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   403篇
  免费   2篇
  国内免费   3篇
安全科学   11篇
废物处理   19篇
环保管理   15篇
综合类   42篇
基础理论   61篇
环境理论   1篇
污染及防治   157篇
评价与监测   61篇
社会与环境   40篇
灾害及防治   1篇
  2022年   6篇
  2021年   6篇
  2020年   2篇
  2019年   13篇
  2018年   14篇
  2017年   17篇
  2016年   19篇
  2015年   12篇
  2014年   16篇
  2013年   64篇
  2012年   20篇
  2011年   31篇
  2010年   27篇
  2009年   16篇
  2008年   20篇
  2007年   22篇
  2006年   23篇
  2005年   13篇
  2004年   8篇
  2003年   6篇
  2002年   3篇
  2001年   3篇
  2000年   6篇
  1998年   1篇
  1997年   1篇
  1996年   1篇
  1995年   1篇
  1994年   1篇
  1992年   3篇
  1986年   1篇
  1985年   1篇
  1984年   1篇
  1983年   1篇
  1982年   3篇
  1981年   1篇
  1978年   1篇
  1974年   1篇
  1973年   2篇
  1972年   2篇
  1970年   1篇
  1969年   1篇
  1968年   2篇
  1966年   1篇
  1960年   2篇
  1959年   4篇
  1958年   2篇
  1957年   1篇
  1956年   5篇
排序方式: 共有408条查询结果,搜索用时 15 毫秒
21.
The widespread public belief that during the bombardment of Vojvodina (Yugoslavia) this region was contaminated by depleted uranium has recently raised public concern with respect to the potential contamination of agricultural products due to soil radioactivity. Based on the gamma-spectrometric analysis of 50 soil samples taken from the region of Vojvodina we concluded that there is no increase of radioactivity that could endanger the food production. Taking into account the transfer factors of 137Cs to plants, the measured activity concentrations of this isotope should not endanger the health safety of the produced food. No traces of depleted uranium have been found. The natural radioactivity levels are compared with the results form other countries.  相似文献   
22.
23.
24.
The purpose of this investigation was to determine the influence of humic acids (HA) and Ca-montmorillonite (CaM) on the solid-phase extraction (SPE) efficiency of atrazine, alachlor and alpha-cypermethrin from water samples at various pH-values. The nature and intensity of binding of the studied pesticides to CaM were determined by X-ray diffraction analysis and termogravimetric analysis (TGA) test. The studied pesticides eluted from discs were analysed by thin-layer chromatography (TLC). The effects of CaM and humic acid were generally pH-dependent and acted independently in extraction efficiency influence. Lower recovery of pesticides was observed at higher pH values when CaM was > or =0.1 g and was attributed to greater dispersion of clay, increased surface area and subsequent adsorption. Concentrations of dissolved organic carbon (DOC) in humic acid had less effect on the extraction efficiency when water was at pH 8 compared to water at pH 2, which was probably due to greater nonpolar interactions of the pesticides to the charge-neutralized humic acid molecule.  相似文献   
25.
A new approach to surface water analysis has been investigated in order to enhance the detection of different organic contaminants in Nathan Creek, British Columbia. Water samples from Nathan Creek were prepared by liquid/liquid extraction using dichloromethane (DCM) as an extraction solvent and analyzed by gas chromatography mass spectrometry method in scan mode (GC-MS scan). To increase sensitivity for pesticides detection, acquired scan data were further analyzed by Automated Mass Spectrometry Deconvolution and Identification Software (AMDIS) incorporated into the Agilent Deconvolution Reporting Software (DRS), which also includes mass spectral libraries for 567 pesticides. Extracts were reanalyzed by gas chromatography mass spectrometry single ion monitoring (GC-MS-SIM) to confirm and quantitate detected pesticides. Pesticides: atrazine, dimethoate, diazinone, metalaxyl, myclobutanil, napropamide, oxadiazon, propazine and simazine were detected at three sampling sites on the mainstream of the Nathan Creek. Results of the study are further discussed in terms of detectivity and identification level for each pesticide found. The proposed approach of monitoring pesticides in surface waters enables their detection and identification at trace levels.  相似文献   
26.
Environmental Geochemistry and Health - Extreme flooding in May, 2014 affected the sub-catchments of six major rivers in Serbia. The goal of the study was to evaluate the contents of potentially...  相似文献   
27.
28.
Objective: This study examined the risk factors of driving under the influence of alcohol (DUI) among drivers of specific vehicle categories (DSC). On the basis of this research, the variables related to DUI and involvement in traffic crashes were defined. The analysis was conducted for car drivers, bicyclists, motorcyclists, bus drivers, and truck drivers.

Method: The research sample included drivers involved in traffic crashes on the territory of Serbia in 2016 (60,666). Two types of analyses were conducted in this study. Logistic regression established the correlation between DUI and DSC and the The Technique for Order of Preference by Similarity to Ideal Solution (Multi-criteria decision making) method was applied to consider the scoring and explore the potential for the prevalence of DUI on the basis of 2 data sets (DUI and non DUI).

Results: The study results showed that driver error and male drivers were the 2 most significant risk factors for DUI, with the highest scores and potential for prevalence. The nonuse of restraint systems, driver experience, and driver age are the factors with a significant prediction of involvement in an accident and an insignificant prediction of DUI.

Conclusions: Following the development of the logistic prediction models for DUI drivers, testing of the model was conducted for 3 control driver groups: Car, motorcycle, and bicycle. The prediction model with a probability greater than 50% showed that 77% of car drivers were under the influence of alcohol. Similarly, the prediction percentage for motorcyclists and bicyclists amounted to 71 and 67%, respectively. The recommendation of the study is that drivers whose DUI probability is above 50% should be potentially suspected of DUI. The results of this study can help to understand the problem of DUI among specific driver categories and detect DUI drivers, with the aim of creating successful traffic safety policy.  相似文献   

29.
Uptake of 51Cr(III) is faster than uptake of 51Cr(VI), but it occurs mainly on the surface of the animals. Steady state is attained after 28 d. The resulting concentration factor is about 200. Although the uptake of 51Cr(VI) is slower, it is more intensively distributed into the organs and tissues of the animals. Steady state was not attained during the experiments (35 d); the highest concentration factor reached was about 10. The uptake of both 51Cr(III) and 51Cr(VI) seems to be passive. For both chemical forms of chromium, the loss rate is inversely proportional to the exposure time. When the uptake lasted longer, owing to the distribution of Cr(VI) into the organs and tissues, the loss rate of Cr(III) is somewhat faster relative to the loss rate of 51Cr(VI). The opposite is the case when the uptake of both forms lasts only two days. On the basis of the distribution and loss experiments, we argue that hexavalent chromium in living organisms is reduced to the trivalent form and then complexed with organic molecules.  相似文献   
30.
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