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   33323篇
  免费   347篇
  国内免费   284篇
安全科学   1068篇
废物处理   1543篇
环保管理   4325篇
综合类   5874篇
基础理论   8372篇
环境理论   11篇
污染及防治   8019篇
评价与监测   2316篇
社会与环境   2235篇
灾害及防治   191篇
  2022年   288篇
  2021年   354篇
  2020年   214篇
  2019年   267篇
  2018年   480篇
  2017年   495篇
  2016年   777篇
  2015年   566篇
  2014年   933篇
  2013年   2702篇
  2012年   1095篇
  2011年   1462篇
  2010年   1180篇
  2009年   1254篇
  2008年   1515篇
  2007年   1449篇
  2006年   1300篇
  2005年   1166篇
  2004年   1106篇
  2003年   1083篇
  2002年   1015篇
  2001年   1187篇
  2000年   837篇
  1999年   525篇
  1998年   397篇
  1997年   414篇
  1996年   413篇
  1995年   539篇
  1994年   446篇
  1993年   400篇
  1992年   426篇
  1991年   404篇
  1990年   384篇
  1989年   361篇
  1988年   337篇
  1987年   283篇
  1986年   278篇
  1985年   278篇
  1984年   285篇
  1983年   294篇
  1982年   289篇
  1981年   251篇
  1980年   190篇
  1979年   211篇
  1978年   180篇
  1977年   154篇
  1976年   145篇
  1975年   167篇
  1973年   191篇
  1972年   167篇
排序方式: 共有10000条查询结果,搜索用时 843 毫秒
121.
Taylor AJ 《Disasters》1986,10(1):70-73
This paper was prepared in 1978 on the basis of a review of sociological and anthropological fieldwork conducted up to that time. Although theoretical in presentation its conclusions are formulated in accordance with the author's own extensive observations of organizational response to natural disasters in developing countries, especially those having sudden onset. Practical implications for co-ordination agencies and pre-disaster training are drawn.  相似文献   
122.
Environment, Development and Sustainability - Realisation of the sustainable development goals (SDGs) will provide improvements to people's lives and longevity of the planet. The architectural,...  相似文献   
123.
Russian Journal of Ecology - Populations at the border of ranges are considered more vulnerable than those in the center. However, some recent reviews contradict this hypothesis. We have studied...  相似文献   
124.
Russian Journal of Ecology - Abstract—We tested a hypothesis about the different abilities of alien and native plants to form arbuscular mycorrhizae. The studies were carried out in the...  相似文献   
125.
126.
127.
The distribution and sources of organochlorine pesticides (OCPs) in air and surface waters were monitored in Nairobi City using triolein-filled semipermeable membrane devices (SPMDs). The SPMDs were extracted by dialysis using n-hexane, followed by cleanup by adsorption chromatography on silica gel cartridges. Sample analysis was done by GC-ECD and confirmed by GC–MS. Separation of means was achieved by analysis of variance, followed by pair-wise comparison using the t-test (p≤ 0.05). The total OCPs ranged between 0.018 – 1.277 ng/m3 in the air and <LOD – 1391.000 ng/m3 in surface waters. Based on the results, the means of Industrial Area, Dandora and Kibera were not significantly different (p≤ 0.05), but were higher (p≤ 0.05) than those of City square and Ngong’ Forest. The results revealed non-significant (p≤ 0.05) contribution of long-range transport to OCP pollution in Nairobi City. This indicated possible presence of point sources of environmental OCPs in the city. The water-air fugacity ratios indicated that volatilization and deposition played an important role in the spatial distribution of OCPs in Nairobi City. This indicated that contaminated surface waters could be major sources of human exposure to OCPs, through volatilization. The incremental lifetime cancer risks (ILCR) determined from inhalation of atmospheric OCPs were 2.3745  ×  10?13 – 1.6845  ×  10?11 (adult) and 5.5404  ×  10?13 – 3.9306  ×  10?11 (child) in the order: Dandora > Kibera > Industrial Area > City Square > Ngong’ Forest. However, these were lower than the USEPA acceptable risks, 10?6 – 10?4. This study concluded that atmospheric OCPs did not pose significant cancer risks to the residents.  相似文献   
128.
Advanced oxidation technologies are a friendly environmental approach for the remediation of industrial wastewaters. Here, one pot synthesis of mesoporous WO_3 and WO_3-graphene oxide(GO) nanocomposites has been performed through the sol–gel method. Then, platinum(Pt) nanoparticles were deposited onto the WO_3 and WO_3-GO nanocomposite through photochemical reduction to produce mesoporous Pt/WO_3 and Pt/WO_3-GO nanocomposites. X-ray diffraction(XRD) findings exhibit a formation of monoclinic and triclinic WO_3 phases. Transmission Electron Microscope(TEM) images of Pt/WO_3-GO nanocomposites exhibited that WO_3 nanoparticles are obviously agglomerated and the particle sizes of Pt and WO_3 are ~ 10 nm and 20–50 nm, respectively. The mesoporous Pt/WO_3 and Pt/WO_3-GO nanocomposites were assessed for photocatalytic degradation of Methylene Blue(MB) as a probe molecule under visible light illumination.The findings showed that mesoporous Pt/WO_3, WO_3-GO and Pt/WO_3-GO nanocomposites exhibited much higher photocatalytic efficiencies than the pure WO_3. The photodegradation rates by mesoporous Pt/WO_3-GO nanocomposites are 3, 2 and 1.15 times greater than those by mesoporous WO_3, WO_3-GO, and Pt/WO_3, respectively. The key factors of the enhanced photocatalytic performance of Pt/WO_3-GO nanocomposites could be explained by the highly freedom electron transfer through the synergetic effect between WO_3 and GO sheets, in addition to the Pt nanoparticles that act as active sites for O2 reduction, which suppresses the electron hole pair recombination in the Pt/WO_3-GO nanocomposites.  相似文献   
129.
130.
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