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   3769篇
  免费   336篇
  国内免费   513篇
安全科学   152篇
废物处理   28篇
环保管理   1224篇
综合类   1258篇
基础理论   1339篇
环境理论   2篇
污染及防治   165篇
评价与监测   117篇
社会与环境   239篇
灾害及防治   94篇
  2023年   56篇
  2022年   103篇
  2021年   114篇
  2020年   136篇
  2019年   109篇
  2018年   111篇
  2017年   160篇
  2016年   168篇
  2015年   185篇
  2014年   162篇
  2013年   250篇
  2012年   190篇
  2011年   278篇
  2010年   194篇
  2009年   219篇
  2008年   213篇
  2007年   251篇
  2006年   196篇
  2005年   185篇
  2004年   143篇
  2003年   134篇
  2002年   91篇
  2001年   85篇
  2000年   88篇
  1999年   94篇
  1998年   63篇
  1997年   56篇
  1996年   68篇
  1995年   56篇
  1994年   40篇
  1993年   30篇
  1992年   34篇
  1991年   24篇
  1990年   18篇
  1989年   17篇
  1988年   16篇
  1987年   25篇
  1986年   26篇
  1985年   24篇
  1984年   25篇
  1983年   13篇
  1982年   13篇
  1980年   15篇
  1979年   17篇
  1978年   20篇
  1977年   14篇
  1975年   10篇
  1973年   17篇
  1972年   15篇
  1971年   16篇
排序方式: 共有4618条查询结果,搜索用时 812 毫秒
711.
我国规划环评相关技术问题探析   总被引:5,自引:0,他引:5  
中国是立法认可规划环评并作为促进环境保护和可持续发展重要手段的亚洲国家之一。由于我国环评法2003年9月1日才施行,可以说我国规划环评技术尚处于探索中。文章回顾了国际上和我国规划(战略)环评的主流概念、主要任务、基本型式和总体技术路线,提出了我国规划环评的主要任务及适宜的基本型式和总体技术路线。  相似文献   
712.
As part of the right of indigenous cultures to self-determination, several international bodies have recognized and addressed the role of indigenous communities in natural resources management, including the conservation of biodiversity. In the United States, disagreements regarding the application of the federal Endangered Species Act to Native American tribes have hindered the relationship between the federal and tribal governments on endangered species recovery. Our research examines the efforts of one Native American tribe, the Nez Perce, and the United States federal government to collaborate on federal gray wolf recovery in central Idaho. We interviewed members of the Nez Perce Tribe and U.S. Fish and Wildlife Service to characterize their relationship and explore the context in which the recovery program was implemented. Respondents attributed the success of the biological aspects of wolf recovery to the robustness of the wolf as a species and to close interagency coordination at the operational level. However, differences of opinion existed between the Tribe and Service concerning program funding, policy planning, and the rights and role of the Tribe in wolf management via co-management and cooperative management regimes. Respondents from both governments noted a clear hierarchical relationship at the strategic level, where policy planning and decision-making rested with the federal government. Lessons drawn from this case study can be applied across the international spectrum to improving partnerships, particularly at the strategic level, between indigenous and non-indigenous governance structures for protecting endangered species.  相似文献   
713.
湿地是分布于陆生生态系统和水生生态系统之间具有独特水文、土壤、植被与生物特征的生态系统。盛泽湖是位于苏州相城区东北部的天然浅水湖泊,东临阳澄湖,面积为3.86 km^2。由于当地居民对湖泊进行过度养殖和捕捞、大量的围湖造田和进行农业生产建设、工农业废水和生活污水直接排入水体及湿地附近砖瓦厂的取土等原因引起盛泽湖湿地的生态退化。用生态规划的方法来探讨如何对盛泽湖湿地进行生态恢复,并从环境效益、社会效益和经济效益来分析规划方案实施后的效果。  相似文献   
714.
针对沈阳市经济发展和污染加剧的特点,为合理充分利用浑河水环境容量,节约投资,建立了浑河沈阳段主要排污口最优化模型,并应用分段线性化对该模型进行了线性化,进而确定排污口最优化线性模型,最后通过M atlab软件求解出各排放口的污水允许排放浓度及最低的处理费用。  相似文献   
715.
新农村建设中的环境问题与规划对策   总被引:3,自引:0,他引:3  
文章对新世纪农村环境问题的内涵进行了探讨,结合新农村规划的实践提出了有针对性的建议与对策,并进一步以新农村建设中产业选择和污水处理问题为例进行了具体的分析研究。  相似文献   
716.
天目山国家级保护区加入世界生物圈保护区网络已经10年,为了更好地保护其生物多样性和文化多样性,并可持续地利用好该保护区的自然资源,需适应客观形势发展的要求,把天目山国家级保护区建成为名副其实的生物圈保护区。采用现场实地考察、社区居民访谈、保护区管理者和政府人员座谈、历史资料查询等方法,了解到天目山保护区在自然资源保护、科研监测、教育培训、资源持续利用和生态旅游等方面取得了不少的成绩,但也存在诸如保护区面积尚欠不够、毛竹林资源能否合理利用和柳杉林的衰亡与病虫害的防治等问题。按照生物圈保护区的管理理念并参照以上的调查和思考,提出下列3条建议:一是扩大保护区的面积,二是建立一个完善的保护区共管机制,三是建立学术顾问委员会协助推动保护区各方面的工作。  相似文献   
717.
The composition and structure of the Gray mussel (Crenomytilus grayanus) community in Vostok Bay of the Sea of Japan have been studied. A total of 165 species have been identified in the macrobenthos. Its species composition has changed insignificantly since the 1970s. The total biomass of the biocenosis has decreased, and the size-age composition of the C. grayanus population has changed due to poaching. The trophic structure of the community has also changed, with the Shannon indices of species diversity and equitability (E) becoming lower, due to intensive organic pollution of Vostok Bay resulting from increasing recreational activities and sewage discharge.  相似文献   
718.
In this paper, we present an integrated intuitive system for assembly operators training and assembly process planning by combining virtual reality with motion-tracking technologies. The developed conceptual prototype for assembly planning and training enables individuals to interact with a virtual environment in real time. It extends the new technologies of motion tracking and integrates them with virtual environment technologies to create real-time virtual work cell simulations in which assembly operators may be immersed with hands-on experiences. In addition to operators training, the experimental results to date are presented to demonstrate the potential contributions of human skills in achieving effective assembly planning including disassembly operations. It is expected that this approach will lead to environment-friendly and sustainable operations by conserving energy and cost that are first tested in a human-emerged virtual system.  相似文献   
719.
ABSTRACT

This essay examines the mediation of the threat of Asian carp as an invasive species in American waterways based on analysis of 43 articles published in local and national periodicals from 2009 to 2017. Rhetorical and proximization analysis reveals the consistent establishment of carp as an outsider threat and a continual narrowing of the gap between this threat and the deictic center: the Great Lakes. In addition, the notion of the spectacle of the Asian carp’s physiological and behavioral features (i.e. leaping) was found to fade across time in favor of arguments based upon widespread ecosystem and economic damage. This essay argues that the use of these yoked strategies not only prioritizes the threat of Asian carp over other more insidious invasive species but also displays a potentially harmful anti-immigrant preference through metaphor.  相似文献   
720.
Community participation and community based management are topical themes in current policy and discussion revolving around decision-making processes especially those dealing with natural resources management.This review shows that while governments have accepted the need to either cede or devolve control and management of natural resources to the local communities,the communities are not part and parcel of the planning and budgeting which are crucial in decisionmaking.Communities were seen to be more involved in the implementation of natural resource management programs but lacked ownership of the projects.This causes lack of commitment to the programs and at times hostile reaction from the communities.The communities are always at the receiving end when it pertains to losses in the exchange.Community participation was shown to be effective when the local population is involved not as co-operating users but as natural resource managers or owner managers.  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