毛细管气相色谱法测定烟草中有机氯农药残留

研究了烟草中六六六及滴滴涕异构体含量的气相色谱分析方法.样品以石油醚 丙酮在索氏提取器中提取,提取液以浓硫酸净化.采用DB-5弹性石英毛细管柱分离样品,GC-ECD检测农药六六六、滴滴涕的残留量.方法的线性范围为2.27×10-13～7.66×10-11g;最小检测量为1.3×10-8～3.0×10-7 μg,加标平均回收率为95.3%～103.3%,RSD为2.8%～4.5%.     

A review of mechanochemistry applications in waste management

Mechanochemistry is defined to describe the chemical and physicochemical transformation of substances during the aggregation caused by the mechanical energy. Mechanochemical technology has several advantages, such as simple process, ecological safety and the possibility of obtaining a product in the metastable state. It potentially has a prospective application in pollution remediation and waste management. Therefore, this paper aims to give an overall review of the mechanochemistry applications in waste management and the related mechanisms. Based on our study, the modification of fly ash and asbestos-containing wastes (ACWs) can be achieved by mechanochemical technology. Waste metal oxides can be transformed into easily recyclable sulfide by mechanochemical sulfidization. Besides, the waste plastics and rubbers, which are usually very difficult to be recycled, can also be recycled by mechanochemical technology.     

Effects of leachate accumulation on landfill stability in humid regions of China

Leachate levels are important to landfill stability and safety. High leachate or water levels often lead to landfill instability, which can cause accidents. Here a case study of a landfill located in a humid region of southern China is presented. Leachate distribution and quality were systematically analyzed, and the effect of leachate level on waste-mass stability was assessed. Boreholes were drilled in the field, samples were analyzed in the laboratory, and a simulation was performed. In addition, the safety and stability of the landfill was evaluated. The leachate level in the landfill was 9–19 m, which was higher than the top of the dam crest (8–20 m). Leachate accounted for more than 1/4 of the total landfill storage capacity. The contaminant concentration of the leachate samples collected directly from the waste body was very high, with large variation among the samples. The mean concentrations of NH₃–N, BOD, and COD from the waste body were 5404, 14,136, and 22,691 mg/L, nearly 2.7, 2.4, and 1.8 times the mean concentrations in the leachate pond, respectively. Three series of shear strength parameters were used in a slope stability analysis, and a limit equilibrium method was used to calculate the factor of safety (Fs). The analysis showed that Fs could be affected by potential anisotropy in the shear strength of the waste. The minimum values of Fs corresponding to series I were 1.84 and 1.17 for units ? and II, respectively. The Fs value of unit II was significantly lower than the safe design value (1.25). In addition, Fs decreased with increase in the normalized height of the leachate level, h/H, where h is the height of the leachate mound and H is the maximum thickness of the landfill. If the h/H values of units I and II are kept below 50% and 40%, respectively, a safe design value of 1.25 for Fs can be guaranteed. Therefore, some measures to prevent risk should be considered.     

Willingness and behavior towards e-waste recycling for residents in Beijing city,China

This paper is to investigate the behavior of residents towards electrical and electronic waste (e-waste) recycling in Beijing. For this purpose a large sample questionnaire survey was performed to explore the residents’ characteristics of recycling behavior and preference of e-waste recycling pattern. Besides, the willingness of residents to participate in e-waste recycling was also assessed in our study. For this a logistic regression model was developed to estimate and explain residents’ willingness in e-waste recycling. The model showed that Convenience of recycling facilities and service, Residential conditions, Recycling habit and Economic benefits are four determinants of Beijing residents’ willingness and behavior in e-waste recycling. And centralized recycling pattern by professional recovery spots would have a broad prospect if various kinds of channels can be provided to make the residents feel more convenient in e-waste recycling.     

试论沙漠化灾害危险度评价因子体系

本文通过对国内外沙漠化灾害危险度评价因子体系研究现状的分析，从我国实际出发，根据沙漠化灾害危险度的基本内容，首次提出了沙漠化灾害危险度评价因子体系，并给出了相应因子的分级标准。     

中国沙漠化灾害现状及其趋势分析

沙漠化灾害是危及我国广大干旱半干旱及部分半湿润地区持续发展的重大灾种之一。我国现有沙漠化土地２０．１万ｋｍ＾３，造成的年直接经济损失１７．４－２０．４亿元。年总损失达７８３－９１８亿元，受危害的２１２个县（旗、市）的沙漠化灾害程度分别是１３４个轻度、５４个中度和２４个重度，随着沙漠化灾害的不断发展，预计到２０００年时我国沙漠化土地的面积将达到２３．３万ｋｍ＾２，１０７个县（旗、市）的沙漠化灾害程度     

计算机局域网络保密措施

随着计算机的普及 ,局域网络越来越广为利用 ,但也出现了相应的失密问题。本文从信息及实体两个方面 ,论述了局域网络的保密措施。     

浅谈工伤事故的应急救护常识

通过典型事故案例的分析，介绍了不同类型的伤害事故的应急救护常识。     

静电除尘在烧结机头烟尘治理中的应用

通过对安钢烧结机一、二期工程中烧结机头电除尘器结构性能和运行效果对比，结合安钢实际运行情况，分析了一期工程中电除尘器的运行存在的问题，重点对电除尘器的结构特点进行阐述，以提供一种适用于烧结机头烟尘治理的电除尘技术。     

矿井主通风机叶轮磨损失效的评价

矿井主通风机叶轮严重磨损威胁着矿井安全生产 ,研究主通风机叶轮磨损和正确地评价叶轮的磨损失效 ,对煤矿安全生产具有重大的现实意义。应用气—固两相流动理论分析了主通风机叶轮的磨损部位 ,结论与现场叶轮的实际磨损相吻合。提出了叶轮磨损过程的 3个阶段。利用材料磨损理论分析了主通风机叶轮磨损机理 ,得出了叶轮磨损是以气体动力学磨料的冲蚀磨损为主 ,低应力擦伤型磨料磨损、腐蚀磨损为辅的结论。依据国家标准 ,结合矿井主通风机工作特点 ,从安全角度提出了矿井主通风机叶轮磨损永久失效的判据 ,并给出了判定标准。