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   13427篇
  免费   474篇
  国内免费   1488篇
安全科学   532篇
废物处理   932篇
环保管理   1570篇
综合类   3738篇
基础理论   3641篇
污染及防治   2461篇
评价与监测   1219篇
社会与环境   1121篇
灾害及防治   175篇
  2024年   25篇
  2023年   98篇
  2022年   255篇
  2021年   248篇
  2020年   273篇
  2019年   202篇
  2018年   1679篇
  2017年   1618篇
  2016年   1395篇
  2015年   418篇
  2014年   347篇
  2013年   408篇
  2012年   870篇
  2011年   1732篇
  2010年   1046篇
  2009年   897篇
  2008年   1195篇
  2007年   1497篇
  2006年   225篇
  2005年   151篇
  2004年   128篇
  2003年   116篇
  2002年   163篇
  2001年   78篇
  2000年   57篇
  1999年   41篇
  1998年   42篇
  1997年   35篇
  1996年   20篇
  1995年   25篇
  1994年   21篇
  1993年   22篇
  1992年   16篇
  1991年   7篇
  1990年   2篇
  1989年   3篇
  1987年   2篇
  1986年   2篇
  1984年   13篇
  1983年   10篇
  1982年   2篇
  1981年   2篇
  1976年   1篇
  1935年   2篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
131.
132.
Environmental Science and Pollution Research - Water conservation and soil retention are two essential regulating services that are closely related, and their relationship might produce synergies...  相似文献   
133.
134.
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   
135.
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   
136.
In the global campaign against biodiversity loss in forest ecosystems, land managers need to know the status of forest biodiversity, but practical guidelines for conserving biodiversity in forest management are lacking. A major obstacle is the incomplete understanding of the relationship between site primary productivity and plant diversity, due to insufficient ecosystem‐wide data, especially for taxonomically and structurally diverse forest ecosystems. We investigated the effects of site productivity (the site's inherent capacity to grow timber) on tree species richness across 19 types of forest ecosystems in North America and China through 3 ground‐sourced forest inventory data sets (U.S. Forest Inventory and Analysis, Cooperative Alaska Forest Inventory, and Chinese Forest Management Planning Inventory). All forest types conformed to a consistent and highly significant (P < 0.001) hump‐shaped unimodal relationship, of which the generalized coefficients of determination averaged 20.5% over all the forest types. That is, tree species richness first increased as productivity increased at a progressively slower rate, and, after reaching a maximum, richness started to decline. Our consistent findings suggest that forests of high productivity would sustain few species because they consist mostly of flat homogeneous areas lacking an environmental gradient along which a diversity of species with different habitats can coexist. The consistency of the productivity–biodiversity relationship among the 3 data sets we examined makes it possible to quantify the expected tree species richness that a forest stand is capable of sustaining, and a comparison between the actual species richness and the sustainable values can be useful in prioritizing conservation efforts.  相似文献   
137.
138.
随着集成电路的功能越来越复杂,超大规模集成电路的动态老炼越来越成为一项困难的工作。传统针对超大规模集成电路的老炼多采用静态老炼方法,这种方法不能使电路内部的功能节点动作起来,无法保证老炼效果,因此能够实现电路内部所有功能模块全动态激励的TDBI技术越来越受到人们的关注。本文以国产多核处理器芯片为测试对象,为研究多核处理器芯片的TDBI方法进行了芯片老炼测试软硬件系统开发,解决了多核处理器老炼中大功率电源供电、图形存储空间不足等关键技术。  相似文献   
139.
140.
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