根据通用性能条件(CPC)及功能输入耦合端口构建功能评价体系,针对评价体系中存在的不确定性信息融合及建模问题,采用模糊证据推理技术,通过模糊信度结构建立、数据处理、信息融合测度后获得功能的风险指数;以既有铁路危险品运输事故为例,验证方法的可行性。结果表明:Fuzzy FRAM模型的评估结果较为精确,是FRAM分析方法的有效补充。     

Dechlorination and conversion mechanism of trichlorobenzene as a model compound of chlorine-containing wastes by different base-catalyzed combinations

Environmental Science and Pollution Research - Chlorine-containing organic waste (COWs) is a big threat for the waste incineration because of the dioxin generation and equipment corrosion....     

油漆挥发分爆炸特性及浓度检测装置设计研究

为了实现对喷涂车间内挥发分浓度的检测,进行20 L球形爆炸特性测试实验,分析了油漆挥发分主成分及爆炸特性,根据油漆挥发分受热易挥发遇冷易凝结的物理特性、采样器采样原理、滤膜增重法测量原理以及基于单机片C++软件程序编写的电路智能控制技术,设计1种喷涂车间挥发分浓度检测装置。研究结果表明:油漆挥发分主成分具有爆炸性,且随着油漆颗粒物浓度增大,爆炸压力也增加。设计的装置对挥发分的采集率都在90%以上,总采集率为93.1%~98.9%,装置能够较为准确地检测挥发分浓度。     

危险品集装箱堆场人因失误概率量化方法研究

由于人因失误是引发危险品集装箱堆场事故的主要原因,特别以成功似然指数法为框架研究了危险品集装箱堆场人因失误概率的量化方法。考虑了影响因子的主观特性,重点结合认知可靠性与失误分析方法对成功似然指数法进行修正,确定了培养与组织管理、同时出现的目标数量等6项行为形成因子。通过建立熵权法、模糊集合理论与专家判断的融合实现人因失误概率的计算。最后,用算例验证了方法的有效性,结果表明,本方法不但可将测算精度控制在有效区间(0,0.059 5),而且相较其他方法将危险系数降低了6.97%。针对危险品集装箱堆场管理这类高危行业,较高的人因失误率有利于风险辨识和风险预防。     

三峡库区移民贫困致因的精准识别与减贫路径的实证研究

随着我国经济发展和扶贫成效的显现,老区、山区、民族地区和移民库区等集中连片的特殊贫困区已经成为我国当前精准扶贫的主战场。由于面临生产资料匮乏、生态环境恶化和地质灾害频发等恶劣环境,库区移民贫困问题已成为新时期扶贫攻坚最难啃的"硬骨头"。因此,开展库区移民贫困致因的精准识别与减贫路径研究具有重要的现实意义。基于对库区移民贫困现状的扎根理论分析,本文提出了分析农户生计的新框架。在此基础上,本文以三峡库区26个县(区)为研究对象,随机抽取4县(区)796户移民作为样本,首先,采用灰色关联分析法和熵权法对库区移民主要致贫因子进行挖掘;接着,采用PLS-SEM模型分析影响库区移民生计状况的关键因子和关键路径。研究表明:(1)三峡库区移民贫困现象仍很严重,患病、劳动能力弱和失地是移民致贫的三大主因。三峡库区仍有175.94万人生活在贫困线以下,三大致贫原因依次是:因病致贫26.49%、因劳动能力弱致贫22.10%和失地致贫21.65%。(2)心理资本可有效促进移民其他资本效能的发挥,对生计状况存在着显著的直接效应和间接效应。(3)在影响生计状况的四类资本中,人力资本对库区移民生计状况影响最大。基于以上发现,本文提出了实现库区移民精准脱贫的政策建议:(1)国家应高度重视三峡库区移民贫困问题,大力开展精准扶贫;(2)增加心理干预措施以提高移民心理资本存量,帮助移民摆脱心理贫困;(3)开展劳动力技能培训,提高库区移民人力资本水平。     

Evaluation of phenanthrene toxicity on earthworm (Eisenia fetida): An ecotoxicoproteomics approach

The goal of this study was to identify promising new biomarkers of phenanthrene by identifying differentially expressed proteins in Eisenia fetida after exposure to phenanthrene. Extracts of earthworm epithelium collected at days 2, 7, 14, and 28 after phenanthrene exposure were analyzed by two dimensional electrophoresis (2-DE) and quantitative image analysis. Comparing the intensity of protein spots, 36 upregulated proteins and 45 downregulated proteins were found. Some of the downregulated and upregulated proteins were verified by MALDI-TOF/TOF-MS and database searching. Downregulated proteins in response to phenanthrene exposure were involved in glycolysis, energy metabolism, chaperones, proteolysis, protein folding and electron transport. In contrast, oxidation reduction, oxygen transport, defense systems response to pollutant, protein biosynthesis and fatty acid biosynthesis were upregulated in phenanthrene-treated E. fetida. In addition, ATP synthase b subunit, lysenin-related protein 2, lombricine kinase, glyceraldehyde 3-phosphate dehydrogenase, actinbinding protein, and extracellular globin-4 seem to be potential biomarkers since these biomarker were able to low levels (2.5 mg kg⁻¹) of phenanthrene. Our study provides a functional profile of the phenanthrene-responsive proteins in earthworms. The variable levels and trends in these spots could play a potential role as novel biomarkers for monitoring the levels of phenanthrene contamination in soil ecosystems.