PROCEDURES FOR THE EVALUATION OF ENGINEERING ALTERNATIVES1

ABSTRACT: This paper describes a method of analyzing the nonquantifiable parameters which should be considered in the evaluation of engineering alternatives. The nonquantifiable parameters can include environmental impact, feasibility of implementation, and performance. The method considers rating all the alternatives on the basis of a set of criteria which reflect these parameters. A procedure is discussed for obtaining review and guidance in the evaluation of engineering alternatives from the local elected officials or governing bodies and for obtaining the views and desires of the local communities. This is achieved through the formation of project review committees and an evaluation procedure which allows for the technical rating of alternatives by the engineer and the weighing of the evaluation criteria by the political and social groups. With the growing environmental concern and the high cost of engineering projects, the involvement of the public during the evaluation of engineering projects is becoming increasingly important to the final success of the project.     

RESERVOIR OPERATION THROUGH OBJECTIVE TRADE-OFFS1

ABSTRACT: Water resource development has progressed to the stage where various human factors are now being considered in reservoir design and operation. The introduction of human factor objectives complicates the problem since they are noncommensurate with other objectives and they are difficult to identify quantitatively. Some of the problems that now arise concern the proper methods for consideration of several different, sometimes subjectively identified, objectives in reservoir planning. The classical systems analysis approach to decision making for multiple objective problems is outlined and the inherent difficulties associated with multiple objectives and subjective estimates are identified. Techniques being used in reservoir design and operation are reviewed and discussed. An alternate technique for considering noncommensurate, subjectively identified, objectives, which relates the objectives in terms of real trade-off costs and eliminates the need for a priori estimates of objective worth is then presented. The method is illustrated with three examples, including a reservoir operation problem and a cooling tower design problem.     

遥感在生态与环境监测中的主要应用领域

遥感是一种以物理手段、数学方法和地学分析为基础的综合应用技术 ,具有宏观、综合、动态和快速的特点。在解决宏观尺度的环境问题时 ,卫星遥感可重复获取多种空间、不同时相和不同波谱分辨率的地球信息 ,是适宜于调查和研究这些主题的唯一的、最有效的工具。本文通过对遥感在环境与生态监测的主要应用领域进行概要阐述 ,旨在抛砖引玉 ,推动遥感在环境与生态监测中的广泛应用。     

Liver glutathione content and glutathione‐dependent enzymes of two species of freshwater fish as bioindicators of chemical pollution

Abstract

Glutathione content and glutahione‐dependent enzymes were measured in the liver of two fish species, gudgeon (Gobio gobio) and roach (Rutilus arcasii), from the river Bernesga (Spain) caught downstream and upstream of the waste site of several chemical industries. Animals from contaminated sites display a reduced glutathione concentration and a tendency to the decrease of glutathione S‐transferase activity. Glutathione peroxidase activity was significantly elevated only in the liver of Gobio gobio and glutathione reductase activity in that of Rutilus arcasii. Our data indicate that the glutathione system constitutes a sensitive biochemical indicator of chemical pollution. Relative changes of glutathione and glutathione‐dependent enzymes in both fish species suggest a different susceptibility to toxins.     

酒精在常见可燃地面材料燃烧痕迹特征规律研究

易燃液体燃烧痕迹识别对助燃剂放火火灾调查至关重要。选用丙纶地毯和PVC地板革作为纤维和塑料地板的代表,以工业酒精作为易挥发助燃剂的代表,研究酒精用量、灭火方式等对燃烧痕迹形成及痕迹稳定性的影响。通过与未加载酒精的痕迹对比,发现丙纶地毯因热稳定性较差,燃烧后往往能形成烧坑或烧洞,其燃烧轮廓以典型的灰化形式存在,加载酒精的部位熔融严重,与地面紧紧粘连在一起;PVC地板革因为表面光滑,酒精在其表面不断流淌,燃烧后会留下清晰的轮廓,类似于细线状的印痕,而地板革本身基本不会燃烧。燃烧熄灭的方式也会对其炭化程度、燃烧图痕、残余形状产生影响。     

职业安全卫生标准体系建设初探

职业安全卫生标准体系是企业安全科研生产工作的基础 ,是推广试行职业安全卫生管理体系 (OHSMS)的有效技术支撑条件。笔者通过分析职业安全卫生标准应用的实际 ,探索性地提出建立适应企业职业安全卫生管理、研究以及 OHSMS需要的标准化管理体系 ;论述并研讨该体系建立的思路、原则和查询方法以及应用过程的管理 ;以此为职业安全卫生管理、研究和试行OHSMS奠定基础并提供有益的帮助。     

空间视角下湖北省环境绩效评估及影响因素分析

以湖北省为例，基于压力-状态-响应（PSR）模型构建环境绩效评估指标体系，运用空间自相关和标准差椭圆对湖北省各地区绩效指数空间特征及影响因素进行探讨，结果显示：湖北省各地区环境绩效指数（EPI）均高于60，但普遍处于中等水平，良好及优秀所占比例低.EPI较高的地区主要位于湖北省西部和中部，压力和状态指数从西至东递减，响应指数则呈现东部高于西部高于中部的态势.状态指标绩效指数在空间上显著正相关，即环境质量状况较好（或较差）的地区在空间上集聚.EPI及二级指标绩效指数均以西北-东南为布局方向，且EPI椭圆重心较于基准重心偏向于西南方向.各地区环境指数除受到资源禀赋的影响外，还与城镇化率和人口密度显著相关.     

酒泉地区城镇体系可持续发展构想

酒泉地区城镇类型较多，城镇体系中的许多关系需要统筹协调，本文侧重从城镇的规模和空间关系分析，城乡一体化和区一发展，基础产业和环境建设等三个角度，探讨了区域城市可持续发展问题。     

磨细粉煤灰自动装车除尘系统的研制

针对磨细粉煤灰由储料仓向罐式汽车内装料的作业特点,研制了自动化装车除尘系统,解决了装车过程中的粉尘污染问题,并实现了装车过程的自动化。     

风对定日镜影响的计算流体动力学数值模拟

利用linux系统下软件平台Fluent 6.3的并行计算技术和实用的结构网格划分方法,基于Reynolds 时均方程,分别采用两种湍流封闭模型:标准k-ε和MMK修正的k-ε模型,模拟计算了定日镜结构的平均风压系数、阻力、升力以及力矩系数和平均风流场.分析了定日镜镜体平均风压、平均风流场的分布规律和特点;并将数值计算结果与风洞试验进行了比较.结果表明,基于Fluent 6.3的MMK修正的k-ε模型较之标准k-ε模型有更好的预测效果.