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281.
Although there is continuing debate surrounding biofuel cultivation (especially in developing nations) in relation to issues of exploitation, land grabbing, poverty alleviation and energy security, there is a lack of empirical evidence to assess how these debates are playing out in practice on the ground. Drawing on political ecology discourse, this paper examines case studies of biofuel production in Zambia and the effects they have on environmental and social sustainability. During April and May 2011, data were collected on two case study projects involving Jatrophacurcas feedstock cultivation in Zambia. Semi‐structured interviews were used to ascertain views from affected stakeholders (local farmers, local environmental, social, and agronomic experts, and investors) on the biofuel projects and their environmental and social impacts. The findings suggest that the uneven distribution of costs and benefits are brought about by imbalances in knowledge, access to resources and the allocation of social and political influence (often associated with broader discourses of development), and this provides a likely rationale for a lack of sustainability in biofuel projects. Drawing on these viewpoints, as well as on field observations, this paper outlines the barriers and opportunities linked to Jatrophacurcas project sustainability.  相似文献   
282.
对国内外PM2.5的研究现状、方向、结论及方法进行回顾,以武汉市1个监测点为例,提出一种与PM2.5强相关因素的分析方法,对PM2.5数值进行预测,并对我国PM2.5研究展望并提出研究发展方向。  相似文献   
283.
汽车辅助制动装置发展综述   总被引:3,自引:0,他引:3  
平均行驶速度和载重量的增加,要求车辆具有更大的制动效能,为了有效分流制动负荷常采用辅助制动系统.介绍国内外制动法规的发展和现状,排气辅助制动装置、发动机缓速器、电涡流缓速器和液力缓速器的结构、工作原理及各辅助制动装置的制动性能;比较各辅助制动装置的优缺点,有利于汽车制动技术的发展,全面提高汽车行驶安全性能;展望未来汽车辅助制动装置的两大发展趋势,一是电子控制技术在汽车制动上的应用,二是多种辅助制动装置的联合制动.  相似文献   
284.
海岸带是人地关系矛盾较为突出的地带.浙江乐清湾海岸带地区在著名的"温州模式"的熏陶下,其城镇发展具有典型的乡村城市化的特征.本文选取乐清海沿岸的乐清市、玉环县和温岭的23个建制乡镇为研究范围,在阐述乐清湾海岸带地区乡村城市化特征的基础上,从隐性机制和显性机制两方面探讨了研究区以市场推导为主动力的"自下而上"的乡村城市化发展机制.隐性机制,包括农村内部的推动力、城市的拉动力和农民主体观念的转变;显性机制,包括市场激励、政策环境、资金因素、政府作用和交通发展.最后提出了加快小城镇发展的若干调控对策,即进一步加快基础设施建设、优化生产力布局、重点培育优势城镇等.  相似文献   
285.
本文介绍了自动喷水灭火系统的发展和技术进步,阐述了自动喷水灭火系统的分类、结构和原理,指出了其应用优势和发展方向。  相似文献   
286.
城市复合生态系统能值整合分析研究方法论   总被引:12,自引:0,他引:12  
系统阐述了城市复合生态系统能值分析的基本概念原理与方法步骤,总结了城市可持续发展综合能值评价指标体系。在此基础上,从能值转换率的积累和统一、多尺度研究的整合与尺度推绎、城市功能流分析与空间结构分析的整合、能值成本价值论与使用(市场)价值论的整合等方面,讨论了能值研究方法在城市生态系统研究中的应用前景和发展方向。  相似文献   
287.
ABSTRACT

Developing countries, which often have emerging or fledgling civil societies, are vulnerable to disasters, and especially devastating earthquakes. The long-term influence of devastating earthquakes on civil societies in developing countries is a critical research topic while receives relatively little attention. From a comprehensive literature review, this study identified four key areas of the civil society: civic participation, voluntary organizations, social capital, and democratic governance, and then examined four devastating earthquakes in India, Iran, Pakistan and China in the first decade of the twenty-first century as case studies, to identify the effects these earthquakes had on these four areas. It was found that from a long-term perspective, while the earthquakes strengthened the civil society, they had beneficial but limited effects. We argue that by promoting local community participation, facilitating extensive non-government organization (NGO) cooperation, and streamlining state-civil society relationships, an enabling environment can be developed to further sustain the advances made by a civil society after a disaster.  相似文献   
288.
Municipal solid waste generation in Kathmandu, Nepal   总被引:1,自引:0,他引:1  
Waste stream characteristics must be understood to tackle waste management problems in Kathmandu Metropolitan City (KMC), Nepal. Three-stage stratified cluster sampling was used to evaluate solid waste data collected from 336 households in KMC. This information was combined with data collected regarding waste from restaurants, hotels, schools and streets. The study found that 497.3 g capita(-1) day(-1) of solid waste was generated from households and 48.5, 113.3 and 26.1 kg facility(-1) day(-1) of waste was generated from restaurants, hotels and schools, respectively. Street litter measured 69.3 metric tons day(-1). The average municipal solid waste generation rate was 523.8 metric tons day(-1) or 0.66 kg capita(-1) day(-1) as compared to the 320 metric tons day(-1) reported by the city. The coefficient of correlation between the number of people and the amount of waste produced was 0.94. Key household waste constituents included 71% organic wastes, 12% plastics, 7.5% paper and paper products, 5% dirt and construction debris and 1% hazardous wastes. Although the waste composition varied depending on the source, the composition analysis of waste from restaurants, hotels, schools and streets showed a high percentage of organic wastes. These numbers suggest a greater potential for recovery of organic wastes via composting and there is an opportunity for recycling. Because there is no previous inquiry of this scale in reporting comprehensive municipal solid waste generation in Nepal, this study can be treated as a baseline for other Nepalese municipalities.  相似文献   
289.
本文给出了微振动台阵的波长与台站对间距离的半理论-半经验关系;根据前人的理论和实验,指出微振动波场存在优势方向,即在有效波长范围内,微振动的各道记录存在相位差;提出了投影到某方位的相位校正公式和校正方法,由此实现空间自相关法的相关函数和相速度曲线的时间延迟校正,通过实例验证了该方法的有效性.  相似文献   
290.
环境监测是环境保护工作的技术基础、信息源泉和执法保障。环境监测工作应以改善环境质量为出发点。以满足环境管理现代化需要为方向,用科学的数据准确、及时、全面地反映环境状况和变化规律,本文通过分析,阐述今后中国环境监测事业的主要发展方向将是有机污染物水质监测、农村环境监测和生态环境监测,并探讨了主要监测内容。  相似文献   
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