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   4300篇
  免费   34篇
  国内免费   14篇
安全科学   96篇
废物处理   275篇
环保管理   302篇
综合类   543篇
基础理论   889篇
环境理论   7篇
污染及防治   1539篇
评价与监测   413篇
社会与环境   274篇
灾害及防治   10篇
  2023年   49篇
  2022年   121篇
  2021年   162篇
  2020年   65篇
  2019年   71篇
  2018年   167篇
  2017年   162篇
  2016年   235篇
  2015年   135篇
  2014年   269篇
  2013年   430篇
  2012年   300篇
  2011年   302篇
  2010年   231篇
  2009年   151篇
  2008年   222篇
  2007年   259篇
  2006年   193篇
  2005年   157篇
  2004年   111篇
  2003年   98篇
  2002年   87篇
  2001年   48篇
  2000年   40篇
  1999年   24篇
  1998年   17篇
  1997年   14篇
  1996年   10篇
  1995年   18篇
  1994年   11篇
  1993年   7篇
  1992年   6篇
  1991年   5篇
  1990年   6篇
  1980年   4篇
  1970年   9篇
  1967年   7篇
  1966年   8篇
  1965年   5篇
  1964年   12篇
  1963年   5篇
  1962年   5篇
  1961年   8篇
  1960年   9篇
  1959年   10篇
  1958年   25篇
  1957年   11篇
  1956年   6篇
  1955年   5篇
  1931年   3篇
排序方式: 共有4348条查询结果,搜索用时 15 毫秒
51.
52.
53.
54.
How do youth learn through participation in efforts to study and change the school food system? Through our participatory youth action research (YPAR) project, we move beyond the “youth as consumer” frame to a food justice youth development (FJYD) approach. We track how a group of youth learned about food and the public policy process through their efforts to transform their own school food systems by conducting a participatory evaluation of farm-to-school efforts in collaboration with university and community partners. We used the Photovoice research method, placing cameras in the hands of young people so that they themselves could document and discuss their concerns and perspectives. The research was designed to gain insight about youths’ knowledge of food, health, and community food systems. Drawing upon the youth group’s insights, we build a framework for building critical consciousness through FJYD.  相似文献   
55.
Environmental Science and Pollution Research - The assessment of productivity change over time and its drivers is of great significance for water companies and regulators when setting urban water...  相似文献   
56.
57.
58.
Regional Environmental Change - Understanding drivers of forest-cover change is essential for a broad range of ecosystem properties. In this work, we assessed changes in forest cover using...  相似文献   
59.
In general, tourism plays a significant role in the economy of archipelagos and islands. The Autonomous Region of the Azores has a great potential for tourism, offering multiple attractions, both natural and cultural, creating a big challenge for a sustainable tourism policy since little attention has been paid to the archipelagos and their special needs. This work aims to understand the profile and type of ecotourist that visits the Azores. This knowledge is of great importance for a better management and development of nature-based tourism, and products tailored to the needs and expectations of visitors. The data were collected by means of exit surveys conducted at the Airport of São Miguel Island, the larger and most populated island of the archipelago, during the high tourist season—July–September 2009. The analysis of the visitor’s profile and preferences is crucial to draw adequate strategies of management for tourism, while it helps to adequate the offer to the demand. Results showed that 41.1 % of the tourists claimed to be attracted to the islands due to their “natural values” (e.g., landscape, biodiversity, and geodiversity). The most practiced activities were whale-watching (32.4 %) and mountaineering/hiking (31.6 %), followed by diving (7 %) and other sports (5.1 %). The tourists’ profile points to a mainstream, soft, and incidental type of ecotourist. This information helps to develop and support a strategic planning and management, both at local and regional levels, for sustainable tourism policies.  相似文献   
60.
The use of recurrence plots have been extensively used in various fields. In this work, recurrence plots investigate the changes in the non-linear behaviour of urban air pollution using large datasets of raw data (hourly). This analysis has not been used before to extract information from large datasets for this type of non-linear problem. Two different approaches have been used to tackle this problem. The first approach is to show results according to monitoring network. The second approach is to show the results by particle type. This analysis shows the feasibility of using recurrence analysis for pollution monitoring and control.  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