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   164篇
  免费   14篇
  国内免费   11篇
安全科学   13篇
废物处理   4篇
环保管理   78篇
综合类   40篇
基础理论   24篇
污染及防治   5篇
评价与监测   7篇
社会与环境   17篇
灾害及防治   1篇
  2024年   1篇
  2023年   4篇
  2022年   3篇
  2021年   10篇
  2020年   4篇
  2019年   5篇
  2018年   2篇
  2017年   5篇
  2016年   5篇
  2015年   8篇
  2014年   10篇
  2013年   12篇
  2012年   11篇
  2011年   12篇
  2010年   7篇
  2009年   14篇
  2008年   9篇
  2007年   10篇
  2006年   9篇
  2005年   11篇
  2004年   5篇
  2003年   1篇
  2002年   1篇
  2001年   2篇
  2000年   1篇
  1998年   2篇
  1997年   4篇
  1995年   1篇
  1994年   4篇
  1993年   1篇
  1992年   2篇
  1991年   1篇
  1990年   1篇
  1989年   2篇
  1988年   2篇
  1987年   3篇
  1986年   2篇
  1985年   1篇
  1977年   1篇
排序方式: 共有189条查询结果,搜索用时 31 毫秒
111.
The Ozegahara peatland, in the Nikko-Oze National Park in Japan, is ecologically significant because of its oligotrophic environment; it is one of the most strictly preserved areas in the country. The isotope ratio of nitrogen (15N/14N) and carbon (13C/12C) and C/N ratio of peat moss (Sphagnum spp.) and sundew (Drosera rotundifolia) in the peatland were analyzed. The correlation of the isotope ratio with some parameters (sundew population density, number of trapped insects, water level, bog myrtle coverage, and visitor density) was investigated. The nitrogen isotope ratio of sundew showed the most significant covariation with visitor density, where sundew from lunch areas or along busy walkways showed a higher nitrogen isotope ratio. The nitrogen isotope ratio of peat moss covaried, not only with route traffic frequency but also with water level, bog myrtle coverage, and number of trapped insects by sundew, indicating that factors other than the visitor level influence the local nitrogen cycle. This study suggests that the nitrogen imported into the peatland by visitors is a principal factor to be monitored for the maintenance of the natural environment.  相似文献   
112.
生态工业园区产品体系规划的模糊综合评判法   总被引:2,自引:1,他引:1  
张叶红  王海燕 《四川环境》2005,24(6):102-104
生态工业园区是循环经济在工业上的表现形式,在构建生态工业园区时必须要对产品体系进行规划。本文从经济、环境和社会三个方面讨论了生态工业园区产品体系规划的原则,引入了模糊重心综合评价理论,通过定量的方法对生态工业园区的多个产品体系进行综合评价,选择最优的产品体系,为生态工业园区产品体系规划决策提供一定的指导和参考作用。  相似文献   
113.
上海市工业园区投资环境评价研究   总被引:5,自引:0,他引:5  
在回顾大量关于投资环境评价方法相关文献的基础上,考虑了传统的区位因子和现代工业园区布局要素条件,建立了区位条件、腹地支撑能力、微观环境、规模及发育程度和创新能力5个子系统,并相应选取了16项评价因素和40个评价指标。选用主成分分析方法计算出权重值,然后根据权重计算出上海工业园区综合评价值,最后对上海市工业园区的投资环境做出总体评价。总体上,上海市级以上工业园区的投资环境接近中等水平,整体水平仍有待于进一步提高。各子系统对综合评价值的贡献程度不一,综合评价值高的园区,每个子系统的贡献率比较均匀,差异性比较小。综合评价值比较低的园区,各子系统的贡献率不均匀,差异性比较大。尤其在创新能力方面,所有工业园区都表现出不足, 今后要重点改善,以进一步提升上海市整体工业园区的投资环境。  相似文献   
114.
The present study provides an evaluation of noise pollution in six Urban Parks located in the city of Curitiba, Brazil. Equivalent noise levels (L eq) were measured in 303 points (each point measured during 3 min) spread throughout the Parks. Measured values were confronted with local legislation (Law 10625) allowed limits, and the Parks were thus classified as “acoustically polluted or unpolluted”. Measured values were also evaluated according to international legislation: Decree no. 12 of the City Council of Rome, DIN 18005 for German cities, the World Health Organization, and the United States Environmental Protection Agency. Urban parks in the downtown area of Curitiba, surrounded by roads of heavy traffic and in the midst of intense commercial activities, do not satisfy any of the standards used. The most noise-polluted parks in Curitiba were the Public Walk Park and the Botanical Garden Park, with measured L eq of 64.8 dB(A) and 67 dB(A).  相似文献   
115.
This paper addresses the challenge of appropriate governance of complexity and diversity in the Dutch national park of Alde Feanen. The issue is how to enhance ecosystem resilience. Our focus relates to a navigable waterway within the park that affects the natural values of the area. The governance assessment tool is used to assess the governance context of the waterway and ecosystem resilience in the area. The study shows that a lack of a long-term integrated vision makes the governance context less supportive. Such a vision could maximize the focus on the resilience of the park's nature and motivate actors to work towards a common future for a concerned area. However, institutional complexity, combined with institutional inertia, is revealed as a hindrance to the quality of governance and shapes a weak ability to adapt the current situation to move towards resilience.  相似文献   
116.
工业园区水污染防治技术与管理政策需求分析   总被引:2,自引:0,他引:2  
工业园区水污染防控是“十二五”期间我国水环境治理的重要任务之一,但目前还普遍存在一些技术和管理上的不足,导致处理效果不理想。本文就此问题,对园区企业在废水预处理、收集和处理、末端排放、水循环利用和管理机制方面存在的问题进行了讨论和分析;从技术和管理两大方面,对园区水污染防治的需求进行了分类探讨,并对环境主管部门、园区管理者和环境服务商提出了工作建议。  相似文献   
117.

The release of carbon dioxide from the burning of fossil fuels is believed to be responsible for climate change. In the UK, road transport emits 22% of the total output of carbon dioxide. This study applies the ecological footprint to Merseyside to ascertain the global environmental impact of passenger transport (expressed in hectares). Results show that car travel has a footprint of 704 000 hectares, which is 87% of the total footprint. It is demonstrated in scenarios that Policy initiatives involving the Local Transport Plan will cause the footprint to increase. It is also shown that individual behaviour could be influenced when highlighting the impacts of different modes of transport along the same route. By using the ecological footprint in educational programmes, the effect can be shown of carbon emissions and land appropriation on the 'school run'; these issues could be promoted alongside others such as health, safety, congestion, global equity and fairness.  相似文献   
118.
Public agencies sometimes seek outside guidance when capacity to achieve their mission is limited. Through a cooperative agreement and collaborations with the U.S. National Park Service (NPS), we developed recommendations for a conservation program for migratory species. Although NPS manages ~36 million hectares of land and water in 401 units, there is no centralized program to conserve wild animals reliant on NPS units that also migrate hundreds to thousands of kilometers beyond parks. Migrations are imperiled by habitat destruction, unsustainable harvest, climate change, and other impediments. A successful program to counter these challenges requires public support, national and international outreach, and flourishing migrant populations. We recommended two initial steps. First, in the short term, launch or build on a suite of projects for high‐profile migratory species that can serve as proof to demonstrate the centrality of NPS units to conservation at different scales. Second, over the longer term, build new capacity to conserve migratory species. Capacity building will entail increasing the limited knowledge among park staff about how and where species or populations migrate, conditions that enable migration, and identifying species’ needs and resolving them both within and beyond parks. Building capacity will also require ensuring that park superintendents and staff at all levels support conservation beyond statutory borders. Until additional diverse stakeholders and a broader American public realize what can be lost and do more to protect it and engage more with land management agencies to implement actions that facilitate conservation, long distance migrations are increasingly likely to become phenomena of the past. Optimismo y Retos para la Conservación Científicamente Basada de Especies Migratorias Dentro y Fuera de Parques Nacionales de E.U.A.  相似文献   
119.
Conservation of wide‐ranging species, such as the African forest elephant (Loxodonta cyclotis), depends on fully protected areas and multiple‐use areas (MUA) that provide habitat connectivity. In the Gamba Complex of Protected Areas in Gabon, which includes 2 national parks separated by a MUA containing energy and forestry concessions, we studied forest elephants to evaluate the importance of the MUA to wide‐ranging species. We extracted DNA from elephant dung samples and used genetic information to identify over 500 individuals in the MUA and the parks. We then examined patterns of nuclear microsatellites and mitochondrial control‐region sequences to infer population structure, movement patterns, and habitat use by age and sex. Population structure was weak but significant, and differentiation was more pronounced during the wet season. Within the MUA, males were more strongly associated with open habitats, such as wetlands and savannas, than females during the dry season. Many of the movements detected within and between seasons involved the wetlands and bordering lagoons. Our results suggest that the MUA provides year‐round habitat for some elephants and additional habitat for others whose primary range is in the parks. With the continuing loss of roadless wilderness areas in Central Africa, well‐managed MUAs will likely be important to the conservation of wide‐ranging species. Utilización de Perfiles Genéticos de Elefantes Africanos para Inferir su Estructura Poblacional, Movimientos y Uso del Hábitat en un Paisaje con Conservación y Desarrollo en Gabón Resumenfgs  相似文献   
120.
运用数据包络分析DEA方法,建立了太湖殷村港流域工业园区企业污水治理效率评价体系,并利用该体系对园区内企业污水治理效率进行了实证研究。利用效率评价函数对园区内20家企业进行评价,结果表明,其中4家企业达到环境治理效率相对高效;20家企业的废水排放量、COD和NH3-N排放削减总量分别为3691860、217.53和14.64t/a,削减潜力较大。实证研究结果表明,该环境绩效评价系统可为园区企业污水治理调控提出定量化的调整建议。  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