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   19851篇
  免费   79篇
  国内免费   49篇
安全科学   226篇
废物处理   1348篇
环保管理   2024篇
综合类   2452篇
基础理论   5387篇
环境理论   6篇
污染及防治   4788篇
评价与监测   1820篇
社会与环境   1886篇
灾害及防治   42篇
  2023年   97篇
  2022年   243篇
  2021年   211篇
  2020年   97篇
  2019年   118篇
  2018年   1610篇
  2017年   1534篇
  2016年   1478篇
  2015年   344篇
  2014年   449篇
  2013年   908篇
  2012年   923篇
  2011年   1843篇
  2010年   1123篇
  2009年   1006篇
  2008年   1371篇
  2007年   1723篇
  2006年   508篇
  2005年   401篇
  2004年   385篇
  2003年   412篇
  2002年   400篇
  2001年   370篇
  2000年   235篇
  1999年   154篇
  1998年   76篇
  1997年   81篇
  1996年   65篇
  1995年   98篇
  1994年   94篇
  1993年   75篇
  1992年   75篇
  1991年   74篇
  1990年   76篇
  1989年   63篇
  1988年   65篇
  1987年   61篇
  1986年   57篇
  1985年   49篇
  1984年   59篇
  1983年   62篇
  1982年   53篇
  1980年   32篇
  1979年   37篇
  1974年   32篇
  1973年   30篇
  1965年   32篇
  1964年   54篇
  1959年   35篇
  1958年   49篇
排序方式: 共有10000条查询结果,搜索用时 359 毫秒
271.
272.
273.
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   
274.
This study aimed at finding effective strategies for high-performance removal of reactive blue 19 (RB19) dye from aqueous solution. Chitosan (CS) films had been prepared by using solvent casting with mild drying for this purpose. The CS films were characterized by X-ray diffraction, field-emission scanning electron microscopy, and Fourier transform infrared (FTIR) spectroscopy. The performance of RB19 removal using CS were evaluated by varying contact time, solution pH, initial dye concentration, and adsorbent dosage. Adsorption isotherms, kinetics, and desorption were investigated by batch experiments. Results showed that CS films exhibited the optimal adsorption performance for RB19 removal and high maximum adsorption capacities of RB19, which were 799 and 822.4 mg g?1 at 20 and 40 °C, respectively. Adsorption kinetic data were well described by the pseudo-second-order kinetic model. FTIR analyses further indicated that interactions between RB19 and the CS film occurred during adsorption. The CS films also exhibited satisfactory desorption of RB19 at about 80 % after 30 min of desorption at pH 11. Our study demonstrated that the CS films can be easily prepared and applied for effective removal of RB19 in treatment of wastewater.  相似文献   
275.
The fifth meeting of INRA’s national network of ecotoxicologists took place on 25 to 27 November 2014 in Biarritz, France. The main aim of the meeting was to bring together ecotoxicologists from INRA and associated partners, providing them ample opportunity to share and discuss their latest scientific results as well as the national policy of research in ecotoxicology and to precise perspectives for the network.  相似文献   
276.
277.
278.
279.
280.
This study examines the relationship between national-level militarism and consumption-based carbon dioxide emissions. We analyze panel data from 1990 to 2010 for 81 nations to determine whether the magnitude of the effects of (1) military expenditures as percent of total gross domestic product and (2) military personnel as percent of total labor force on carbon emissions change over time. Results of two-way fixed effects models highlight the temporal stability of the environmental impacts of both national-level military characteristics. The findings also reveal that the effect of military expenditures on emissions is larger in the more developed OECD nations than in the developing non-OECD nations. Overall, the results support the treadmill of destruction perspective, which suggests that the nations’ militaries are an important social institution to consider in sustainability science research on the human drivers of global environmental change.  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