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   500篇
  免费   1篇
  国内免费   6篇
安全科学   9篇
废物处理   36篇
环保管理   34篇
综合类   44篇
基础理论   84篇
污染及防治   192篇
评价与监测   59篇
社会与环境   49篇
  2023年   8篇
  2022年   36篇
  2021年   41篇
  2020年   15篇
  2019年   16篇
  2018年   24篇
  2017年   16篇
  2016年   36篇
  2015年   13篇
  2014年   23篇
  2013年   46篇
  2012年   20篇
  2011年   45篇
  2010年   19篇
  2009年   23篇
  2008年   25篇
  2007年   19篇
  2006年   25篇
  2005年   13篇
  2004年   12篇
  2003年   7篇
  2002年   9篇
  2001年   4篇
  2000年   2篇
  1999年   2篇
  1996年   2篇
  1993年   1篇
  1992年   1篇
  1970年   1篇
  1968年   2篇
  1957年   1篇
排序方式: 共有507条查询结果,搜索用时 218 毫秒
51.
Anguilla anguilla L. were exposed to 0, 0.1, 0.3, 0.9 and 2.7 microM abietic (AA), dehydroabietic (DHAA) acids and retene (Re) during 8, 16, 24 and 72 h. The eels plasma cortisol, glucose and lactate were measured. A significant decrease in plasma cortisol was observed at 72 h exposure to 0.9 and 2.7 microM Re. DHAA (0.1 microM) significantly decreased plasma cortisol in eels after 8 and 24 h exposure. However, a significant plasma cortisol increase was found after 16 h, 2.7 microM AA exposure and after 24 h exposure to 0.1 microM and 2.7 microM AA. Furthermore, 72 h exposure to 0.9 microM AA also induced a plasma cortisol increase. A general rise in plasma glucose was detected after all exposure periods to Re. The plasma lactate also increased after 72 h exposure to 2.7 microM AA and after 8 h exposure to 0.1 microM DHAA.  相似文献   
52.
The concentrations of the naturally occurring radionuclides 232Th, 238U, 210Pb, 226Ra and 238Ra were determined in the vegetables (leafy vegetables, fruit, root, bean and rice) and derived products (sugar, coffee, manioc flour, wheat flour, corn flour and pasta) consumed most by the adult inhabitants of Rio de Janeiro City. A total of 88 samples from 26 different vegetables and derived products were analyzed. The highest contribution to radionuclide intake arises from bean, wheat flour, manioc flour, carrot, rice, tomato and potato consumption. The estimated daily intakes due to the consumption of vegetables and derived products are 1.9 mBq of 232Th (0.47 microg), 2.0 mBq of 238U (0.17 microg), 19 mBq of 236Ra, 26 mBq of 210Pb and 47 mBq of 228Ra. The estimated annual effective dose due to the ingestion of vegetables and their derived products with the long-lived natural radionuclides is 14.5 microSv. Taking into account literature data for water and milk from Rio de Janeiro the dose value increases to 29 microSv, with vegetables and derived products responsible for 50% of the dose and water for 48%. 210Pb (62%) and 228Ra (24%) were found to be the main sources for internal irradiation.  相似文献   
53.
Exposure of workers in mineral processing industries in Brazil   总被引:2,自引:0,他引:2  
The mining, milling and processing of uranium and thorium bearing minerals may result in radiation doses to workers. A preliminary survey pilot program, that included six mines in Brazil (two coal mines, one niobium mine, one nickel mine, one gold mine and one phosphate mine), was launched in order to determine the need to control the radioactive exposure of the mine-workers. Our survey consisted of the collection and analysis of urine samples, complemented by feces and air samples. The concentrations of uranium, thorium and polonium were measured in these samples and compared to background data from family members of the workers living in the same dwelling and from residents from the general population of Rio de Janeiro. The results from the coal mines indicated that the inhalation of radon progeny may be a source of occupational exposure. The workers from the nickel, gold and phosphate mines that were visited do not require a program to control internal radiological doses. The niobium mine results showed that in some areas of the industry exposure to thorium and uranium might occur.  相似文献   
54.
Abstract

Glutathione content and glutahione‐dependent enzymes were measured in the liver of two fish species, gudgeon (Gobio gobio) and roach (Rutilus arcasii), from the river Bernesga (Spain) caught downstream and upstream of the waste site of several chemical industries. Animals from contaminated sites display a reduced glutathione concentration and a tendency to the decrease of glutathione S‐transferase activity. Glutathione peroxidase activity was significantly elevated only in the liver of Gobio gobio and glutathione reductase activity in that of Rutilus arcasii. Our data indicate that the glutathione system constitutes a sensitive biochemical indicator of chemical pollution. Relative changes of glutathione and glutathione‐dependent enzymes in both fish species suggest a different susceptibility to toxins.  相似文献   
55.
56.
57.
58.
59.
Food and Environmental Virology - The use of natural resources for the prevention and treatment of diseases considered fatal to humanity has evolved. Several medicinal plants have nutritional and...  相似文献   
60.
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