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   15277篇
  免费   582篇
  国内免费   1928篇
安全科学   656篇
废物处理   972篇
环保管理   1785篇
综合类   4781篇
基础理论   3949篇
污染及防治   2773篇
评价与监测   1379篇
社会与环境   1216篇
灾害及防治   276篇
  2024年   27篇
  2023年   107篇
  2022年   315篇
  2021年   256篇
  2020年   331篇
  2019年   232篇
  2018年   1707篇
  2017年   1649篇
  2016年   1454篇
  2015年   449篇
  2014年   419篇
  2013年   532篇
  2012年   969篇
  2011年   1914篇
  2010年   1165篇
  2009年   1076篇
  2008年   1303篇
  2007年   1659篇
  2006年   410篇
  2005年   306篇
  2004年   242篇
  2003年   230篇
  2002年   270篇
  2001年   158篇
  2000年   154篇
  1999年   90篇
  1998年   67篇
  1997年   56篇
  1996年   44篇
  1995年   38篇
  1994年   31篇
  1993年   35篇
  1992年   28篇
  1991年   13篇
  1990年   6篇
  1989年   3篇
  1988年   4篇
  1987年   6篇
  1986年   1篇
  1984年   14篇
  1983年   11篇
  1982年   3篇
  1973年   1篇
  1935年   2篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
231.
Loss of zooxanthellae (dinoflagellate Symbiodinium) from corals will sometimes lead to mass mortality of corals. To detect and quantify Symbiodinium released from corals, we developed a zooxanthellae “trap” and a quantitative PCR (qPCR) system with Symbiodinium clades A–F-specific primer sets. The trap was attached to a branch or the surface of several wild stony corals, and the water samples within the traps, including released Symbiodinium, were subjected to qPCR. All tested corals released clade C Symbiodinium at estimates of ~5,900 cells h−1 cm−2 of coral surface. Although all tested Pocillopora eydouxi harboured both clades C and D, some of these colonies released only clade C or released a lesser amount of clade D than that in the tissues. Our Symbiodinium quantification system revealed that wild hermatypic corals constantly release Symbiodinium to the environment. Our result suggests that some corals may discharge certain clades of Symbiodinium alternatively.  相似文献   
232.
233.
采用紫外可见光谱(UV-Vis)、傅立叶变换红外光谱(FTIR)及离子色谱(IC)技术对HNO3在α-Fe2O3表面暗反应和308nm下光解反应进行了研究.考察了时间、HNO3浓度、相对湿度(RH)等条件对反应的影响.结果表明,随着HNO3浓度、光照时间的增加,HNO3在气相与α-Fe2O3表面光解产物浓度均呈指数增加;HNO3在α-Fe2O3表面光解产生的NO2、NO分别为气相产生的3.27及3.87倍,而无论气相还是表面光解的NO2浓度均约为NO的2倍.随着RH的增加,HNO3光解产生的HONO的浓度随之呈指数增大,其产率从RH 20%时的0.023增加到90%时的0.087.α-Fe2O3的表面效应在HNO3的表面光解反应中起主导作用.  相似文献   
234.
Environmental Science and Pollution Research - The massive use of silver nanoparticles (AgNPs) is potentially harmful to exposed humans. Although previous studies have found that AgNPs can induce...  相似文献   
235.
Environmental Science and Pollution Research - In the process of water treatment, excessive nitrogen and phosphorus pollutants are of great concern. Therefore, we prepared nanoscale zerovalent iron...  相似文献   
236.
Environmental Science and Pollution Research - Co3O4 nanorods with diameters of ~0.15 μm and lengths of ~1 μm were prepared using a hydrothermal method via the assembly of microcrystals...  相似文献   
237.
Environmental Science and Pollution Research - Caffeine is considered the most representative pharmaceutical emerging contaminant (PEC) because of its ubiquity, high environmental abundance,...  相似文献   
238.
Environmental Science and Pollution Research - Due to their different abilities to improve financial growth and improve social development, small and medium enterprises (SMEs) have been referred to...  相似文献   
239.
Environmental Science and Pollution Research - The abatement of SO2 and the utilization of copper tailings are identified as two attention-attracting environmental issues in the copper smelter. In...  相似文献   
240.

Surface sediments were collected from 122 sites in the upstream of the Yellow River, China. The concentration of Fe, Mn, Cu, Ni, Zn, Cr, Pb, and Cd in sediments was investigated to explore the spatial distribution based on statistics and interpolation method. The results suggested that the concentrations of heavy metals were lower than potential effect levels (PEL). The samples above threshold effect level (TEL) for Pb and Zn were less than 10%, while almost 50% of samples for Ni exceeded PEL. Pb and Zn in sediments performed little or no adverse effects on the aquatic ecosystems. Higher concentrations of all heavy metals occurred in Qinghai and Gansu sections; the concentrations of Cu, Ni, and Zn were significantly higher than the Inner Mongolia section. Lower concentration of Fe, Mn, Cu, Ni, and Zn appeared in Qinghai section; the concentrations of Fe, Mn, Cr, and Pb manifested relatively steady and similar distributions and approximately decreasing tendency along the upstream of Yellow River.

  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