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   119篇
  免费   3篇
  国内免费   1篇
安全科学   5篇
废物处理   16篇
环保管理   59篇
综合类   7篇
基础理论   16篇
污染及防治   14篇
评价与监测   4篇
社会与环境   2篇
  2021年   3篇
  2017年   2篇
  2015年   1篇
  2014年   1篇
  2013年   6篇
  2012年   2篇
  2011年   3篇
  2010年   1篇
  2009年   3篇
  2008年   10篇
  2007年   4篇
  2006年   4篇
  2005年   5篇
  2004年   4篇
  2003年   6篇
  2002年   6篇
  2001年   1篇
  2000年   4篇
  1999年   2篇
  1998年   3篇
  1997年   3篇
  1996年   3篇
  1995年   2篇
  1994年   2篇
  1993年   6篇
  1992年   6篇
  1991年   4篇
  1990年   1篇
  1989年   3篇
  1988年   5篇
  1987年   3篇
  1985年   2篇
  1984年   4篇
  1982年   2篇
  1981年   1篇
  1977年   1篇
  1976年   1篇
  1973年   1篇
  1967年   1篇
  1963年   1篇
排序方式: 共有123条查询结果,搜索用时 31 毫秒
81.
Abstract

Some neighbourhood environments have become dumping grounds for locally unwanted land uses (LULUs) that middle-class Americans do not want near their homes. LULUs may combine with other pariah land uses to collectively undermine the quality of the local environment, reduce investment, government services, the proportion of middle-income people and associated businesses. As important neighbourhood attributes are lost, illegal activities, derelict structures, trash-strewn lots and the concentration of poor and unhealthy people may increase. This paper describes the theory behind the impact of pariah land uses through examples of the downward spiral experienced by Camden, New Jersey and the south Bronx, New York. It then documents the experience of one community, Elizabethport, New Jersey, in reversing that downward spiral. Success in Elizabethport came from the synergistic activities of local, state and federal governments, community groups, and not-for-profit organizations as they struggled to regain control through local environmental management, rebuilding, and reducing crime. Social capital was also strengthened by using a local community health concern—that of childhood asthma. Efforts to reverse the downward spiral of urban decay from pariah land uses should be multi-faceted, spurred by local efforts that address local concerns.  相似文献   
82.
83.
84.
By comparing the polymorphisms of Q-banded karyotypes of a mother and her female fetus, it is possible to confirm that maternal cell contamination is a rare event in prenatal diagnosis. The frequency with which any given polymorphism is distinctive is directly correlated to its prevalence in the population. Hence, since the polymorphisms on bands 3c, 13p and 21s are the most prevalent in the population, comparison of these maternal bands with the corresponding fetal ones is most likely to yield a distinctive pattern between a mother and her female fetus. However, in light of the rarity of maternal cell contamination, comparison of chromosomal polymorphisms is not cost-effective for all cases, and is recommended only for high-risk situations such as prenatal diagnosis of recessive or X-linked diseases, where maternal age is over 40, or when amniotic fluid is grossly bloody.  相似文献   
85.
86.
Smart growth policies direct development towards existing communities already served by roads, sewer systems and other infrastructure. The increased development in these communities in turn should enable them to benefit from a stronger tax-base, more efficient use of their schools and other public facilities, and the renewed economic vitality of their urban centres. These goals and objectives appear to complement and support the efforts of urban mayors to attract new property tax rateables and better-paying jobs, but they may conflict with the desires of residents to reduce densities and improve the quality of life. We use a visual GIS-based model to assist five small contiguous older suburbs individually and collectively to evaluate their current redevelopment plans and to understand the implications of their land-use decisions on the quality of life in their communities. By bringing them together as a group, and our raising broader redevelopment and impact issues, they have begun to rethink how these properties could be best used to meet the community's needs and to see them in the context of similar redevelopment plans within their mini-region. One of the changes emerging is a greater role for certain types of residential development and a concurrent reduction in the amount of commercial space being considered. The authors would like to thank the Geraldine R. Dodge Foundation for funding this project, the Somerset County Planning Board and mayors of the five towns for actively supporting and participating in the study and the Regional Planning Partnership for its co-operation and assistance in refining its GOZ model to promote regional planning from the bottom up. The authors accept full responsibility for the ideas and recommendations in this report.  相似文献   
87.
A sample of 873 residents of Accra, Ghana, and 504 residents of the state of New Jersey, USA, stratified by type of neighbourhood was gathered in order to determine the sources of information residents rely on for accurate information about their neighbourhoods. In both countries residents relied most heavily on personal contacts, television and radio, and much less on community organisations. Residents who rely on many sources for reliable information tend to have lived in their neighbourhood for a long time and to be more engaged in neighbourhood activities than those who reach out to fewer sources. Those who rely on secular community organisations tend to mistrust science, experts and local officials. Those who rely on faith-based organisations are much more trusting of local officials but are even less trusting of science and experts than their counterparts. The implications of these results for building and sustaining community organisations are discussed.  相似文献   
88.
Commercial fisheries industry structure often suggests exvessel price formation occurs in the context of a competitive harvesting sector and an oligopsonistic processing sector. However, industry conduct leading to a determination of exvessel price can be notably at odds with this inference. This paper presents empirical evidence that the conduct of at least one such fishery, the Alaska king crab industry, may emulate bilateral monopoly. Exvessel price determination is consistent with an implicit formula price contract in which fishers behave as monopolists through bargaining associations, while processors behave as countervailing monopsonists, even in the absence of explicit collusion. Both sectors appear to behave in a manner consistent with joint expected profit maximization, with profit shares apportioned via the implicit formula price contract. This price formation process simplifies empirical analysis of the bilateral monopoly conduct by avoiding complicated game theoretic/bargaining models.  相似文献   
89.
summary This article presents a study of the association of perceived neighbourhood hazards, neighbourhood quality, and resident behavioural responses in two New Jersey, USA, communities that contain multiple technological hazards and populations that are relatively poor and racially homogeneous. The number of neighbourhood problems was highest among residents who engaged in activities to protect their neighbourhood and perceived that their neighbourhood was of poor or fair quality. These respondents perceived three to five times as many hazards as their counterparts who were passive and perceived that their neighbourhood was of excellent or good quality. Respondents' age, education, gender, type of residential unit occupied, and length of residence in the neighbourhood, were not associated with their evaluation of neighbourhood hazards. The authors argue that multiple-hazard neighbourhoods are excellent environments to learn about perception of hazards.Professor Michael Greenberg is Head of the Department of Urban Studies and Community Health where Professor Dona Schneider and Jim Parry are associates.  相似文献   
90.
The operation of Trinity and Lewiston Dams on the Trinity River in northern California in the United States, combined with severe watershed erosion, has jeopardized the existence of prime salmonid fisheries. Extreme streamflow depletion and stream sedimentation below Lewiston have resulted in heavy accumulation of coarse sediment on riffle gravel and filling of streambed pools, causing the destruction of spawning, nursery, and overwintering habitat for prized chinook salmon (Salmo gairdnerii) and steelhead trout (Oncorhynchus tschawytscha). Proposals to restore and maintain the degraded habitat include controlled one-time remedial peak flows or annual maintenance peak flows designed to flush the spawning gravel and scour the banks, deltas, and pools. The criteria for effective channel restoration or maintenance by streambed flushing and scouring are examined here, as well as the mechanics involved.The liabilities of releasing mammoth scouring-flushing flows approximating the magnitude that preceded reservoir construction make this option unviable. The resulting damage to fish habitat established under the postproject streamflow regime, as well as damage to human settlements in the floodplain, would be unacceptable, as would the opportunity costs to hydroelectric and irrigation water users. The technical feasibility of annual maintenance flushing flows depends upon associated mechanical and structural measures, particularly instream maintenance dredging of deep pools and construction of a sediment control dam on a tributary where watershed erosion is extreme. The cost effectiveness of a sediment dam with a limited useful economic life, combined with perpetual maintenance dredging, is questionable.  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