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991.
由于土地与其他自然资源的限制,经济增长速度相比没有限制情况下降低的现象,即为资源对经济增长的阻尼效应。本文将土地资源与生态环境影响因素合并,利用生态足迹模型解释资源环境复合要素,对传统的阻尼模型进行修正,定量测算资源环境对南京市经济发展的增长阻尼。结果表明,南京市经济发展迅速,土地资源和生态环境对经济发展产生了较为明显的制约作用,其对经济发展的增长阻尼为0.03611。充分发挥资本对资源环境的替代作用,合理利用土地资源,优化产业结构,降低人口的增长率是实现南京市经济可持续发展的基本途径。 相似文献
992.
A pilot biotrickling filter (BTF) packed with ZX02 fibrous balls as packing material was tested for the treatment of ammonia (NH3) released from a composting plant of dairy manure. In order to investigate the effects of three compost aeration modes (mode Co-I, Co-II and In-II) on the NH3 removal efficiency, a field experiment was continuously carried out for more than eight months. The results demonstrated that under the intermittent aeration mode (In-II), the NH3 removal efficiency reached 99.2 ± 0.1% when the inlet NH3 concentration was 7.5-32.3 mg m−3 (9.8-42.5 ppmv). The maximum and critical elimination capacity of the biotrickling filter was 22.6 and 4.9 g NH3 m−3 h−1, respectively. The effluent concentration of NH3 was lower than 1.0 mg m−3, which meets the first class discharge standards of GB14554-93. When the concentration of free ammonia in the trickling liquid was varied from 0.1 to 0.4 mg L−1, the nitrification yield was between 47.9% and 103.8%. In addition, the optimum liquid tricking velocity (LTV) of the biotrickling filter was 0.5 m3 m−2 h−1 for low inlet concentrations and 2.2 m3 m−2 h−1 for high inlet concentrations. Therefore, the use of the biotrickling filter for the compost under the third aeration mode (In-II) yielded an effective optimum NH3 removal and reduced the nitrogen loss in the compost. 相似文献
993.
994.
Bing Xue Yong Geng Wan-xia Ren Zi-long Zhang Wei-wei Zhang Chen-yu Lu Xing-peng Chen 《Journal of Material Cycles and Waste Management》2011,13(4):283-292
Rapid industrialization and urbanization in developing countries have created serious problems in municipal solid waste (MSW)
management. New case studies can shed light on these problems and point the way to potential solutions for improving the overall
eco-efficiency of MSW management. This paper employs a case study approach, analyzing MSW management in Inner Mongolia. This
study encompasses all aspects of MSW management, including collection, separation, recycling, and disposal. Problems and challenges
are identified through our analysis, and recommendations are raised by considering the local realities. Our main findings
are: (1) while large cities have already established a solid foundation for MSW management, small- and medium-sized cities
deserve more attention; (2) MSW in rural areas is even worse than urban areas; (3) enforcement of MSW regulations is ineffective
and needs improvement; (4) lack of funds, R&D efforts and advanced technologies have impeded sustainable MSW management; (5)
lack of coordination and communication among different stakeholders further damages the efforts for improvement of MSW management.
Therefore, integrated efforts that combine the above concerns should be initiated so that the overall effectiveness and efficiency
of MSW management can be improved. 相似文献
995.
随着社会经济发展和市场化、全球化的推进,城市在区域发展中的地位和作用日益加强,区域内部与区域之间生态经济联系更加密切与复杂。基于改进的万有引力模型,将城市生态系统服务价值引入区域生态经济联系系统,测算了河西走廊星火产业带城市间生态经济联系强度及隶属度。结果表明,产业带城市生态经济联系强度整体偏低,两极分化显著。 相似文献
996.
997.
998.
天津市灰霾评价等级指标体系研究 总被引:2,自引:0,他引:2
根据天津市2003—2007年灰霾日的污染物浓度和气象资料,应用主成分分析方法得出影响灰霾的5个主要因子(SO2、相对湿度、总云量、PM10和风速)。对相对湿度、总云量和风速3个气象因子的历史资料进行频数统计分析,并建立了各气象因子的等级划分标准。利用灰色聚类法构建了天津市灰霾评价的等级指标体系,灰霾等级划分结果表明,天津市轻度灰霾和重度灰霾出现天数相对较少,均以中度灰霾为主;轻度灰霾大多出现在春季和夏季;重度灰霾主要出现在冬季,春季出现的比例最小;综合评价分析,冬季灰霾污染程度最为严重。 相似文献
999.
摒弃传统的城市化模式,走建设可持续发展的城市化道路,是城市可持续发展规划决策中最重要的议题。运用公共政策理论,分析了湛江城市可持续发展存在的问题,并针对性地提出了采取科学规划、合理制定产业政策、加强基础设施建设、推动制度建设等城市可持续发展的政策措施。 相似文献
1000.
Bioaccumulation and physiological effects of tetrabromobisphenol A in coontail Ceratophyllum demersum L 总被引:2,自引:0,他引:2
Tetrabromobisphenol A (TBBPA) is one of the most widely used brominated flame retardants. In the present study, the accumulation of TBBPA and its consequent biological responses were examined in coontail (Ceratophyllum demersum L.) over 14 days' exposure. Most of the TBBPA was accumulated after 4d exposure and TBBPA concentration in plant increased with increasing TBBPA concentration in growth solution (R(2)=0.99). By using electron paramagnetic resonance (EPR), we found that the TBBPA exposure significantly increased total free radicals generation in the plants. A good positive relationship (R(2)=0.99) was found between the free radicals formation and accumulation level of TBBPA in plant. Lipid peroxidation was enhanced and chlorophyll content showed declined after TBBPA exposure. The activities of superoxide dismutase (SOD), peroxidase (POD), and the contents of glutathione were also detected. The results suggest that TBBPA accumulation in C. demersum induces oxidative stress and the level of tolerance depends on the antioxidative capacity of the plants. 相似文献