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291.
通过介绍秦皇岛市创建国家环境保护模范城市的规划范围、规划目标及创建过程,分析了秦皇岛市"创模"的主要制约因素,并重点阐述了为完成创模目标所采取的主要对策,包括:实施"旅游立市"发展战略,加快产业结构调整和发展方式转变;优化能源结构,深入开展节能工作;强化污染减排,改善环境质量等。  相似文献   
292.
浙江省农村生活污水处理现状及其对策   总被引:5,自引:0,他引:5  
基于浙江省67个县的农村生活污水处理设施的问卷调查结果,统计分析浙江农村生活污水处理设施现状,包括动力情况、处理工艺、执行标准、运维模式、经费来源等,并探讨分析了农村生活污水处理设施排放标准及运维管理的长效性.结果表明:目前浙江农村生活污水处理设施以中小规模(30~60 t·d-1)为主,约80%的设施采用了无动力厌氧+人工湿地处理技术,出水一般执行GB 18918-2002《城镇污水处理厂污染物排放标准》中的一级B标准,以村镇自管的运维模式为主,年均运维成本为1.3万元·座-1.从省级管理层面应加快制订符合浙江省情的农村生活污水处理设施排放标准,其指标项目数量不宜过多,指标限值可略宽于GB 18918-2002中的一级A标准;并应尽快形成针对责任主体、资金保障、第三方运维的农村生活污水处理设施长效管理机制.  相似文献   
293.
Abstract: Open access (OA) publishing, whereby authors, their institutions, or their granting bodies pay or provide a repository through which peer‐reviewed work is available online for free, is championed as a model to increase the number of citations per paper and disseminate results widely, especially to researchers in developing countries. We compared the number of citations of OA and non‐OA papers in six journals and four books published since 2000 to test whether OA increases number of citations overall and increases citations made by authors in developing countries. After controlling for type of paper (e.g., review or research paper), length of paper, authors’ citation profiles, number of authors per paper, and whether the author or the publisher released the paper in OA, OA had no statistically significant influence on the overall number of citations per journal paper. Journal papers were cited more frequently if the authors had published highly cited papers previously, were members of large teams of authors, or published relatively long papers, but papers were not cited more frequently if they were published in an OA source. Nevertheless, author‐archived OA book chapters accrued up to eight times more citations than chapters in the same book that were not available through OA, perhaps because there is no online abstracting service for book chapters. There was also little evidence that journal papers or book chapters published in OA received more citations from authors in developing countries relative to those journal papers or book chapters not published in OA. For scholarly publications in conservation biology, only book chapters had an OA citation advantage, and OA did not increase the number of citations papers or chapters received from authors in developing countries.  相似文献   
294.
In this paper, we examine the consequences of rapid climate change on lake ecosystems in terms of two main effects: variability effects and magnitude effects. How these factors influence life history selection is considered by focusing upon body size as a quantifiable and strong correlate of life history variation (Pianka 1970, McNab 1980, Charnov 1991). We then consider the relationship between the concept of biological diversity and the diversity of life history strategies in the context of rapid climate change.  相似文献   
295.
掘进巷道瓦斯分布数值实验研究   总被引:4,自引:1,他引:4  
根据局部通风流场特点确定适合矿井局部通风掘进巷道工作面瓦斯与风流质量交换的数学模型,在近壁面使用标准壁面函数法解决近壁面的流动,在湍流充分发展区,使用RNG k-ε双方程湍流模型;讨论考虑巷道支护的情况下壁面粗糙度的影响,确定矿井掘进工作面局部通风模型网格划分的方法、掘进头瓦斯涌出的边界条件;利用计算流体力学(CFD)软件Fluent对掘进工作面的风流与瓦斯的混合过程进行了模拟;得出不同瓦斯涌出量情况下掘进巷道工作面风流分布和瓦斯浓度的分布规律。研究表明:瓦斯涌出量和风速对流场分布有影响,随着瓦斯涌出量的增大和风速的降低,瓦斯对流场的影响越来越明显。  相似文献   
296.
流动人员职业健康监护存在的问题与对策   总被引:2,自引:0,他引:2  
流动人口的职业健康监护问题是职业卫生工作的重点与难点,是预防控制职业病,是保障流动人口职业健康和公平劳动权益的重要环节。根据对北京、浙江、山东、湖北、内蒙等地的调研,对流动人口职业健康监护存在的问题及原因进行了总结分析,结合目前我国职业卫生资源提出了政策建议。  相似文献   
297.
Small island developing states (SIDS) in the Caribbean have long specialised in primary commodity exports, and traditional export sectors continue to be a major source of employment. The challenge of sustainable development for the Caribbean SIDS has two dimensions. The first is to adjust to the economic and social impact of the loss of preferential markets for traditional exports and of the dismantling of the ISI apparatus erected during the post-World War II period. The second is to ensure that existing and new patterns of production and consumption comply with the criteria for sustainable development, which is here defined as environmental, socio-cultural and economic sustainability.
This article outlines the potential contribution of sustainable tourism to the larger goal of sustainable development in the SIDS in the Caribbean. It reviews current literature on sustainable development and sustainable tourism, particularly their application to the Caribbean SIDS, and evaluates the Caribbean tourism industry from the point of view of sustainable tourism. Conclusions are drawn and proposals made for a policy-oriented agenda in support of the quest for sustainable tourism in the SIDS in the Caribbean.  相似文献   
298.
ABSTRACT: In areas where water is scarce, drip irrigation provides the most efficient way to conserve irrigation water, but its cost of £1000 an acre is prohibitive for most small farmers in developing countries. The cost was reduced by 90 percent by (1) making dripper lines moveable, so that each line reaches ten rows instead of one; (2) replacing 25-cent emitters with simple 0.70 mm holes punched by a heated needle; and (3) using £3.00 off-the-shelf 20 liter containers with cloth filters in place of expensive filter systems. This reduced the cost of a half-acre system to £50. The low cost system was field tested in the hill areas of Nepal, and in mulberry cultivation in Andhra Pradesh, India. Uniformity of flow from emitters was 73–84 percent. Small farmers reported that the low cost trickle irrigation system cut labor requirements in half, and doubled the area irrigated by the same amount of water. The low cost drip system is likely to be widely adopted by small farmers in semi-arid and hilly regions.  相似文献   
299.
以某炼化企业污水处理厂为研究对象,对其恶臭治理设施外排气体的组成特征及其健康风险进行了分析。外排气体中的恶臭物质主要是氨、硫化氢、非甲烷总烃、芳香烃、有机含硫化合物;其中,氨、硫化氢、甲硫醇、甲硫醚、二甲二硫、二硫化碳和4-乙基甲苯的浓度均高于嗅阈值;甲硫醇、硫化氢的理论臭气浓度最高,是关键的致臭物质;生化设施恶臭治理单元的外排气体对污水厂整体恶臭污染的贡献度最高(77%);外排气体中,20种恶臭污染物的非致癌健康风险指数(HItotal≈10−4)和终生致癌风险(LCRtotal≈10−8)低。  相似文献   
300.
为了使分布式能量系统(Distributed Energy System,简称DES)在我国更好地发展,本文从我国未来20年的能源发展战略出发,介绍了我国能源发展中依然存在的矛盾和问题,并通过对分布式能量系统组成、特点的研究,认为目前正是分布式能量系统发展的良好机遇:通过对分布式能量系统利用方式的研究,指出了分布式能量系统将在我国未来20年能源发展战略中的地位以及需要解决的相关问题。  相似文献   
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