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   16402篇
  免费   592篇
  国内免费   2705篇
安全科学   511篇
废物处理   1032篇
环保管理   1788篇
综合类   5651篇
基础理论   4244篇
环境理论   1篇
污染及防治   3444篇
评价与监测   1459篇
社会与环境   1293篇
灾害及防治   276篇
  2024年   47篇
  2023年   182篇
  2022年   454篇
  2021年   395篇
  2020年   400篇
  2019年   314篇
  2018年   1761篇
  2017年   1746篇
  2016年   1632篇
  2015年   640篇
  2014年   544篇
  2013年   658篇
  2012年   1097篇
  2011年   1991篇
  2010年   1267篇
  2009年   1148篇
  2008年   1350篇
  2007年   1660篇
  2006年   421篇
  2005年   265篇
  2004年   202篇
  2003年   258篇
  2002年   276篇
  2001年   155篇
  2000年   159篇
  1999年   126篇
  1998年   97篇
  1997年   80篇
  1996年   83篇
  1995年   61篇
  1994年   60篇
  1993年   52篇
  1992年   28篇
  1991年   13篇
  1990年   14篇
  1989年   7篇
  1988年   6篇
  1987年   5篇
  1986年   6篇
  1985年   2篇
  1984年   15篇
  1983年   11篇
  1982年   2篇
  1981年   1篇
  1977年   1篇
  1972年   2篇
  1935年   2篇
  1918年   1篇
  1917年   1篇
  1916年   1篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Environmental Science and Pollution Research - The concentrations of major and trace elements in the sediments from the Four River inlets of Dongting Lake were analysed. The results show that the...  相似文献   
62.
Environmental Science and Pollution Research - In recent years, the development and utilization of water resources have imposed great impacts on hydrological characteristics and ecological...  相似文献   
63.
Environmental Science and Pollution Research - Nitrogen-doped carbon nanotubes (N-CNTs) were synthesized via a hydrothermal method and further modified with magnetic Co0.5Cu0.5Fe2O4 nanoparticles...  相似文献   
64.
Environmental Science and Pollution Research - It is of great significance for the coordinated development of the environment and the economy to study the impact of the human driving factors of...  相似文献   
65.
Environmental Science and Pollution Research - The occurrence and progression of ovarian cancer are closely related to genetics and environmental pollutants. Poly(ADP-ribose) polymerase (PARP)...  相似文献   
66.
Environmental Science and Pollution Research - Production of the greenhouse gas nitrous oxide (N2O) from the completely autotrophic nitrogen removal over nitrite (CANON) process is of growing...  相似文献   
67.
钢渣吸附-微波降解法处理碱性品红废水   总被引:1,自引:0,他引:1  
谢复青  何星存 《化工环保》2006,26(2):129-132
研究了钢渣对碱性品红染料的吸附性能、影响因素以及微波对吸附在钢渣-焦炭上的染料的降解作用。实验表明,在中性条件下,钢渣对碱性品红具有优良的吸附性能,饱和吸附量可达到42.4mg/g。以钢渣处理质量浓度为100mg/L的碱性品红溶液,当固液质量比为1:50、振荡吸附1h后,染料溶液脱色率达97%。实验还表明,焦炭可吸收微波产生高温,用钢渣-焦炭混合物(质量比1:1)吸附染料后,以微波辐照可使物料达到665℃的高温,吸附的染料降解。吸附剂再生后重复使用4次,脱色率都达到95%以上。  相似文献   
68.
Russian Journal of Ecology - The present study was conducted to investigate the n-alkane composition of typical alpine meadows. Plant and soil samples were collected and analyzed to characterize...  相似文献   
69.
安选军  王黎  张霖  邵鹏程  何兴 《化工环保》2007,27(4):364-366
针对聚α-烯烃合成油(PAO)生产旧工艺存在的问题,介绍了以固载化AlCl3为催化剂的PAO生产新工艺,考察了各种因素对PAO收率的影响。实验结果表明,在反应温度为100℃、反应时间为8h、A1C1,与α-烯烃质量比为10:75的条件下,PAO收率为48.8%。采用新工艺后,PAO产品质量有了明显提高,黏度指数为132,碱和白土的消耗为零,且没有废渣产生,可实现清洁化生产。  相似文献   
70.
From April 2008 to November 2009, a field decomposition experiment was conducted to investigate the effects of sediment burial on macro (C, N) and microelement (Pb, Cr, Cu, Zn, Ni, and Mn) variations in decomposing litter of Phragmites australis in the coastal marsh of the Yellow River estuary. Three one-off sediment burial treatments [no sediment burial (0 mm year?1, S0), current sediment burial (100 mm year?1, S10), and strong sediment burial (200 mm year?1, S20)] were laid in different decomposition sites. Results showed that sediment burials showed significant influence on the decomposition rate of P. australis, in the order of S10 (0.001990 day?1)?≈?S20 (0.001710 day?1)?>?S0 (0.000768 day?1) (p?<?0.05). The macro and microelement in decomposing litters of the three burial depths exhibited different temporal variations except for Cu, Zn, and Ni. No significant differences in C, N, Pb, Cr, Zn, and Mn concentrations were observed among the three burial treatments except for Cu and Ni (p?>?0.05). With increasing burial depth, N, Cr, Cu, Ni, and Mn concentrations generally increased, while C, Pb, and Zn concentrations varied insignificantly. Sediment burial was favorable for C and N release from P. australis, and, with increasing burial depth, the C release from litter significantly increased, and the N in litter shifted from accumulation to release. With a few exceptions, Pb, Cr, Zn, and Mn stocks in P. australis in the three treatments evidenced the export of metals from litter to environment, and, with increasing burial depth, the export amounts increased greatly. Stocks of Cu and Ni in P. australis in the S10 and S20 treatments were generally positive, evidencing incorporation of the two metals in most sampling times. Except for Ni, the variations of C, N, Pb, Cr, Cu, Zn, and Mn stocks in P. australis in the S10 and S20 treatments were approximated, indicating that the strong burial episodes (S20) occurred in P. australis marsh in the future would have little influence on the stocks of these elements. With increasing burial depths, the P. australis was particularly efficient in binding Cu and Ni and releasing C, N, Pb, Cr, Zn, and Mn, implying that the potential eco-toxic risk of Pb, Cr, Zn, and Mn exposure might be very serious. This study emphasized the effects of different burials on nutrient and metal cycling and mass balance in the P. australis marsh of the Yellow River estuary.  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