全文获取类型
收费全文 | 1635篇 |
免费 | 50篇 |
国内免费 | 24篇 |
专业分类
安全科学 | 64篇 |
废物处理 | 72篇 |
环保管理 | 383篇 |
综合类 | 131篇 |
基础理论 | 503篇 |
环境理论 | 4篇 |
污染及防治 | 327篇 |
评价与监测 | 115篇 |
社会与环境 | 87篇 |
灾害及防治 | 23篇 |
出版年
2023年 | 11篇 |
2022年 | 26篇 |
2021年 | 35篇 |
2020年 | 26篇 |
2019年 | 32篇 |
2018年 | 39篇 |
2017年 | 56篇 |
2016年 | 57篇 |
2015年 | 54篇 |
2014年 | 56篇 |
2013年 | 141篇 |
2012年 | 78篇 |
2011年 | 126篇 |
2010年 | 79篇 |
2009年 | 93篇 |
2008年 | 113篇 |
2007年 | 102篇 |
2006年 | 81篇 |
2005年 | 62篇 |
2004年 | 62篇 |
2003年 | 56篇 |
2002年 | 39篇 |
2001年 | 20篇 |
2000年 | 19篇 |
1999年 | 20篇 |
1998年 | 17篇 |
1997年 | 16篇 |
1996年 | 19篇 |
1995年 | 17篇 |
1994年 | 22篇 |
1993年 | 15篇 |
1992年 | 16篇 |
1991年 | 10篇 |
1990年 | 7篇 |
1989年 | 9篇 |
1988年 | 8篇 |
1987年 | 5篇 |
1986年 | 7篇 |
1985年 | 4篇 |
1984年 | 4篇 |
1983年 | 10篇 |
1982年 | 7篇 |
1981年 | 6篇 |
1980年 | 9篇 |
1978年 | 4篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1973年 | 3篇 |
1957年 | 1篇 |
排序方式: 共有1709条查询结果,搜索用时 109 毫秒
621.
Andrew P. Barnes 《Regional Environmental Change》2016,16(8):2269-2278
Full-scale technical potential provides a clear horizon for agricultural technology policy to meet the dual and urgent challenge of meeting food security and minimising the effects of climate change. A common stated goal is to double food production by 2050 to meet the needs of 9 billion people. The frontier of full-scale technical potential embodies this goal and provides a panacea for policy makers. However, the pathway between the present adoption of technologies towards this frontier is paved with some hazards which may be insurmountable. We develop a conceptual framework based on adoption levels of technology. The key criteria between current and potential adoption of technologies is the role of enablers, that is interventions which create changes in structural, distributional, technical, social and behavioural cultures. Policy must find optimal mixtures of regulation and voluntary mechanisms to fully encourage uptake of technologies and shift current adoption to meet full-scale technical potential. A range of technologies can be aligned with sustainable intensification and are examined in terms of this enabler framework. Further examination of the framework allows us to conclude that full-scale technical potential will never be achieved due to the stochastic nature of agricultural production, the diversity of motivations and institutional structures operating within food supply chains, as well as unbalanced cost-effectiveness criteria. We argue that sustainable intensification may provide a direction of travel for attaining food security but its poor conception, limited acceptability and understanding amongst the communities of interest lead to over-optimism in determining the journey to this final destination. 相似文献
622.
623.
With approximately 20 % of the world’s population living in its downstream watersheds, the Qinghai-Tibetan Plateau (QTP) is considered “Asia’s Water Tower.” However, grasslands of the QTP, where most of Asia’s great rivers originate, are becoming increasingly degraded, which leads to elevated population densities of a native small mammal, the plateau pika (Ochotona curzoniae). As a result pikas have been characterized as a pest leading to wide-spread poisoning campaigns in an attempt to restore grassland quality. A contrary view is that pikas are a keystone species for biodiversity and that their burrowing activity provides a critical ecosystem service by increasing the infiltration rate of water, hence reducing overland flow. We demonstrate that poisoning plateau pikas significantly reduces infiltration rate of water across the QTP creating the potential for watershed-level impacts. Our results demonstrate the importance of burrowing mammals as ecosystem engineers, particularly with regard to their influence on hydrological functioning. 相似文献
624.
Future agriculture with minimized phosphorus losses to waters: Research needs and direction 总被引:3,自引:0,他引:3
Andrew N. Sharpley Lars Bergström Helena Aronsson Marianne Bechmann Carl H. Bolster Katarina Börling Faruk Djodjic Helen P. Jarvie Oscar F. Schoumans Christian Stamm Karin S. Tonderski Barbro Ulén Risto Uusitalo Paul J. A. Withers 《Ambio》2015,44(2):163-179
The series of papers in this issue of AMBIO represent technical presentations made at the 7th International Phosphorus Workshop (IPW7), held in September, 2013 in Uppsala, Sweden. At that meeting, the 150 delegates were involved in round table discussions on major, predetermined themes facing the management of agricultural phosphorus (P) for optimum production goals with minimal water quality impairment. The six themes were (1) P management in a changing world; (2) transport pathways of P from soil to water; (3) monitoring, modeling, and communication; (4) importance of manure and agricultural production systems for P management; (5) identification of appropriate mitigation measures for reduction of P loss; and (6) implementation of mitigation strategies to reduce P loss. This paper details the major challenges and research needs that were identified for each theme and identifies a future roadmap for catchment management that cost-effectively minimizes P loss from agricultural activities. 相似文献
625.
Balancing urban growth and ecological conservation: A challenge for planning and governance in China
China has high biodiversity and is rapidly urbanizing. However, there is limited understanding of how urban expansion in the country is likely to affect its habitats and biodiversity. In this study, we examine urban expansion patterns and their likely impacts on biodiversity in China by 2030. Our analysis shows that most provinces are expected to experience urban expansion either near their protected areas or in biodiversity hotspots. In a few provinces such as Guangdong in the south, urban expansion is likely to impinge on both protected areas and biodiversity hotspots. We show that policies that could facilitate the integration of natural resource protection into urban planning exist on paper, but the prevailing incentives and institutional arrangements between the central and local governments prevent this kind of integration. Removing these obstacles will be necessary in order to safeguard the country’s rich biodiversity in light of the scale of urbanization underway. 相似文献
626.
Behavioral Ecology and Sociobiology - The associative learning of spatial and reward information is generally considered an adaptive behavior of foraging animals that collect food from renewable... 相似文献
627.
A fresh perspective on policy-making and planning has emerged which views disproportionate policy as an intentional policy response. A disproportionate policy response is understood to be a lack of ‘fit’ or balance between the costs of a public policy and the benefits that are derived from this policy, and between policy ends and means. This paper applies this new perspective on the proportionality of policy-making to the area of climate change. The first part of the paper discusses the underlying causes of disproportionate policy responses in broad terms and then applies the theoretical reasoning to understand the conditions in which they are likely to appear in relation to climate change. These conditions are hypothesized to relate to four main factors: economic considerations; levels of public demand; focusing events; and strategic considerations. It concludes with the suggestion that societal actors may be able to manipulate these four factors to encourage politicians to adopt policies that mitigate climate change more rapidly than is currently the case in most countries. 相似文献
628.
AbstractWater is a key resource for all life. Recent droughts have also exemplified the importance for manufacturers to understand their impact on water resources. While most manufacturers typically know the amount of water they use in their facilities, they have little knowledge about the indirect effects they have on water resources. In this paper, the indirect impact from the automakers’ electricity use and work force on water resources is examined. Water withdrawal and consumption from electricity use by hypothetical but representative facilities around the world is quantified and analysed. Water withdrawal by the workers is also quantified and analysed. The results indicate that the water withdrawal and consumption by the workforce and caused by the use of electricity is larger than the direct water use and consumption in the facilities themselves. 相似文献
629.
Environmental Management - In the past decade, municipalities across North America have increased investment in their urban forests in an effort to maintain and enhance the numerous benefits... 相似文献
630.
Andrew Turner Nimisha Singh Jonathan P. Richards 《Environmental pollution (Barking, Essex : 1987)》2009,157(5):1526-1532
Fragments of antifouling paint and environmental geosolids have been sampled from the island of Malta and analysed for total and bioaccessible metals. Total concentrations of Ba, Cd, Cu, Pb, Sn and Zn were two to three orders of magnitude higher in spent antifouling composites relative to respective values in background soils and road dusts. Paint fragments were visible in geosolids taken from the immediate vicinity of boat maintenance facilities and mass balance calculations, based on Ba as a paint tracer, suggested that the most contaminated soils, road dusts and boatyard dusts contained about 1%, 7% and 9%, respectively, of antifouling particles. Human bioaccessibilities of metals were evaluated in selected samples using a physiologically based extraction technique. Accessibilities of Cd, Cu, Pb and Zn in the most contaminated solids were sufficient to be cause for concern for individuals working in the boat repair industry and to the wider, local community. 相似文献