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   322篇
  免费   16篇
  国内免费   8篇
安全科学   72篇
废物处理   1篇
环保管理   105篇
综合类   74篇
基础理论   27篇
环境理论   1篇
污染及防治   7篇
评价与监测   11篇
社会与环境   28篇
灾害及防治   20篇
  2023年   7篇
  2022年   13篇
  2021年   7篇
  2020年   9篇
  2019年   10篇
  2018年   8篇
  2017年   20篇
  2016年   15篇
  2015年   8篇
  2014年   8篇
  2013年   25篇
  2012年   14篇
  2011年   13篇
  2010年   13篇
  2009年   32篇
  2008年   16篇
  2007年   23篇
  2006年   21篇
  2005年   19篇
  2004年   11篇
  2003年   5篇
  2002年   10篇
  2001年   8篇
  2000年   6篇
  1999年   5篇
  1998年   1篇
  1997年   3篇
  1996年   1篇
  1995年   1篇
  1993年   1篇
  1992年   1篇
  1991年   1篇
  1990年   1篇
  1988年   1篇
  1987年   1篇
  1983年   1篇
  1978年   2篇
  1974年   2篇
  1971年   3篇
排序方式: 共有346条查询结果,搜索用时 15 毫秒
281.
AHP与SMART方法在环境工程方案评比中的应用   总被引:3,自引:0,他引:3  
本文以某大型污水海洋处置工程的方案评选工作为背景,介绍了AHP和SMART多目标决策方法在环境规划与决策中的应用。具体叙述了方案选优的总技术路线,目标体系的建立,目标相对权重的确定,指标值的评判与规范、方案排序与结果灵敏度和合理性分析等内容。结果表明,AHP与SMART方法相结合,是适于环境工程方案评选的一种较科学合理的方法。  相似文献   
282.
战略环境评价研究与实践进展   总被引:17,自引:0,他引:17  
回顾了战略环境评价的起源,发展历程,尤其是90年代以来的实践与研究成果;分析了当前研究趋势并提出了今后我国战略环境评价工作的重点,包括加强研究,建立保证体系和进行试点等。  相似文献   
283.
284.
Vegetation changes in Sahelian West Africa have been increasingly investigated since 1970 due to the catastrophic droughts in the early 1970s and 1980s and the following decades with below average precipitation. In most cases this was done by remote sensing and vegetation studies. In recent years, local knowledge of farmers and pastoralists about vegetation changes has been increasingly investigated. In this paper, information from different case studies in three West African countries (Burkina Faso, Niger, Senegal) was used to analyse and evaluate vegetation changes in the Sahel. In total, data were analysed from 25 villages, where the local people were asked to mention plant species and qualify their present occurrence compared to the past. In total, 111 woody species were mentioned as having changed compared to the past, of which 79% were classified as having decreased or disappeared. For each single location 8–59 different woody species were mentioned. In most cases, these are valuable species of socio-economic importance. Only 11% of the species was classified as increasing or new (0–12 were mentioned per location), the later being mainly exotic species. Ten percent were categorised differently among villages. A comparison of local knowledge from different locations provide regional scale information on endangered species and thereby crucial information for making insightful priorities for assisted regeneration, reforestation and conservation strategies.  相似文献   
285.
The increasing energy demand, increasing energy dependency, energy supply security, and environmental concerns have become a part of business policies since COP21 agreements in Paris, 2015. Combined cooling, heating, and power (CCHP or tri-generation) systems play an important role in paying the necessary attention to these policies. Tri-generation investment is a complex decision with hybrid use of energy resources. This article aims to reduce the complexity of this decision by the use of Bayesian belief networks in pre-investment stage of tri-generation investment project cycle. The proposed model gives an insight into decision analysis and helps the decision-makers either generate or purchase from it in order to meet the energy demand with different scenarios. The model is studied for a university case. The investment decision for a CCHP (tri-generation) system will be discussed as an alternative for purchasing the electricity and natural gas from the national grids.  相似文献   
286.
Nest site selection in the open-nesting honeybee Apis florea   总被引:1,自引:0,他引:1  
We studied nest site selection by swarms of the red dwarf honeybee, Apis florea. By video recording and decoding all dances of four swarms, we were able to determine the direction and distances indicated by 1,239 dances performed by the bees. The bees also performed a total of 715 nondirectional dances; dances that were so brief that no directional information could be extracted. Even though dances converged over time to a smaller number of areas, in none of the swarms did dances converge to one site. As a result, even prior to lift off, bees performed dances indicating nest sites in several different directions. Two of four swarms traveled directly in what seemed to be the general direction indicated by the majority of dances in the half hour prior to swarm lift off. The other two traveled along circuitous routes in the general direction indicated by the dances. We suggest that nest site selection in A. florea has similar elements to nest site selection in the better-studied Apis mellifera. However, the observation that many more locations are indicated by dances prior to lift off also shows that there are fundamental differences between the two species.  相似文献   
287.
Rural-urban land conversion is an inevitable phenomenon in urbanization and industrialization. And the decision-making issue about this conversion is multi-objective because the social decision maker (the whole of central government and local authority) has to integrate the requirements of different interest groups (rural collective economic organizations, peasants, urban land users and the ones affected indirectly) and harmonize the sub-objects (economic, social and ecological outcomes) of this land allocation process. This paper established a multi-objective programming model for rural-urban land conversion decision-making and made some social welfare analysis correspondingly. Result shows that the general object of rural-urban land conversion decision-making is to reach the optimal level of social welfare in a certain state of resources allocation, while the preference of social decision makers and the value judgment of interest groups are two crucial factors which determine the realization of the rural-urban land conversion decision-making objects.  相似文献   
288.
289.
290.
The irrational use of water in agriculture is often responsible for several problems concerning the depletion and/or the pollution of water resources. In these cases specific policy measures should be taken to protect water resources from harmful agricultural activities, mitigating at the same time their potential impact on farmers’ welfare. To this end, a multicriteria decision-making model is formulated that aims at allocating efficiently water and land resources in a rural area of Greece, by optimizing a set of important socio-economic and environmental objectives. According to the model’s output, past and current decisions on irrigated agriculture turned out to be oriented towards meeting exclusively the socio-economic objectives. Yet, there are several other possible allocations schemes that could be applied in order to improve the performance of environmental indicators and to contribute to a more sustainable use of natural resources. Moreover, the decision-making model can be further employed to assess a number of additional policy measures in irrigated agriculture. In this framework, the outcome of imposing various water pricing policies was evaluated. The efficiency of these policies was found tightly connected to the elasticity of water demand. Namely, higher elasticity seems to enhance the flexibility in resource allocation and the movement towards environmental objectives. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.  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