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   176篇
  免费   2篇
安全科学   2篇
废物处理   3篇
环保管理   6篇
综合类   131篇
基础理论   17篇
污染及防治   16篇
评价与监测   1篇
社会与环境   2篇
  2018年   2篇
  2013年   6篇
  2012年   2篇
  2011年   2篇
  2010年   2篇
  2009年   3篇
  2008年   8篇
  2007年   4篇
  2006年   2篇
  2005年   2篇
  2004年   3篇
  2002年   5篇
  2000年   5篇
  1999年   4篇
  1991年   2篇
  1986年   2篇
  1981年   2篇
  1980年   5篇
  1979年   5篇
  1978年   3篇
  1977年   2篇
  1975年   6篇
  1974年   2篇
  1972年   2篇
  1971年   3篇
  1969年   2篇
  1968年   2篇
  1967年   3篇
  1966年   3篇
  1965年   3篇
  1964年   4篇
  1963年   3篇
  1962年   4篇
  1958年   2篇
  1957年   8篇
  1956年   2篇
  1940年   3篇
  1939年   3篇
  1938年   2篇
  1937年   3篇
  1935年   4篇
  1934年   3篇
  1932年   3篇
  1926年   1篇
  1925年   2篇
  1924年   1篇
  1922年   1篇
  1921年   3篇
  1919年   1篇
  1915年   1篇
排序方式: 共有178条查询结果,搜索用时 15 毫秒
101.
102.
103.
Separate collection and exploitation of used batteries facilates the recycling and eventual waste management of such heavy metals as mercury and cadmium. It is thereby possible to regain raw materials like zinc, manganese and iron for the raw material cycle. Although the collection and recycling of used batteries in Switzerland is financed by a prepaid disposal fee, their returning rate of almost 60% is too low for several reasons. A questionnaire survey carried out on 2000 households revealed the following frequenthy: People collecting paper, glass, aluminium, compost and tinplate, are more separate used batteries from ordinary garbage. The number of collecting points is supposed to be sufficient, but not all of them are sufficiently marked. The prepaid disposal fee (VEG) should become obligatory so that it would be possible to compensate the collecting points. It is not obvious from the results of the survey if the introduction of a deposit of batteries would raise the retourning rate. As far as advertising is concerned, only the “battery bag” sent to every household by the BESO seemed to influence the collecting behaviour in a positive way, poster advertising had only little effect. Appeals in newspapers, radio and television did not show any changement of the collecting behaviour. However, information and knowledge about batteries and their recycling do have a positive influence in the collecting behaviour of the consumers in this specific case.  相似文献   
104.
Sturm A  Radau TS  Hahn T  Schulz R 《Chemosphere》2007,69(4):605-612
Cadmium (Cd) adsorption on 14 non-calcareous New Jersey soils was investigated with a batch method. Both adsorption edge and isotherm experiments were conducted covering a wide range of soil composition, e.g. soil organic carbon (SOC) concentration ranging from 0.18% to 7.15%, and varying Cd concentrations and solution pH. The SOC and solution pH were the most important parameters controlling Cd partition equilibrium between soils and solutions in our experimental conditions. The Windermere humic aqueous model (WHAM) was used to calculate Cd adsorption on soils. The effect of solution chemistry (various pH and Cd concentrations) on Cd adsorption can be well accounted for by WHAM. For different soil compositions, SOC concentration is the most important parameter for Cd binding. Only a fraction of SOC, the so-called active organic carbon (AOC), is responsible for Cd binding. We found a linear relationship between SOC and AOC based on the adsorption edge data. The linear relationship was validated by the independent data sets: adsorption isotherm data, which presumably can be used to predict Cd partition equilibrium across a wide range of soil compositions. The modeling approach presented in this study helps to quantitatively predict Cd behavior in the environment.  相似文献   
105.
The fate and effects of selected heavy metals were examined in sediment from a restored salt marsh. Sediment cores densely covered with Spartina patens were collected and kept either un-amended or artificially amended with nickel (Ni) under standardized greenhouse conditions. Ni-amendment had no significant effect on the fate of other metals in sediments, however, it increased root uptake of the metals. Metal translocation into the shoots was small for all metals. Higher Ni concentrations in plants from amended cores were accompanied by seasonal reductions in plant biomass, photosynthetic capacity and transfer efficiency of open photosystem II reaction centers; these effects, however, were no longer significant at the end of the growing season. Root colonization by arbuscular mycorrhizal fungi (AMF) resembled that of natural salt marshes with up to 20% root length colonized. Although Ni-amendment increased AMF colonization, especially during vegetative growth, in general AMF were largely unaffected.  相似文献   
106.
Environmental Chemistry Letters - The presence of liquid water makes our planet habitable. Water in soils, sediments, lakes, rivers and the ocean forms the largest habitat for life on Earth. During...  相似文献   
107.
108.
Achondroplasia is the most common form of short-limbed dwarfism in humans and is caused by mutations in the FGFR3 gene. Currently, prenatal diagnosis of this disorder relies on invasive procedures. Recent studies have shown that fetal single gene point mutations could be detected in cell-free DNA (cf-DNA) from maternal plasma by either the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) assay with single allele base extension reaction (SABER) approach or the size fractionation of cf-DNA in maternal plasma. Here, we combined the two approaches to non-invasively examine the fetal G1138A mutation in maternal plasma. cf-DNA was extracted from maternal plasma samples obtained from two pregnant women at risk for achondroplasia. The fetal G1138A mutation was determined by the analysis of size-fractionated cf-DNA in maternal plasma using MALDI-TOF MS with SABER approach and homogenous MassEXTEND (hME) assay, respectively. The fetal G1138A mutation was detectable in the two achondroplasia-affected pregnancies by the analysis of cf-DNA in maternal plasma using MALDI-TOF MS. However, the size-fractionation approach led to a more precise detection of the fetal mutation in both analyses. This analysis would be suitable for non-invasive prenatal diagnosis of diseases caused by fetal single gene point mutations. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   
109.
110.
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