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591.
可持续发展的理论与宏观调控模式 总被引:8,自引:0,他引:8
从可持续发展观和可持续发展战略出发,分析了传统发展观和发展模式的特点及其主要弊端;进而根据有关国际性文件中的可持续发展概念,给出了中国人易于理解的描述及其基本内涵,强调了人与自然和谐、发展与资源环境相协调是可持续发展的核心,并结合实例阐明了协同学理论是可持续发展的基本理论依据;在分析发展与资源环境相协调的基础条件之后,重点论述了它们之间的协调机制,提出了可持续发展的宏观调控模式。 相似文献
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593.
以易燃易爆重大危险源的控制系统(包括易燃易爆重大危险源的辨识、评价、管理、监察、应急计划)为基础,探讨性地提出了进行标准化管理的思路与方法,旨在建立一种标准化管理的新模式. 相似文献
594.
用灰色建模法预测矿井瓦斯涌出量 总被引:13,自引:4,他引:9
在分析了传统的矿井瓦斯涌出量预测方法的基础上 ,应用灰色系统理论 GM(1,1)模型 ,对矿井瓦斯涌出量进行预测 ,并在实际中得到了较好的验证。 相似文献
595.
596.
Numerical simulation of a fine-grained denitrification layer for removing septic system nitrate from shallow groundwater 总被引:1,自引:0,他引:1
Kerry T. B. MacQuarrie Edward A. Sudicky William D. Robertson 《Journal of contaminant hydrology》2001,52(1-4):29-55
One of the most common methods to dispose of domestic wastewater involves the release of septic effluent from drains located in the unsaturated zone. Nitrogen from such systems is currently of concern because of nitrate contamination of drinking water supplies and eutrophication of coastal waters. It has been proposed that adding labile carbon sources to septic distribution fields could enhance heterotrophic denitrification and thus reduce nitrate concentrations in shallow groundwater. In this study, a numerical model which solves for variably saturated flow and reactive transport of multiple species is employed to investigate the performance of a drain field design that incorporates a fine-grained denitrification layer. The hydrogeological scenario simulated is an unconfined sand aquifer. The model results suggest that the denitrification layer, supplemented with labile organic carbon, may be an effective means to eliminate nitrogen loading to shallow groundwater. It is also shown that in noncalcareous aquifers, the denitrification reaction may provide sufficient buffering capacity to maintain near neutral pH conditions beneath and down gradient of the drain field. Leaching of excess dissolved organic carbon (DOC) from the denitrification layer is problematic, and causes an anaerobic plume to develop in simulations where the water table is less than 5-6 m below ground surface; this anaerobic plume may lead to other down gradient changes in groundwater quality. A drain field and denitrification layer of smaller dimensions is shown to be just as effective for reducing nitrate, but has the benefit of reducing the excess DOC leached from the layer. This configuration will minimize the impact of wastewater disposal in areas where the water table is as shallow as 3.5 m. 相似文献
597.
A comparison of simulated and observed ozone mixing ratios for the summer of 1998 in Western Europe 总被引:1,自引:0,他引:1
H. Schmidt C. Derognat R. Vautard M. Beekmann 《Atmospheric environment (Oxford, England : 1994)》2001,35(36):6277-6297
This study describes and evaluates the newly developed European scale Eulerian chemistry transport model CHIMERE-continental. The model is designed for seasonal simulations and real time forecasts without the use of super-computers. For the purpose of model evaluation simulated ozone mixing ratios for the period between 1 May 1998 and 30 September 1998 are compared to observational data from 115 European surface sites. In order to facilitate the interpretation of future forecasts a statistic is established to estimate the reliability of a simulated pollution level. Besides this, the comparison is done by means of time series, scatter plots, a spectral analysis and the calculation of RMS-errors and biases of the model results corresponding to each observation site. It turns out that the mean RMS-error of the simulated daily maximum ozone mixing ratio for the sites considered a priori as well suited for a model comparison is about 10 ppb. For the same period but a reduced number of sites observed concentrations of NO2 and ethene are compared to simulated values. Difficulties encountered with the representativeness of observations when trying to evaluate a mesoscale air pollution model are discussed. 相似文献
598.
人因失误的机理及其可靠性研究 总被引:28,自引:7,他引:21
随着科技的发展 ,在系统安全中 ,机器设备可靠性越来越高 ,由于人本身的复杂性 ,人因失误变得愈来愈严重。本文基于人行为的原理 ,对人因失误的机理、影响人失误的因素、人行为的模型和失误模型及其可靠性的量化进行了分析 ,建立了计算人可靠性的威布尔分布模型 ,并对其参数进行了讨论 ,可用此来评价人的可靠性。 相似文献
599.
环境CGE模型的发展及特征分析 总被引:6,自引:1,他引:6
随着CGE模型在环境与经济政策分析领域中的应用不断拓展 ,环境CGE模型的研究和应用也逐渐走向深入。本文在简要介绍CGE模型的发展状况和主要特征之基础上 ,对环境CGE模型的发展、类别、特征及其局限性进行了较为详细的分析 相似文献
600.
H. Randal Gimblett John E. Fitzgibbon Kevin P. Bechard J. A. Wightman Robert M. Itami 《Environmental management》1987,11(3):359-367
Incorporation of aesthetic considerations in the process of landscape planning and development has frequently met with poor results due to its lack of theoretical basis, public involvement, and failure to deal with spatial implications. This problem has been especially evident when dealing with large areas, for example, the Adirondacks, Scenic Highways, and National Forests and Parks. This study made use of public participation to evaluate scenic quality in a portion of the Niagara Escarpment in Southern Ontario, Canada. The results of this study were analyzed using thevisual management model proposed by Brown and Itami (1982) as a means of assessing and evaluating scenic quality. Themap analysis package formulated by Tomlin (1980) was then applied to this assessment for the purpose of spatial mapping of visual impact. The results of this study illustrate that it is possible to assess visual quality for landscape/management, preservation, and protection using a theoretical basis, public participation, and a systematic spatial mapping process. 相似文献