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   784篇
  免费   7篇
  国内免费   34篇
安全科学   16篇
废物处理   43篇
环保管理   41篇
综合类   54篇
基础理论   115篇
污染及防治   439篇
评价与监测   66篇
社会与环境   47篇
灾害及防治   4篇
  2023年   30篇
  2022年   158篇
  2021年   145篇
  2020年   50篇
  2019年   46篇
  2018年   41篇
  2017年   53篇
  2016年   45篇
  2015年   31篇
  2014年   37篇
  2013年   50篇
  2012年   22篇
  2011年   26篇
  2010年   11篇
  2009年   11篇
  2008年   17篇
  2007年   11篇
  2006年   8篇
  2005年   7篇
  2004年   7篇
  2003年   4篇
  2001年   1篇
  2000年   2篇
  1999年   1篇
  1998年   1篇
  1995年   1篇
  1994年   1篇
  1992年   1篇
  1991年   1篇
  1990年   1篇
  1989年   2篇
  1988年   1篇
  1985年   1篇
  1974年   1篇
排序方式: 共有825条查询结果,搜索用时 46 毫秒
761.
Environmental Science and Pollution Research - Good brain health refers to a condition in which a person may fully realize their talents and improve their psychological, emotional, cognitive, and...  相似文献   
762.
Myanmar's water‐related sectors are subject to intensive changes, as the country's abundant land and water resources provide substantial scope for development. Recent steps towards economic reform in Myanmar have led to a surge of foreign investment directed towards intensified natural resource extraction. Both the agricultural and the energy sector are increasingly affected by foreign investments that will impact the status of water, energy and food security in the country. With these on‐going developments, Myanmar's future is largely dependent on how its natural resources are managed and how the benefits from the resource extraction are shared. With various institutional changes and new actors welcomed to the sectors, existing livelihoods and ecosystems dependent on the land and water resources are to face increasing competition for the shared resources, while lacking secured access to them. There are increasing concerns that this sectoral development is occurring at the expense of environmental and social sustainability. As one way to tackle these challenges, the water‐energy‐food nexus approach could help in finding synergies and co‐benefits across sectors by addressing the imbalances along the nexus and externalities derived from the on‐going intensification.  相似文献   
763.
Biomass estimation in agroecosystems (AESs) is important to understand their role in carbon exchange for a sustainable environment. We used field spectra and sampled biomass of an AES including cultivated and abandoned croplands to develop a simple biomass estimation model. The digital number (DN) of a QuickBird (QB) satellite image was converted to a reflectance factor using the dark object subtraction method and the spectral reflectance of asphalt. The relationship between the reflectance factor of field-based spectra and the QB image obtained in early July 2007 was insignificant in the blue (R 2 = 0.15) and green (R 2 = 0.18) bands but was significant (p < 0.05) in the red (R 2 = 0.57) and near-infrared (NIR, R 2 = 0.45) bands in the AES. Better correlations were obtained between field-based and QB-based vegetation indices (VIs). The best correlations were obtained with the normalized difference vegetation index (NDVI) (R 2 = 0.97, p < 0.001) and the ratio vegetation index (RVI) (R 2 = 0.99, p < 0.001). Biomass was significantly correlated with both field-based NDVI and RVI (R 2 = 0.79 and 0.72, respectively, p < 0.001). Although RVI saturated at higher biomass densities (>600 g m?2), NDVI showed a linear relationship. Other field-based VIs showed poorer correlations with biomass. The model was evaluated by incorporating it into high-resolution QB images to obtain the observed biomass. The relationship between field-estimated and QB-observed biomass appeared to be a one-to-one linear relationship (R 2 = 0.79). Thus, models using field spectra and sampled biomass can be applied to QB images for remote estimation of biomass in an AES.  相似文献   
764.
Goo JH  Irfan MF  Kim SD  Hong SC 《Chemosphere》2007,67(4):718-723
The selective catalytic reduction (SCR) characteristics of NO and NO(2) over V(2)O(5)-WO(3)-MnO(2)/TiO(2) catalyst using ammonia as a reducing agent have been determined in a fixed-bed reactor at 200-400 degrees C. The presence of NO(2) enhances the SCR activity at lower temperatures and the optimum ratio of NO(2)/NO(x) is found to be 0.5. During the SCR reactions, there are some side reactions occurred such as ammonia oxidation and N(2)O formation. At higher temperatures, the selective catalytic oxidation of ammonia and the nitrous oxide formation compete with the SCR reactions. The denitrification (DeNO(x)) conversion decreases at lower temperatures but it increases at higher temperatures with increasing SO(2) concentration. The presence of SO(2) in the feeds inhibits N(2)O formation.  相似文献   
765.
Global warming, the major environmental issue confronted by humanity today, is caused by rising level of green house gases. Carbon capture and storage technologies offer potential for tapering CO2 emission in the atmosphere. Adsorption is believed to be a promising technology for CO2 capture. For this purpose, a polyester was synthesized by polycondensation of1,3,5-benzenetricarbonyl trichloride and cyanuric acid in pyridine and dichloromethane mixture. The polymer was then characterized using FT-IR, TGA, BET surface area and pore size analysis, FESEM and CO2 adsorption measurements. The CO2 adsorption capacities of the polyester were evaluated at a pressure of 1 bar and two different temperatures(273 and 298 K).The performance of these materials to adsorb CO2 at atmospheric pressure was measured by optimum CO2 uptake of 0.244 mmol/g at 273 K. The synthesized polyester, therefore, has the potential to be exploited as CO2 adsorbent in pre-combustion capture process.  相似文献   
766.
Environmental Science and Pollution Research - The increasing intensification of the aquaculture industry requires the development of new strategies to reduce the negative impacts of wastewater on...  相似文献   
767.
Environmental Science and Pollution Research - Natural resources, especially agrarian soils, have been much contaminated with various pollutants including heavy metals since industrial revolution,...  相似文献   
768.
Environmental Science and Pollution Research - Anthropogenic and natural factors lead to substantial environmental degradation. This shift is aligned with the country's overall development,...  相似文献   
769.
770.
Environmental Science and Pollution Research - The literature review of ample body indicates that the majority of the studies rely on a single proxy, while exploring the determinants of...  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