国标法测定无色透明清洁水中硫化物错误的原因

硫化物在进行显色反应时,溶液中酸度的增高生成亚甲兰的产率也随之增加。国标法规定分析无色透明清洁水样时,不加20ml乙酸锌-乙酸钠溶液,这样分析的结果不正确。正确的方法应与绘制标准曲线的操作步骤完全一样,需加20ml乙酸锌-乙酸钠溶液。     

城市垃圾填埋中甲烷排放的研究——以南宁市为例

采用《省级温室气体清单编制指南(试行)》中提供的质量平衡法和美国环境保护局填埋气排放模型(LandGEM)两种计算方法,参考1995～2006南宁市统计年鉴年间有关数据。对这11年间,南宁城市垃圾填埋所产生的甲烷量进行估算。结果表明,短期内城市垃圾填埋量变化缓慢,采用两种方法计算的结果都可行;当城市垃圾填埋量变化大,并且填埋时间比较长时,建议采用LandGEM模型计算出的结果。     

基于模糊综合评判法的矿山地质环境质量评价——以陕南铅锌矿为例

在明晰地质灾害频发、生态环境恶化、水土环境污染严重三位一体是陕南铅锌矿山地质环境质量最核心问题的基础上,构建了陕南铅锌矿地质环境质量评价体系;基于模糊综合评判法建立了评价模型,并运用AHP法计算评价指标体系权重。应用构建的评价指标体系和方法,对陕南8个典型铅锌矿的地质环境质量进行综合评价。结果表明:其中5个铅锌矿地质环境质量为优;1个铅锌矿地质环境质量为良;2个铅锌矿地质环境质量为差。     

SH-A工艺处理煤焦油加工废水的研究

采用"SH-A节能型强化生物脱氮除碳工艺"进行煤焦油加工废水处理的研究,讨论了各个处理环节的运行情况和处理效果。经该工艺对煤焦油加工废水进行处理后,COD、NH-N和矿物油的去除率均可达到98%,色Cr 3度和酚的去除率均可达到99%,氰的去除率可达到95%,各项指标均可达到国家《污水综合排放标准》(GB8978-1996)一级。     

Plant vintages, grandfathering, and environmental policy

Environmental regulations that grandfather existing plants, by not holding them to the same strict standards as new plants, may have the unintended consequence of retarding new investment. If new plants are cleaner, then this effect may increase pollution in the short run. I develop a dynamic model of a facility’s decisions over scrapping and abatement, which depend on capital depreciation, profitability shocks, and environmental policy. Using data from fossil fuel fired boilers at electric power plants, I estimate the structural parameters of the model and assess the impact of grandfathering in the Clean Air Act on sulfur dioxide emissions. Counterfactual policy simulations show that an increase in the stringency of performance standards would have led to a decrease in investment in new boilers. However, this does not lead to increased emissions, since there is less investment in dirtier coal boilers as compared to relatively cleaner oil or natural gas boilers.     

"三点比较式臭袋法"嗅辨员的优化选择

在利用"三点比较式臭袋法"测定恶臭时,嗅辨员发挥关键作用.在实际测定过程中,由于嗅辨员的嗅觉阈值不同,嗅觉敏感度不同,从而造成监测结果产生较大差别.通过细分嗅辨员的级别,优化嗅辨小组的人员结构,从而保证监测结果的准确性.     

Two leaks detection in viscoelastic pipeline systems by means of transient

This paper presents a technique for detecting and locating leaks in a single viscoelastic pipe, by means of transient analysis. The system studied is a reservoir-pipe-valve structure. The viscoelastic behavior of the pipe wall material is modeled by a generalized KelvinVoigt model. To determine the leak location, the mathematical formulation has been solved by the method of characteristics. The approach by the method of characteristics is often chosen because it is based on the concept of acoustic wave propagation which is the main mechanism of all transient events considered. The presence of the two leaks in a pipe partially reflects pressure waves initiated by the sudden closure of a downstream shut-off valve. These waves affect the shape and the amplitude of the time-history-pressure. The computed results describe the influence of the presence of two leaks on pressure time-history and the effect of leaks locations and sizes on the pressure signal behavior. The effect of the pipe wall viscoelasticity on the two leaks detection and sizing is also discussed. The leaks discharges are determined by resolving two independent equations derived from literatures and based on transient analysis. The friction and leaks depths effects on two leaks locations and sizing are involved.     

钢结构栓接板面抗滑移系数试验新法

此文详细介绍了一种钢结构栓接板面抗滑移系数试验的新方法,该方法简便、实用.     

建设节水型社会评价指标体系及赋权方法研究

针对某市10个县区节水的实际情况,依据层次分析法原理建立了节水型社会评价指标体系,分别采用两种客观性赋权方法(相关系数法、相似系数法)来确定指标体系中各层指标的权重,这样即保留了层次分析法分类清楚、解释性强的特点,又发挥了客观赋权法人为因素少的优点。     

流动注射分析法测定水中的总磷

应用LACHATQC8500型三通道流动注射分析仪,采用过硫酸钾在线紫外消解不同形态的磷,使其转化为磷酸盐。正磷酸盐与钼酸铵和酒石酸锑钾反应,生成磷钼化合物。此磷钼化合物被抗坏血酸还原,形成蓝色化合物,它在880nm处有吸收。仪器检出限为0.0012mg/L,线性范围为0.05～1mg/L(r>0.9990),加标回收率为95.0%～104%。与GB11893-89钼酸铵分光光度法比较,其结果无显著差异。实验结果表明,该方法简便、快速、准确,适用于水中总磷的测定。