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   199篇
  免费   1篇
  国内免费   4篇
安全科学   3篇
废物处理   17篇
环保管理   13篇
综合类   21篇
基础理论   26篇
污染及防治   82篇
评价与监测   22篇
社会与环境   20篇
  2023年   4篇
  2022年   14篇
  2021年   12篇
  2020年   6篇
  2019年   7篇
  2018年   8篇
  2017年   12篇
  2016年   12篇
  2015年   10篇
  2014年   14篇
  2013年   27篇
  2012年   11篇
  2011年   16篇
  2010年   11篇
  2009年   6篇
  2008年   5篇
  2007年   8篇
  2006年   5篇
  2005年   4篇
  2004年   1篇
  2003年   3篇
  2002年   5篇
  2001年   1篇
  1999年   1篇
  1998年   1篇
排序方式: 共有204条查询结果,搜索用时 15 毫秒
111.
The residue (vinasse) formed during the distillation of bio-ethanol and cachaça, a traditional rum-type spirit produced from sugar-cane in Brazil, is highly harmful if discharged into the environment due to high values of COD and BOD. One possibility for minimizing the impact of vinasse in soils and waters is to use the residue in the production of microbial biomass for use as an animal feed supplement that will provide high levels on nitrogen (>9% d.m.) and low content of nucleic (?10% d.m.) This paper reports the production and quality of biomass produced from fermentation of Saccharomycescerevisiae and Candidaparapsilosis in culture media under 12 different culture conditions and the respective effects of each variable (glucose, yeast extract, peptone, potassium phosphate, vinasse, pH and temperature). Of the S. cerevisiae isolates tested, two (VR1 and PE2) originating from fuel alcohol-producing plants were identified as offering the best potential for the industrial production of single cell protein from vinasse due to highest biomass productivity. Our results showed a potential viable and economic use of vinasse.  相似文献   
112.
113.
Fences are very common in rural areas, and represent important landscape elements in both tropical and temperate climate regions. In spite of their marked presence and importance, fences have been little studied, principally in Brazil. The present study examined the types of fences, the diversity of species used in their construction, as well as the diversity of their uses in a rural community in the municipality of Caruaru, Pernambuco State, northeastern Brazil. Fifty meters of fence-line in each of 50 rural properties in the community were examined, noting the diameter, height and identity of all vegetation elements used in their composition. Semi-structured interviews were also held with their builders in order to obtain information concerning fence uses. In the total of 2,500 linear meters of fence-line, 4,953 individual plant elements were identified, belonging to 51 different species. A majority of the fence elements were non-living fence posts, although the number of living posts was high. Of the total number of fence elements, 66.7% were native to the caatinga region. The large number of native species used as non-living fence posts indicates an intensive use of the caatinga vegetation and suggests the need to stimulate the use of living fence posts for conservation purposes.  相似文献   
114.
Hunting plays an important socioeconomic role in the semi-arid region of Brazil, by supplying meat and other products. Nevertheless, there is a lack of information on which species are most used by the local populations and what are the implications for conservation of exploited animals. This paper explores the bushmeat consumption in the Brazilian Caatinga region, where wild animals comprise an important protein source. A questionnaire was used to gather information from hunters, and the consumption of bushmeat by their families was monitored. Interviews revealed that 58 vertebrate species could potentially be consumed as bushmeat, but the samples provided by the monitored families comprised only 28 species. Birds were the animals most consumed, followed by mammals, although the biomass of both groups was similar. The consumption of bushmeat was not correlated with hunters’ socioeconomic data (income, age or schooling). Hunters recognized that the populations of some game species appeared to be declining, showing that bushmeat consumption, together with the cultural, economic and social aspects of the human populations involved in hunting, should be considered when discussing the conservation of animal resources in the Caatinga region.  相似文献   
115.
The ecological apparency hypothesis in ethnobotanical studies predicts that the apparent plants (i.e., the most easily found in the vegetation) would be the most commonly collected and used by people. To test this hypothesis, it has been used the concept of use value (VU), which measures the relative importance of useful plants for a group of people. However, the use value has got some limitations, including the fact that it does not distinguish "current use" (plants which are effectively used) from "potential use" (well known plants, however not used). Therefore, this study has tested whether the obtained results through three different use value calculations could be useful in testing the ecological apparency hypothesis. These calculations have included the current use value, the potential use value, and the general use value. It has been carried out a vegetation survey and an interview for residents from the rural communities from Barrocas and Cachoeira (Soledade, Paraíba, Brazil). It has been used Spearman's coefficient to correlate phytosociological and ethnobotanical data. It has been observed that phytosociological parameters in Cachoeira were not correlated with any of the use values calculations, except the relationship between the current use value and the relative dominance (r(s)?=?0.57; p?相似文献   
116.
An indoor/outdoor monitoring programme of PM10 was carried out in two sports venues (a fronton and a gymnasium). Levels always below 50 μg m?3 were obtained in the fronton and outdoor air. Due to the climbing chalk and the constant process of resuspension, concentrations above 150 μg m?3 were registered in the gymnasium. The chalk dust contributed to CO3 2? concentrations of 32?±?9.4 μg m?3 in this sports facility, which represented, on average, 18 % of the PM10 mass. Here, the carbonate levels were 128 times higher than those registered outdoors. Much lower concentrations, around 1 μg m?3, were measured in the fronton. The chalk dust is also responsible for the high Mg2+ concentrations in the gym (4.7?±?0.89 μg m?3), unfolding a PM10 mass fraction of 2.7 %. Total carbon accounted for almost 30 % of PM10 in both indoor spaces. Aerosol size distributions were bimodal and revealed a clear dependence on physical activities and characteristics of the sports facilities. The use of climbing chalk in the gymnasium contributed significantly to the coarse mode. The average geometric mean diameter, geometric standard deviation and total number of coarse particles were 0.77 μm, 2.79 cm?3 and 28 cm?3, respectively.  相似文献   
117.
Enzymatic hydrolyzates of recycled paper sludge were tested as suitable feedstock for biological desulfurization by Gordonia alkanivorans strain 1B. Only the hydrolyzate obtained after enzymatic mixture dialysis (dialyzed hydrolyzate) allowed dibenzothiophene (DBT) desulfurization, in spite of faster bacterial growth did occur on non-dialyzed hydrolyzate. For dialyzed hydrolyzate, 250microM DBT was consumed after 96h displaying a maximum specific productivity of 2-hydroxybiphenyl of 1.1micromol g(-1)(dry cell weight) h(-1). A comparison of the kinetics of biodesulfurization was assessed according to the type of hydrolyzate supplementation. Complete consumption of DBT was observed upon the addition of only phosphates and ammonia although further addition of zinc did increase the 2-hydroxybiphenyl production by 14%. Strain 1B was able to desulfurize a model oil containing DBT, 4-methylDBT and 4,6-dimethylDBT, reducing by 63% the total sulfur content in 168h.  相似文献   
118.
Journal of Material Cycles and Waste Management - In this work, food wastes (FWs) and domestic sewage sludge (DSS) were used as raw materials for energy recovery by anaerobic digestion (AD). AD was...  相似文献   
119.
The development of environmental performance policy indicators for public services, and in particular for the defence sector, is an emerging issue. Despite a number of recent initiatives there has been little work done in this area, since the other sectors usually focused on are agriculture, transport, industry, tourism and energy. This type of tool can be an important component for environmental performance evaluation at policy level, when integrated in the general performance assessment system of public missions and activities. The main objective of this research was to develop environmental performance policy indicators for the public sector, specifically applied to the defence sector. Previous research included an assessment of the environmental profile, through the evaluation of how environmental management practices have been adopted in this sector and an assessment of environmental aspects and impacts. This paper builds upon that previous research, developing an indicator framework--SEPI--supported by the selection and construction of environmental performance indicators. Another aim is to discuss how the current environmental indicator framework can be integrated into overall performance management. The Portuguese defence sector is presented and the usefulness of this methodology demonstrated. Feasibility and relevancy criteria are applied to evaluate the set of indicators proposed, allowing indicators to be scored and indicators for the policy level to be obtained.  相似文献   
120.
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