Insights into reactive oxygen species formation induced by water-soluble organic compounds and transition metals using spectroscopic method

Ambient particulate matter (PM) can cause adverse health effects via their ability to produce Reactive Oxygen Species (ROS). Water-Soluble Organic Compounds (WSOCs), a complex mixture of organic compounds which usually coexist with Transition Metals (TMs) in PM, have been found to contribute to ROS formation. However, the interaction between WSOCs and TMs and its effect on ROS generation are still unknown. In this study, we examined the ROS concentrations of V, Zn, Suwannee River Fulvic Acid (SRFA), Suwannee River Humic Acid (SRHA) and the mixtures of V/Zn and SRFA/SRHA by using a cell-free 2′,7′-Dichlorodihydrofluorescein (DCFH) assay. The results showed that V or Zn synergistically promoted ROS generated by SRFA, but had an antagonistic effect on ROS generated by SRHA. Fluorescence quenching experiments indicated that V and Zn were more prone to form stable complexes with aromatic humic acid-like component (C1) and fulvic acid-like component (C3) in SRFA and SRHA. Results suggested that the underlying mechanism involving the fulvic acid-like component in SRFA more tending to complex with TMs to facilitate ROS generation through π electron transfer. Our work showed that the complexing ability and complexing stability of atmospheric PM organics with metals could significantly affect ROS generation. It is recommended that the research deploying multiple analytical methods to quantify the impact of PM components on public health and environment is needed in the future.     

Detecting forest landcape boundary between Mountain Birch and evergreen eoniferous forest in the northern slope of Changbai Mountain

Boundaries between different forest types in Changbai Mountain Eatern China are results from complex interactions between forest ecosystems,topogrphy,and geomorphology.Detecting and quantifying the transitional zones are highly important since high environmental beterogeneity and biodiversity are ofter found within these zpmes.In this study,we used GIS and multivariate statistics techniques(PCA and MSWA) to analyze data from Landsat TM satellite imageries and quantitatively determined the positions and widths of the landscape boundary betweeen mountain birch and evergreen coniferous forests in the northern slope of Changbai Mountain.The results showed that the widths of the landscape boundary ranges from 30-50 m while using the MWW A or/and PC method.Such detected widths are consistent with field transect data that suggest a 50m tranistional zone width.The results further suggest that TM data can be used in combination with GIS and statistical techniques in determining forest landscape boundaries.MSWA is more reliable than PCA,while PCA can also be used to determine the landscape boundary when transects are properly located.     

高职电子技术课程改革探讨

本文首先分析了高等职业教育电子技术课程的传统教学方式和弊端，随后探讨了电子技术教学的改革途径：包括高职教材内容的修订和更新，通过多媒体技术与EDA技术改善电子技术的课堂教学；精选验证性实验及强化EDA技术在实验和设计环节中的比例等多方面措施。     

基于集集地震的建筑物易损性统计分析

文章收集了台湾921集集地震的强地震动和震害调查资料，利用统计分析的方法，分析了建筑物破坏的数量、震中距、地表加速度之间的关系，对集集地震做了基于地震动参数的易损性初步分析。     

Mercury consumption and contamination of environment in gold mining in China

1　ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｇｏｌｄｉｎｄｕｓｔｒｙｉｎＣｈｉｎａｇｒｏｗｓｕｐｑｕｉｃｋｌｙｗｉｔｈｔｈｅｇｒｏｗｔｈｒａｔｅｏｆａｂｏｕｔ 10 %ｓｉｎｃｅ 90’ｓ.Ｉｎ 1995,ｔｈｅｐｒｏｄｕｃｔｉｏｎｏｆｇｏｌｄｗａｓｏｖｅｒ10 0ｔｏｎｓ/ａ,ａｎｄｉｎ 1996ｒｅａｃｈｅｄ 12 0ｔｏｎｓ/ａ .Ｉｔｉｓｒａｎｋｅｄｓｉｘｔｈｉｎｔｈｅｗｏｒｌｄ(Ｃｈａｎｇ ,1995) .Ｔｈｅｉｒｍａｉｎｐｒｏｃｅｄｕｒｅｓｏｆｇｏｌｄｅｘｔｒａｃｔｉｏｎａｒｅ :(1)ｃｙａｎｉｚａｔｉｏｎｉｎｔｏｔａｌｏｒｅ ｃａｒｂｏ…     

北方庭院生态系统能量分析及养分平衡研究

以基于食用菌生产的北方庭院生态系统为研究对象，通过对沈阳南郊一典型农户庭院生态系统的能量分析与养分平衡研究表明，该庭院生态系统的产品总输出能为４１８７２１４ＭＪ／ａ，其中平菇产品的生物能占６５４％；输入输出系统的Ｎ、Ｐ２Ｏ５及Ｋ２Ｏ基本上保持着养分平衡；该庭院生态系统是一个生产力高、综合效益可观的系统，对指导该地区农村庭院生态系统建设具有重要的现实意义。     

小诺霉素发酵废水好氧生物处理试验研究

对具有强抑制性污染物的抗生素小诺霉素发酵废水，选择活性污泥、粉末活性炭（ＰＡＣＴ）、纯氧曝气等３种好氧生物处理法进行了比较试验。根据实验结果，小诺霉素发酵废水的生物降解呈抑制动力学，采用Ｍａｒｑｕａｒｔ方法对动力学模式进行参数估计。ＰＡＣＴ能够有效地降低降解过程中微生物受到的抑制作用，从而明显地改善了生物处理过程动力学。     

上海市PM2.5的物理化学特征及其生物活性研究

采集了上海市区和郊区春季和夏季的大气PM2.5样品,分析了市区和郊区春夏2季PM2.5质量浓度变化的规律,使用PIXE(Proton Induced X-ray Emission)分析技术获得S、K、Ca、Ti、Cr、Mn、Fe、Ni、Cu、Zn、As、Se、Br、Sr、Pb等15种元素的质量浓度.结果表明,上海PM2.5中化学元素的质量浓度在春季(5038.6ng·m-3)比在夏季(3810.6ng·m-3)高,春季郊区(2528.9ng·m-3)和市区(2509.7ng·m-3)PM2.5中化学元素的质量浓度相当,夏季市区样品(1674.2ng·m-3)中化学元素质量浓度的总量比郊区(2136.3 ng·m-3)的低,但来自人为污染的化学元素(Cr、Mn、Ti、Ni、Cu、Zn、As、Br、Sr、Pb)在市区PM2.5中的含量较高;场发射扫描电镜(FESEM)分析显示,上海PM2.5主要由烟尘集合体、燃煤飞灰、矿物颗粒、生物质颗粒和不明物质组成,质粒DNA评价揭示上海市区PM2.5比郊区的具有更强的生物活性,主要原因可能在于市区样品中含有较高的重金属元素和较多的烟尘集合体.     

半导体制造业的环境污染与清洁生产

在分析半导体制造过程中不同工艺产生的环境污染问题的基础上，讨论了半导体制造业开展清洁生产的原则和途径，介绍了一些成功的清洁生产方案。     

上海市沿海滩涂土地资源圈围与潮滩发育演变分析

上海市62%的土地是近2 000 年来长江来沙堆积而成, 尤其近50 余年来, 采用围垦-促 淤-围垦等有效的拦沙造地方式, 圈围滩涂1.01×105hm2, 为缓解上海城市发展所需的土地资源紧 缺、促进工农业发展和城市基本建设发挥了巨大的作用。论文将GIS 平台获取大量滩涂变化的基本 数据和长期现场观测资料相结合, 总结并提出: 充分利用长江来沙资源, 采用中高潮滩种青和工程 促淤拦沙圈围方法, 可加速潮滩淤涨发育和滩涂土地资源增长, 而低滩工程促淤虽然不利于潮滩地 形快速恢复, 但可快速获得大片土地资源。因而, 保证了50 余年来上海市在圈围土地与基本保持沿 海潮滩湿地面积总量变幅较少方面取得双赢效果。