森林火险的序贯分析初探

本文利用森林着火危险度指标属于正态分布的特点,根据正态型序贯分析的原理,提出了确定林火危险性的序贯分析方法;建立了长白山林区5个站点森林火险的“安全域”与“危险域”的模型;并以东岗(长白山西坡)为例,作了正态型序贯分析全过程的应用示例。结果证明,利用正态型序贯分析来确定林火的等级是可行的、可靠的,具有实用价值。     

生态旅游及其可持续发展战略研究之二--生态旅游的可持续发展模式探讨

为衡平旅游开发过程中的经济与环保利益，作为一种全新旅游理念与旅游发展形式的“生态旅游”应运而生，也对传统旅游结构的演变提出挑战，本文通过对“生态旅游”的可持续发展的目标、原则及模式的选择等问题解析，以求能为结合“经济效益”、“生态支柱”、“文化内涵”的新型旅游发展模式提出思考。     

农业非点源模型--AGNPS概述

非点源污染在国内外已越来越受到关注，其中农业非点源又占相当大的份额。由于非点源污染产生机制的特殊性。导致实地调查和试验研究不易实行。故而数学模型方法在这一领域尤其能够体现出它的优点，对它的研究也受到了学术界越来越多的重视。目前，国外已开发出了大量的非点源数学模型，而其中A3NPS模型是应用较为广泛者之一，并已在我国得到了应用。基于此，文中介绍了AGNPS模型的基本结构，主要包括水文、侵蚀和化学污染物的迁移三部分。自从该模型被建立以来，国外已对它进行了大量的研究，本文从研究最多的几个方面进行了讨论，即计算网格的优化、模型输入输出与GIS的结合以及模型的风险性等，以期为在我国的具体应用提供一定的参考。     

新时期消防工作发展思路

随着我国社会主义市场经济的发展和社会管理体制的变化 ,消防工作也面临着新形势。笔者认为 ,消防工作社会化是适应形势发展的必然要求 ,要在全社会建立起各级人民政府领导下的单位责任自负、隐患自除、风险自担 ,公安消防机构依法实施监督的消防社会化运行机制。新时期消防工作应通过以下方式实现社会化 :进一步完善消防法规体系 ;强化消防安全的基础性地位 ;加强宣传普及基本的消防知识 ;发展消防安全中介组织 ;建立消防安全评价制度和科学评价体系 ;依法实施消防监督     

无线数据传输技术在列车安全监控系统中的应用

笔者将GSM网的无线数据传输技术成功应用到列车安全监控系统中 ,系统监测数据经转储发送系统中转 ,由移动台系统实时、无线传输到基站微机系统 ,通过VC ++语言编制的软件系统实时统计分析数据 ,来监控列车运行状况 ,达到列车安全运行的目标。在列车安全监控系统中 ,不仅实现了数据无线实时传输 ,而且提高了工作效率和减轻了工作强度。在济南铁路局装车试验并广泛使用 ,表明了无线数据传输技术应用到列车安全监控系统中具有较高的可靠性和实用性     

炼油厂"三泥"离心脱水处理研究

通过对目前炼油厂“三泥”性状的调查，利用已有污泥处理设施进行了炼油厂“三泥”离心分离的现场试验，并分析了影响“三泥”离心分离处理工艺的主要因素，发现了离心机转速和絮凝剂投加量对“三泥”离心分离的有关规律和最佳操作条件，在此基础上，提出了适合炼油厂“三泥”处理系统的优化方案。     

Management of hazardous waste in Thailand: present situation and future prospects

 This paper deals with the present scenario of hazardous waste management practices in Thailand, and gives some insights into future prospects. Industrialization in Thailand has systematically increased the generation of hazardous waste. The total hazardous waste generated in 2001 was 1.65 million tons. It is estimated that over 300 million kg/year of hazardous waste is generated from nonindustrial, community sources (e.g., batteries, fluorescent lamps, cleansing chemicals, pesticides). No special facilities are available for handling these wastes. There are neither well-established systems for separation, storage, collection, and transportation, nor the effective enforcement of regulations related to hazardous wastes management generated from industrial or nonindustrial sectors. Therefore, because of a lack of treatment and disposal facilities, these wastes find their way into municipal wastewaters, public landfills, nearby dump sites, or waterways, raising serious environmental concern. Furthermore, Thailand does not have an integrated regulatory framework regarding the monitoring and management of hazardous materials and wastes. In addition to the absence of a national definition of hazardous wastes, limited funding has caused significant impediments to the effective management of hazardous waste. Thus, current waste management practices in Thailand present significant potential hazards to humans and the environment. The challenging issues of hazardous waste management in Thailand are not only related to a scarcity of financial resources (required for treatment and disposal facilities), but also to the fact that there has been no development of appropriate technology following the principles of waste minimization and sustainable development. A holistic approach to achieving effective hazardous waste management that integrates the efforts of all sectors, government, private, and community, is needed for the betterment of human health and the environment. Received: February 26, 2001 / Accepted: October 11, 2002     

COMPARATIVE STUDY OF OPTIMIZATION TECHNIQUES FOR IRRIGATION PROJECT PLANNING1

ABSTRACT: This study presents three optimization techniques for on‐farm irrigation scheduling in irrigation project planning: namely the genetic algorithm, simulated annealing and iterative improvement methods. The three techniques are applied to planning a 394.6 ha irrigation project in the town of Delta, Utah, for optimizing economic profits, simulating water demand, and estimating the crop area percentages with specific water supply and planted area constraints. The comparative optimization results for the 394.6 ha irrigated project from the genetic algorithm, simulated annealing, and iterative improvement methods are as follows: (1) the seasonal maximum net benefits are $113,826, $111,494, and $105,444 per season, respectively; and (2) the seasonal water demands are 3.03*10³ m³, 3.0*10³ m³, and 2.92*10³ m³ per season, respectively. This study also determined the most suitable four parameters of the genetic algorithm method for the Delta irrigated project to be: (1) the number of generations equals 800, (2) population size equals 50, (3) probability of crossover equals 0.6, and (4) probability of mutation equals 0.02. Meanwhile, the most suitable three parameters of simulated annealing method for the Delta irrigated project are: (1) initial temperature equals 1,000, (2) number of moves equal 90, and (3) cooling rate equals 0.95.     

池州国家级生态经济示范区生态系统价值的计算

利用Mark·T·Brown的自然资本能值法和Costanza的生态系统效益价值法,从经济角度分别计算了池州生态经济示范区的生态系统的资本价值和效益价值,得出该示范区生态资本可达7899亿美元,其中缓慢可更新生态资本和不可更新资本分别占24 8%和75 2%,是2001年本地区GDP值的1000倍;生态效益价值达192 3亿元人民币,是2001年本地区GDP的3 1倍,生态系统对环境贡献率大。通过价值计算进一步论证了池州生态经济示范区的生态示范作用,为充分合理地发挥生态系统效益促进经济与自然协调发展提供科学依据。     

三峡库区降雨径流水体中铜、锰、镍、锌、铅含量及分布特征

本文按时段和随机采集了三峡库区降雨径流水体样品，测定了水体中Ｃｕ、Ｍｎ、Ｎｉ、Ｚｎ、Ｐｂ含量，统计结果表明：Ｍｎ、Ｚｎ、Ｐｂ在径流水体中的含量趋于平均，变异系数较小。随产流时间的变化，水体中５种元素的变化规律不明显