2013年1月8~14日,北京出现了严重的霾污染.霾污染时高浓度的大气颗粒物增加了暴露人群的健康风险,而大气中的微生物也可能带来一些风险,但目前对霾污染时大气中微生物组成了解较少.本研究选取了2013年1月8~14日北京7d的PM2.5和PM10采样样本,通过对细菌16S rRNA基因V3区扩增和Mi Seq测序,得到PM2.5和PM10中的细菌群落结构特征,并将结果与相同采样样本的宏基因组测序结果及三项国外基于16S rRNA基因测序方法的大气中细菌研究结果进行了比较.研究发现7 d连续采样条件下,PM2.5中细菌群落结构在门和属的水平上均差别不大.在属级别上,节杆菌属(Arthrobacter)和弗兰克氏菌属(Frankia)是北京冬季大气中细菌群落的主要类群.16S rRNA基因测序与宏基因组测序结果对比分析发现,在属级别上,两种分析方法中有39个相同的属类群(两种分析方法丰度前50的细菌类群合并所得),弗兰克氏菌属(Frankia)和副球菌属(Paracoccus)在16S rRNA基因测序分析结果中相对含量较多,而考克氏菌属(Kocuria)和地嗜皮菌属(Geodermatophilus)在宏基因组测序结果中相对含量较高.在门和属的水平上,PM2.5和PM10中细菌群落结构特征呈现出相似的规律.在门水平上,放线菌门(Actinobacteria)在PM2.5中的相对百分比较大,而厚壁菌门(Firmicutes)在PM10中的相对百分比较大.在属水平上,梭菌属(Clostridium)在PM10中的相对百分比较大.与三项国外基于16S rRNA基因测序研究结果对比发现,尽管在采样地点和采样时间上有较大差异,大气中普遍存在一些相同的细菌类群,且近地面大气细菌群落结构特征相似度较高,区别于高空对流层中细菌群落结构特征.

关键词：北京；霾污染；PM2.5；16S rRNA基因；细菌群落

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采用磷脂脂肪酸方法和Biolog-ECO微平板检测法,以吉林省长春市双阳区农业技术推广站实验区的土壤为对象,研究了水稻种植对黑土微生物生态结构和功能的影响.结果表明空地中有机质含量最高,其次为田间土,根际土中有机质含量最低;在夏季的样品中有机质含量最高,土壤中全氮的变化趋势与土壤有机质比较相似.土壤微生物群落功能多样性指数则表现为夏季显著高于秋季和春季,春、秋两季差异不明显,冬季最低,空地中微生物群落的Shannon-Wiener指数和Pielou均匀度指数高于田间和根际.全部样品微生物生长步入稳定期时间和碳源的颜色平均变化率变化范围不同,时间分别为216、192、216、120 h,范围分别为0.52~0.84、0.82~1.28、0.40~0.84、0.05~0.48,表明春秋季微生物步入稳定期和对碳源的代谢量比较相似,夏季最大,冬季最小.研究结果为科学评价典型水稻种植黑土区土壤生境质量退化与恢复过程中微生物特征的变化提供参考.

关键词：黑土；磷脂脂肪酸；平均颜色变化率；Biolog方法；微生物群落

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为揭示硫丹在紫色土中的残留过程、保护土壤生态环境,采用静态吸附和解吸实验,研究了紫色土对硫丹的吸附与解吸特征,考察了温度、吸附剂用量和吸附液初始p H等因素对吸附量的影响.结果表明紫色土对硫丹的吸附动力学过程可以用二级动力学方程很好地描述,获得α-,β-硫丹的初始吸附速率常数分别为0.157 mg·(g·min)-1和0.115 mg·(g·min)-1;吸附热力学过程可以用Langmuir等温吸附模型很好地描述,获得α-,β-硫丹的最大吸附量分别为0.257 mg·g-1和0.155mg·g-1,紫色土吸附硫丹是放热的物理化学过程,但以物理吸附为主.在本研究所设条件下,吸附液初始p H对吸附量的影响较大,温度和吸附剂用量的影响相对较小.解吸实验发现,紫色土吸附的α-,β-硫丹分别在6和4 h时达到最大解吸量(0.029mg·g-1和0.017 mg·g-1),分别占最大吸附量的10.5%和16.1%.

关键词：紫色土；硫丹；持久性有机污染物；吸附；解吸

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于2013年1月8日~2013年2月4日雾霾频繁暴发期间,使用定量空气微生物采样器和气溶胶粒谱测试仪测试并比较了雾霾天和之后的清朗天气下细菌、真菌气溶胶浓度变化、粒谱分布及不同粒径大小颗粒物的数量浓度差异和粒谱分布特征.结果表明,采样周期内真菌气溶胶小于5μm的粒子(可吸入肺粒子)所占百分比显著高于细菌气溶胶小于5μm的粒子百分比.雾霾过后的晴朗天气下细菌、真菌气溶胶浓度高于雾霾天气时的浓度,而颗粒物浓度则相反.无论雾霾天或晴朗天微生物气溶胶的粒谱分布无显著差别,空气中的颗粒物以PM1.0占绝大多数.

关键词：雾霾；细菌气溶胶；真菌气溶胶；粒径分布；颗粒物

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为了减少多环芳烃(polycyclic aromatic hydrocarbons,PAHs)在作物体内的富集,降低食源性PAHs对人类的潜在风险,提高PAHs污染土壤的农用安全性,在受到PAHs污染的麦田中施用类球红细菌(Rhodobacter sphaeroide)菌剂(RS)进行原位修复.以叶面喷施(B)和根部喷施(D)50倍稀释的RS两种方式处理,以喷施等量清水的处理为对照(A),不做任何处理的麦田为空白(CK),从小麦苗期开始处理,到小麦成熟期测定了土壤和小麦籽粒中PAHs含量以及根际土壤微生物群落结构的变化,探讨了施用RS对PAHs污染土壤的强化修复作用.结果表明,施加RS的B区、D区与空白(CK)区相比,标识土壤微生物的磷脂脂肪酸(PLFAs)种类均有29.6%变异率;土壤PAHs的去除率分别提高了1.59倍和1.68倍;富集因子分别降低了58.9%和62.2%;50穗小麦籽粒的干重分别提高了8.95%和12.5%.RS的施用改变了土壤微生物群落结构,活化了土壤微生物的代谢活性,从而加快了土壤PAHs的降解;同时,RS的施用也降低了PAHs在小麦籽粒的富集量,提高了小麦的产量,显示出RS在提高PAHs污染土壤的农用安全性方面具有应用潜力.

关键词：类球红细菌；微生物菌剂；多环芳烃；污染土壤；原位生物修复

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Water purification is the process to remove unwanted chemicals, biological contaminants, suspended solids, and gases from contaminated water. Purification decreases the concentration of particulate matter, reduces the chance of waterborne diseases, and makes contaminated water fit for drinking. The major segments by product type in the home water purifier market in India are RO water purifier, UV water purifier, and gravity water purifier.

关键词：水净化过程；去除；化学品；生物；污染物；悬浮物；降低水性；疾病；RO 净水器；紫外线净水器；重力净水器

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Water treatment chemicals are used to eliminate impurities or suspended substances from contaminated water and make it fit for industrial or domestic uses. These chemicals can be used to purify sea water, ground water, municipal drinking water, as well as industrial waste water. The choice of chemical primarily depends on the cost and the end outcome sought. The scope of usage of these chemicals is continuously expanding on account of increased demand from various end-use industries such as power plants, food and beverages, metal and mining, pulp and paper, oil and gas, and chemical processing. The widely used chemicals in these contexts are biocides, antifoams, coagulants, flocculants, disinfectants, oxidants, scale inhibitors, and pH conditioners.

关键词：水处理化学品；消除杂质；工业；住宅用途；杀生物剂；消泡剂；凝结剂；絮凝剂；消毒剂；氧化剂

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Personal protective equipment is the products and accessories used for employee safety purposes during on-site and off-site work. RPE is the type of personal protective equipment used in various commercial and industrial sectors to protect employees from being adversely affected by the various contaminants, aerosolized chemicals, and harmful gases in the breathing air in their workplaces.

关键词：呼吸防护；防护装置；安全卫生

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Among the vehicles that run on alternative energy sources, FFVs account for the highest volume and are the most practical in terms of vehicle performance, reliability, and stability. FFVs are designed to run on a blend of gasoline and ethanol (E85). Henry Ford introduced the concept of flexible fuel engines in 1920. However, this idea could be transformed into a practical and feasible technology only by 1990s.

关键词：替代；能源运行车辆；灵活燃料汽车；最实用；车辆性能；稳定性；灵活燃料汽车

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Water quality monitoring is critically important in efforts to both limit human exposure to toxic chemicals and to protect ecosystems. This study integrates artificial neural network (ANN) processing with MFC-based biosensing in the detection of three organic pollutants that have relevance to DoD operations: aldicarb, dimethyl-methylphosphonate (DMMP), and bisphenol-A (BPA). Overall, the use of the ANN proved to be more reliable than direct correlations with raw data in the prediction of both chemical concentration and type. The ANN made no errors in the identification and quantification of all chemicals in three concentration ranges. Additionally, chemical mixtures and chemicals dissolved in the standard feed medium were accurately identified by the ANN. Finally, the newly-tested metrics of 10-hour Subsidence Rate (10SR) and First Moment (FrM) proved to be useful in ANN development. This study is the first to incorporate ANN modeling with MFC-based biosensing for the detection and quantification of organic pollutants that are not readily biodegradable. It is also the first to evaluate the utility of 10-hr SR and FM as metrics. Furthermore, this work provides insight into MFC-based biosensing as it pertains to limits of detection and its applicability to scenarios where mixtures of pollutants and unique solvents are involved.

关键词：燃料电池；化学反应；环境检测

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