城市应急避难场所层次布局研究(Ⅱ)——三级层次选址模型

分析应急避难场所层次选址的目标因素:建设成本和避难效果,提出总的移动距离最短和建设成本最小两类选址目标,立足城市发展程度差异和现状应急避难场所建设情况分析,将应急避难场所选址类型分为规划性选址、老城新选址、补充性选址三种。依据应急避难场所的三级层次划分,以及单一流、嵌套、空间非匹配的层次特点,分别建立了应急避难场所的规划性选址、老城新选址、补充性选址共8个三级层次选址模型,并通过模拟实验对模型的效果进行了检验。     

机械排烟系统优化设计数值模拟研究

本文以一超市建筑为例,运用火灾模拟软件FDS对排烟口位置、排烟口数量、排烟量、排烟口面积等对机械排烟效果的影响进行了研究。研究表明顶棚排烟优于侧壁排烟;排烟口应尽量远离疏散出口;排烟量达到一定数值之后,再增加排烟量,对排烟效果影响不大;增加排烟口数量,并合理分布其位置,可以得到良好的排烟效果。     

基于BP神经网络的污水格栅间气体监测

为实现对城市污水泵站格栅间内H₂S和CO有害气体浓度实时准确监测分析,设计气体传感器阵列监测系统,建立单隐层BP神经网络模型对气体浓度样本进行训练,确定网络隐含层数为9,训练函数为traindm,模型优化后输出的H₂S和CO气体浓度与实测值的平均相对误差分别为1.3%与0.4%。研究结果表明：采用BP神经网络模型对传感器阵列采集到的样本数据进行训练,可提高其测量精度,提升精度范围在57%～75%之间,能够满足对污水泵站有害气体监测的基本要求,所建立模型表现出良好效果。研究结果可为污水格栅间有害气体监测提供新方法。     

关于我国首都迁址的再探讨

北京作为中国首都已经出现了许多不相适应的弊端,困扰着首都功能的正常发挥,而且这些问题呈进一步恶化的趋势。无论改都论、双都论还是展都论,都不能从根本上解决北京日趋集中的问题。从北京存在的一系列问题入手,指出了迁都的必要性;然后从迁都的历史可行性、经验可行性、经济可行性和操作可行性4个方面论证了迁都的可行性;运用定量与定性相结合的方法,构建理想首都区位模型,对迁都方位进行了选择。认为长江中游地区是建立新都的最理想方位,并从首都安全、定都成本和区位影响角度,分析了长江中游地区建设中国新都的不可替代的优势,最后还探讨了模型的计算尺度问题和迁都应注意的问题。     

基于GIS的城市重大危险源选址研究

近年来,城市重大危险源的安全问题日益突出,对城市的健康安全发展构成了极大威胁,因此,如何进行城市重大危险源选址成为现代社会研究的重要内容。利用GIS空间分析技术,对影响重大危险源选址布局的空间信息进行处理,将道路图、土地利用规划图、城市遥感影像、城市基础设施等与城市区划图相结合,以获取适宜选址的可行域。利用模糊综合评价理论,选出影响选址的因素集和评语集,通过模糊运算评判可行域,并由实例验证了该选址方法,最终得出城市重大危险源最优选址方案。因此,进行城市重大危险源的选址研究具有现实可行的意义,有助于提高城市的整体安全水平。     

山东省不同下垫面大气扩散参数的对比分析

利用在山东各地进行的多次建设项目大气环境影响评价中的大气扩散试验结果,对不同垫面的大气扩散参数做对比分析,讨论下垫面的变化对大气扩散参数的影响以及大气扩散能力与大气污染物浓度分布的关系,试验均采用平衡法进行。结果表明：不同地形下的大气扩散参数有明显差异。与国际扩散参数值相比,山区比平原高０．５－１级,平原地区与国标基本一致,工业区模向扩散参数与国标基本相当,垂直扩散参数１个级别以上;沿海地区横向扩     

AN ASSESSMENT OF WATER UTILITY INFORMATION SYSTEMS AND THEIR USE OF COMPUTERS1

To provide an overview of water utility information systems and the extent of computer use, a direct mail survey of all water utilities serving populations of 2,000 or more in the tri-state area - Ohio, Indiana, and Kentucky - was conducted. The following was determined: 1) utility profile information, e.g., public/private ownership, age, number of accounts, etc.; 2) an assessment of the degree of computerization presently in place to perform various functions; and 3) an assessment of any plans that the utilities may have for future computerization. To analyze the data, an index of computerization was defined as the number of departments or major activity areas of each utility that presently have some computerization. The relationship between the degree of computerization (measured by this index) and a utility's profile in terms of population served, annual revenue generated, and the number of customer accounts is discussed for each state in the survey. Discriminant analysis revealed strong significant differences between utilities that plan to use computers and those that do not. The differences were identified by the authors. Survey results revealed a rather limited use of computers in the tri-state area. Enormous potential exists in small and medium sized utilities for computerization to improve operational efficiency.     

SUITABILITY ANALYSIS FOR SELECTION OF PIPELINE ROUTES1

ABSTRACT: A brief review of environmental assessment methods is presented as an introduction to a study of environmental management problems in a coastal area of southern Louisiana. The assessment method used in the study is called suitability analysis and involves the use of matrices. The matrix approach is simply a convenient method for organizing all factors representing environmental concerns in a region. The matrices proved to be very useful in defining the present state of an environmental regime and in maintaining an inventory of regional features and potential impacts. The method is described in detail and illustrated by evaluating the potential impacts of a major pipeline construction job in the area. Of major concern is the potential impact on the water resources of the region. Disruption to the natural drainage could be detremental, and affect the suitability of available water for a given use. Limitations of the method are discussed and potential areas for improvement and research are noted. Coupled with an economic assessment, the suitability analysis method should prove beneficial for selecting development sites for industries, residential areas, and other construction activities.     

The environmental regulator and industrial development

Environmental regulatory agencies' administrative procedures have a significant impact on plant location. The authors review the basic reasons why companies build new plants and the constraints they operate under during site searches. The relationship between these issues and the regulatory agencies' administrative procedures is then shown, as well as the manner in which these procedures influence the site search. On the basis of this discussion, recommendations are made about how state environmental protection agencies can assist site seekers in a manner consistent with their regulatory responsibilities.     

固定化酶制备方法研究进展

对固定化酶的主要制备方法进行了系统的阐述,根据作者本人的试验经验对目前应用的研究得较多的方法作了详细的说明,对所阐述的各种固定化酶的制备方法的优缺点进行了比较。