全文获取类型
收费全文 | 266篇 |
免费 | 17篇 |
国内免费 | 4篇 |
专业分类
安全科学 | 22篇 |
废物处理 | 8篇 |
环保管理 | 42篇 |
综合类 | 28篇 |
基础理论 | 88篇 |
环境理论 | 3篇 |
污染及防治 | 62篇 |
评价与监测 | 17篇 |
社会与环境 | 12篇 |
灾害及防治 | 5篇 |
出版年
2023年 | 7篇 |
2022年 | 2篇 |
2021年 | 4篇 |
2020年 | 4篇 |
2019年 | 7篇 |
2018年 | 12篇 |
2017年 | 19篇 |
2016年 | 13篇 |
2015年 | 10篇 |
2014年 | 7篇 |
2013年 | 23篇 |
2012年 | 16篇 |
2011年 | 23篇 |
2010年 | 15篇 |
2009年 | 17篇 |
2008年 | 18篇 |
2007年 | 17篇 |
2006年 | 8篇 |
2005年 | 10篇 |
2004年 | 6篇 |
2003年 | 6篇 |
2002年 | 3篇 |
2000年 | 4篇 |
1999年 | 6篇 |
1998年 | 6篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1977年 | 1篇 |
1954年 | 1篇 |
排序方式: 共有287条查询结果,搜索用时 187 毫秒
181.
Jeremy S. Simmonds James E. M. Watson Alvaro Salazar Martine Maron 《Conservation biology》2019,33(6):1438-1447
Habitat destruction is among the greatest threats facing biodiversity, and it affects common and threatened species alike. However, metrics for communicating its impacts typically overlook the nonthreatened component of assemblages. This risks the loss of habitat going unreported for species that comprise the majority of assemblages. We adapted a widely used measure for summarizing researcher output (the h index) to provide a metric that describes natural habitat loss for entire assemblages, inclusive of threatened and nonthreatened species. For each of 447 Australian native terrestrial bird species, we combined information on their association with broad vegetation groups with distributional range maps to identify the difference between the estimated pre-European and current extents of potential habitat, defined as vegetation groups most closely associated with each species. From this, we calculated the loss index (LI), which revealed that 30% of native birds have each lost at least 30% of their potential natural habitat (LI = 30). At the subcontinental scale, LIs ranged from 15 in arid Australia to 61 in the highly transformed southeastern part of the country. Different subcomponents of the assemblage had different LI values. For example, Australia's parrots (n = 52 species) had an LI of 38, whereas raptors (n = 32 species) had an LI of 25. The LI is simple to calculate and can be determined using readily available spatial information on species distributions, native vegetation associations, and human impacts on natural land cover. This metric, including the curves used to deduce it, could complement other biodiversity indices if it is used for regional and global biodiversity assessments that compare the status of natural habitat extent for assemblages within and among nations, monitor changes through time, and forecast future changes to guide strategic land-use planning. The LI is an intuitive tool that can be used to summarize and communicate how human actions affect whole assemblages, not just threatened species. 相似文献
182.
Striped trumpeter (Latris lineata) is a demersal teleost distributed around the temperate clines of all the major oceans in the southern hemisphere. Within
Tasmanian waters the species is managed as a single stock, although no studies have been performed to confirm genetic panmixia.
A protracted pelagic larval phase and a recent transoceanic tag recapture of an adult fish suggest significant potential for
genetic mixing between widely separated populations. Phylogenetic analysis of mitochondrial DNA control region sequences suggested
no genetic mixing between Tasmania, New Zealand and St Paul/Amsterdam Islands, evidence for the first time that there is population
structure at a transoceanic scale for this species. In addition, an analysis of molecular variance coupled with phylogenetic
analyses suggested no significant structuring of striped trumpeter from three locations around Tasmania. The information provided
in this study is useful for the design of modern fisheries management techniques such as spatially implemented marine reserves.
In addition, species-by-species knowledge about population structures of marine species facilitates ecologically useful generalizations
concerning their population dynamics and key issues on the broader ecology of the oceans. 相似文献
183.
Andrea Ross Jeremy Rowan-Robinson 《Journal of Environmental Planning and Management》1997,40(1):111-124
This paper focuses on one aspect of industry's contribution to safeguarding the environment: the use and production of environmental information. Access to such information is an important part of the government strategy for promoting shared responsibility for the environment. The objective of the paper is to assess how far public regulation, private regulation and self regulation provide an incentive to industry to use and produce environmental information. 相似文献
184.
185.
186.
187.
188.
Increasing interest in biofuels trade between developed and developing countries has spurred worldwide discussions on issues such as subsidies and the ‘food for fuel’ crisis. One issue missing in recent discourse is the pressure exerted on developing countries to adopt large-scale mechanized farming practices to increase economic efficiencies. Such approaches often exclude small-scale farmers from participating in the emerging biofuels market, thus exacerbating poverty and social exclusion. Drawing on both qualitative and technical data, we discuss such pressures using Brazilian ethanol and biodiesel production. Pressure from international markets to become more economically efficient may contribute towards the erosion of recent schemes to encourage social benefits for small farmers in biodiesel production. We conclude with trade and policy implications. 相似文献
189.
190.
Water demand management, or making better use of the water we have — as opposed to augmenting supply — is increasingly proposed as a way of mitigating water-scarcity problems. Moving water away from agriculture to uses with higher economic value is one of the main measures widely seen as desirable. Sectoral "allocation stress" is seen as resulting from the disproportionate share, and inefficient use of water in the agricultural sector. This apparent misallocation is often attributed to the failure of government to allocate water rationally.
This paper revisits this commonly-accepted wisdom and examines the nature of urban water scarcity, showing the importance of economic and political factors, shaped by incentives to decision-makers, and sometimes compounded by climatic conditions. It shows that cities' growth is not generally constrained by competition with agriculture. In general, rather than using a narrow financial criterion, cities select options that go along the "path of least resistance," whereby economic, social and political costs are considered in conjunction. The question of allocation stress is thus reframed into an inquiry of how transfers effectively occur and can be made more effective. 相似文献
This paper revisits this commonly-accepted wisdom and examines the nature of urban water scarcity, showing the importance of economic and political factors, shaped by incentives to decision-makers, and sometimes compounded by climatic conditions. It shows that cities' growth is not generally constrained by competition with agriculture. In general, rather than using a narrow financial criterion, cities select options that go along the "path of least resistance," whereby economic, social and political costs are considered in conjunction. The question of allocation stress is thus reframed into an inquiry of how transfers effectively occur and can be made more effective. 相似文献