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   94篇
  免费   0篇
  国内免费   1篇
安全科学   7篇
废物处理   4篇
环保管理   8篇
综合类   17篇
基础理论   19篇
污染及防治   27篇
评价与监测   8篇
社会与环境   3篇
灾害及防治   2篇
  2023年   1篇
  2022年   1篇
  2021年   2篇
  2020年   1篇
  2018年   2篇
  2017年   6篇
  2016年   5篇
  2015年   5篇
  2014年   10篇
  2013年   9篇
  2012年   11篇
  2011年   4篇
  2010年   7篇
  2009年   6篇
  2008年   4篇
  2007年   3篇
  2006年   1篇
  2005年   3篇
  2004年   1篇
  2002年   1篇
  2000年   3篇
  1996年   1篇
  1995年   1篇
  1994年   1篇
  1993年   1篇
  1992年   1篇
  1991年   1篇
  1987年   1篇
  1984年   1篇
  1954年   1篇
排序方式: 共有95条查询结果,搜索用时 435 毫秒
81.
Atmospheric nitrophenols (NPs) were determined both in the gas and particle phases by combining the annular denuder sampling technique with GC-MS analysis. The phase distribution of six mono-NPs identified in air sampled in downtown Rome was assessed. 4-NP, 3-methyl-4-NP and 2,6-dimethyl-4-NP were found for more than 75% in the particle phase, whilst 2-NP, 4-methyl-2-NP and 5-methyl-2-NP predominated in the gas phase. Concentration levels lower than 20 ng m-3 were observed for all NPs, among which 4-NP (17.8+/-5.6 ng m-3) and 2-NP (10.4+/-4.2 ng m-3) were the most abundant congeners in the two phases, respectively.  相似文献   
82.
83.
84.
We studied the impact of demographic diversity on individual attachment and firm unit performance in a relatively diverse organization. We implemented cross‐level regression to study gender and race/ethnic categorical, relational, and organizational demography in a sample of 26 units part of a regional restaurant chain. At the individual level, we found that diversity climate (DC) moderates the impact of relational and categorical demography on affective organizational commitment, organizational identification, and intention to quit. At the organizational level, we found that DC moderates the impact of organizational diversity on firm productivity and return on profit. We discuss the importance of organizational DC as organizational context on individual attachment, and implications for firm effectiveness in diverse organizations. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   
85.
Ozone and energy fluxes have been measured using the eddy covariance technique, from June to December 2004 in Castelporziano near Rome (Italy), and compared to similar measurements made in the previous year. The studied ecosystem consisted in a typical Mediterranean Holm oak forest. Stomatal fluxes have been calculated using the resistance analogy and by inverting the Penmann-Monteith equation. Results showed that the average stomatal contribution accounts for 42.6% of the total fluxes. Non-stomatal deposition proved to be enhanced by increasing leaf wetness and air humidity during the autumnal months. From a comparison of the two years, it can be inferred that water supply is the most important limiting factor for ozone uptake and that prolonged droughts alter significantly the stomatal conductance, even 2 months after the soil water content is replenished. Ozone exposure, expressed as AOT40, behaves similarly to the cumulated stomatal flux in dry conditions whereas a different behaviour for the two indices appears in wet autumnal conditions. A difference also occurs between the two years.  相似文献   
86.
Mono- and dicarboxylic n-alkyl acids were extensively investigated in downtown Rome, Italy, and in Montelibretti, ~30 km NE of the city, during 2005–2007. Congeners ranging from lauric to mellisic, and from succinic to α,ω-docosanedioic acids were evaluated as well as phthalic, palmitoleic and oleic acids, by solvent extraction of airborne particulates followed by derivatization with propanol in the presence of boron trifluoride, and gas chromatographic-mass spectrometric analysis. Shorter measurements were made in Milan, in Taranto, at suburban and rural sites of Italy, and in the polar regions, from 1996 to 2005. The predominance of palmitic and stearic acids observed elsewhere was confirmed, and the behaviour of azelaic and phthalic acids resulted strongly dependent upon the year season. In the urban sites, among the long-chain compounds, the lignoceric acid was usually the most abundant, while the cerotic, montanic and mellisic homologues cumulatively never exceeded 8% of the total. Unlike other contaminants, the concentrations of organic acids remained fairly invariant over the last decade, suggesting that more attention must be paid to them in the future.  相似文献   
87.
88.
This paper reports the results obtained from the data collected within the European Commission funded project SAFEFOODNET regarding the state of the art in the control of chemical food contaminants in twelve European New Member States and one Associated Candidate Country (Turkey). Information has been gathered on institutions involved in food chemical contamination control, types of contaminants and matrices analyzed, procedures for data quality assurance, purposes of the analyses and accessibility of data in the participant countries. The resulting picture points out the general availability of adequate capabilities for the analysis of food contaminants in the laboratories in charge of control and the performance of the analysis of a large variety of chemicals (persistent organic pollutants, polycyclic aromatic hydrocarbons, pesticides, mycotoxins, heavy metals, radionuclides) in almost each country with few exceptions (dioxins in Bulgaria, Turkey, Latvia, persistent organic pollutants in Lithuania and Malta, polycyclic aromatic hydrocarbons in Malta). The application of validated analytical methods and the process of laboratory accreditation are partially fulfilled within the investigated countries, but still forthcoming for some countries, as in Romania, Turkey and Malta. Information collected on food controls is only partially available online and the language used is prevalently local and English to a lesser extent.  相似文献   
89.
This study used Lazarus and Folkman's ( 1984 ) cognitive–phenomenological model of coping and Lazarus's ( 1991 ) theory of emotions to develop and test a model of how individuals cope with an organizational acquisition. The model identifies the origins and process used to select both problem‐focused and emotion‐focused coping strategies. Covariance structure analysis of data from 172 individuals indicated that problem‐focused coping was directly influenced by primary appraisal and negative emotion, while only certain types of emotion‐focused coping were directly related to negative emotion. All coping strategies were impacted by social support. Furthermore, negative emotion was predicted by primary appraisal, which in turn was related to perceived control, coping efficacy, and environmental conditions. Recommendations for future research and applications are discussed. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   
90.
Cestone A  Di Natale M  De Rosa S 《Chemosphere》2008,71(8):1440-1445
The main objective of this study, within development of engineering solutions for coastal areas depuration, was to establish the role of the benthic macro-organisms in the biodegradation of the detergents in marine environment and to estimate the toxicity of these substances for a particular marine species: the ascidian Styela plicata. The experimental studies undertaken in aquarium with seawater enriched in a pure lynear alkylbenzene sulfonate (LAS), the 1-(p-sulfophenyl)nonane (1C9-LAS), showed that the degradation was two times more fast in presence of the S. plicata, than of the only marine bacteria. The toxicity of this pollutant was also determined. This study demonstrates that the ascidia S. plicata can be a potential biomediator for the surfactant 1C9-LAS, and it can be used to design a pilot project, to bioremediate harbours and the coastal areas interested from the urban pollution.  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