全文获取类型
收费全文 | 1535篇 |
免费 | 81篇 |
国内免费 | 77篇 |
专业分类
安全科学 | 69篇 |
废物处理 | 7篇 |
环保管理 | 491篇 |
综合类 | 444篇 |
基础理论 | 392篇 |
污染及防治 | 82篇 |
评价与监测 | 62篇 |
社会与环境 | 133篇 |
灾害及防治 | 13篇 |
出版年
2024年 | 3篇 |
2023年 | 11篇 |
2022年 | 16篇 |
2021年 | 35篇 |
2020年 | 34篇 |
2019年 | 23篇 |
2018年 | 22篇 |
2017年 | 32篇 |
2016年 | 43篇 |
2015年 | 41篇 |
2014年 | 43篇 |
2013年 | 70篇 |
2012年 | 50篇 |
2011年 | 107篇 |
2010年 | 92篇 |
2009年 | 123篇 |
2008年 | 103篇 |
2007年 | 101篇 |
2006年 | 103篇 |
2005年 | 88篇 |
2004年 | 69篇 |
2003年 | 73篇 |
2002年 | 61篇 |
2001年 | 61篇 |
2000年 | 62篇 |
1999年 | 27篇 |
1998年 | 26篇 |
1997年 | 27篇 |
1996年 | 14篇 |
1995年 | 24篇 |
1994年 | 14篇 |
1993年 | 11篇 |
1992年 | 13篇 |
1991年 | 8篇 |
1990年 | 10篇 |
1989年 | 6篇 |
1988年 | 13篇 |
1987年 | 6篇 |
1986年 | 3篇 |
1985年 | 6篇 |
1984年 | 5篇 |
1983年 | 2篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1978年 | 1篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1972年 | 2篇 |
1971年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有1693条查询结果,搜索用时 125 毫秒
761.
Andreas Mölder Marcus Schmidt Tobias Plieninger Peter Meyer 《Conservation biology》2020,34(6):1444-1451
The protection and sustainable management of habitat trees is an integral part of modern forest nature conservation concepts such as retention forestry. Bats, cavity-nesting birds, arboreal marsupials, and many different saproxylic species depend on habitat trees and their great variety of microhabitats and old-growth characteristics. With a focus on insights from temperate forests, we traced the development of habitat-tree protection over 200 years. The idea was first conceptualized by foresters and natural scientists in the early 19th century. At that time, utilitarian conservation aimed to protect cavity trees that provided roosts and nesting holes for insectivorous bats and birds. By the second half of the 19th century, habitat-tree protection was well known to foresters and was occasionally implemented. Knowledge of the protection of large old trees, a special kind of habitat tree, for sociocultural and aesthetic reasons developed similarly. But, many foresters of that time and in the following decades fundamentally rejected protection of habitat trees for economic reasons. Beginning in the 1970s, forest conservation and integrative forest management became increasingly important issues worldwide. Since then, the protection of habitat trees has been implemented on a large scale. Long-term views on the development of conservation concepts are important to inform the implementation of conservation today. In particular, historical analyses of conservation concepts allow the testing of long-term conservation outcomes and make it possible to study the resilience of conservation approaches to changing social or ecological conditions. We encourage all conservation ecologists to assess the practical and conceptual impact of the initial ideas that led to modern conservation concepts in terms of long-term biodiversity conservation. 相似文献
762.
《Environmental Communication: A Journal of Nature and Culture》2013,7(4):529-547
This essay provides a critical account of Wal-Mart's rhetoric of environmental stewardship. By situating this discourse within a new political economy of production and governance that Michael Hardt and Antonio Negri have termed empire, I argue that environmental communication scholars should limit the rush to deploy ideological criticism when explaining the corporation's rhetorical motives. Instead, I advocate reading Wal-Mart's rhetoric as a problem of historical conjunctures, a critical move that seeks to highlight, not only the structural interests of capital, but also the centrality of social antagonism. In the case of Wal-Mart, this means accounting for the increased significance of demand to economic production, changes in the composition of sovereignty, and the transgressive function of environmentalism at the beginning of the twenty-first century. 相似文献
763.
张保伟 《中国人口.资源与环境》2013,23(8)
从利益、价值与认知三维视域出发,分析了环境冲突的形成原因,考察了环境伦理对环境冲突的调适机理.环境冲突是社会主体利益、价值、认知多元化背景下多种因素综合的结果.从彼此间独断性的对立和冲突转向建设性的生态与互动,是化解环境冲突的根本路径.对此,环境伦理学具有其独特的价值和意义.环境伦理通过对环境价值的辩护,将自然拉进道德关注的视野,塑造和影响人们的利益、价值和认知结构,调适人类社会中工业文明以来不断制度化的生态缺失,从而作为一种积极的要素,推进各主体的利益、价值和认知由对立和冲突走向彼此共存的生态互动. 相似文献
764.
Abstract Regional vegetation pattern dynamics has a great impact on ecosystem and climate change. Remote sensing data and geographical information system (GIS) analysis were widely used in the detection of vegetation pattern dynamics. In this study, the Yellow River Delta was selected as the study area. By using 1986, 1993, 1996, 1999 and 2005 remote sensing data as basic information resource, with the support of GIS, a wetland vegetation spatial information dataset was built up. Through selecting the land-scape metrics such as class area (CA), class percent of landscape (PL), number of patch (NP), largest patch index (LPI) and mean patch size (MPS) etc., the dynamics of vegetation pattern was analyzed. The result showed that the change of vegetation pattern is significant from 1986 to 2005. From 1986–1999, the area of the vegetation, the percent of vegetation, LPI and MPS decreased, the NP increased, the vegetation pattern tends to be fragmental. The decrease in vegetation area may well be explained by the fact of the nature environment evolution (Climate change and decrease in Yellow River runoff) and the increase in the population in the Yellow River Delta. However, from 1999–2005, the area of the vegetation, the percent of vegetation, LPI and MPS increased, while the NP decreased. This trend of restoration may be due to the implementation of water resources regulation for the Yellow River Delta since 1999. 相似文献
765.
Modifications to ecosystems often lead to externalities that can be assigned an economic value and traded in ecosystem service markets. One such value may include the provisioning of nest sites for organisms that would otherwise be ousted from the surrounding cultural landscape, such as the sand martin (Riparia riparia), small passerine utilizing river bank rippings when available. The studied sand martin population was initially characterized as relying heavily on human activities for habitat, as extensive river regulation caused the relocation of 97% of Czech sand martins to man-made habitats, most commonly sandpits and gravel-sandpits. The socioeconomic changes and strict implementation of the EIA law had further detrimental effects on this species, which already adjusted to the human-dominated landscape, ousting it for a second time from its key nesting habitats, causing closure 86% of sandpits with only occasional quarrying and closure of 47% of those with regular small-scale regular quarrying. Meanwhile, large-scale quarries remained nearly unaffected. Conversion of any actively quarried site to that with vertical slopes present, but with quarrying absent, led to the progressive disappearance of sand martin colonies in 73% of sandpits with ceased occasional quarrying and in 87% of sandpits with ceased regular small-scale quarrying. The sharp decrease in the number of nest-sites of a bird protected by law is a gloomy result of the hypertrophied business regulation (EIA is estimated to cost € 970 million annually in the E.U. alone) aimed, paradoxically, to support the environment. 相似文献
766.
随着经济全球化、城市化进程的加剧,城市生态的规划建设对社会经济发展起着至关重要的作用。从可持续发展视域探讨当前城市规划建设中存在的由规划滞后、规划重复、规划片面、执法不严等造成的城市规划环境污染、资源浪费和生态破坏的问题,提出构建城市生态规划的现实必然性和基本原则,从强化机制、转变观念、以人为本、健全法制、合理规划等角度探讨可持续发展视阈下城市生态规划的途径。 相似文献
767.
Laura Mannocci Sébastien Villon Marc Chaumont Nacim Guellati Nicolas Mouquet Corina Iovan Laurent Vigliola David Mouillot 《Conservation biology》2022,36(1):e13798
Deep learning has become a key tool for the automated monitoring of animal populations with video surveys. However, obtaining large numbers of images to train such models is a major challenge for rare and elusive species because field video surveys provide few sightings. We designed a method that takes advantage of videos accumulated on social media for training deep-learning models to detect rare megafauna species in the field. We trained convolutional neural networks (CNNs) with social media images and tested them on images collected from field surveys. We applied our method to aerial video surveys of dugongs (Dugong dugon) in New Caledonia (southwestern Pacific). CNNs trained with 1303 social media images yielded 25% false positives and 38% false negatives when tested on independent field video surveys. Incorporating a small number of images from New Caledonia (equivalent to 12% of social media images) in the training data set resulted in a nearly 50% decrease in false negatives. Our results highlight how and the extent to which images collected on social media can offer a solid basis for training deep-learning models for rare megafauna detection and that the incorporation of a few images from the study site further boosts detection accuracy. Our method provides a new generation of deep-learning models that can be used to rapidly and accurately process field video surveys for the monitoring of rare megafauna. 相似文献
768.
Transport of fish from Norway: energy analysis using industrial ecology as the framework 总被引:1,自引:0,他引:1
In this article, industrial ecology is used as a framework for analysing transport energy and its implication for products. The importance of the energy use for transport in a natural resource production system is analysed. By using fish as a case study, it is shown that the amount of energy for transport is highly dependent on the transport mode used. When applying industrial ecology principles for making assessments of the environmental impacts of products, the whole product chain is examined. This is an extended life-cycle approach, which also includes the transport of the finished products from the exporter to the importing country. This last part of the transport chain can be extremely energy demanding, as is shown for the case of fish transport. This finding has implications for the products, and for the form in which the products should be transported. Increasing the energy efficiency of production systems is an important industrial ecology principle, and must be taken into consideration when analysing product chains. A revision of today's practice of transporting large quantities of fresh whole fish by transcontinental airliners is bound to be necessary. This is a consequence of the demands for increased energy efficiency of tomorrow's industrial production systems. 相似文献
769.
景观健康及其评价初探 总被引:3,自引:0,他引:3
生态系统健康是环保领域新兴的、正崭露头角的科学,将生态系统健康科学应用于景观评价是基于人类管理景观严重受到威胁和趋于退化的现实。在论述景观健康概念及其特征的基础上,探讨对景观健康进行整体评价的方法和指标。 相似文献
770.
Development projects that impact wetlands commonly require compensatory mitigation, usually through creation or restoration
of wetlands on or off the project site. Over the last decade, federal support has increased for third-party off-site mitigation
methods. At the same time, regulators have lowered the minimum impact size that triggers the requirement for compensatory
mitigation. Few studies have examined the aggregate impact of individual wetland mitigation projects. No previous study has
compared the choice of mitigation method by regulatory agency or development size. We analyze 1058 locally and federally permitted
wetland mitigation transactions in the Chicago region between 1993 and 2004. We show that decreasing mitigation thresholds
have had striking effects on the methods and spatial distribution of wetland mitigation. In particular, the observed increase
in mitigation bank use is driven largely by the needs of the smallest impacts. Conversely, throughout the time period studied,
large developments have rarely used mitigation banking, and have been relatively unaffected by changing regulatory focus and
banking industry growth. We surmise that small developments lack the scale economies necessary for feasible permittee responsible
mitigation. Finally, we compare the rates at which compensation required by both county and federal regulators is performed
across major watershed boundaries. We show that local regulations prohibiting cross-county mitigation lead to higher levels
of cross- watershed mitigation than federal regulations without cross-county prohibitions. Our data suggest that local control
over wetland mitigation may prioritize administrative boundaries over hydrologic function in the matter of selecting compensation
sites. 相似文献