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。     

土壤悬浮液中五氯酚钠（PCP-Na）的分析方法研究

探索了利用紫外分光光度法测定土壤悬浮液中五氯酚钠的方法。采用紫外可见分光光度计,选定在波长255．6nm处测定土壤悬浮液中五氯酚钠的含量,所得线性回归方程为Y=0．0287X＋0．0022,相关系数r=0．9999,检测限为0．016mg／L,加标回收率为93．357％～95．907％,实验结果表明此法简单、快速,准确性较高。     

重点区域环境空气质量监测方案与评价方法探讨

我国区域性大气污染问题频频发生,成为当前亟待解决的重大环境问题。区域联防联控工作需要建立相应的区域空气质量监测体系和评价方法,这对已有的监测体系提出了新的要求。在区域监测体系中需要增加臭氧、细粒子等区域性污染物及其前体物的监测,同时设立区域监控点使监测网络覆盖面由城市建成区拓展到广大近郊及农村地区。采用移动式柱浓度监测和卫星遥感监测等多样化监测手段结合超级空气站来增强区域综合监测和源解析能力。在区域内搭建监测信息共享平台和实时发布机制并建立区域空气质量预警预报系统。建立区域内统一的质量管理和质量控制方案,城市监测点质控工作由所在省市管理,区域监控点质控工作由国家统一直管。采用分区分层次的区域空气质量评价方法,评价因子包括所有六项监测指标。     

氨法脱硫试验研究分析

为研究氨法脱硫中气液比、吸收液pH值、吸收液浓度以及进口烟温对脱硫效果的影响,设计了一套实验台,以亚硫酸铵为吸收剂进行了实验研究和分析.结果表明,气液比越小,脱硫效率越高;吸收液pH值越大,脱硫效果越好;脱硫效率随吸收液浓度的增大先增加后减小,中间存在最大值;而温度对脱硫效果的影响不大.同时可根据此结果,气液比选择在0.2～0.25L/m3范围,pH值选择为6～7.5范围,吸收液浓度为5.5％左右时,可使脱硫效果达到最好.     

复合过滤法处理生物质焦油废水技术的研究

采用"复合过滤法"处理生物质焦油废水,通过分析生物质焦油废水水质特点,筛选出滤料的种类、确定滤料的配置比,并经实验对比分析。结果表明,经复合过滤法处理后的焦油废水COD、焦油、SS的去除率分别达到54%、60%、68%。该技术工艺简单,运行成本低,管理方便,可广泛用于农村生物质气化站的焦油废水处理。