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   151篇
  免费   2篇
  国内免费   4篇
安全科学   10篇
废物处理   15篇
环保管理   16篇
综合类   18篇
基础理论   23篇
污染及防治   51篇
评价与监测   15篇
社会与环境   5篇
灾害及防治   4篇
  2023年   4篇
  2022年   17篇
  2021年   14篇
  2020年   6篇
  2019年   3篇
  2018年   6篇
  2017年   12篇
  2016年   13篇
  2015年   3篇
  2014年   4篇
  2013年   16篇
  2012年   7篇
  2011年   7篇
  2010年   7篇
  2009年   4篇
  2008年   5篇
  2007年   8篇
  2006年   3篇
  2005年   5篇
  2004年   2篇
  2003年   5篇
  2002年   3篇
  2000年   1篇
  1992年   1篇
  1990年   1篇
排序方式: 共有157条查询结果,搜索用时 15 毫秒
141.
Environment, Development and Sustainability - This study is an attempt to develop ecotourism in Nehbandan County, in the South Khorasan Province, Iran, by representing unknown areas that have...  相似文献   
142.
The option of reusing greywater is proving to be increasingly attractive to address the water shortage issue in many arid and semiarid countries. Greywater represents a constant resource, since an approximately constant amount of greywater is generated from kitchen, laundries, bathroom in every household daily, independent of the weather. However, the use of greywater for irrigation in particular for household gardening may pose major hazards that have not been studied thoroughly. In this study, a 1-year monitoring was conducted in four selected households in Perth, Western Australia. The aim of the monitoring works is to investigate the variability in the greywater flow and quality, and to understand its impact in the surrounding environments. Case studies were selected based on different family structure including number, ages of the occupants, and greywater system they used. Samples of greywater effluent (showers, laundries, bathtub, and sinks), leachate, soil, and plants at each case study were collected between October 2008 and December 2009 which covered the high (spring/summer) and low (autumn/winter) production of greywater. Physical and chemical tests were based on the literature and expected components of laundry and bathroom greywater particularly on greywater components likely to have detrimental impacts on soils, plants, and other water bodies. Monitoring results showed the greywater quality values for BOD, TSS, and pH which sometimes fell outside the range as stipulated in the guidelines. The soil analyses results showed that salinity, SAR, and the organic content of the soil increased as a function of time and affected the plant growth. Nutrient leaching or losses from soil irrigated with greywater shows the movement of nutrients and the sole impact from greywater in uncontrolled plots in case studies is difficult to predicted due to the influence of land dynamics and activities. Investigative and research monitoring was used to understand greywater irrigation in households. Greywater quality is very site specific and difficult to predetermine or control except for the use of some recommended household products when using greywater. Investigative and research monitoring was indicated that greywater quality is very site specific and difficult to predetermine or control except for the use of some recommended household products when using greywater.  相似文献   
143.
Objective. Construction is a hazardous occupation due to the unique nature of activities involved and the repetitiveness of several field behaviors. The aim of this methodological and theoretical review is to explore the empirical factors influencing unsafe behaviors and accidents on construction sites. Methods. In this work, results and findings from 56 related previous studies were investigated. These studies were categorized based on their design, type, methods of data collection, analytical methods, variables, and key findings. A qualitative content analysis procedure was used to extract variables, themes, and factors. In addition, all studies were reviewed to determine the quality rating and to evaluate the strength of provided evidence. Results. The content analysis identified 8 main categories: (a) society, (b) organization, (c) project management, (d) supervision, (e) contractor, (f) site condition, (g) work group, and (h) individual characteristics. The review highlighted the importance of more distal factors, e.g., society and organization, and project management, that may contribute to reducing the likelihood of unsafe behaviors and accidents through the promotion of site condition and individual features (as proximal factors). Conclusion. Further research is necessary to provide a better understanding of the links between unsafe behavior theories and empirical findings, challenge theoretical assumptions, develop new applied theories, and make stronger recommendations.  相似文献   
144.
Blubber samples of Indo-Pacific bottlenose (Tursiops aduncus) and spinner (Stenella longirostris) dolphins from Zanzibar, East Africa, were analyzed for a wide range of organohalogen compounds. Methoxylated polybrominated diphenyl ethers (MeO-BDEs), presumably biogenic, were found at higher concentrations than anthropogenic organochlorine pesticides (OCPs). Only traces of industrial pollutants, such as polychlorinated biphenyls, were detected. The OCP levels found off Zanzibar were lower than those reported from other regions while MeO-BDE levels were higher. The relative composition of the OCPs indicated recent use of lindane (γ-hexachlorocyclohexane) and aged residues of DDT and technical HCH. Placental transfer was estimated to 2.5% and 0.5% of the total burden of OCPs and MeO-BDEs, respectively. Overall transfer from mother to calf in Indo-Pacific bottlenose dolphins was estimated to 72% and 85% for the OCPs and MeO-BDEs burdens, respectively. Health effects of MeO-BDEs are not known, but structural similarities with well-known environmental toxins are cause for concern.  相似文献   
145.
Environment, Development and Sustainability - Several models with a variety of concepts and approaches have been proposed to address different aspects of the Water-Energy-Food (WEF) nexus system....  相似文献   
146.
Biodegradation Study of Starch-graft-Acrylonitrile Copolymer   总被引:1,自引:0,他引:1  
In this study the biodegradability of starch-graft-acrylonitrile (St-g-AN) copolymer has been investigated using some microorganisms including Aspergillus niger. The fungus A. niger was isolated from the soil and from the wastewater of an acrylic fiber company. The effects of four factors including environment temperature, primary inoculum concentration, pH and weight of copolymer film, on the biomass generation as a measure of biodegradation rate of copolymer, were studied using Taguchi experimental design. The statistical analysis of the results showed that the primary inoculum concentration and temperature were the most important factors affecting the biodegradation of St-g-AN copolymer. The optimum levels of temperature, pH, inoculum concentration, and weight of films to attain the maximum biodegradation (as much as 8.59 % by weight percentage during 28 days) were obtained as 30 °C, 4.75, 108 spore/mL, and 1.1 g, respectively. The changes in the structure and morphological properties of the copolymer before and after degradation were determined using transform infrared spectroscopy and scanning electron microscopy.  相似文献   
147.
Suspended atmospheric particles were collected in Israel in order to identify their nature and relationships with the major synoptic-scale circulation patterns. The particles were analyzed for their major and trace element concentrations and mineralogical composition. Samples were collected during three synoptic systems associated with desert dust storms: Red Sea trough, Sharav cyclone and cold depression, and during deep and shallow modes of Persian Gulf trough, which prevails in the summer months and is not associated with dust storms.All samples mostly contain particles smaller than 2 μm. The suspended desert dust is composed primarily of illite–smectite and calcite. Some indicative secondary minerals were found for each of the dust transporting synoptic systems (e.g., palygorskite for Red Sea trough). The bulk chemistry data support the mineralogical observations and reveal additional chemical signatures of each dust transporting system. For instance, Red Sea trough samples have significantly higher Ca/Al and Ca/Mg in the carbonate and Mg/Al in Al-silicate fraction than cold depression samples. Nevertheless, Sharav cyclone samples have intermediate values in spite of the fact that the source of the dust during these conditions is similar to cold depression (i.e., North Africa). Even though differences in the chemical and the mineralogical composition of desert dust do exist, this study reveals their overall chemical and mineralogical similarities.In contrast to the synoptic systems that carry desert dust, the inorganic fraction of the Persian Gulf trough samples contains significant amount (up to 50%) of non-mineral material that has a pronounced chemical signature in terms of major element concentrations (e.g., Al, Ca, Mg, Na, S) implying their anthropogenic nature, probably from countries around the Black Sea. This striking finding is indicative for atmospheric pollution in the Eastern Mediterranean region during the summer.  相似文献   
148.
149.
Environmental Fluid Mechanics - The aim of the present study is to numerically investigate the scouring phenomenon downstream of a stilling basin for a wide range of Froude number and size of bed...  相似文献   
150.
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