全文获取类型
收费全文 | 16537篇 |
免费 | 147篇 |
国内免费 | 91篇 |
专业分类
安全科学 | 409篇 |
废物处理 | 706篇 |
环保管理 | 2057篇 |
综合类 | 2734篇 |
基础理论 | 4483篇 |
环境理论 | 4篇 |
污染及防治 | 4192篇 |
评价与监测 | 1103篇 |
社会与环境 | 991篇 |
灾害及防治 | 96篇 |
出版年
2022年 | 135篇 |
2021年 | 111篇 |
2020年 | 124篇 |
2019年 | 146篇 |
2018年 | 204篇 |
2017年 | 248篇 |
2016年 | 345篇 |
2015年 | 293篇 |
2014年 | 474篇 |
2013年 | 1296篇 |
2012年 | 510篇 |
2011年 | 740篇 |
2010年 | 638篇 |
2009年 | 615篇 |
2008年 | 715篇 |
2007年 | 755篇 |
2006年 | 638篇 |
2005年 | 534篇 |
2004年 | 545篇 |
2003年 | 548篇 |
2002年 | 518篇 |
2001年 | 668篇 |
2000年 | 492篇 |
1999年 | 263篇 |
1998年 | 181篇 |
1997年 | 217篇 |
1996年 | 221篇 |
1995年 | 247篇 |
1994年 | 245篇 |
1993年 | 188篇 |
1992年 | 205篇 |
1991年 | 193篇 |
1990年 | 213篇 |
1989年 | 193篇 |
1988年 | 155篇 |
1987年 | 170篇 |
1986年 | 160篇 |
1985年 | 163篇 |
1984年 | 161篇 |
1983年 | 152篇 |
1982年 | 138篇 |
1981年 | 138篇 |
1980年 | 119篇 |
1979年 | 130篇 |
1978年 | 105篇 |
1977年 | 118篇 |
1975年 | 88篇 |
1974年 | 93篇 |
1973年 | 99篇 |
1972年 | 87篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
992.
Vulnerability is a term frequently used to describe the potential threat to rural communities posed by climate variability and change. Despite growing use of the term, analytical measures of vulnerability that are useful for prioritising and evaluating policy responses are yet to evolve. Demand for research capable of prioritising adaptation responses has evolved rapidly with an increasing awareness of climate change and its potential impacts on rural communities. Research into the climate-related vulnerability of Australian rural communities is only just beginning to emerge. Current research is dominated by hazard/impact modelling, drawing on a heritage of managing the risks posed by seasonal climate variability. There is a natural tendency to use the same risk management approach to understand the emergent nature of vulnerability. In this paper, we explore the consequences for policy advice of imperfectly examining vulnerability through the lens of an impact/hazard modelling approach to risk management. In a second paper in this series, we show how hazard/impact modelling can be complemented with more holistic measures of adaptive capacity to provide quantitative insights into the vulnerability of Australian rural communities to climate variability and change. 相似文献
993.
994.
Lensu T Komonen A Hiltula O Päivinen J Saari V Kotiaho JS 《Journal of environmental management》2011,92(10):2539-2546
Habitat loss is one of the greatest threats for biodiversity. In Finland, two thirds of natural mires have been drained for silviculture, which transforms open wetlands into dense forests. However, vegetation management of power line rights-of-way (ROW) maintain the drained mires as open areas. The aim of this study was to determine the effect of the power line ROW vegetation management on butterfly abundance, species richness and community structure by comparing the managed power line ROWs to unmanaged drained control sites and to natural mires. The species richness or abundance of mire butterflies did not differ between the power line ROWs and natural mires. In contrast, both species richness and abundance of butterflies was low on the unmanaged control sites. Tree canopy cover had a negative effect on mire butterflies and this is most likely related to changes in microclimate. The results indicate that the active vegetation removal in the power line ROWs maintain alternative habitats for mire butterflies; yet, the power line ROWs cannot substitute the natural mires. 相似文献
995.
We report relatively high citrulline concentration in amniotic fluid of a citrullinemic fetus suggesting that prenatal detection of this condition could be done on this basis in conjunction with a direct or an indirect determination of argininosuccinate synthetase activity in amniotic fluid cells. 相似文献
996.
Partial desynapsis in pearl millet 总被引:1,自引:0,他引:1
Prem P. Jauhar 《Die Naturwissenschaften》1969,56(11):571-572
997.
Lilburne LR Hewitt AE Sparling GP Selvarajah N 《Journal of environmental quality》2002,31(6):1768-1773
Soil depletion and degradation have been increasingly recognized as important environmental issues in many parts of the world. Over the last decade a number of political and legislative measures have been introduced to encourage and enforce sustainable soil management in New Zealand. Application of the new legislation has highlighted gaps in our knowledge of soil quality and a lack of scientific methods to assess and monitor soil quality. This paper describes the legislative measures and outlines the sdentific response to the needs of regulatory agencies responsible for maintaining environmental quality. The research recommended a set of indicators to assess soil quality. Each soil quality attribute has an associated "target range" defining the acceptable value for the attribute. The paper also discusses the communication of results to end-users, including the development of a computerized assessment tool. The legislative measures and scientific response have fostered a closer relationship between the policy and science communities, leading to more well-focused research, but greater collaboration is still required. 相似文献
998.
Libor Pátý 《Die Naturwissenschaften》1959,46(13):422-423
999.
1000.