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991.
A modeling concept, based on a network of ideal reactor elements, is illustrated with tracer data for the Passaic River of New Jersey. This approach to simulation permits evaluation of mixing without detailed knowledge of internal processes or concentration profiles. The effect of dispersion can be superimposed on first-order decay processes, such as oxygen demand, and evaluated with this method. Application as a water quality management tool extends present use of this concept to wastewater treatment plant analyses. 相似文献
992.
内蒙古主要畜牧气象灾害减灾对策研究 总被引:5,自引:0,他引:5
针对内蒙古自治区草地畜牧业生产中长期存在的实际问题,从草地雪灾、暴风雪、风冷灾害、旱灾等方面讨论了气象灾害对草地畜牧业生产的影响,并提出了相应的减灾对策,为草原牧区防灾减灾决策提供科学依据。 相似文献
993.
避洪耐涝生态农业的发展方向与思路——洞庭湖退田还湖区案例研究 总被引:1,自引:0,他引:1
在退田还湖区发展避洪耐涝生态农业,是提高移民收入、脱贫致富奔小康、提高移民安置质量和拓展安置容量的重要途径。根据洞庭湖区的农业优势和退田还湖区发展高效生态农业的基础和条件,将其发展的总体方向确定为实现避洪耐涝高效特色生态农业产业化。其基本思路是:(1)双退垸行洪区面对洪水渍水重点发展耐涝性强的水生蔬菜、水生饲料及特种名优渔类产业;(2)单退垸区避开洪水重点发展粮油、林草、畜牧业等主导产业;面对洪水、渍水发展耐涝性强的水禽和特种水产养殖业;(3)蓄洪垸区避开特大洪水大力发展粮食、经济作物,突出发展草食牧畜业,积极发展水禽和特种渔类养殖业。通过发展差异性的避洪耐涝生态农业,建设具有支柱产业链特色的粮油生产基地、畜禽生产基地、林木、蔬菜生产基地,特种水产养殖基地,最终实现高效生态农业产业化。 相似文献
994.
Juergen Vehlow Britta Bergfeldt Rian Visser Carl Wilén 《Journal of Material Cycles and Waste Management》2007,9(2):130-139
In the European Union (EU), waste management is almost totally regulated by EU directives, which supply a framework for national
regulations. The main target in view of sustainability is the prevention of direct disposal of reactive waste in landfills.
The tools to comply with these principles are recycling and material recovery as well as waste incineration with energy recovery
for final inertization. The adaptation of the principles laid down in EU directives is an ongoing process. A number of countries
have already enacted respective national regulations and their realization shows that recycling and incineration are not in
competition but are both essential parts of integrated waste management systems. In the EU, the amount of residual waste available
for energy recovery can supply approximately 1% of the primary energy demand. About 50% of the energy inventory of municipal
solid waste (MSW) in most EU countries is of biogenic origin, and MSW is to the same extent to be looked upon as regenerative
fuel. Hence part of the CO2 released from waste incineration is climate neutral. In the EU, this share could produce savings of the order of 1% of annual
CO2 emissions if energy from MSW replaced that derived from fossil fuel. 相似文献
995.
由伦敦地铁连环爆炸案引发对我国城市安全应急体系的思考 总被引:3,自引:1,他引:3
林兵 《中国安全生产科学技术》2005,1(5):72-75
以伦敦最近发生的恐怖袭击为背景,介绍了英国政府和伦敦市府所启动的城市安全应急体系的相关内容,由此分析了我国在城市安全应急机制方面的现状和不足,并根据多年的实际工作经验,提出了加强和完善我国城市安全应急的对策和思考. 相似文献
996.
/ Arthropod communities from several habitats on and adjacent to the El Segundo dunes (Los Angeles County, CA) were sampled using pitfall and yellow pan traps to evaluate their possible use as indicators of restoration success. Communities were ordinated and clustered using correspondence analysis, detrended correspondence analysis, two-way indicator species analysis, and Ward's method of agglomerative clustering. The results showed high repeatability among replicates within any sampling arena that permits discrimination of (1) degraded and relatively undisturbed habitat, (2) different dune habitat types, and (3) annual change. Canonical correspondence analysis showed a significant effect of disturbance history on community composition that explained 5-20% of the variation. Replicates of pitfall and yellow pan traps on single sites clustered together reliably when species abundance was considered, whereas clusters using only species incidence did not group replicates as consistently. The broad taxonomic approach seems appropriate for habitat evaluation and monitoring of restoration projects as an alternative to assessments geared to single species or even single families. 相似文献
997.
人因事故纵深防御系统模型 总被引:13,自引:2,他引:13
复杂社会技术系统发展的特征对系统中人因产生了极大的影响。对该系统中人因事故的防范采取基于多米诺骨牌原理的对策已难奏效 ,而须采用技术手段、组织手段、文化手段融为一体的纵深防御策略。笔者提出并建立了一个主动型人因事故纵深防御系统模型 ,它包含 5个阶段 :方针确立、预测分析、事故减少策略、运行、反馈 ,突出主动去探查与辨识可能的人因事故 ,并采取技术、组织和文化相结合的措施达到减少和预防事故的目的。 相似文献
998.
调查了水泥厂机立窑各类除尘设备的现状 ,结果表明 ,干法静电除尘器是目前机立窑烟尘治理的首选除尘器 相似文献
999.
1000.
Georgina Davis Adam Read Hugh Bulson David Harrison Eric Billett 《Resources, Conservation and Recycling》2004,40(4):1808
The compostability of degradable polymers under open windrow composting conditions is explored within this paper. Areas for consideration were the use of, and impacts of, degradable polyethylene (PE) sacks on the composting process and the quality of the finished compost product. These factors were investigated through polymer weight loss over the composting process, the amount of polymer residue and chemical contaminants in the finished compost product, the windrow temperature profiles and a bioassay to establish plant growth and germination levels using the final compost product. This trial also included a comparative study of the weight loss under composting conditions of two different types of ‘degradable’ polymer sacks currently on the European market: PE and a starch based product. Statistical analysis of the windrow temperature profiles has led to the development of a model, which can help to predict the expected trends in the temperature profiles of open compost windrows where the organic waste is kerbside collected using a degradable PE sack. 相似文献