上海宝山区酸雨特征分析

分析了连续七年(2004年-2010年)上海宝山区的降水的化学特征。从酸雨发生频率来看,2004年-2007年酸雨频率为:78.6%、75.9%、89.5%和94.6%,呈逐年加重的趋势,表明降水的酸性及酸化频率非常高,雨水酸化已非常严重。但从2008开始酸雨状况开始改善,酸雨频率开始降低,分别为:78.6%、41.1%和23.6%,同时其pH值开始高于全市平均水平;对降水中的各种阴阳离子进行数理统计分析:SO24-对降水的酸化起主要作用,但其作用在逐步减小,而NO3-和Cl-的作用呈上升的趋势;c(Cl-)/c(Na+)总体呈下降趋势,说明化工、有色金属冶金等工业生产废气中Cl2和HCl等污染物作用减少;因子分析反映了降水的来源成因机制,其结果与相关性分析一致。     

老工业区大气中挥发性有机物的分布和组成特征

以老工业区大气中有机污染物为研究对象,采用预浓缩-GC/MS方法分析了老工业区大气中挥发性有机物(VOCs)的分布和组成特征。结果表明,老工业区内工业行业的复杂性和规划的不合理性,导致有机物分布和组成的差异。混杂区和工业集中区VOCs的浓度大于居住区和对照区,并且有机物的浓度存在垂直分布规律。卤代烃是老工业区大气中含量最高的挥发性有机物,占TVOC的27%,其次是饱和烷烃和芳烃,分别占TVOC的21%和20%。     

雪玉洞表土有机氯农药的分布及来源研究

为研究有机氯农药(OCPs)在重庆丰都雪玉洞表土中的水平分布趋势、组成特征和来源,采用气相色谱-微池电子捕获检测器(GC-μECD)分析了10个代表性表层土样中18种OCPs.结果表明,研究区表层土壤中18种OCPs除o,p'-DDD、ε-HCH、艾氏剂和狄氏剂外均有不同程度的检出,其中,HCH、DDT、七氯和甲氧滴滴涕的检出率高达100%,是主要的污染物.土壤中总有机氯农药的含量范围为1.24~750.56 ng·g^-1,平均值为79.57 ng·g^-1.DDTs和HCHs可能分别来自于工业DDTs和林丹的非法使用,并且近期可能有新的输入.通过相关分析得出,研究区10个采样点有机氯农药基本具有相同的来源,并且土壤有机碳是影响有机氯农药分布的重要因素.对比中国的土壤质量标准(GB15618-95)发现,研究区土壤中HCHs和DDTs的残留均处于较低水平.由于岩溶地区地表土层厚度分布不连续,且地下岩溶形态较为发育,有机氯农药可能通过裂隙或落水洞进入地下河系统,对洞穴滴水和地下河水造成潜在的污染风险.     

食品垃圾好氧降解过程中挥发性有机物(VOCs)排放特征

采用实验室模拟方法,研究了混合食品垃圾(FW)及以橙子、生菜、土豆和西红柿为代表的4种植物性易降解有机垃圾组分好氧降解过程中排放出来的117种挥发性有机物(VOCs)的排放量和组成特征.结果表明,混合食品垃圾好氧降解过程中VOCs总排放量为951.80mg·kg-1,主要为有机硫、含氧化合物和萜烯,分别占VOCs总排放量的43.1%、53.3%和2.1%.橙子、生菜、土豆和西红柿4种植物性易降解有机垃圾好氧降解过程中VOCs的总排放量分别为12736.72、118.67、57.40和228.08mg·kg-1,主要成分均为含氧化合物和萜烯;含氧化合物分别占橙子、生菜、土豆和西红柿4种植物性易降解有机垃圾VOCs总排放量的13.5%、80.9%、85.9%和79.5%,萜烯分别占4种植物性易降解有机垃圾VOCs总排放量的86.5%、16.6%、8.2%和15.6%.     

多功能细菌复合系NSC-7的菌种组成多样性

NSC-7是一组具有降解纤维素和林丹双重功能的细菌复合系.为系统了解复合系的菌种组成,在有氧条件下,利用传统的平板画线法分离到11株单菌,将11株单菌按体积比1∶1重新组合并不具备分解纤维素的能力,利用单层和双层平板滤纸法检测NSC-7的分解能力,发现只有双层平板上的滤纸变黄且降解,说明复合系内纤维素降解的关键菌是厌氧或微好氧菌.利用现代分子生物学技术对NSC-7构建克隆文库,获得了195个16S rDNA片断,经DGGE筛选获得25个代表克隆,其序列数据库比对结果中有60％的近缘种为已知菌,分别归属于Clostridium、Petrobacter、Bacteria、Paenibacillus、Proteobacterium 5个属,其余40％的近缘种为难培养菌株.     

非质量氧同位素分馏效应研究进展

非质量氧同位素分馏效应(mass independent oxygenisotope fractionation)研究为一些重大地质科学问题的解释开辟了一条新途径。在简要介绍非质量分馏理论后,重点评述了非质量氧同位素分馏效应的研究进展,包括非质量同位素分馏效应的成因机制、氧同位素组成分析方法建立及其在环境地学领域的应用。并对非质量氧同位素分馏领域未来研究趋势作了进一步探讨。     

Multiple visions of Indonesia's mud volcano: understanding representations of disaster across discursive settings

The Lapindo mudflow is one of the most controversial disasters in Indonesian history. Despite its unique biophysical features, most consider the mudflow a social disaster as scientific conflicts about its main trigger have evolved into legal disputes over accountability and rights. This paper examines this ‘trigger debate’, the stakes of scientific contention and the broader social and natural dynamics that shape the terms of this debate. A Latourian impulse drives this analysis, which aims to improve both understandings of—and responses to—complex disasters. This paper also notes that the stakes of representation extend to constructions of its stakeholders, especially to victims. As socionatural disasters become an increasingly common feature of the contemporary world, from mud volcanoes to extreme weather events caused by global warming, it is more important than ever to understand the dynamics of representing disasters and stakeholders.     

Numerical simulation and experimental study on metallographic structure characteristics of melting trace caused by overcurrent fault of copper wire

The microscopic characteristics of melting trace caused by copper wire fault are an important basis for the physical evidence identification of electrical fires. Metallography is an important method in electrical fire research, and computer-aided quantitative analysis on metallographic structure is common in materials aspect. In this study, the metallographic structure and phase composition characteristics of melting trace caused by overcurrent fault were explored with the aid of a metallographic microscope and an X-ray diffractometer (XRD). The results show that the grains are mainly slender dendritic and columnar crystals when the current is 128 A, while they are coarse dendritic and cellular crystals when the current is greater than 192 A; the average grain diameter of melting trace of copper wire grows with the increase in current. The main phases of melting trace caused by overcurrent fault of copper wire are α-Cu base and Cu₂O, and the new phases Cu₄Si and Cu₂Mg are formed when the current is higher than 160 A. In addition, the solidification process of metallographic structure of copper wire under different currents was simulated by the Procast software. It is found that the simulation results are basically in agreement with the experimental data, which suggests that this model can effectively predict the microstructure characteristics of melting trace of copper wire under different currents. The research results can provide a sound basis for the physical evidence identification of electrical fire and improve the accuracy and scientificity of electrical fire investigation.     

青檀天然群落土壤成分及其对青檀生长的影响

对湖北省三潭风景区青檀（Pteroceltis tatarinowii）天然群落土壤主要元素进行测定,并通过因子相关分析,探讨了土壤成分与青檀生长指标之间的相关性,研究结果可为青檀野生资源的保护和合理利用提供科学依据。结果表明,土壤水溶性Ca2＋、Mg2＋平均质量分数为3.598和0.176 g·kg-1,速效钾、全氮、有效磷的平均质量分数分别是133.324 mg·kg-1、4.413 g·kg-1和3.569 mg·kg-1,有机质平均质量分数为3.295%。土壤水溶性Ca2＋与青檀生长指标之间无显著相关关系;土壤可溶性Mg2＋与乔木、灌木的丛生植株数量呈显著正相关,当Mg2＋浓度处于0.191~0.221 g·kg-1之间时,青檀的丛生植株数量大;全氮与青檀乔木平均高度、平均胸径呈极显著正相关,与单生植株数量呈显著负相关;有效磷与乔木平均高度和胸径呈显著正相关;速效钾与乔木丛生植株数量及乔木总数量呈显著正相关;有机质灌木冠幅呈显著正相关。按土壤成分可将青檀群落聚成3类,3个聚类组的土壤水溶性Mg2＋、全氮（TN）、速效钾（TK）、有效磷（TP）、有机质以及青檀乔木植株总数量存在着显著差异。