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   9719篇
  免费   0篇
安全科学   7篇
废物处理   772篇
环保管理   1213篇
综合类   934篇
基础理论   3112篇
污染及防治   1758篇
评价与监测   1021篇
社会与环境   902篇
  2023年   2篇
  2022年   5篇
  2021年   2篇
  2019年   1篇
  2018年   1474篇
  2017年   1373篇
  2016年   1194篇
  2015年   123篇
  2014年   21篇
  2013年   15篇
  2012年   466篇
  2011年   1339篇
  2010年   695篇
  2009年   601篇
  2008年   884篇
  2007年   1233篇
  2006年   5篇
  2005年   21篇
  2004年   39篇
  2003年   67篇
  2002年   100篇
  2001年   14篇
  2000年   11篇
  1999年   3篇
  1998年   9篇
  1997年   1篇
  1984年   11篇
  1983年   8篇
  1935年   2篇
排序方式: 共有9719条查询结果,搜索用时 0 毫秒
31.
32.
33.
A new approach to the problem of environmental hazard assessment and monitoring for pollutant biodegradation reaction systems in the presence of uncertainty is proposed using soft sensor-based pollutant concentration dynamic profile reconstruction techniques. In particular, a robust reduced-order soft sensor is proposed that can be digitally implemented in the presence of inherent complexity and the inevitable model uncertainty. The proposed method explicitly incorporates all the available information associated with a process model characterized by varying degrees of uncertainty, as well as available sensor measurements of certain physicochemical quantities. Based on the above information, a reduced-order soft sensor is designed enabling the reliable reconstruction of pollutant concentration profiles in complex biodegradation systems that can not be always achieved due to physical and/or technical limitations associated with current sensor technology. The option of using the aforementioned approach to compute toxic load and persistence indexes on the basis of the reconstructed concentration profiles is also pursued. Finally, the performance of the proposed method is evaluated in two illustrative environmental hazard assessment case studies.  相似文献   
34.
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   
35.
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   
36.
37.
The aim of this study was to assess the seasonal development of the physicochemical (pH, organic C, organic N, extractable P, Ca2+, Mg2+) and biological soil properties (microbial biomass, activities of urease, dehydrogenase and alkaline phosphatase) of the topsoil of mine deposition sites that differed based on the material used exclusively for their creation: (a) marlstones, (b) red-grey formations (RGF), and (c) fly ash (FA), during the first year after their creation. Our hypothesis was that all deposition sites, regardless the material they consist of, present equal opportunities for the establishment of spontaneous vegetation. All macronutrients concentrations (P, Ca2+, and Mg2+) remained constant with time and were found to be higher in the FA sites. Organic C, organic N, all enzyme activities, and microbial biomass were higher in the RGF and marl depositions, with marl sites presenting the highest values. All values of biological variables, with the exception of alkaline phosphatase, increased with time. The alkaline environment along with the slow improvement in soil biological properties of the FA sites seemed to present the most unfavorable conditions for spontaneous vegetation growth. On the contrary, the other two spoil materials presented significant improvement in the initial stages of soil formation in terms of soil functionality.  相似文献   
38.
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   
39.
40.
This study examines the relation between CO2 emissions, income, non-renewable, and renewable energy consumption in Algeria during the period extending from 1980 to 2011. Our work gives particular attention to the validity of environmental Kuznets curve (EKC) hypothesis. The autoregressive distributed lag (ARDL) with break point method outcome demonstrates the positive effect of non-renewable type of energy on CO2 emissions consumption. On the contrary, the results reveal an insignificant effect of renewable energy on environment improvement. Moreover, the results accept the existence of EKC hypothesis but the highest gross domestic product value in logarithm scale of our data is inferior to the estimated turning point. Consequently, policy-makers in Algeria should expand the ratio of renewable energy and should decrease the quota of non-renewable energy consumption.  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