《大气污染防治行动计划》对郑州市冬季PM2.5浓度及化学组成影响

基于《大气污染防治行动计划》实施前后,在污染严重的冬季（2013年和2018年12月同期）,采集郑州市监测站的PM_2.5样品,分析PM_2.5化学组成,通过对比分析PM_2.5中的EC、OC、水溶性离子和金属元素的浓度变化来评估PM_2.5浓度及化学组成的变化,同时选取不同阶段重污染过程,探究PM_2.5浓度及组成的变化. 结果表明：①郑州市冬季ρ（PM_2.5）平均值由2013年的（215.38 ±107.28） μg·m^-3 下降至2018年的（77.45 ±49.81） μg·m^-3,下降率高达64%. ②PM_2.5中EC、K⁺、SO₄^2-和Cl^-,分别下降了85%、80%、78%和72%;OC、NH₄⁺和NO₃^-下降幅度较小,分别为50%、41%和32%. ③与2013年冬季相比,2018年冬季OC/EC的值升高了2.6倍,二次有机碳在OC中占比升高至57%;同时,硫氧化率和氮氧化率的值分别升高了1.5倍和1.0倍,表明郑州市二次污染较为严重,二次转化程度升高. ④NO₃^-/SO₄^2-（质量比）由2013年的0.8 ±0.2升高至2018年2.5 ±1.0,表明郑州市移动源贡献上升并且超过固定源成为冬季大气污染的主要来源. ⑤不同阶段重污染过程对比结果显示,与2013年相比,2018年重污染过程中PM_2.5浓度下降显著,峰值浓度下降了61%,主要化学组成由OC、NO₃^-、SO₄^2-和NH₄⁺变为OC、NO₃^-和NH₄⁺. 研究结果表明郑州市一次排放源管控取得了显著的成效,但二次生成对PM_2.5贡献呈现升高趋势,因此未来需要关注二次生成的影响.     

四川及重庆蕨类植物区系组成、特有现象和珍稀种类

四川及重庆为我国蕨类植物最丰富的区域之一,总计有52科,141属,约880种。鳞毛蕨科、蹄盖蕨科和水龙骨科是最重要的3个科,其种数占本区种数的50.5%,金星蕨科、中国蕨科和铁角蕨科在本区也有较多的种类分布。在本区主要的属为耳蕨属、鳞毛蕨属和蹄盖蕨属,它们的种数都超过50种,合计占本区种数的22.8%,其次有铁角蕨属、瓦韦属和毛蕨属,其种数都逾25种,而有近85%的属不足10种。热带成分的属在本区占53.9%,但它们的区系存在度不大;东亚分布的属占16.3%,其区系存在度相对较大;温带分布的属占12.7%。本区无特有科;仅光叶蕨属1个特有属,还有6个中国特有属;有387种为中国特有种,约占本区种数的44%。特有种的32%为本区特有,其余以与中国西南片区（占22.5%）和整个南方片区（占26.1%）共有为主。本区被列入国家重点保护的珍稀濒危蕨类植物有10种,其中1级3种,2级7种。     

砷尾矿污染土壤的细菌群落结构多样性及其相关环境影响因子分析

以湖南石门雄黄尾矿污染土壤为对象,研究纵向不同深度、横向不同距离土样中的重金属污染程度以及细菌群落结构变化规律,查明砷污染土壤的核心微生物组成并将其与土壤理化指标进行共存网络图分析.结果表明:该尾矿区的土壤各项重金属指标严重超标,尤以铅(626.54 mg·kg?1,Ei=105.48)、砷(1804.75 mg·kg...     

A Scottish approach to training for the unemployed: work‐start Ltd., Dundee

This article discusses the structure and performance of Work‐Start Ltd., a company located in Dundee and providing training for the unemployed. The company has attracted national and international attention by its innovative approach. Set up to meet the specific problems of peripheral housing estates, it is now responding to rapid changes in the local labour market.     

社会发展综合实验区生态建设及科技引导途径

本文提出了社会发展综合实验区建设的实质就是协调好人口、资源与环境间的生态关系，为了促进社会—经济—自然复合生态系统的持续发展，探讨了科技引导实验区生态建设的途径。     

Environmental care in agricultural catchments: Toward the communicative catchment

Substantial land degradation of agricultural catchments in Australia has resulted from the importation of European farming methods and the large-scale clearing of land. Rural communities are now being encouraged by government to take responsibility for environmental care. The importance of community involvement is supported by the view that environmental problems are a function of interactions between people and their environment. It is suggested that the commonly held view that community groups cannot care for their resources is due to inappropriate social institutions rather that any inherent disability in people. The communicative catchment is developed as a vision for environmental care into the future. This concept emerges from a critique of resource management through the catchment metaphors of the reduced, mechanical, and the complex, evolving catchment, which reflect the development of systemic and people-centered approaches to environmental care. The communicative catchment is one where both community and resource managers participate collaboratively in environmental care. A methodology based on action research and systemic thinking (systemic action research) is proposed as a way of moving towards the communicative catchment of the future. Action research is a way of taking action in organizations and communities that is participative and informed by theory, while systemic thinking takes into account the interconnections and relationships between social and natural worlds. The proposed vision, methodology, and practical operating principles stem from involvement in an action research project looking at extension strategies for the implementation of total catchment management in the Hunter Valley, New South Wales.     

四川盆地海相三叠系硫同位素组成及其地质意义

系统整理研究了四川盆地海相三叠系硬石膏和卤水的硫同位素组成、演化特点及其地质意义。这对促进四川和全球海相三叠系硫酸盐硫同位素的研究有重要参考价值。     

Diagenesis of Upper Carboniferous rocks in the Ouachita foreland shelf in mid-continent USA: an overview of widespread effects of a Variscan-equivalent orogeny

Diagenesis of Upper Carboniferous foreland shelf rocks in southeastern Kansas took place at temperatures as high as 100–150° C at a depth of less than 2 km. High temperatures are the result of the long distance (hundreds of kilometers) advection of groundwater related to collisional orogeny in the Ouachita tectonic belt to the south. Orogenic activity in the Ouachita area was broadly Late Carboniferous, equivalent to the Variscan activity of Europe. Mississippi Valley-type Pb-Zn deposits and oil and gas fields in the US midcontinent and elsewhere are commonly attributed to regional groundwater flow resulting from such collisional events. This paper describes the diagenesis and thermal effects in sandstone and limestone of Upper Carboniferous siliciclastic and limestone-shale cyclothems, the purported confining layer of a supposed regional aquifer. Diagenesis took place in early, intermediate, and late stages. Many intermediate and late stage events in the sandstones have equivalents in the limestones, suggesting that the causes were regional. The sandstone paragenesis includes siderite cement (early stage), quartz overgrowths (intermediate stage), dissolution of feldspar and carbonates, followed by minor Fe calcite, pore-filling kaolinite and sub-poikilotopic Ca ankerite (late stage). The limestone paragenesis includes calcite cement (early stage); megaquartz, chalcedony, and Fe calcite spar (intermediate stage); and dissolution, Ca-Fe dolomite and kaolinite (late stage). The R _m value of vitrinite shows a regional average of 0.6–0.7%; Rock-Eval T _maX suggests a comparable degree of organic maturity. The T _h of aqueous fluid inclusions in late stage Ca-Fe-Mg carbonates ranges from 90 to 160° and T _mice indicates very saline water (>200000 ppm NaCl equivalent); ¹⁸O suggests that the water is of basinal origin. Local warm spots have higher R _m, T _max, and T _h. The results constrain numerical models of regional fluid migration, which is widely viewed as an artesian flow from recharge areas in the Ouachita belt across the foreland basin onto the foreland shelf area. Such models must account for heating effects that extend at least 500 km from the orogenic front and affect both supposed aquifer beds and the overlying supposed confining layer. Warm spots indicate either more rapid or more prolonged flow locally. T _h and T _mice data show the highest temperatures coincided with high salinity fluids.     

上海江湾机场植物群落多样性研究

以市区内江湾机场失去管理后出现的自然植被为研究对象，通过群落学调查研究，分析了群落的种类组成以及结构特征，阐明了群落的恢复过程和潜力。结果表明，江湾机场的植被可划分为4个外貌类型，16个群落类型。自然植被表现为以草本群落为主、辅以少量木本植物群落为特征的分布格局。非地带性因素主导着植被发生和演替，很难达到上海以亚热带常绿阔叶林为主的地带性植被类型。     

威远震旦系天然气与油气生运聚

根据威远震旦系气藏天然气组成、同位素特征、储层包裹体的对比研究 ,我们认为该气藏的天然气主要来源于下寒武统筇竹寺组泥岩 ,其天然气主要是干酪根裂解气 ,次为油的裂解气。威远震旦系气藏是喜山期形成的 ,威远的天然气无论是干酪根裂解气还是油裂解气都由北面古构造聚集的干酪根裂解气和油裂解气转移而来 ,威远构造之所以能形成工业聚集的重要原因就是威远构造的形成与北面古构造的消失的良好匹配关系