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   202篇
  免费   8篇
  国内免费   1篇
安全科学   7篇
废物处理   21篇
环保管理   24篇
综合类   32篇
基础理论   24篇
环境理论   1篇
污染及防治   65篇
评价与监测   21篇
社会与环境   15篇
灾害及防治   1篇
  2023年   8篇
  2022年   15篇
  2021年   13篇
  2020年   7篇
  2019年   11篇
  2018年   17篇
  2017年   10篇
  2016年   16篇
  2015年   8篇
  2014年   8篇
  2013年   10篇
  2012年   17篇
  2011年   16篇
  2010年   5篇
  2009年   9篇
  2008年   8篇
  2007年   5篇
  2006年   6篇
  2005年   8篇
  2004年   2篇
  2003年   2篇
  2002年   3篇
  2001年   3篇
  2000年   1篇
  1999年   1篇
  1995年   1篇
  1971年   1篇
排序方式: 共有211条查询结果,搜索用时 31 毫秒
141.
Environment, Development and Sustainability - This review aimed to analyze plastic lumber manufacturing in Brazil, a country with a large amount of natural wood, and devise strategies to boost...  相似文献   
142.
A new method, based on separation with gas chromatography and detection with a quartz crystal microbalance, was used for the quantification of ethane-1-thiol, propane-1-thiol, ethyl methyl sulfide, propane-2-thiol, butane-2-thiol and butane-1-thiol. The analytical error, the analysis time and the general analytical performance are identical for gas chromatography-mass spectrometry (GC-MS) and gas chromatography-quartz crystal microbalance (GC-QCM). However, the GC-QCM method constitutes a low cost alternative to GC-MS for monitoring individual sulfur compounds in landfill gas. It is an easily assembled apparatus made with an injection device, a furnace, a column, a crystal cell and a quartz crystal.  相似文献   
143.
An external monitoring plan (EMP) is being implemented in the region of Oporto, Portugal, to follow the potential effects of a future incinerator of municipal solid waste. Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/PCDF) were measured during 1998 and the first semester of 1999, prior to the working up of the incineration unit. The baseline levels obtained through this intensive monitoring work are presented and discussed in the present paper.  相似文献   
144.
Bordado JC  Gomes JF 《Chemosphere》2001,44(5):1011-1016
This paper describes work performed on the sampling and analysis of non-condensable gases (NCG) emitted from diffuse sources of a Portuguese Kraft pulp mill, which is the background information for a NCG collection, treatment and disposal system. The variability found in the composition of the gaseous compounds showed the existence of gaseous streams other than typical total reduced sulphur (TRS) compounds as usually described. From the measured TRS concentrations and the gas flow rate from each source it was possible to calculate the emission flow rate, E, of each source. These emission flow rates were then divided into three categories which are quite useful to identify significant sources and to choose abatement techniques. The methodology presented allows for a precise quantification of sources so that similar emissions can be grouped for treatment purposes. Sources with an emission flow rate bigger than 1 kg/h have a marked effect on the overall TRS emissions of the mill, as they are major contributors. It was also found that a new analytical procedure using Restek columns is more easy to use and overcomes operational problems noticed previously, namely a run time of 20-25 min instead of 50-60 min.  相似文献   
145.
The environmental problems associated with textile activities are represented mainly by the extensive use of organic dyes. A great number of these compounds are recalcitrant and shown carcinogenic or mutagenic character. In this work three processes were studied for degradation of an anthraquinone dye (C.I. reactive blue-19). The ozonation process leads to complete decolorization with a very short reaction time; however, effective mineralization of the dye was not observed. The enzymatic process promotes quick decolorization of the dye; nevertheless, maximum decolorization degrees of about 30% are insignificant in relation to the decolorization degree achieved by the other processes. The best results were found for the photocatalytical process. The use of ZnO or TiO2 as photocatalysts, permits total decolorization and mineralization of the dye with reaction times of about 60 min.  相似文献   
146.
Soil erosion and the invasion of exotic plant species are major constraints to achieve sustainable development around the world. Currently, we find few products devoted concomitantly to combatting soil erosion as well as the establishment of unwanted exotic plants. In this paper, we introduce a new product, called herein a bioblanket, that protects the soil and impedes the establishment of exotic plant species. This product is of simple design, and to manufacture it, we use two biodegradable materials: jute tissue and grass wastes. We designed this product to combat soil erosion and the germination and establishment of new, unwanted, invasive plant species. In this paper, we describe our evaluation of how successful this product was in terms of improving the chemical attributes of soil. We also identified the product's potentialities and weaknesses by means of strengths, weaknesses, opportunities, and threats (SWOT) analysis. The bioblanket ameliorated the chemical attributes of the soil, as evidenced especially by the neutralization of acidity (8.5%) and aluminum toxicity (33%), and by an increment in nutrients concentration. We argue that after adequate treatment and management, the residues of plants that are normally considered unwanted materials can be transformed into a raw material to control the propagation of unwanted plant species, and concomitantly control soil erosion while improving the chemical conditions of the soil. The improvement of the soil chemical attributes was one of the main positive effects reported through the SWOT analysis. In addition, the SWOT analysis revealed some features that need improvement in future generations of the product, but we argue that these features do not impede the benefits for the use of the product in its present form.  相似文献   
147.
The objective of this study was to determine the concentrations of trace elements in sediment samples taken from impermeable urban areas of a city with predominantly agroindustrial development characteristics. For this, samples were taken every month from paved streets in the city of Toledo, Paraná State (PR), Brazil. Thus, trace element levels were obtained through analysis performed by optical emission spectrometry with inductively coupled plasma. Levels of total organic carbon were also obtained through the dry combustion method. When compared to local background levels, the trace element levels were shown to be enriched in the following percentage proportions: barium (Ba) (45.4%), copper (Cu) (48.6%), chromium (Cr) (37.2%), manganese (Mn) (81.6%), nickel (Ni) (0%), lead (Pb) (40%), zinc (Zn) (283.7%), magnesium (Mg) (34.3%), and sodium (Na) (250.2%), whereas the carbon (C) percentages were around 1%. The most significant enrichment factors occurred for Ba, Cr, Pb, Zn, Mg, and Na. The highest rates occurred in geoaccumulation where the sediments were enriched by zinc. According to the principal guidelines, the concentrations obtained for cadmium (Cd), Cr, Cu, Ni, and Zn can cause adverse environmental impacts.  相似文献   
148.
Energy is an essential asset for the existence of industrial activities, however, the absence of energy use management may lead to numerous environmental, economic, and social impacts. Thus, industries, which are major consumers of energy, play an essential role in seeking to preserve the energy system. This study aimed at analyzing the practices of energy use management and their relation to sustainable performance in the industries within the Brazilian mineral sector. The practices of energy use management were measured using the model proposed by Liu et al. (2012, Journal of Cleaner Production, 26, 79–89). After that, evidence of sustainable performance was identified based on performance indicators developed by the Global Reporting Initiative (2006, 2010, 2014). The study is characterized as quantitative, and it was conducted through a survey of industries linked to the Brazilian Mining Association. Through our results, we verified that the practices related to energy use management existent in the companies that we studied are subjected to periodic verification of the impacts caused by company activities on the environment, and that attention to energy use provides an incentive to daily practices of energy saving. On the other hand, the practices of energy use management are still little disseminated among these companies, as is certification to the International Organisation for Standardization's (ISO) Energy Management Systems framework, ISO 50001. In general, through the analyses that we performed, we can verify the existence of positive associations between the factors related to the practices of energy use management and to corporate sustainable performance.  相似文献   
149.
150.
(14)C specific activities were measured in grass samples collected around Brazilian nuclear power reactors. The specific activity values varied between 227 and 299 Bq/kg C. Except for two samples which showed (14)C specific activities 22% above background values, half of the samples showed background specific activities, and the other half had a (14)C excess of 1-18%. The highest specific activities were found close to the nuclear power plants and along the main wind directions (NE and NNE). The activity values were found to decrease with increasing distance from the reactors. The unexpectedly high (14)C excess values found in two samples were related to the local topography, which favors (14)C accumulation and limits the dispersion of the plume. The results indicate a clear (14)C anthropogenic signal within 5 km around the nuclear power plants which is most prominent along northeastwards, the prevailing wind direction.  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