全文获取类型
收费全文 | 1887篇 |
免费 | 234篇 |
国内免费 | 53篇 |
专业分类
安全科学 | 39篇 |
废物处理 | 16篇 |
环保管理 | 465篇 |
综合类 | 336篇 |
基础理论 | 1069篇 |
环境理论 | 3篇 |
污染及防治 | 63篇 |
评价与监测 | 46篇 |
社会与环境 | 131篇 |
灾害及防治 | 6篇 |
出版年
2024年 | 3篇 |
2023年 | 72篇 |
2022年 | 57篇 |
2021年 | 82篇 |
2020年 | 84篇 |
2019年 | 77篇 |
2018年 | 74篇 |
2017年 | 84篇 |
2016年 | 90篇 |
2015年 | 103篇 |
2014年 | 91篇 |
2013年 | 124篇 |
2012年 | 78篇 |
2011年 | 99篇 |
2010年 | 121篇 |
2009年 | 115篇 |
2008年 | 106篇 |
2007年 | 122篇 |
2006年 | 82篇 |
2005年 | 75篇 |
2004年 | 70篇 |
2003年 | 27篇 |
2002年 | 30篇 |
2001年 | 42篇 |
2000年 | 33篇 |
1999年 | 20篇 |
1998年 | 21篇 |
1997年 | 19篇 |
1996年 | 20篇 |
1995年 | 18篇 |
1994年 | 16篇 |
1993年 | 19篇 |
1992年 | 11篇 |
1991年 | 8篇 |
1990年 | 5篇 |
1989年 | 4篇 |
1988年 | 4篇 |
1987年 | 10篇 |
1986年 | 4篇 |
1985年 | 4篇 |
1984年 | 3篇 |
1983年 | 7篇 |
1982年 | 8篇 |
1981年 | 8篇 |
1980年 | 7篇 |
1979年 | 4篇 |
1978年 | 4篇 |
1972年 | 1篇 |
1971年 | 4篇 |
1968年 | 1篇 |
排序方式: 共有2174条查询结果,搜索用时 0 毫秒
991.
Oisín F. Sweeney John Turnbull Menna Jones Mike Letnic Thomas M. Newsome Andy Sharp 《Conservation biology》2019,33(4):812-820
Rewilding is increasingly recognized as a conservation tool but is often context specific, which inhibits broad application. Rewilding in Australia seeks to enhance ecosystem function and promote self-sustaining ecosystems. An absence of large-bodied native herbivores means trophic rewilding in mainland Australia has focused on the restoration of functions provided by apex predators and small mammals. Because of the pervasive influence of introduced mesopredators, predator-proof fences, and establishment of populations on predator-free islands are common rewilding approaches. This sets Australian rewilding apart from most jurisdictions and provides globally relevant insights but presents challenges to restoring function to broader landscapes. Passive rewilding is of limited utility in arid zones. Although increasing habitat extent and quality in mesic coastal areas may work, it will likely be necessary to undertake active management. Because much of Australia's population is in urban areas, rewilding efforts must include urban areas to maximize effectiveness. Thus rewilding is not synonymous with wilderness and can occur over multiple scales. Rewilding efforts must recognize human effects on other species and benefit both nature and humans. Rewilding in Australia requires development of a shared vision and strategy and proof-of-concept projects to demonstrate the benefits. The repackaging of existing conservation activities as rewilding may confuse and undermine the success of rewilding programs and should be avoided. As elsewhere, rewilding in Australia should be viewed as an important conservation tool. 相似文献
992.
江西庐山自然保护区主要森林植被水土保持功能评价 总被引:1,自引:0,他引:1
随着环境压力的与日俱增以及森林过度采伐带来的生态危机的加剧,森林生态系统控制水土流失与涵养水源功能的量化及机理研究已成为各国生态学家、林学家、水土保持学家共同关注的课题。以江西庐山自然保护区的6种主要森林植被为研究对象,基于野外调查和室内实验获取的相关数据,采用层次分析法,选取郁闭度、丰富度指数、土壤容重、毛管孔隙度、土壤稳渗速率、枯落物储量、枯落物分解强度、海拔、坡度等15个指标构建多层次多指标的水土保持功能评价体系,根据层次总排序结果,分别计算出各指标的权重,并利用线型评分函数求出各森林植被类型水土保持功能的综合评价值,即6种主要森林植被类型水土保持功能排序为:常绿阔叶林玉山竹林常绿-落叶阔叶混交林落叶阔叶林黄山松林马尾松林。 相似文献
993.
本文将金融节能与金融发展同时引入传统LMDI分解模型,并融合脱钩弹性指数,分析了两者对碳排放变化的影响机理。在此基础上,本文还检验了1997—2015年中国29个省区金融节能与金融发展的碳排放效应。研究发现:首先,尽管1997—2015年中国碳排放规模的扩张趋势较为明显,短期来看,这一演变仍然大体经历了三个阶段,即碳排放增量持续扩张期、碳排放增量波动下降期以及碳排放增量平稳期。其次,不仅金融节能、金融发展以及经济增长是在短期和长期诱发中国碳排放变化的三个最主要因素,而且前两者对中国碳排放变化的影响还大于后者。再次,金融节能对中国碳排放变化的短期和长期作用方向始终与金融发展对中国碳排放变化的短期和长期作用方向相反。最后,金融节能和金融发展与中国碳排放变化之间在短期内基本维持弱脱钩或强负脱钩两种状态,而在长期呈现强负脱钩状态,通过分解这些脱钩弹性状态的诱因,不仅直接影响和交互影响的作用方向始终相反,而且两者还分别在金融节能与中国碳排放脱钩弹性变动以及金融发展与中国碳排放脱钩弹性变动中发挥截然相反的作用。 相似文献
994.
滨岸潮滩是海岸带的重要组成部分和主要的地理景观 ,具有多种环境功能和生态价值 ,对沿海地区的经济发展起着重要的作用 ;同时滨岸潮滩又是一个环境脆弱带和敏感区 ,极易受人为活动的干扰和破坏。生物多样性是人类生存和经济得以持续发展的基础。滨岸潮滩是生物多样性最为丰富的生态系统之一。通过对上海滨岸潮滩生物多样性影响因素的调查与分析 ,研究了目前人类活动对上海滨岸潮滩生物多样性造成的严重威胁 ,污水的排放使滨岸潮滩水质和底质严重污染 ,对滨岸潮滩的围垦改变了潮滩的自然本底状态 ,造成潮滩生物生长发育和栖息的环境受到破坏 ,影响滨岸潮滩生物多样性。指出滨岸潮滩等方面的社会与环境价值 ,并探讨了上海滨岸带开发与滨岸潮滩生物多样性的保护和利用问题 相似文献
995.
在长江流域丘陵城镇重庆永川区和平原城镇常州金坛区分别选取各含合流制和分流制2种排水体制的4个区域作为研究对象,监测雨天4个区域的河流、沿河排口和下垫面径流相关数据,分别采用河流质量守恒法、PMF模型和地表径流质量守恒法解析2类城镇4个区域面源对河流污染贡献、沿河排口污染来源贡献和各下垫面污染贡献。结果表明,城镇面源对4个研究区域内河流的5项水质指标 (SS、COD、NH3-N、TN和TP) 均有一定程度的贡献,其贡献率与降雨等级、地区特征和排水体制有关;降雨期间,在2类城镇2种排水体制的沿河排口污染负荷来源中,地表径流是SS和COD负荷的主要来源,生活污水和管道沉积物是NH3-N、TN和TP负荷的主要来源;受地形坡度和人口密度等因素影响,永川和金坛的主要产污下垫面不同,永川为小区道路,金坛为交通道路和屋顶。为提高上述研究区域面源污染的精细化管理,提出了针对性的控制措施。 相似文献
996.
Ecological restoration and conservation are primary components of sustainable development around the world, particularly during the contemporary era of climate change. However, restoration and conservation are not free; they consume huge amounts of resources that would otherwise support social and economic development. Therefore, excessive conservation creates a risk of creating rather than eliminating poverty. Unfortunately, scientists have largely ignored the balance between these contrasting goals. Here, we discuss the concept of finding the threshold that represents a suitable balance between ecological conservation and economic development, thereby maximizing the benefits for both humans and the environment and promoting sustainable development. To demonstrate the concept, we examined China’s ecological restoration achievements and discussed some of the unforeseen negative consequences that accompanied these achievements to discuss how future policies could better balance ecological and socioeconomic goals. 相似文献
997.
There is increasing recognition that diverse knowledge systems can work in mutually enriching ways and that Indigenous and Local Knowledge (ILK) can enhance biodiversity conservation. However, studies using scientific knowledge and ILK in a complementary manner, and acknowledging convergent and especially divergent insights have remained limited. In this study, we contrasted proxies of abundances and trends of threatened and conflict-prone carnivores (caracal, cheetah, jackal, lion, leopard, spotted hyaena, striped hyaena) derived separately from scientific knowledge and ILK. We conducted camera trapping, track surveys and semi-structured interviews with local pastoralists from northern Kenya. We found convergences highlighting the need for conservation action and divergences suggesting scientific ecological sampling limitations or underlying socio-psychological phenomena. Overall, our study shows that complementing scientific knowledge and ILK as separate sources of information and opening up space for discrepancies can enrich our understanding of the status and trends of carnivores, as well as recognizing human-carnivore relationships.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01443-4) contains supplementary material, which is available to authorized users. 相似文献
998.
BRADLEY W. COMPTON‡ KEVIN McGARIGAL ‡ SAMUEL A. CUSHMAN‡ † LLOYD R. GAMBLE‡ 《Conservation biology》2007,21(3):788-799
Abstract: Pool-breeding amphibian populations operate at multiple scales, from the individual pool to surrounding upland habitat to clusters of pools. When metapopulation dynamics play a role in long-term viability, conservation efforts limited to the protection of individual pools or even pools with associated upland habitat may be ineffective over the long term if connectivity among pools is not maintained. Connectivity becomes especially important and difficult to assess in regions where suburban sprawl is rapidly increasing land development, road density, and traffic rates. We developed a model of connectivity among vernal pools for the four ambystomatid salamanders that occur in Massachusetts and applied it to the nearly 30,000 potential ephemeral wetlands across the state. The model was based on a modification of the kernel estimator (a density estimator commonly used in home range studies) that takes landscape resistance into account. The model was parameterized with empirical migration distances for spotted salamanders ( Ambystoma maculatum ), dispersal distances for marbled salamanders ( A. opacum ), and expert-derived estimates of landscape resistance. The model ranked vernal pools in Massachusetts by local, neighborhood, and regional connectivity and by an integrated measure of connectivity, both statewide and within ecoregions. The most functionally connected pool complexes occurred in southeastern and northeastern Massachusetts, areas with rapidly increasing suburban development. In a sensitivity analysis estimates of pool connectivity were relatively insensitive to uncertainty in parameter estimates, especially at the local and neighborhood scales. Our connectivity model could be used to prioritize conservation efforts for vernal-pool amphibian populations at broader scales than traditional pool-based approaches. 相似文献
999.
1000.
The Kuna are a strong and independent culture, however outside influences are imposing growing pressure on their people. Overpopulation and large-scale overfishing are among the most severe threats. The Kuna have developed their own management strategies to address these pressing issues. This study presents local perceptions and attitudes towards marine resource management of six indigenous fishing communities in Kuna Yala, Panama. Results highlight significant general and comparative differences in fishermen's attitudes and perceptions based on socio-cultural structures of communities, occupation and role in local decision-making. The level of cultural survival in communities was a strong indicator for different priorities and attitudes. Differences were also evident based on the level of marine resources used for income generation. Participation in local decision-making processes had positive impacts on levels of knowledge and information, and fostered critical thinking among participants. In addition, the results also denoted that conservation and development were more effective in the long term if the host population could develop strategies and plans for biodiversity conservation. Ownership and empowerment were strong indicators that influenced local livelihood to promote sustainable use of marine resources. 相似文献