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   1870篇
  免费   18篇
  国内免费   14篇
安全科学   56篇
废物处理   67篇
环保管理   315篇
综合类   317篇
基础理论   447篇
环境理论   4篇
污染及防治   474篇
评价与监测   134篇
社会与环境   83篇
灾害及防治   5篇
  2024年   9篇
  2023年   27篇
  2022年   21篇
  2021年   27篇
  2020年   29篇
  2019年   27篇
  2018年   39篇
  2017年   47篇
  2016年   46篇
  2015年   47篇
  2014年   52篇
  2013年   128篇
  2012年   75篇
  2011年   108篇
  2010年   77篇
  2009年   94篇
  2008年   95篇
  2007年   115篇
  2006年   85篇
  2005年   75篇
  2004年   73篇
  2003年   68篇
  2002年   79篇
  2001年   34篇
  2000年   26篇
  1999年   19篇
  1998年   20篇
  1997年   24篇
  1996年   18篇
  1995年   24篇
  1994年   25篇
  1993年   15篇
  1992年   16篇
  1991年   15篇
  1990年   13篇
  1989年   12篇
  1988年   17篇
  1987年   12篇
  1986年   15篇
  1984年   8篇
  1983年   10篇
  1982年   11篇
  1981年   9篇
  1980年   7篇
  1979年   10篇
  1978年   7篇
  1976年   6篇
  1974年   6篇
  1955年   5篇
  1954年   8篇
排序方式: 共有1902条查询结果,搜索用时 15 毫秒
141.
    
A membrane unit in pilot scale is operated to provide a CO2‐enriched product stream from flue gas of a natural‐gas‐fuelled heating system. The CO2 stream is fed to a cultivation medium of photobioreactors that are integrated in the façade of the building project ‘BIQ – The Algae House’ (International Building Exhibition 2013/Hamburg), where CO2 is required as the carbon source for the growth of algae, which are cultivated in the bioreactors. This work presents a long‐term field test. Furthermore, a possibility for the usage of CO2 separated de‐centrally is given. The operational conditions for the membrane module cause additional mechanical stress on the membrane material since the pilot plant is operated with periodic start‐ups and shut‐downs. The occurrence of acidic water on the membrane generates additional potential damage of the material. The field test is planned to be carried out for several years to prove the reliability of this membrane technology in flue gas treatment. © 2015 Society of Chemical Industry and John Wiley & Sons, Ltd  相似文献   
142.
One of the objectives of US environmental regulations was to reduce industrial air pollution emissions, especially from the electric utility industry, the major industrial air polluter. In this study, a comparative analysis of air pollution emissions from fossil-fuel-burning electric utility plants is conducted. The analysis focuses on a 12-yr period from 1975 to 1987 for three air pollutants: particulates, surfur dioxide, and nitrogen oxides. The results indicate that particulate emissions have been significantly reduced but that sulfur dioxide and nitrogen oxides are still major problems for a number of plants. Furthermore, the disparity in the performance by plants indicates that by using current technology, the industry as a whole could greatly reduce these emissions. These results have policy implication for future environmental legislation.  相似文献   
143.
144.
This paper presents the story of a project undertaken by researchers who are active participants in the national Australian debate over place and belonging. It arose from the desire to ground this debate, which brings issues of ecological sustainability, reconciliation and multiculturalism together, in more localised action aimed at building a 'place-responsive society'. The project was carried out as a case study in a region that combines part of the Sydney metropolitan area and the separate 'city' of the Blue Mountains, and involved a consultative committee and then a regional forum of conservationists, environmental educators and community workers. The researchers explored existing place-oriented initiatives in the region and developed practical projects for the future, most notably a proposal for 'totemic species' work within schools involving local Aboriginal people. The research demonstrated, more than anything else, that indigenous Australian approaches to 'place awareness' and nature conservation remain highly relevant in contemporary Australia. It also showed that bioregional awareness and the notion of place responsiveness can add value to more traditional approaches to nature conservation and environmental education. There are opportunities to galvanise local action that can integrate community and environmental work and revitalise professional practice in both areas, but the effort involves working constantly with difference and conflict.  相似文献   
145.
The knowledge of the environmental fate of polycyclic aromatic hydrocarbons (PAHs) is restricted to few climatic regions of the world almost excluding the Taiga. Our objectives were to (i) separate anthropogenic from background contributions to PAH concentrations and (ii) determine temporal trends in PAH concentrations during the last century including the change in distribution of PAHs in interior and exterior portions of aggregates in soils of the Moscow region. Along a southeast-bound transect from Moscow (windward in winter) and at a background location northeast of Moscow (leeward in winter), seven topsoil samples were collected in 1910-1954 and 35 in 1998-2003. We fractionated the soils in interior and exterior portions of aggregates > 10 mm and remaining soil without aggregates. The sum of 21 PAHs (sigma21PAHs) concentrations in recent bulk soil ranged from 59 to 1350 ng g(-1). The concentrations of all PAHs were lower outside than in Moscow. The range of the concentrations of the sigma21PAHs in archived soil samples (159-1280 ng g(-1)) was similar as in recent soils. In most recent and archived samples, naphthalene and phenanthrene, were most abundant. The concentrations of low-molecular-weight PAHs decreased during the last century at most sites; those of high-molecular-weight compounds increased. The sigma21PAHs concentrations were accumulated in the exterior of aggregates (109%) and depleted in the interior (95%) relative to the concentration in bulk soil (defined as 100%), which was similar to that in the soil without aggregates (99%). The differences between aggregate interior and exterior did not change during the last century. The dominance of naphthalene and phenanthrene is typical of remote regions. The urban influence on PAH concentrations in the last century was small.  相似文献   
146.
    
This article explores the recent growth and current trends in outsourcing EHS services. More and more organizations are recognizing that outsourcing can cut costs, save time, improve staffing flexibility, and enhance the overall quality of EHS programs. © 2001 John Wiley & Sons, Inc.  相似文献   
147.
This paper examines the rationale underlying the ‘strategic approach’ to the prevention and reclamation of derelict land proposed in research recently published by the Department of the Environment. It outlines the main features and the processes involved in this approach and indicates the form and content of the documentation which might accompany its adoption. The paper focuses upon the tasks involved in the preparation of strategies for derelict land but the principles it examines will have wider application in other policy fields. It concludes with an examination of the practical problems which the adoption of a strategic approach may entail and the ways in which it would enhance the activities of the recently announced Urban Regeneration Agency for England.  相似文献   
148.
Despite the fact that virtual environments are increasingly deployed to study the relation between urban planning, physical and social disorder, and fear of crime, their ecological validity for this type of research has not been established. This study compares the effects of similar signs of public disorder (litter, warning signs, cameras, signs of vandalism and car burglary) in an urban neighborhood and in its virtual counterpart on the subjective perception of safety and livability of the neighborhood. Participants made a walking tour through either the real or the virtual neighborhood, which was either in an orderly (baseline) state or adorned with numerous signs of public disorder. During their tour they reported the signs of disorder they noticed and the degree to which each of these affected their emotional state and feelings of personal safety. After finishing their tour they appraised the perceived safety and livability of the environment. Both in the real and in the simulated urban neighborhood, signs of disorder evoked associations with social disorder. In all conditions, neglected greenery was spontaneously reported as a sign of disorder. Disorder did not inspire concern for personal safety in reality and in the virtual environment with a realistic soundscape. However, in the absence of sound disorder compromised perceived personal safety in the virtual environment. Signs of disorder were associated with negative emotions more frequently in the virtual environment than in its real-world counterpart, particularly in the absence of sound. Also, signs of disorder degraded the perceived livability of the virtual, but not of the real neighborhood. Hence, it appears that people focus more on details in a virtual environment than in reality. We conclude that both a correction for this focusing effect and realistic soundscapes are required to make virtual environments an appropriate medium for both etiological (e.g. the effects of signs of disorder on fear of crime) and intervention (e.g. CPTED) research.  相似文献   
149.
This paper sets out a few results of research on waste prevention, recycling and disposal in The Netherlands. First, an outline is given of the actual waste disposal. Secondly, a projection is made of the different waste categories as a result of independent developments for the year 2000. Finally, a scenario is presented in which recent Dutch policy on the prevention and recycling of waste, as well as incineration, play important roles. The waste policy will be based on the long-term objective of sustainable development, as mentioned in the Brundtland Commission report. Results are given concerning space, costs and emissions.  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