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821.
模糊多属性决策在垃圾卫生填埋场选址中的应用 总被引:1,自引:0,他引:1
根据垃圾卫生填埋场选址的影响因素及其权重具有模糊性的特点,提出采用模糊多属性决策方法来解决垃圾卫生填埋场选址的问题。本文在分析垃圾卫生填埋场选址的主要影响因素的基础上,阐述了采用模糊多属性决策进行填埋场场址优选的思路、原理和方法,并通过具体算例证明了该法应用于填埋场选址的可行性与合理性。 相似文献
822.
Xuehua Liu Shuang Zhang Haoyang Xu Xiaoming Shao 《Frontiers of Environmental Science & Engineering》2008,2(3):311-317
Ecosystem health assessment is one of the most important issues in regional ecological quality and safety studies. It also has a great significance to ecological conservation and regional development. This study focused on assessing the health status of forest, agriculture and urban ecosystems in the southwestern Beijing, China, including the Fangshan and Fengtai Districts. Based on field surveys and data collection, an assessment index system containing the vigor, organization and resilience factors was developed to measure the ecosystem health. Each index was scored from 1 to 5, representing five levels that contribute to the whole ecosystem health. The analytic hierarchy process (AHP) method was used to measure the weights of each index and three factors, and thus an overall score for a certain ecosystem was calculated. The results show that the forest ecosystem in the Fangshan District had higher health value than the Fengtai District, while the urban ecosystem had a slightly lower value in the Fangshan District than the Fengtai District. Both districts show lower resilience values in forest and urban ecosystems. Maintaining the ecosystem health will definitely benefit the long-term development of two districts. This study suggested that an approach for assessing the regional ecosystem health could be further developed to address spatial and synergy relationships between ecosystems and the three health factors. 相似文献
823.
Recent tests have detected high lead (Pb) concentrations in some commercial brands of tea leaves and this finding has raised concerns due to the possible health-related problems associated with Pb poisoning. In present research, we investigated the Pb contamination in tea leaves produced in Zhejiang province in China. Pb concentrations in all tea leaves sampled were below 5 mg/kg, the permissible levels given by Chinese Ministry of Agriculture, indicating that Pb contamination in this province is not excessive. We then investigated the non-edaphic factors that may potentially contribute to Pb accumulation in tea leaves. Pb concentration in tea leaves was found to be positively correlated with the industrialization level of a district (R = 0.83, the significant level at P < 0.05), and greater amounts of Pb were washed from the leaves of plants in districts with more industrial activity. This suggests that Pb accumulation in tea leaves could, in part, be attributed to industrial activity through the precipitation of atmospheric Pb. Furthermore greater amounts of Pb were washed from the leaves of plants growing near road than those growing farther away from road. This trend indicates that automobile activity was another likely contributor to Pb accumulation in tea. Pb content of green tea was also affected by the processing of the leaves in the factory. In particular the twisting and water-removal stages caused increases in Pb content in the tea product. This study suggests that non-edaphic factors also contribute to the Pb accumulation in tea. 相似文献
824.
Glass has been obtained by melting red mud from Shandong Province in China with different additives. Suitable thermal treatments were employed to convert the obtained glass into nano-crystal glass-ceramics. X-ray diffraction (XRD) patterns showed that the main crystalline phase in both the glass-ceramics is wollastonite (CaSiO3). These crystals are homogeneously dispersed within the parent glass, with an average crystal size of less than 100 nm. The size of nano-crystals varies when different thermal processes were used. Physical and mechanical properties, such as density, thermal expansion coefficient, hardness, and bending strength, of the two glasses have been examined and the corresponding microstructures are discussed. These results demonstrate that both glass-ceramics have potential for a wide range of construction application. 相似文献
825.
论发展中国家在经济全球化中的环境安全对策 总被引:2,自引:0,他引:2
环境安全是国家安全的重要组成部分。随着人口的增长和人类生产规模的扩大,环境安全问题已经引起了人们越来越多的关注。在经济全球化过程中,由于发达国家掠夺式的原料进口、污染转移,发展中国家的环境安全问题变得尤为突出。因此,发展中国家应处理好经济全球化、发展与环境安全之间的关系,从国际经济交往和环境合作中寻求机遇,从发展中维护环境安全。 相似文献
826.
视频干扰是电视监控工程中最为头痛的事,如何抑制或解除干扰?针对这一问题,笔者和同事们进行了“实用视频干扰抑制器”的研究与开发工作。历经两年时间,在受到不同性质干扰的电视监控工程(电梯、石化、医院、电信、铁路、电台和电力等)中实地反复试验测试,找出解除干扰的办法,应用研发的“实用视频干扰抑制器”解除了这些电视监控工程中图像受到的干扰。 相似文献
827.
港口环境风险管理探讨——以天津港为例 总被引:1,自引:0,他引:1
中国是一个海洋大国,海洋和港口的环境保护得到了国家的高度重视。港口的环境风险防范管理是一个较新的研究领域,当前中国港口经济的高速增长必然带来港口环境风险的增加,对风险进行有效地评价和管理对国家的经济发展和环境保护具有重要意义。本文对天津港环境风险管理的过程进行了较为系统的探讨,分析了天津港环境风险管理技术思路和主要内容,对天津港存在的环境风险因子做了识别,并对环境风险的评估方法做了针对性总结,为港口的风险防范措施提供了一些建议。 相似文献
828.
829.
运用生态足迹方法对辽宁省2000年-2009年生态足迹和生态承载力进行了计算,并对辽宁省可持续发展程度进行了分析和预测。结果表明2000年-2009年期间辽宁省人均生态足迹快速增长,增幅达58.5%;而人均生态承载力基本不变,造成其生态赤字不断加大,涨幅达73.7%,生态系统处于一种不可持续发展状态。在此基础上利用非线性回归预测模型,对辽宁省未来十年的生态赤字进行了预测。并根据辽宁省近年来可持续发展与经济发展状况,提出遏制生态环境恶化、促进区域可持续发展的一些建议。 相似文献
830.
The combination of leachate recirculation and aeration to landfill may be an efficient way for in-situ nitrogen removal. However,
nitrogenous substances contained in the landfill layer are concomitantly transformed into N2O and NH3, leading to increased emissions
into the atmosphere. In the present study, the emissions of N2O and NH3 were measured under conditions of fresh or partially stabilized
refuse with or without leachate recirculation or intermittent aeration. The results showed that the largest N2O emission (12.4 mg-N/L
of the column) was observed in the aerated column loaded with partially stabilized refuse and recycled with the leachate of low C/N
ratio; while less than 0.33 mg-N/L of the column was produced in the other columns. N2O production was positively correlated with the
prolonged aerobic time and negatively related with the C/N ratio in the recycled leachate. NH3 volatilization increased with enhanced
gas flow and concentration of free ammonia in the leachate, and the highest cumulative volatilization quantity was 1.7 mg-N/L of the
column. 相似文献