全文获取类型
收费全文 | 8111篇 |
免费 | 296篇 |
国内免费 | 314篇 |
专业分类
安全科学 | 335篇 |
废物处理 | 117篇 |
环保管理 | 2407篇 |
综合类 | 2598篇 |
基础理论 | 865篇 |
环境理论 | 7篇 |
污染及防治 | 167篇 |
评价与监测 | 162篇 |
社会与环境 | 1831篇 |
灾害及防治 | 232篇 |
出版年
2024年 | 12篇 |
2023年 | 64篇 |
2022年 | 116篇 |
2021年 | 151篇 |
2020年 | 149篇 |
2019年 | 132篇 |
2018年 | 118篇 |
2017年 | 215篇 |
2016年 | 206篇 |
2015年 | 171篇 |
2014年 | 212篇 |
2013年 | 545篇 |
2012年 | 441篇 |
2011年 | 517篇 |
2010年 | 380篇 |
2009年 | 340篇 |
2008年 | 308篇 |
2007年 | 500篇 |
2006年 | 501篇 |
2005年 | 417篇 |
2004年 | 404篇 |
2003年 | 383篇 |
2002年 | 389篇 |
2001年 | 310篇 |
2000年 | 339篇 |
1999年 | 278篇 |
1998年 | 202篇 |
1997年 | 176篇 |
1996年 | 121篇 |
1995年 | 121篇 |
1994年 | 88篇 |
1993年 | 89篇 |
1992年 | 58篇 |
1991年 | 27篇 |
1990年 | 35篇 |
1989年 | 12篇 |
1988年 | 16篇 |
1987年 | 11篇 |
1986年 | 17篇 |
1983年 | 7篇 |
1982年 | 23篇 |
1981年 | 8篇 |
1980年 | 15篇 |
1979年 | 20篇 |
1978年 | 11篇 |
1977年 | 9篇 |
1975年 | 7篇 |
1974年 | 7篇 |
1973年 | 6篇 |
1971年 | 14篇 |
排序方式: 共有8721条查询结果,搜索用时 828 毫秒
601.
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
602.
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
603.
Zagonari F 《Journal of environmental management》2008,88(4):796-804
In this paper, a dynamic model is developed in which coastal quality can be improved, restored, or maintained by two distinct user groups; this is done by identifying a context that ensures an increase (or a greater increase) in coastal quality in terms of specific features that characterise the user groups. The results demonstrate that integrated coastal management is always better than non-integrated management. Moreover, when there is a low degree of interest in maintaining the coastal use over time, only integrated community-based (CB) coastal management will increase the coastal quality. Even when the interest in maintaining the coastal use over time is high, an integrated CB approach is preferred if the willingness to pay for coastal improvements is great and the marginal inefficiency of investments in coastal improvements is low, because the coastal quality improves to a greater extent; if not, only an integrated top-down (TD) approach to coastal management will increase the coastal quality. These results suggest that developing countries should always adopt a CB approach; in contrast, developed countries should adopt a CB approach where local stakeholders attach direct values to the coastal quality, and adopt a TD approach where the general population attaches indirect (option or existence) values to coastal quality. 相似文献
604.
605.
606.
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
607.
对外开放度是测量一个地区经济发展国际化程度的一个重要标志。以SPSS12.0为分析工具,运用回归分析方法,对安徽省四大区域对外开放度差异进行了测定和分析。2000年以来,安徽省四大经济区域对外开放度有了明显提高,但基础设施、区位条件、产业结构等方面的差异导致四大区域之间、区域内部以及地市之间的对外开放度存在明显差异。回归分析显示,对外开放度与安徽区域经济增长有着显著的相关性。 相似文献
608.
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
609.
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
610.
C. A. Bishop N. A. Mahony J. Struger P. Ng K. E. Pettit 《Environmental monitoring and assessment》1999,57(1):21-43
Significantly lower anuran species diversity and density was recorded in a vegetable growing area relative to upstream and downstream sites in the Holland River watershed, Ontario, Canada. Egg hatching success and tadpole deformity rates of American toads (Bufo americanus americanus), green frogs (Rana clamitans melanota) and northern leopard frogs (Rana pipiens) eggs in water from field sites and control water were assessed. Compared to the control and the upstream site, the total abnormality rate (unhatched eggs plus deformed tadpoles) was higher for American toads in water from the agricultural and downstream sites. Total abnormality was higher in green frog eggs in water from the agricultural site and a downstream site. Trace concentrations of organophosphorus pesticides were detected most often in agricultural zone water and sediments than in upstream and downstream sites. Organochlorine pesticide residues, especially in agricultural zone samples, exceeded the no effect level guidelines for the protection of aquatic life. Ammonia, phosphorus, particulates, BOD and TKN were highest in the agricultural zone. Significant correlations between these parameters and anuran development suggest nutrient run-off as a causal or contributing factor in lower anuran diversity, density and reproductive success of American toads and green frogs in the site dominated by agriculture. 相似文献