首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   935篇
  免费   13篇
  国内免费   2篇
安全科学   46篇
废物处理   37篇
环保管理   121篇
综合类   297篇
基础理论   179篇
环境理论   3篇
污染及防治   187篇
评价与监测   36篇
社会与环境   32篇
灾害及防治   12篇
  2023年   12篇
  2021年   17篇
  2020年   24篇
  2019年   8篇
  2018年   22篇
  2017年   26篇
  2016年   23篇
  2015年   26篇
  2014年   22篇
  2013年   46篇
  2012年   55篇
  2011年   61篇
  2010年   32篇
  2009年   44篇
  2008年   56篇
  2007年   42篇
  2006年   39篇
  2005年   30篇
  2004年   25篇
  2003年   21篇
  2002年   25篇
  2001年   17篇
  2000年   9篇
  1999年   8篇
  1998年   12篇
  1997年   9篇
  1996年   6篇
  1995年   11篇
  1994年   13篇
  1993年   6篇
  1991年   8篇
  1990年   4篇
  1988年   4篇
  1981年   6篇
  1980年   5篇
  1977年   4篇
  1973年   6篇
  1972年   6篇
  1971年   4篇
  1970年   4篇
  1967年   6篇
  1965年   5篇
  1963年   6篇
  1961年   4篇
  1960年   5篇
  1959年   7篇
  1957年   5篇
  1956年   9篇
  1955年   10篇
  1934年   4篇
排序方式: 共有950条查询结果,搜索用时 15 毫秒
61.
Adaptation to climate change has been reviewed in several developed nations, but in none where consideration of the effects of climate change is required by statute and devolved to local government. We examine the role of institutional arrangements, the players operating under them, the barriers and enablers for adaptation decision-making in the developed nation of New Zealand. We examine how the roles and responsibilities between national, regional and local governments influence the ability of local government to deliver long-term flexible responses to changing climate risk. We found that the disciplinary practices of law, engineering and planning, within legal frameworks, result in the use of static mechanisms which create inflexible responses to changing risk. Several enablers are identified that could create greater integration between the different scales of government, including better use of national policy instruments, shared professional experience, standardised information collection and risk assessment methods that address uncertainties. The framing of climate risk as dynamic and changing that differentiates activities over their lifetime, development of mechanisms to fund transitions towards transformational change, are identified as necessary conditions for delivering flexible responses over time.  相似文献   
62.
63.
Increasingly, performance measurement is being used to hold federal agencies accountable, represent environmental progress, and evaluate the effectiveness of environmental programs. The need to track measurable outputs has created a tendency to present programmatic progress solely by quantifiable data, despite the inherent complexity of natural resource management. Wetlands and fire management programs are two specific environmental arenas that have come to overemphasize the tracking of acreage numbers to validate existing policy direction. In both of these arenas, we find the definition and categorization of "countable" acres to be inconsistent and unreliable. We explore this systemic flaw for both wetlands and fire programs and describe its implications for environmental policy and natural resource management more broadly. We conclude with recommendations for improved performance measurement in these arenas.  相似文献   
64.
Urban stream restoration continues to be used as an ecological management tool, despite uncertainty about the long‐term sustainability and resilience of restored systems. Evaluations of restoration success often focus on specific instream indicators, with limited attention to the wider basin or parallel hydrologic and geomorphic process. A comprehensive understanding of urban stream restoration progress is particularly important for comparisons with nonurban sites as urban streams can provide substantial secondary benefits to urban residents. Here, we utilize a wide range of indicators to retrospectively examine the restoration of Nine Mile Run, a multi‐million dollar stream restoration project in eastern Pittsburgh (Pennsylvania, USA). Examination of available continuous hydrological data illustrates the high cost of failures to incorporate the data into planning and adaptive management. For example, persistent extreme flows drive geomorphic degradation threatening to reverse hydrologic connections created by the restoration and impact the improved instream biotic communities. In addition, human activities associated with restoration efforts suggest a positive feedback as the stream restoration has focused effort on the basin beyond the reach. Ultimately, urban stream restoration remains a potentially useful management tool, but continued improvements in post‐project assessment should include examination of a wider range of indicators.  相似文献   
65.
66.
67.
Ecological philosophy requires a significant orientation to the role of hope in both theory and practice. I trace the limited presence of hope in ecological philosophy, and outline reasons why environmental hopelessness is a threat. I articulate and problematize recent environmental publications on the topic of hope, the most important worry being that current literature fails to provide the necessary psychological grounding for hopeful action. I turn to the psychology of hope to provide direction for conceptualizing hope and actualizing hoped for states of affairs. If positive moral action is the goal, hope is a vital concept for underwriting ecological philosophy and a practice requiring considerably more attention.  相似文献   
68.
The assessment of eco-toxicological impacts related to the emission of contaminants into the environment has peculiar characteristics in the context of Life Cycle Assessment (LCA), and many different Life Cycle Impact Assessment (LCIA) methodologies can be used. However, previous studies recognized the presence of high uncertainties in the process, in particular when the analysis focuses on metal emissions. Metals are diverse inorganic substances relevant for their characteristic environmental chemistry, their high persistency into the environment and their toxicity at even low environmental concentrations. This study aims at expanding the discussion about how, and how differently, various methods for LCIA are estimating the impacts related to metals emissions, with a focus on eco-toxicological impacts. A comparison between eight different LCIA methods is presented in relative terms, using a contribution analysis at two levels: general and specific. Results show that there is a poor agreement between methods in the determination of the total eco-toxic impact attributable to metals, and in defining which metal provokes the highest eco-toxic impact per unitary emission. Furthermore, the characterization phase is critical in determining the disagreement between methods. However, some similarities were found: there is the tendency in most methods to associate the largest share of the total eco-toxicological impacts to metals. Theoretical and practical differences between methods are discussed and suggestions for the choice of the proper, case-specific, LCIA method are provided.  相似文献   
69.
70.
Both exposures to toxic metals, as well as deficiencies in essential metals, during pregnancy has been linked to a variety of negative reproductive outcomes. The exact etiologies of such outcomes and the effects of fetal exposure to these metals are largely unknown. Therefore, the ability to assess levels of these elements is critical to determining the underlying causes of such conditions and the effects that both essential and nonessential metals have on fetal development. Thus, using cell-free fetal RNA from amniotic fluid, we set out to measure the association between amniotic fluid levels of toxic and essential metals and fetal gene expression. We find that arsenic was associated with increased expression of 3 genes known to play roles in both birth-related and reproductive effects. The results highlight the potential for detrimental health effects of prenatal metals exposure and the potential to identify biomarkers of environmental exposure during this critical developmental period.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号