全文获取类型
收费全文 | 2401篇 |
免费 | 126篇 |
国内免费 | 116篇 |
专业分类
安全科学 | 95篇 |
废物处理 | 74篇 |
环保管理 | 727篇 |
综合类 | 999篇 |
基础理论 | 223篇 |
环境理论 | 1篇 |
污染及防治 | 46篇 |
评价与监测 | 43篇 |
社会与环境 | 411篇 |
灾害及防治 | 24篇 |
出版年
2024年 | 3篇 |
2023年 | 13篇 |
2022年 | 46篇 |
2021年 | 51篇 |
2020年 | 52篇 |
2019年 | 41篇 |
2018年 | 43篇 |
2017年 | 62篇 |
2016年 | 74篇 |
2015年 | 64篇 |
2014年 | 71篇 |
2013年 | 110篇 |
2012年 | 134篇 |
2011年 | 157篇 |
2010年 | 125篇 |
2009年 | 123篇 |
2008年 | 93篇 |
2007年 | 185篇 |
2006年 | 125篇 |
2005年 | 132篇 |
2004年 | 117篇 |
2003年 | 106篇 |
2002年 | 91篇 |
2001年 | 66篇 |
2000年 | 83篇 |
1999年 | 75篇 |
1998年 | 45篇 |
1997年 | 50篇 |
1996年 | 53篇 |
1995年 | 40篇 |
1994年 | 41篇 |
1993年 | 44篇 |
1992年 | 24篇 |
1991年 | 23篇 |
1990年 | 14篇 |
1989年 | 6篇 |
1988年 | 4篇 |
1986年 | 4篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1982年 | 2篇 |
1980年 | 6篇 |
1979年 | 11篇 |
1978年 | 4篇 |
1977年 | 4篇 |
1975年 | 2篇 |
1973年 | 7篇 |
1972年 | 3篇 |
1971年 | 7篇 |
1970年 | 1篇 |
排序方式: 共有2643条查询结果,搜索用时 250 毫秒
991.
The conservation of biodiversity is an important issue world wide and in Australia the maintenance of native biodiversity on farms makes an important contribution to overall conservation objectives. This paper seeks to explain Australian farmers' rationale for maintaining biodiversity on their farms for personal as opposed to business reasons by developing a decision-systems theory from in-depth interviews. This difference has implications for policy development. The decision-systems theory is divided into two main sections. The first section contains five parts. (1) A hierarchy of motivation stories, (2) the concept of suitability and availability of opportunities, (3) a hierarchy of three decision-systems, (4) the concept of personal career paths, (5) the concept of Lenses. The second section contains one part, a policy classification system called 'boxes of influence' that suggests how policy developers can use the information in the first section to develop new biodiversity conservation policy. The paper suggests that decision-systems theory could be used to shed new light on current trends in agriculture and become an important investigative tool for policy development concerning the conservation of biodiversity on farms. 相似文献
992.
Learning for sustainability: participatory resource management in Cambodian fishing villages 总被引:1,自引:0,他引:1
Considerable attention is now being given to the role and importance of education and learning implications of participatory resource and environmental governance. The contention is that such learning has the potential to transform behaviour, and in the case of resource management, may help change current patterns in resource use towards a more sustainable social-ecological system. Our purpose is to establish the opportunities for learning afforded to those participating in local level resource management committees in two Cambodian fishing communities and consider the learning outcomes from such opportunities. Our approach was qualitative and used a case study design. The findings establish a wide range of committee resource management activities that resulted in both instrumental (e.g., learning about administrative procedures) and communicative (e.g., insights into the need to conserve mangroves) learning. It was revealed that such learning can lead to changes in behaviour at the community level (e.g., managing local waste). Our findings also indicated a number of motivators and enablers of learning such as opportunities for dialogue, leadership and the presence of declining resources. 相似文献
993.
The present optimisation model described in Part I of this work is applied to optimise water resources in the Haihe river basin, an important basin in north China that covers 31.82 million km2. Results show that this optimisation model with the HGSAA solution is feasible and effective in the long-term optimisation of water resource use. It is shown that the combined forecasting method can improve the forecast precision. The results obtained indicate that the mean relative errors of BP and polynomial models are 2.3% and 4.9%, respectively, while that of the combined forecasting method is 1.93% in a case study on the Tumahe River for 2010. The combined forecasting method performs better because it incorporates various forecasting methods. The optimisation results show that both domestic and eco-environmental water demands can satisfy the requirements of the forecasting procedure, and the harmonious indices all exceeded 0.7. The Luanhe River is the most water-scarce sub-basin in the Haihe river basin. 相似文献
994.
采用清罐含油污泥资源化综合利用技术,处理后的含油污泥经检测其灰渣重金属含量均小于我国GB 15618-1995《土壤环境质量标准》和GB 4284-84《农用污泥中污染物控制标准》,灰渣浸出液达到GB5085.3-2007《危险废物鉴别标准浸出毒性鉴别》二级标准、燃烧后产生的废气和烟尘达到GB 13271-2001《锅炉大气污染物排放标准》。解决了清罐油泥处理难的问题,同时符合国家推行清洁生产,大力发展循环经济的要求,使生产过程中的废物减量化、资源化、无害化,减小了油泥排污费用,具有显著环境效益和社会效益。 相似文献
995.
996.
In recent years there has been increasing interest in the study of economic sustainability and its relationship with natural resources. This paper attempts to shed some light on the issue by taking into account the individual variations in time preferences for consumption and resource amenity. We characterize the long-run steady state, analyze its asymptotic stability, and explore the transational dynamics from any initial state. The welfare implications of the optimal path are also discussed. 相似文献
997.
在水资源短缺条件下,垦区农业发展采取了多种经营,发展以棉花、水果和养鹿为主的高效特色农业,同时加强工程建设,进行水资源开源节流,强化管理和对绿洲的保护,这些已成为维持绿洲稳定和促进绿洲农业经济发展的关键措施。 相似文献
998.
通过水土流失地区不同农业生产方式对土地质量及土壤生产力的影响研究,探讨不同作物及其不同的种植方式对农田可持续利用的评价预测模型及土地资源利用的价值核算方法。通过对山西省闻喜县的案例应用验证,表明了在农业可持续发展研究中应用的可行性。 相似文献
999.
土地资源是人类赖以生存的最基本的自然资源,土地资源的永续利用是实现社会、经济和生态全面可持续发展的基础。本文在分析土地资源利用特点,土地资源永续利用的内涵、原则与指南的基础上,提出了实现土地资源永续利用的一系列生态经济对策。 相似文献
1000.
GIS与环境模拟在环境地学研究中的作用和意义 总被引:6,自引:0,他引:6
21世纪全球环境问题将更加突出,环境地学应为研究、解决环境问题做出更多的贡献。但是,环境地学研究所采用的方法和手段还不能满足客观的需要。文章着重讨论了环境模拟系统(EnvironmentalImitationSystem,EIS)的建立及EIS与地理信息系统(GeographicalInformationSystem,GIS)的耦合等问题。作者通过研究,认为上述问题已基本得到解决.从而可以弥补GIS中环境模拟功能的不足,可使EIS纳入GIS的信息空间管理系统,进行信息空间管理、应用分析和信息叠加,并使信息可视化。文章最后指出.目前,可建立GIS-EIS联合系统,以实现信息互换和信息资源的二次开发、利用。 相似文献