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   3615篇
  免费   291篇
  国内免费   1500篇
安全科学   231篇
废物处理   151篇
环保管理   512篇
综合类   2738篇
基础理论   1014篇
环境理论   4篇
污染及防治   317篇
评价与监测   178篇
社会与环境   171篇
灾害及防治   90篇
  2024年   27篇
  2023年   107篇
  2022年   212篇
  2021年   229篇
  2020年   223篇
  2019年   215篇
  2018年   198篇
  2017年   182篇
  2016年   206篇
  2015年   203篇
  2014年   266篇
  2013年   356篇
  2012年   306篇
  2011年   331篇
  2010年   277篇
  2009年   213篇
  2008年   181篇
  2007年   263篇
  2006年   240篇
  2005年   189篇
  2004年   144篇
  2003年   144篇
  2002年   124篇
  2001年   106篇
  2000年   88篇
  1999年   84篇
  1998年   44篇
  1997年   41篇
  1996年   39篇
  1995年   24篇
  1994年   29篇
  1993年   25篇
  1992年   21篇
  1991年   9篇
  1990年   18篇
  1989年   3篇
  1988年   2篇
  1986年   4篇
  1985年   2篇
  1984年   5篇
  1983年   2篇
  1982年   3篇
  1981年   4篇
  1980年   2篇
  1979年   2篇
  1978年   2篇
  1977年   2篇
  1973年   1篇
  1972年   1篇
  1971年   5篇
排序方式: 共有5406条查询结果,搜索用时 46 毫秒
931.
The present study addresses the ongoing debate concerning academic scientific productivity. Specifically, given the increasing number of collaborations in academia and the crucial role networks play in knowledge creation, we investigate the extent to which building social capital within the academic community represents a valuable resource for a scientist's knowledge‐creation process. We measure the social capital in terms of structural position within the academic collaborative network. Furthermore, we analyse the extent to which an academic scientist's research specialization and ties that cross‐community boundaries act as moderators of the aforementioned relationship. Empirical results derived from an analysis of an Italian academic community from 2001 to 2008 suggest academic scientists that build social capital by occupying central positions in the community outperform their more isolated colleagues. However, scientific productivity declines beyond a certain threshold value of centrality, hence revealing the existence of an inverted U‐shaped relationship. This relationship is negatively moderated by the extent to which an academic focuses research activities in few scientific knowledge domains, whereas it is positively moderated by the number of cross‐community ties established. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   
932.
为探明羧甲基纤维素钠(CMC)与麦秸秆纤维对植被混凝土基材力学与植生性能的影响,通过直剪试验、植生试验研究了改性后植被混凝土基材(简称改性基材)的抗剪性能与黑麦草生长性能.结果 表明:①改性基材的剪切强度随CMC掺量的增加呈先增后减的变化趋势,0.5%CMC掺量时基材的剪切强度出现峰值,而随纤维掺量的增加改性基材剪切强...  相似文献   
933.
危险与可操作性分析对于石化装置的工艺安全管理具有重要意义,介绍了HAZOP分析方法在工艺装置上的应用流程,并讨论了HAZOP分析与风险矩阵的结合运用。以克拉玛依石化公司的80吨/小时酸性水汽提装置为例,详细阐述了HAZOP分析的流程及其与半定量分析相结合的方法在实践中的应用,并针对危险源给出了风险削减措施。基于HAZOP分析在实践中的应用情况,总结了一些客观存在的问题,并提出了意见和建议。  相似文献   
934.
以活性污泥技术为主体的好氧工艺是污水生物处理技术方面应用较为广泛的方法。随着现代分子生物学技术的不断发展,人们对活性污泥中微生物菌群多样性的认识逐渐深化,大量用传统方法未检测到,但在活性污泥中发挥关键作用的微生物逐渐引起研究学者的重视。现代分子生物学技术以FISH技术、实时荧光定量PCR技术、DGGE/TGGE技术、16SrRNA序列比较、T—RFLP技术、AFLP技术等为代表已成为研究微生物微观形态及种群结构特征的主要手段。文章就这些技术在活性污泥微生物菌群多样性研究中的应用进行了总结,为进一步研究污水处理领域活性污泥的微生物菌群多样性提供了必要的依据。  相似文献   
935.
While the redevelopment of brownfield sites has been the mainstay of public agencies and private developers, this paper argues that in order to promote just redevelopment that encourages participation and targets weak market sites, a community-based approach to brownfield redevelopment should be encouraged. Furthermore, this paper maintains that community development corporations (CDCs) could be the ideal agents to spur community development and address environmental justice concerns through their increased involvement in brownfield redevelopment projects. In order to promote these positions, we first describe this new approach, which focuses on building the capacity of CDCs to meaningfully participate in brownfield redevelopment. We then offer four proposals designed to increase this capacity. We conclude with a discussion of how community-based brownfield redevelopment connects to larger issues of democratic decision-making, environmental justice, and urban revitalisation.  相似文献   
936.
Climate change and sustainable development concerns have motivated some municipalities in Canada to develop community energy plans, which focus on energy needs at the local level for the development of efficient, economical and environmental energy systems. Five Canadian cities that were early adopters of community energy planning principles were studied to assess whether implementation has occurred and what barriers have been experienced. The cities achieved success in the implementation of energy management in municipal operations despite barriers in jurisdiction, perception of cost, communication and capacity, but energy management in the community had not been fully implemented and long-term changes were not prevalent. While reductions were made in the greenhouse gas (GHG) emissions produced by municipal operations, the community's overall GHG emissions were not significantly reduced. Long-term impacts on a city's function and growth will be key if community energy planning is to significantly impact community-wide GHG emissions and energy use.  相似文献   
937.
With energy crises looming, conflicts over resource extraction and production are on the rise. For communities lacking voice to participate in these conflicts, community-based organisations and local non-governmental organisations help to unite, communicate, and negotiate with other stakeholders. In this paper we compare two cases that demonstrate the roles of organisations in providing voice to citizenry impacted by environmental justice issues. We use Senecah's concept of Trinity of Voice for the purposes of evaluation. These cases provide contrasting examples of how local/regional organisations chose to either expand their organisation's mission to intervene or stick to a strict reading of their mission thus excluding involvement. In both examples we found that organisational involvement, or lack thereof, influenced how citizens were involved in decision-making with one case leading to legislation protecting property owners from industrial activities, and the other leading to a lack of effective involvement and negatively impacted citizens.  相似文献   
938.
This article examines the relevance of environmental justice (EJ) and climate change debates as points of articulation and mobilisation among community groups responding to a proposed refinery. It then compares media coverage of the refinery project, a bi-national pipeline and other energy and climate-related news events. The analytical frame joins the EJ paradigm with citizen mobilisation on issues of climate change and energy projects that emit greenhouse gases and that discourage development of renewable sources. Data were collected and analysed from websites, public message boards and media documents. Findings indicate that a community-based anti-refinery campaign combined local EJ struggles with climate activism, while challenging fossil fuel dependencies and calling for renewable regional energy. A climate justice community formed – yet their voices were in their blogs and websites, not in local or national media.  相似文献   
939.
This article explores community-awareness perspectives and actions towards dioxin-related health exposure in Paritutu Community, New Plymouth, New Zealand. The actions are analysed through media reports, covering a 10-year period from 1998 to 2008. Since 1964, Paritutu Community residents have expressed concern about increased morbidity associated with dioxin contamination from a nearby agrichemical plant. Upon investigation, official agencies were at first unable to verify a causal link between dioxin and morbidity, precipitating community activism and increasing public pressure on relevant authorities. Residents played a major role in alleviating further damage to their community by analysing and evaluating data and providing information that ultimately resulted in both official recognition of their environmental health risk and preventative strategies to alleviate their morbidity. This article backgrounds the Paritutu Community Epidemiology approach and evaluates stages in how the Paritutu Community overcame indifference and lack of precaution and exerted influence leading to the removal of the source of contamination and positive policy changes in public health including the setting up of ameliorative health services for affected people. The findings of this research support theories of popular, lay, community and worker epidemiology.  相似文献   
940.
There has been increased interest in the role of community-based action in promoting sustainable lifestyles in recent years, but relatively limited evidence on the effects of such activity on participants' behaviours. In this paper, I present an evaluation of the effects of community-based action for sustainability on participants' lifestyles. I draw on extensive qualitative research to assess how much change participants of community sustainability projects report, what kinds of participants these projects attract and how the circumstances of these projects affect the changes that participants make. The main findings are that these initiatives have different effects on different people. Those who are new to sustainability and who are actively involved in cohesive groups, which are specifically targeting their lifestyles, are more likely to report substantial changes. I present a model to explain what change occurs, for which types of participants, in what circumstances as a result of community-based action.  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