全文获取类型
收费全文 | 844篇 |
免费 | 16篇 |
国内免费 | 7篇 |
专业分类
安全科学 | 57篇 |
废物处理 | 35篇 |
环保管理 | 136篇 |
综合类 | 86篇 |
基础理论 | 197篇 |
污染及防治 | 225篇 |
评价与监测 | 71篇 |
社会与环境 | 53篇 |
灾害及防治 | 7篇 |
出版年
2023年 | 4篇 |
2022年 | 4篇 |
2021年 | 7篇 |
2020年 | 9篇 |
2019年 | 14篇 |
2018年 | 14篇 |
2017年 | 23篇 |
2016年 | 19篇 |
2015年 | 13篇 |
2014年 | 14篇 |
2013年 | 45篇 |
2012年 | 43篇 |
2011年 | 42篇 |
2010年 | 34篇 |
2009年 | 46篇 |
2008年 | 48篇 |
2007年 | 45篇 |
2006年 | 36篇 |
2005年 | 41篇 |
2004年 | 42篇 |
2003年 | 20篇 |
2002年 | 33篇 |
2001年 | 27篇 |
2000年 | 27篇 |
1999年 | 28篇 |
1998年 | 11篇 |
1997年 | 6篇 |
1996年 | 11篇 |
1995年 | 10篇 |
1994年 | 18篇 |
1993年 | 13篇 |
1992年 | 8篇 |
1991年 | 7篇 |
1990年 | 12篇 |
1989年 | 11篇 |
1988年 | 5篇 |
1987年 | 7篇 |
1984年 | 4篇 |
1983年 | 5篇 |
1982年 | 5篇 |
1981年 | 5篇 |
1980年 | 7篇 |
1979年 | 4篇 |
1978年 | 6篇 |
1977年 | 3篇 |
1976年 | 5篇 |
1975年 | 4篇 |
1974年 | 4篇 |
1973年 | 4篇 |
1972年 | 4篇 |
排序方式: 共有867条查询结果,搜索用时 334 毫秒
411.
Peter J. S. Jones 《Environment, Development and Sustainability》2013,15(1):39-50
This paper considers the implications of the growing recognition of scale challenges, with a particular focus on those concerning the governance of protected areas (PAs), through a critical literature review. Two key scale challenges raised by PAs are considered: (1) the divergence of objectives between resource exploitation and biodiversity conservation; (2) the requirement to fulfil biodiversity conservation obligations. These are explored through a review of a UK marine PA case study which found that even though the state had adopted a controlling role that had created tensions by undermining the authority and livelihoods of some stakeholders, the partnership had been sufficiently strengthened to withstand these tensions through the instrumental development of ??bracing social capital??. Four conclusions for governance research with a particular reference to PA governance are drawn, and it is argued that presumptions based on Habermasian ideals should not constrain governance analyses, in that they should constructively incorporate the instrumental roles of the state. 相似文献
412.
Johnny Boggs Ge Sun David Jones Steven G. McNulty 《Journal of the American Water Resources Association》2013,49(1):132-150
Boggs, Johnny, Ge Sun, David Jones, and Steven G. McNulty, 2012. Effect of Soils on Water Quantity and Quality in Piedmont Forested Headwater Watersheds of North Carolina. Journal of the American Water Resources Association (JAWRA) 1‐19. DOI: 10.1111/jawr.12001 Abstract: Water quantity and quality data were compared from six headwater watersheds on two distinct soil formations, Carolina Slate Belt (CSB) and Triassic Basins (TB). CSB soils are generally thicker, less erodible, and contain less clay content than soils found in TB. TB generated significantly more discharge/precipitation ratio than CSB (0.33 vs. 0.24) in the 2009 dormant season. In the 2009 growing season, TB generated significantly less discharge/precipitation ratio than CSB (0.02 vs. 0.07). Over the entire monitoring period, differences in discharge/precipitation ratios between CSB and TB were not significantly different (0.17 vs. 0.20, respectively). Storm‐flow rates were significantly higher in TB than CSB in both dormant and growing season. Benthic macroinvertebrate biotic index scores were excellent for all streams. Nutrient concentrations and exports in CSB and TB were within background levels for forests. Low‐stream nitrate and ammonium concentrations and exports suggested that both CSB and TB were nitrogen limited. Soils appear to have had a significant influence on seasonal and storm‐flow generation, but not on long‐term total water yield and water quality under forested conditions. This study indicated that watersheds on TB soils might be more prone to storm‐flow generation than on CSB soils when converted from forest to urban. Future urban growth in the area should consider differences in baseline hydrology and effects of landuse change on water quantity and quality. 相似文献
413.
Farrar NJ Prevedouros K Harner T Sweetman AJ Jones KC 《Environmental pollution (Barking, Essex : 1987)》2006,144(2):423-433
A novel design of rapidly equilibrating passive air sampler was deployed at 38 sites across 19 European countries to investigate short-term spatial variability of persistent organic pollutants (POPs). Devices were sealed in airtight containers to eliminate the possibility of contamination during transit and couriered to recipients with deployment instructions. Exposure times of 7days permitted the use of back trajectory analysis to further understand the factors responsible for influencing the large-scale spatial distribution of PCBs, PBDEs, PCNs, PAHs, lindane and HCB. Following sampler harvest, devices were sealed and returned for analysis. Comparison of sequestered levels showed that PAHs exhibited the greatest spatial variability (by a factor of 30) with higher levels often associated with greater population density. In contrast, HCB values were much more uniform, reflecting its well mixed distribution in the atmosphere. Spatial variation was strongly influenced by air mass origin, with lower levels being observed at most sites impacted by maritime air masses. 相似文献
414.
This paper presents the results of research which evaluated the performance of strategic environmental assessment (SEA) practice in South Africa in order to develop understanding of how SEA functions within a developing country with a voluntary SEA system. The research applied a combination of methods in a mixed research strategy, including a macro level survey of the SEA system together with case study reviews exploring micro level application. Three main ‘system features’ emerged, namely expansion of voluntary practice, diversity in practice and general ineffectiveness. The results also highlight a number of ‘application features’ such as a lack of focus due to an inability to deal with the concepts of ‘sustainability’ and ‘significance’, as well as poor understanding and integration with decision-making processes. Moreover, it emerged that none of the case studies seem to have conducted an ‘assessment’ per se, but rather provided a framework for strategic decision-making. The paper puts forward a number of interrelated explanations for these system and application features. In a parallel to the fable of the ‘emperor's new clothes’, SEA in South Africa appears to be regarded as the answer to all environmental problems, whilst being ineffective in practice. 相似文献
415.
Climate change vulnerability and adaptation strategies in Egypt’s agricultural sector 总被引:2,自引:0,他引:2
416.
Above-ground biomass biomass of Molinia caerulea from 36 sites throughout Britain was analysed for concentrations of elements (N, P, K, Ca, Mg, Fe, Mn, Cu, Zn and Na), with matching analyses of soil nutrients, together with pH and LOI. Between-year and seasonal variation in the nutrients was also studied at one of the sites. the grass was found on acid sites ranging between pH 3.1 and 5.8. the soil humus content varied widely, and there were significant correlations between that and elements (N, P, K, Ca, Mg and Na) in the soil. Concentrations of calcium, magnesium, zinc and manganese in the plant material were significantly correlated with extractable levels in the soils. Between year variation in the plant nutrient concentrations at one site was of a similar order to variation between the sites. Generally there was less variation in nitrogen, phosphorus and potassium tissue levels than in calcium, magnesium, zinc and copper. Iron and sodium were the most variable. Tissue concentrations of nitrogen, phosphorus, potassium and copper declined throughout the growing season, whereas magnesium, calcium and iron built up until August/September after which a decline set in as the leaves senesced. the results are discussed in relation to the importance of standardizing the time of sampling, in comparison with concentrations of tissue levels in other plants and the growth strategy of this deciduous grass. 相似文献
417.
Robin S. Reid Philip K. Thornton Graeme J. McCrabb Russell L. Kruska Fred Atieno Peter G. Jones 《Environment, Development and Sustainability》2004,6(1-2):91-109
Climate change science has been discussed and synthesized by the world's best minds at unprecedented scales. Now that the Kyoto Protocol may become a reality, it is time to be realistic about the likelihood of success of mitigation activities. Pastoral lands in the tropics hold tremendous sequestration potential but also strong challenges to potential mitigation efforts. Here we present new analyses of the global distribution of pastoral systems in the tropics and the changes they will likely undergo in the next 50 years. We then briefly summarize current mitigation options for these lands. We then conclude by attempting a pragmatic look at the realities of mitigation. Mitigation activities have the greatest chance of success if they build on traditional pastoral institutions and knowledge (excellent communication, strong understanding of ecosystem goods and services) and provide pastoral people with food security benefits at the same time. 相似文献
418.
Len Wright Paul Chinowsky Kenneth Strzepek Russell Jones Richard Streeter Joel B. Smith Jean-Marc Mayotte Anthony Powell Lesley Jantarasami William Perkins 《Mitigation and Adaptation Strategies for Global Change》2012,17(8):939-955
We assessed the potential impacts of increased river flooding from climate change on bridges in the continental United States. Daily precipitation statistics from four climate models and three greenhouse gas (GHG) emissions scenarios (A2, A1B, and B1) were used to capture a range of potential changes in climate. Using changes in maximum daily precipitation, we estimated changes to the peak flow rates for the 100-year return period for 2,097 watersheds. These estimates were then combined with information from the National Bridge Inventory database to estimate changes to bridge scour vulnerability. The results indicate that there may be significant potential risks to bridges in the United States from increased precipitation intensities. Approximately 129,000 bridges were found to be currently deficient. Tens of thousands to more than 100,000 bridges could be vulnerable to increased river flows. Results by region vary considerably. In general, more bridges in eastern areas are vulnerable than those in western areas. The highest GHG emissions scenarios result in the largest number of bridges being at risk. The costs of adapting vulnerable bridges to avoid increased damage associated with climate change vary from approximately $140 to $250 billion through the 21st century. If these costs were spread out evenly over the century, the annual costs would be several billion dollars. The costs of protecting the bridges against climate change risks could be reduced by approximately 30% if existing deficient bridges are improved with riprap. 相似文献
419.
420.