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   98291篇
  免费   2188篇
  国内免费   6121篇
安全科学   4730篇
废物处理   3856篇
环保管理   14378篇
综合类   29285篇
基础理论   27659篇
环境理论   74篇
污染及防治   16080篇
评价与监测   5731篇
社会与环境   3739篇
灾害及防治   1068篇
  2023年   650篇
  2022年   1443篇
  2021年   1406篇
  2020年   1189篇
  2019年   1298篇
  2018年   1535篇
  2017年   1749篇
  2016年   2702篇
  2015年   2625篇
  2014年   3718篇
  2013年   10608篇
  2012年   3270篇
  2011年   3306篇
  2010年   4158篇
  2009年   4217篇
  2008年   2571篇
  2007年   2163篇
  2006年   2589篇
  2005年   2473篇
  2004年   2673篇
  2003年   2525篇
  2002年   2061篇
  2001年   2190篇
  2000年   2141篇
  1999年   1712篇
  1998年   1641篇
  1997年   1605篇
  1996年   1703篇
  1995年   1729篇
  1994年   1575篇
  1993年   1429篇
  1992年   1384篇
  1991年   1329篇
  1990年   1255篇
  1989年   1198篇
  1988年   1038篇
  1987年   962篇
  1986年   998篇
  1985年   1056篇
  1984年   1152篇
  1983年   1164篇
  1982年   1175篇
  1981年   1095篇
  1980年   932篇
  1979年   902篇
  1978年   812篇
  1977年   705篇
  1976年   630篇
  1973年   612篇
  1972年   616篇
排序方式: 共有10000条查询结果,搜索用时 453 毫秒
11.
Russian Journal of Ecology - In this paper, Ellenberg’s indicator values were estimated in order to soil nitrogen (N), pH (R) and soil moisture (M) in different subalpine grassland...  相似文献   
12.
Environmental Science and Pollution Research - Nutrient source and transport study in tropical creeks adjacent to megacities are sparse on a regional and global scale. High-frequency chemical data...  相似文献   
13.
Catalytic activity of spinel ferrite in breaking down toxic dye materials are promising due to their uniqueness. In this study, aluminum-doped copper zinc ferrite, Cu0.4Zn0.6-xAlxFe2O4 (x = 0.0, 0.2, 0.4, 0.6), a catalyst for toxic dye degradation is synthesized through chemical co-precipitation route. The formation of the spinel ferrite catalyst is initially confirmed by Fourier transform infrared spectra, which shows the frequency of metal-oxygen bond vibration at 539 and 427 cm−1 attributed to the tetrahedral and octahedral sites respectively. Higher intensity sharp peak of X-ray diffraction for (311) plane is the evidence for the phase purity and the formation of spinel ferrite. The crystallite size is found to decrease with the increase of Al3+ ion. The surface structure of the obtained particles is investigated using a scanning electron microscope. Analyses of the material's magnetic characteristics using a vibrating sample magnetometer (VSM) revealed that it is, in fact, a soft magnet, as evidenced by the loop of its hysteresis, which is narrow. The catalytic degradation of methylene blue dye under the mechanism of the photo-Fenton process is studied with the obtained spinel ferrites and the result is found to be as high as 96.5%. The process follows pseudo-second order kinetics and the Langmuir isotherm.  相似文献   
14.
Huang  Ying  Jiang  Qiongji  Yu  Xubiao  Gan  Huihui  Zhu  Xia  Fan  Siyi  Su  Yan  Xu  Zhirui  He  Cunrui 《Environmental science and pollution research international》2021,28(37):51251-51264
Environmental Science and Pollution Research - Trace copper ion (Cu(II)) in water and wastewater can trigger peroxymonosulfate (PMS) activation to oxidize organic compounds, but it only works under...  相似文献   
15.
Russian Journal of Ecology - A new method for assessing the response of biota to climatic changes in the ecosystem has been tested. In the Central Forest Natural Biosphere Reserve, the average...  相似文献   
16.
Environmental Science and Pollution Research - The impact of high concentrations of air pollution on COVID-19 has been a major air quality and life safety issue in recent studies. This study aimed...  相似文献   
17.
18.
Yan  Mi  He  Lei  Prabowo  Bayu  Fang  Zhumin  Lin  Jie  Xu  Zhang  Hu  Yanjun 《Journal of Material Cycles and Waste Management》2018,20(3):1594-1604
Journal of Material Cycles and Waste Management - Efforts to improve the performance of hydrothermal treatment (HT) in producing high-quality solid fuel from sewage sludge were carried out by...  相似文献   
19.
Journal of Material Cycles and Waste Management - Power generation from municipal solid waste plays significant role to mitigate the environmental pollution. The power generation potential of...  相似文献   
20.
Effective management refers to the ability of a protected area or indigenous territory to meet its objectives, particularly as they relate to the protection of biodiversity and forest cover. Effective management is achieved through a process of consolidation, which among other things requires legally protecting sites, integrating sites into land‐use planning, developing and implementing management and resource‐use plans, and securing long‐term funding to pay for recurrent costs. Effectively managing all protected areas and indigenous territories in the Amazon may be needed to avoid a deforestation tipping point beyond which regional climatic feedbacks and global climate change interact to catalyze irreversible drying and savannization of large areas. At present, protected areas and indigenous territories cover 45.5% (3.55 million km2) of the Amazon, most of the 60–70% forest cover required to maintain hydrologic and climatic function. Three independent evaluations of a long‐term large‐scale philanthropic initiative in the Amazon yielded insights into the challenges and advances toward achieving effective management of protected areas and indigenous territories. Over the life of the initiative, management of sites has improved considerably, particularly with respect to management planning and capacity building, but few sites are effectively managed and many lack sufficient long‐term financing, adequate governance, support of nongovernmental organizations, and the means to withstand economic pressures. The time and money required to complete consolidation is still poorly understood, but it is clear that philanthropic funding is critical so long as essential funding needs are not met by governments and other sources, which could be on the order of decades. Despite challenges, it is encouraging that legal protection has expanded greatly and management of sites is improving steadily. Management of protected areas in other developing countries could be informed by improvements that have occurred in Amazonian countries.  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