全文获取类型
收费全文 | 7161篇 |
免费 | 234篇 |
国内免费 | 256篇 |
专业分类
安全科学 | 279篇 |
废物处理 | 97篇 |
环保管理 | 2124篇 |
综合类 | 2221篇 |
基础理论 | 840篇 |
环境理论 | 11篇 |
污染及防治 | 163篇 |
评价与监测 | 154篇 |
社会与环境 | 1582篇 |
灾害及防治 | 180篇 |
出版年
2024年 | 8篇 |
2023年 | 45篇 |
2022年 | 103篇 |
2021年 | 125篇 |
2020年 | 133篇 |
2019年 | 118篇 |
2018年 | 103篇 |
2017年 | 170篇 |
2016年 | 159篇 |
2015年 | 134篇 |
2014年 | 190篇 |
2013年 | 505篇 |
2012年 | 362篇 |
2011年 | 445篇 |
2010年 | 304篇 |
2009年 | 295篇 |
2008年 | 283篇 |
2007年 | 444篇 |
2006年 | 443篇 |
2005年 | 367篇 |
2004年 | 372篇 |
2003年 | 351篇 |
2002年 | 354篇 |
2001年 | 300篇 |
2000年 | 330篇 |
1999年 | 264篇 |
1998年 | 184篇 |
1997年 | 160篇 |
1996年 | 110篇 |
1995年 | 107篇 |
1994年 | 76篇 |
1993年 | 75篇 |
1992年 | 44篇 |
1991年 | 20篇 |
1990年 | 27篇 |
1989年 | 10篇 |
1988年 | 9篇 |
1987年 | 11篇 |
1986年 | 15篇 |
1985年 | 5篇 |
1984年 | 5篇 |
1982年 | 13篇 |
1981年 | 8篇 |
1980年 | 11篇 |
1979年 | 12篇 |
1978年 | 9篇 |
1977年 | 6篇 |
1975年 | 4篇 |
1973年 | 4篇 |
1971年 | 9篇 |
排序方式: 共有7651条查询结果,搜索用时 609 毫秒
531.
Cosmas Milton Obote Ochieng 《Natural resources forum》2008,32(1):64-76
This paper argues that stakeholder capitalism is more appropriate to natural resource management and rural development in Africa than other varieties of capitalism. It examines different management arrangements in Kenyan Lake Victoria fisheries resources to argue that whilst stakeholder capitalism is still far from being the mainstream model of capitalism in Kenya, theoretically and empirically, it is more appropriate to sustainable development than the Anglo‐Saxon variety of capitalism that the country inherited from its British colonizers. The paper demonstrates that the concepts of ownership and management rights are social, economic and political constructs that are continuously contested, with huge implications for sustainable development and natural resource management. 相似文献
532.
Jon D. Unruh 《Natural resources forum》2008,32(2):103-115
Land tenure plays a primary role in sustainable development efforts. However armed conflict and its repercussions reconfigure the network of social relations upon which all land tenure systems depend. In post‐conflict settings new laws have the opportunity to address tenure issues in the context of what people are already doing ‘on the ground’, with a view to moving from the fluidity of post‐conflict situations to a more solidified and peaceful social and legal environment. However there exists a lack of tools to analyze postwar land tenure and the prospects for reconstituting tenure systems to support recovery and development. This paper uses the Sustainable Livelihoods framework to examine postwar land tenure issues in order to draw out latent opportunities within emergent informal smallholder tenure constructs which may have utility in the reconstitution of national tenure systems. 相似文献
533.
Dryland area occupies 37% of the national territory in China. Desertification and other disasters have limited dryland sustainable development. Here we overview the dryland characteristics and desertification status and introduce four regionally optimized eco‐productive paradigms for dryland sustainable development, i.e., the mountain‐oasis paradigm in arid desert; the small watershed‐based paradigm on the Loess Plateau; the integrated animal husbandry paradigm on the Inner Mongolia Steppe and the agro‐pastoral transitional region; and three circle paradigm on the Ordos Plateau. These paradigms are established on the basis of regional landscape patterns and their underlying material and energy flow rules, and different functional belts are determined and capitalized upon with the integrated consideration of regional biogeophysical processes, biogeochemical cycles and biogeosocial relations. These paradigms cannot cover all complex landscape types, but provide theoretical frameworks and practicable models for dryland sustainable development in China. 相似文献
534.
The aim of this work is (1) to discuss approaches and tools to set management goals using operational indicators for coastal management (i.e., indicators that are easy to measure, understand and predict) and validated predictive models and (2) to discuss remedial strategies for sustainable coastal management regarding water quality and the abundance of fish, waterfowl and large aquatic plants. These approaches are exemplified using data from Ringkøbing Fjord, Denmark, which has undergone two major regime shifts during the last decades. This work discusses the changes taken place during the period from 1980 to 2004 (when there are good empirical data). For Ringkøbing Fjord, which is a very shallow, well-oxygenated lagoon dominated by resuspension processes, we have targeted on the following operational indicators, which are meant to reflect seasonal median values for the entire defined coastal area (the ecosystem scale) and not conditions at individual sites or data from shorter time periods: Secchi depth (as a standard measure of water clarity) and chlorophyll-a concentrations (as a key measure of algal biomass). The operational indicators are regulated by a set of standard abiotic factors, such as salinity, suspended particulate matter (SPM), nutrient concentrations (N and P), coastal morphometry and water exchange. Such relationships are quantified using well-tested, general quantitative models, which illustrate how these indicators are interrelated and how they reflect fundamental aspects of coastal ecosystems. We demonstrate that the regime shift in the lagoon can be modelled and quantitatively explained and is related to changes in salinity and nutrient inflow. A very important threshold is linked to increased salinities in the lagoon. For example, when the mean annual salinity is higher than about 9.5‰, large numbers of saltwater species of clams can survive and influence the structure and function of the ecosystem in profound ways. The model also illustrates the dynamic response to changes in nutrient loading. We have presented several management strategies with the goal of keeping the Secchi depth at 2 m, which would stimulate the growth of higher aquatic plants, which are fundamental for fish production and bird abundance in the lagoon. Given the fact that the Secchi depth depends on many variable factors (temperature, TP-inflow from land, salinity, changes in biomasses of macrophytes and clams, which are accounted for in these simulations), our results indicate that in practice it will likely be very difficult to reach that goal. However, it would be realistic to maintain a Secchi depth of 1.5 m if the variability in salinity is minimized and the mean salinity is kept at about 10.2‰. 相似文献
535.
Ding GK 《Journal of environmental management》2008,86(3):451-464
Construction has been accused of causing environmental problems ranging from excessive consumption of global resources both in terms of construction and building operation to the pollution of the surrounding environment, and research on green building design and using building materials to minimise environmental impact is already underway. However, relying on the design of a project to achieve the goal of sustainable development, or to minimise impacts through appropriate management on site, is not sufficient to handle the current problem. The aim for sustainability assessment goes even further than at the design stage of a project to consider its importance at an early stage, before any detailed design or even before a commitment is made to go ahead with a development. However, little or no concern has been given to the importance of selecting more environmentally friendly designs during the project appraisal stage; the stage when environmental matters are best incorporated. The main objectives of this paper are to examine the development, role and limitations of current environmental building assessment methods in ascertaining building sustainability used in different countries which leads to discuss the concept of developing a. sustainability model for project appraisal based on a multi-dimensional approach, that will allow alternatives to be ranked is discussed in detail in the paper. 相似文献
536.
537.
538.
以市级区域为空间结构研究对象,分析安徽省20世纪80年代以来区域经济空间结构的演化过程。结果表明:①安徽省各市级区域在近20年的发展中,区域差异空间格局整体上变化不大,20世纪80年代初期经济发达的地区现在仍为发达区,原先落后的地区仍落后;②1980年以来,工业化进程的空间差异与区域社会经济发展的空间差异具有很大的相似性,表明工业化是推动区域经济发展的重要力量;③通过分析区域发展差异的空间机制得出:轴线的地位差异显著,以贯穿南北的中轴线和沿江轴线为主,形成经济实力中心,而其它地区相对落后,形成了明显的中心-边缘模式。 相似文献
539.
农业作为国民经济的基础,是生态文明的重要内容,其文明程度直接体现生态文明程度.生态文明建设给农业经营提出了更高的要求,也为农业生产的发展指明了方向.充分认识生态文明建设与农业生产的关系,加强农业相关人员的生态文明教育和农业环保法制建设,实施更加科学、文明的农业经营方式将对促进农业的可持续发展和生态文明建设发挥积极的作用. 相似文献
540.
文章分析了西北地区目前水资源现状、水资源质量状况和开发利用等情况,并对水资源供需发展趋势作出预测。根据西北地区水环境安全面临的严峻形势,提出了构建西北地区水环境安全体系的对策和建议。 相似文献