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   137篇
  免费   0篇
  国内免费   4篇
安全科学   7篇
废物处理   17篇
环保管理   8篇
综合类   18篇
基础理论   37篇
污染及防治   38篇
评价与监测   4篇
社会与环境   11篇
灾害及防治   1篇
  2023年   3篇
  2022年   2篇
  2021年   2篇
  2020年   2篇
  2019年   2篇
  2018年   1篇
  2017年   3篇
  2016年   1篇
  2015年   2篇
  2014年   7篇
  2013年   14篇
  2012年   6篇
  2011年   8篇
  2010年   6篇
  2009年   8篇
  2008年   6篇
  2007年   9篇
  2006年   7篇
  2005年   7篇
  2004年   6篇
  2003年   2篇
  2002年   8篇
  2001年   8篇
  2000年   3篇
  1999年   3篇
  1998年   2篇
  1997年   1篇
  1995年   1篇
  1994年   1篇
  1993年   1篇
  1990年   1篇
  1988年   2篇
  1985年   1篇
  1981年   2篇
  1976年   1篇
  1973年   1篇
  1958年   1篇
排序方式: 共有141条查询结果,搜索用时 15 毫秒
61.
In order to estimate current external gamma doses to the population of the Russian territories contaminated as a result of the Chernobyl accident, absorbed gamma-dose rates in air (DR) were determined at typical urban and suburban locations. The study was performed in the western districts of the Bryansk Region within the areas of 30 settlements (28 villages and 2 towns) with the initial levels of 137Cs deposition ranging from 13 to 4340 kBqm(-2). In the towns, the living areas considered were private one-story wooden and stone houses. DR values were derived from in situ measurements performed with the help of gamma-dosimeters and gamma-spectrometers as well as from the results of soil samples analysis. In the areas under study, the values of DR from terrestrial radionuclides were 25+/-6, 24+/-5, 50+/-10, 32+/-6, 54+/-11, 24+/-8, 20+/-6, 25+/-8, and 18+/-5 nGyh(-1) at locations of kitchen gardens, dirt surfaces, asphalt surfaces, wooden houses, stone houses, grasslands inside settlement, grasslands outside settlement, ploughed fields, and forests, respectively. In 1996-2001, mean normalized (per MBqm(-2) of 137Cs current inventory in soil) values of DR from (137)Cs were 0.41+/-0.07, 0.26+/-0.13, 0.15+/-0.07, 0.10+/-0.05, 0.05+/-0.04, 0.48+/-0.12, 1.04+/-0.22, 0.37+/-0.07, and 1.15+/-0.19 microGyh(-1) at the locations of kitchen gardens, dirt surfaces, asphalt surfaces, wooden houses, stone houses, grasslands inside settlement, grasslands outside settlement, ploughed fields, and forests, respectively. The radiometric data from this work and the values of occupancy factors determined for the Russian population by others were used for the assessments of annual effective doses to three selected groups of rural population. The normalized (per MBqm(-2) 137Cs current ground deposition) external effective doses to adults from 137Cs ranged from 0.66 to 2.27 mSvy(-1) in the years 1996-2001, in accordance with professional activities and structures of living areas. For the areas under study, the average external effective doses from 137Cs were estimated to be in the range of 0.39-1.34 mSvy(-1) in 2001. The average external effective doses from natural radionuclides appeared to be lower than those from the Chernobyl fallout ranging from 0.15 to 0.27 mSvy(-1).  相似文献   
62.
Many firms generate large amounts of carbon dioxide and other greenhouse gases when they burn fossil fuels in their production processes. In addition, production of raw materials and other inputs the firms procure for their operations also generates greenhouse gases indirectly. These direct and indirect greenhouse gas emissions occur in many sectors of our economies. In this paper, we first present sector-specific estimates for such greenhouse gas emissions. We then show that estimates for such sector-specific greenhouse gas emissions are often required for various types of corporate as well as public policy analyses in both domestic and international contexts. Measuring greenhouse gas emissions resulting from firms' multi-stage production processes in a multi-sector context is relevant for policies related to the Kyoto protocol, an international agreement to limit global greenhouse gas emissions. For example, since the protocol allows firms to engage in trading and offsetting of their greenhouse gas emissions across national borders, provided that emissions are correctly measured, the firms can take advantage of such trading schemes by placing their energy-intensive production facilities globally and strategically. We present several case studies which illustrate the importance of this and other aspects of greenhouse gas emissions in firms' environmental management. We also argue that our modeling and estimation methods based on input-output analyses are suitable for the types of research goals we have in this paper. Our methods are applied to data for Canada and Japan in a variety of environmental management circumstances.  相似文献   
63.
64.
The volatilization of mercuric chloride (HgCl2) and methyl mercuric chloride (CH3HgCl) by the 45 strains (35 Pseudoalteromonas sp., 2 Vibrio sp., 1 Aeromonas sp., and 7 unclassified) of the most mercury-resistant bacteria from Minamata Bay seawater was examined in various physiological conditions. The bacteria could grow and volatilize HgCl2 in the liquid medium containing 1-10% NaCl. Two Pseudoalteromonas strains could grow and volatilize HgCl2 at pH levels ranging from 5.0 to 10.0. The resting cells of 43 strains could volatilize HgCl2 at concentrations ranging from 30 to 68% after 1-h incubation at 30vv°C. The resting cells of 41 strains could volatilize CH3HgCl at concentrations ranging from 13 to 88% after 1-h incubation at 30vv°C. Ninety-two percent of mercury was removed from the phosphate buffer containing 0.1 7g/ml by a resting cell of Pseudoalteromonas strain H-4 after 30-min incubation at 30vv°C. We were able to screen the special bacteria, which could volatilize mercury compounds at a high rate in various physiological conditions, for the purpose of developing mercury removal methods using bacteria.  相似文献   
65.
66.
Biwa湖 Yodo河水系为主要的居民中心及其周围的市政机构提供城市用水和工业用水 .它也提供农业用水,主要在 Biwa湖排水区域 .该水系服务的人口总数约为 1400万人 . 这个水系构成了 Keihanshin工业区的主要部分(按照字面上是指京都、大阪和神户),这是一个以沿大阪海湾-濑户内海的狭长地带发展为特征的一个区域 .Keihanshin的工业产值居日本的第三位,约占国内生产总值的 12.4% .一个复杂的供水网和废水网支持着高水平的工业和农业活动 .  相似文献   
67.
Biwa湖-Yodo河水系为主要的居民中心及其周围的市政机构提供城市用水和工业用水 .它也提供农业用水,主要在 Biwa湖排水区域 .该水系服务的人口总数约为 1400万人 .   这个水系构成了 Keihanshin工业区的主要部分(按照字面上是指京都、大阪和神户),这是一个以沿大阪海湾-濑户内海的狭长地带发展为特征的一个区域 .Keihanshin的工业产值居日本的第三位,约占国内生产总值的 12.4% .一个复杂的供水网和废水网支持着高水平的工业和农业活动 .……  相似文献   
68.
69.
70.
A new method to single out the environmental factor limiting the life of any macrobenthic animal under stressed condition is proposed. The method is based on the assumption that the influence of each environmental factor on the life of a species can be expressed by an S-shaped function having lethal, limiting and non-limiting ranges, and the combined effect of several environmental factors is expressed by a multiple of these functions. To single out a lethal factor, we used the cumulative curve of abundance arranged in the order of each environmental factor. Comparison of these curves enables us to identify the most effective environmental factor limiting the life of a particular species and determine its effective range. Determination can be made from a single field observation without recourse to specially prepared experimental data if a sufficiently extensive survey was made in a field observation. The method was applied to the field data obtained from 248 stations at Lake Shinji, Japan, in the summer of 1982.  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