全文获取类型
收费全文 | 545篇 |
免费 | 50篇 |
国内免费 | 93篇 |
专业分类
安全科学 | 44篇 |
废物处理 | 11篇 |
环保管理 | 90篇 |
综合类 | 265篇 |
基础理论 | 124篇 |
污染及防治 | 45篇 |
评价与监测 | 50篇 |
社会与环境 | 55篇 |
灾害及防治 | 4篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 15篇 |
2021年 | 20篇 |
2020年 | 15篇 |
2019年 | 14篇 |
2018年 | 11篇 |
2017年 | 18篇 |
2016年 | 16篇 |
2015年 | 35篇 |
2014年 | 25篇 |
2013年 | 40篇 |
2012年 | 41篇 |
2011年 | 52篇 |
2010年 | 42篇 |
2009年 | 43篇 |
2008年 | 44篇 |
2007年 | 31篇 |
2006年 | 40篇 |
2005年 | 28篇 |
2004年 | 24篇 |
2003年 | 17篇 |
2002年 | 10篇 |
2001年 | 21篇 |
2000年 | 17篇 |
1999年 | 10篇 |
1998年 | 17篇 |
1997年 | 8篇 |
1996年 | 3篇 |
1995年 | 6篇 |
1993年 | 5篇 |
1992年 | 4篇 |
1991年 | 5篇 |
1990年 | 2篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1984年 | 1篇 |
1981年 | 2篇 |
排序方式: 共有688条查询结果,搜索用时 15 毫秒
631.
国内外可持续发展指标体系研究进展 总被引:2,自引:0,他引:2
可持续发展是人类社会发展的必由之路。可持续发展指标的筛选和指标体系的构建,是人类全面实施可持续发展战略的重要组成部分,是人类社会可持续发展研究中的前沿性课题。20世纪90年代以来可持续发展研究的热点已经从可持续发展的定义转向可持续发展的评价,特别是指标体系的构建。20多年来,可持续发展指标体系的研究已经出现了从理论探讨走向了实际应用的趋势。通过分析20世纪90年代以来国内外有代表性的不同尺度上的可持续发展指标体系:联合国可持续发展委员会(UNCSD)的可持续发展指标体系、世界银行衡量可持续发展的新指标体系、波罗的海21世纪议程、英国、瑞典、芬兰、德国、美国、瑞士、丹麦及中国等国的可持续发展指标体系、欧洲城市可持续发展指标体系、新西兰玛努卡市的可持续发展指标体系、美国西雅图市社区可持续发展指标体系、中国的云南省、海南省、山东省等省以及南京市和哈尔滨市的可持续发展指标体系、山西交口县可持续发展指标体系、云南山区民族行政村可持续发展指标体系,对国内外可持续发展指标体系研究进行了总体评价。结果发现如果在以西方文明为主的现代化和城市化的框架下进行区域可持续发展的分析和评判,那得到的结论本质上是区域现代化或城市化程度的反映,而不是对区域可持续发展现状和趋势的评判。20多年来,国内外可持续发展指标体系的研究取得了丰硕的成果,为人类实施可持续发展战略打下了坚实的基础。 相似文献
632.
生态示范区可持续发展指标体系和数学模型--以安徽省岳西县国家级生态示范区为例 总被引:10,自引:2,他引:8
为评价、监控和考核生态示范区可持续发展水平、进程和成效,构建了一套量化评价指标体系和指数叠加、功效系数、模糊综合评价等三种数学模型,并以安徽省岳西县国家级生态示范区为例研究生态示范区多时空尺度的可持续发展态势。结果表明在基准水平年(2000)、近期目标年(2005)和远景目标年(2010)生态示范区复合系统的可持续发展度(0.268、0.541、0.859)、可持续功效系数(0.711、0.812、0.949)和可持续发展隶属度(0.129、0.332、\{0.671\})都逐步增加,而且在不同规划年限中均以自然子系统可持续发展态势为最优,这与该县生态环境优越、经济社会水平低、发展潜力大的客观实际非常符合。 相似文献
633.
深圳市环境影响评价有效性评估 总被引:6,自引:0,他引:6
在总结国内外环境影响评价(EIA)有效性研究的基础上.提出EIA有效性评估的指标体系、分级标准和评估方法。选取1995~2002年间完成的80本环境影响报告书(EIS)对深圳市EIA有效性进行评估。研究结果表明:深圳市EIA有效性指数偏低,有效性一般.EIA制度在发挥积极作用的同时,存在制度体系有待完善、法律法规执行不够严格、评价人员专业素质有待提高等问题。最后提出改进EIA有效性的建议和需要进一步探讨的问题。 相似文献
634.
天津滨海新区黑潴河沉积物中重金属污染特征及地区性重金属污染指标选择 总被引:2,自引:0,他引:2
测定了天津滨海新区境内黑潴河沉积物中8种重金属(Cu,Cd,As,Pb,Cr,Zn,Ni和Hg)的质量分数,用富集因子法和潜在生态危害法进行了风险评价表明,黑潴河表层沉积物中w(Hg)和w(Cd)偏高,存在较高的生态风险,其余重金属的生态风险较低. 采用相关性分析和主成分分析法对重金属的来源进行分析表明,Zn,Cr和Ni主要受控于自然因素,来源于自然环境中的母岩侵蚀;As和Cu主要受控于人为的农业生产活动;Cd和Hg来源于污水灌溉、周围地区化石燃料的燃烧以及生活废物的排放等;Pb的来源同时受控于自然因素和人为活动因素,但以人为因素为主. 此外,对文献报道的天津地区各类水体沉积物和土壤中的重金属的污染程度进行比较分析,并与区域内植物和鱼类体内重金属富集程度相联系, 结果表明,Cd和Hg的富集倍数显著偏高,是天津地区重金属污染的指示指标. 相似文献
635.
Gregor Levin 《Ecological modelling》2010,221(22):2728-2737
In intensively farmed regions, habitat fragmentation represents a major pressure on biodiversity. Depending on its spatial setting, set-aside land can increase size and connectivity of habitats and thus counteract fragmentation. In 2008, the EU-wide set-aside obligation was suspended and a large proportion of set-aside land was re-cultivated. With Denmark as case we apply an indicator to measure the effect of set-aside land on spatial structure of semi-natural habitats in term of habitat size and connectivity. Furthermore, we model effects of a hypothetical spatial regulation, where set-aside land with the greatest benefit for habitat structure is retained as uncultivated, while set-aside land with the least effect is re-cultivated. The model is applied to individual farms and to farm agglomerations of increasing sizes, enabling us to explore potential effects of cross-farm regulation. The novelty of our approach is the application of observed land-uses changes for modelling a hypothetical regulation working on a range of spatial scales. Results show that after abolition of set-aside schemes the effect of set-aside land on habitat structure was more than halved. Modelled spatial regulation considerably reduces impacts. Effects increase with increasing size of farm agglomerations. However, marginal benefits become negligible at agglomeration sizes over 36 km2. 相似文献
636.
随着经济的发展,港口的建设与环境的矛盾日益突出,忽视环境影响的港口规划往往产生各种环境问题。因此必须实施规划环境影响评价,以便从源头上控制港口环境污染。基于可持续发展的要求与环境管理的发展趋势,文中简单介绍了港口规划环境影响评价的目标和一般技术方法。对港口规划环境影响评价指标体系进行初步研究,从港口规划的实际情况出发提出了基于DPSIR模型的环境影响评价指标体系,同时对于实际操作中指标体系的筛选进行了讨论。 相似文献
637.
This study aimed at clarifying the impact of deforestation and afforestation on the quality of life in a village in Sichuan Province, China. We devised a conceptual model of bioresource production and use based on quantified energy flow. The basic structure of the model has three sectors: production, use, and externals. We developed comprehensive methodology to quantify the model. Bioresource use per person in 1997 was 3.7 GJ for food, 10.2 GJ for fodder, 0.2–0.4 GJ for building material, 12.8 GJ for fuel, and 1.8 GJ for fertilizer, totaling 28.6–28.8 GJ.We used four environmental indicators to evaluate bioresource production and use: a biological productivity indicator, a use-efficiency indicator, a supply–demand balance indicator, and a self-sufficiency indicator. Use of these indicators showed that supply-demand balance of fuel was dramatically improved from 30% to 85% by afforestation, but 99% of bioresource use still depends on domestic products. Thus, it is necessary to improve biological productivity and promote the efficient use of bioresources to achieve sustainable living in the area. Massive deforestation in the 1950s caused a direct shortage of building material and fuel wood. The shortage of wood led to a stagnation in the rebuilding of houses, and fuel wood was substituted with crop residues. Because crop residues had been used for fertilizer and fodder, their use as fuel caused a shortage of fertilizer and fodder. This was an indirect impact of deforestation on peoples quality of life. 相似文献
638.
Herzog F Lausch A Müller E Thulke HH Steinhardt U Lehmann S 《Environmental management》2001,27(1):91-107
This investigation tested the usefulness of geometry-based landscape metrics for monitoring landscapes in a heavily disturbed
environment. Research was carried out in a 75 sq km study area in Saxony, eastern Germany, where the landscape has been affected
by surface mining and agricultural intensification. Landscape metrics were calculated from digital maps (1912, 1944, 1973,
1989) for the entire study area and for subregions (river valleys, plains), which were defined using the original geology
and topography of the region. Correlation and factor analyses were used to select a set of landscape metrics suitable for
landscape monitoring. Little land-use change occurred in the first half of the century, but political decisions and technological
developments led to considerable change later. Metrics showed a similar pattern with almost no change between 1912 and 1944,
but dramatic changes after 1944. Nonparametric statistical methods were used to test whether metrics differed between river
valleys and plains. Significant differences in the metrics for these regions were found in the early maps (1912, 1944), but
these differences were not significant in 1973 or 1989. These findings indicate that anthropogenic influences created a more
homogeneous landscape. 相似文献
639.
Rufus K. Guthrie Ure A. Anugwelem Ernst M. Davis 《Journal of the American Water Resources Association》1981,17(6):1005-1007
ABSTRACT: Escherichia coli. Streptococcus faecalis, Salmonella typhimurium, and Staphylococcus aureus were tested in pure culture and in various combined mixed cultures to determine effects of the presence of carbaryl in water. Oxygen uptake of E. coli and S. typhimirium was stimulated by five mg/L carbaryl when mixed together, but no stimulation was observed when either organism was tested alone or with other bacteria. In mixed culture the survival time of S. faecalis was reduced in the presence of five mg/L carbaryl; however, the survival time of both S. aureus and S. typhimurium was increased in the presence of five mg/L carbaryl. Implications of these results are discussed. 相似文献
640.
城市人居环境可持续发展评价研究——以大连市为例 总被引:20,自引:0,他引:20
城市人居环境的可持续发展是现代城市建设和发展的最终目标。本文建立了城市人居环境可持续发展的评价指标体系及评价模型 ;通过对大连市城市人居环境实地调查 ,运用Fuzzy方法对大连市城市人居环境可持续发展进行评价分析 ,确定了城市人居环境发展阶段 ;根据评价结果 ,结合大连市人居环境的具体情况 ,提出了大连市城市人居环境可持续发展的对策 相似文献