双碱法脱硫工艺改进及脱硫塔设计分析

改进优化传统双碱法烟气脱硫工艺,对脱硫塔及附属设施设计要点进行分析,在山西某化工厂2×55t/h三废炉烟气脱硫工程中得到较好运用,为同类烟气脱硫工程提供参考。     

A water quality monitoring network design methodology for the selection of critical sampling points: Part II

In order to resolve the spatial component of the design of a water quality monitoring network, a methodology has been developed to identify the critical sampling locations within a watershed. This methodology, called Critical Sampling Points (CSP), focuses on the contaminant total phosphorus (TP), and is applicable to small, predominantly agricultural-forested watersheds. The CSP methodology was translated into a model, called Water Quality Monitoring Station Analysis (WQMSA). It incorporates a geographic information system (GIS) for spatial analysis and data manipulation purposes, a hydrologic/water quality simulation model for estimating TP loads, and an artificial intelligence technology for improved input data representation. The model input data include a number of hydrologic, topographic, soils, vegetative, and land use factors. The model also includes an economic and logistics component. The validity of the CSP methodology was tested on a small experimental Pennsylvanian watershed, for which TP data from a number of single storm events were available for various sampling points within the watershed. A comparison of the ratios of observed to predicted TP loads between sampling points revealed that the model's results were promising.     

Management and Recovery Options for Ural River Beluga Sturgeon

Abstract: Management of declining fisheries of anadromous species sometimes relies heavily on supplementation of populations with captive breeding, despite evidence that captive breeding can have negative consequences and may not address the root cause of decline. The beluga sturgeon (Huso huso), a species threatened by the market for black caviar and reductions in habitat quality, is managed through harvest control and hatchery supplementation, with an emphasis on the latter. We used yield per recruit and elasticity analyses to evaluate the population status and current levels of fishing and to identify the life‐history stages that are the best targets for conservation of beluga of the Ural River. Harvest rates in recent years were four to five times higher than rates that would sustain population abundance. Sustainable rates of fishing mortality are similar to those for other long‐lived marine species such as sharks and mammals. Yield per recruit, which is maximized if fish are first harvested at age 31 years, would be greatly enhanced by raising minimum size limits or reducing illegal take of subadults. Improving the survival of subadult and adult females would increase population productivity by 10 times that achieved by improving fecundity and survival from egg to age 1 year (i.e., hatchery supplementation). These results suggest that reducing mortality of subadults and adult wild fish is a more effective conservation strategy than hatchery supplementation. Because genetics is not factored into hatchery management practices, supplementation may even reduce the viability of the beluga sturgeon.     

区域规划环评中大气环境监测点位布设研究

探讨了大气环境监测点位的布设方法,在区域规划环境影响评价布设大气监测点位时,应综合考虑开发区的功能区划分、区内产业分布及环境敏感点分布等情况;结合规划区内外现状及规划实施后重点污染源的位置及排放高度,根据区域污染气象条件,采用Gauss模式预测最大浓度落地点,并以此作为区域大气环境监测点的布设依据.对某区域开发规划案例进行了大气环境监测点位布设研究,通过实践,该布设方法不仅可以反映区域大气环境质量现状的空间分布特征,而且可以为区域大气环境预测提供良好的数据支持,为优化区域规划提供依据;同时,对规划后的污染源最大浓度落地点的监测,可以为单个项目的环境预测提供背景值,起到简化入区建设项目环评的作用.     

A national critical loads framework for atmospheric deposition effects assessment: II. Defining assessment end points,indicators, and functional subregions

The United States Environmental Protection Agency, with support from the US Department of Energy and the National Oceanographic and Atmospheric Administration, has been evaluating the feasibility of an effects-based (critical loads) approach to atmospheric pollutant regulation and abatement. The rationale used to develop three of the six steps in a flexible assessment framework (Strickland and others, 1992) is presented along with a discussion of a variety of implementation approaches and their ramifications. The rationale proposes that it is necessary to provide an explicit statement of the condition of the resource that is considered valuable (assessment end point) because: (1) individual ecosystem components may be more or less sensitive to deposition, (2) it is necessary to select indicators of ecosystem condition that can be objectively measured and that reflect changes in the quality of the assessment end point, and (3) acceptable status (i.e., value of indicator and quality of assessment end point at critical load) must be defined. The rationale also stresses the importance of defining the assessment regions and subregions to improve the analysis and understanding of the indicator response to deposition. Subregional definition can be based on a variety of criteria, including informed judgment or quantitative procedures. It also depends on the geographic scale at which exposure and effects models are accurate and on data availability, resolution, and quality. The research described in this article has been funded by the US Environmental Protection Agency. This document has been prepared at the EPA Environmental Research Laboratory in Corvallis, Oregon, through contract #68-C8-0006 with ManTech Environmental Technology, Inc., and Interagency Agreement #1824-B014-A7 with the US Department of Energy and at Oak Ridge National Laboratory managed by Martin Marietta Energy Systems, Inc., under Contract DE-AC05-84OR21400 with the US Department of Energy. Environmental Sciences Division Publication No. 3903. It has been subjected to the agency’s peer and administrative review and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.     

金华市奶牛基地的资源利用问题研究

本文论述了奶牛基地发展与红黄壤资源开发利用之间的内在联系。在分析奶牛基地农业资源利用现状基础上,运用灰色系统理论和多元统计的系统聚类分析方法,对影响奶牛基地发展的因素及区域发展对策作了定量分析,并预测奶牛基地发展趋势,提出奶牛生产不同区域的红黄壤资源开发利用的重点,这为合理开发利用红黄壤资源种草养奶牛提供理论和实际参考依据。     

铁矿洗选项目环评要点探讨

结合铁矿洗选项目环评及运行的实际情况,探讨此类项目环评过程中需要考虑的诸多环节,提出具有可操作性的解决方法,对铁矿洗选企业的环境保护和有关项目的环境影响评价有一定的借鉴意义。     

谈"动态对等"的缺陷

美国著名翻译理论家Nida提出的"动态对等"原则是对翻译理论界的一大贡献.笔者在承认这个原则的同时,从它概念的几个关键词入手,指出这个概念中几个值得商榷的地方,认为它的理论基础不牢靠,并分析了它所忽视的翻译所涉及的几个要素,由此表明,翻译这种涉及到许多因素的复杂活动不能依靠一种理论来指导.     

基于不同时段人群特征的地铁疏散仿真研究

针对地铁不同运行时段人群特征对疏散的影响,对每小时进入地铁站人数进行观测,将地铁运行时段分为高峰时段、平峰时段与低峰时段,并对各时段某一时刻列车到站数量进行记录。对不同运行时段的年龄、携带行李情况、速度等人群特征进行观测记录,根据各时段人群特征对地铁站进行Pathfinder疏散仿真建模。从疏散用时、拥堵点、人员疏散路径、出口利用率等方面对各运行时段人员疏散仿真结果进行分析,得到高峰时段两列列车同时到站时,疏散拥堵现象明显,且两列列车到站与1列车到站两种情况下的人员疏散存在一定差异;平峰与低峰时段两列列车同时到站疏散拥堵点明显,出口利用率情况较为一致。最后,对提高地铁疏散效率提出几点建议措施:注重时段差异性的地铁疏散管理;增强拥堵点的疏散引导;缩短列车行车间隔。     

焦化厂土壤中多环芳烃分布特征及淋洗粒级分割点确定

土壤粒径分布和污染物在不同粒级土壤中的分布特征是污染土壤淋洗可处理性的重要依据,淋洗粒级分割点则是淋洗工艺的重要参数.根据土壤异位淋洗的技术要求,在焦化厂污染场地进行了采样,测定了土样的粒径分布曲线及不同粒级土壤中美国EPA优控的16种多环芳烃(PAHs)的初始浓度,并采用Tween 80和Triton X-100溶液对不同粒级污染土样进行了振荡清洗实验.结果表明,16种PAHs在6个粒级中的总浓度在6.27～40.18 mg/kg范围,呈双峰分布模式,单个PAH污染物的最高浓度大多出现在250～500 μm的颗粒中, 50～75 μm的颗粒中污染物浓度最低;PAHs去除率与其初始浓度及土壤特性有关,初始浓度越低,去除率越高,粗颗粒中由于有机碳含量较高,PAHs去除效率反而低于细颗粒.根据清洗效果并从废物减量化角度出发,确定以50 μm作为土壤淋洗的粒级分割点,这样减容率可以达到82.95％.