全文获取类型
收费全文 | 916篇 |
免费 | 11篇 |
国内免费 | 63篇 |
专业分类
安全科学 | 58篇 |
废物处理 | 11篇 |
环保管理 | 218篇 |
综合类 | 225篇 |
基础理论 | 127篇 |
环境理论 | 1篇 |
污染及防治 | 109篇 |
评价与监测 | 31篇 |
社会与环境 | 71篇 |
灾害及防治 | 139篇 |
出版年
2023年 | 9篇 |
2022年 | 9篇 |
2021年 | 18篇 |
2020年 | 24篇 |
2019年 | 12篇 |
2018年 | 20篇 |
2017年 | 26篇 |
2016年 | 21篇 |
2015年 | 26篇 |
2014年 | 16篇 |
2013年 | 50篇 |
2012年 | 28篇 |
2011年 | 65篇 |
2010年 | 39篇 |
2009年 | 55篇 |
2008年 | 65篇 |
2007年 | 49篇 |
2006年 | 50篇 |
2005年 | 28篇 |
2004年 | 28篇 |
2003年 | 45篇 |
2002年 | 27篇 |
2001年 | 27篇 |
2000年 | 23篇 |
1999年 | 14篇 |
1998年 | 19篇 |
1997年 | 26篇 |
1996年 | 34篇 |
1995年 | 31篇 |
1994年 | 16篇 |
1993年 | 23篇 |
1992年 | 17篇 |
1991年 | 9篇 |
1990年 | 10篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 5篇 |
1985年 | 4篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 5篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1978年 | 1篇 |
排序方式: 共有990条查询结果,搜索用时 78 毫秒
981.
982.
Frederico Neto 《Natural resources forum》2001,25(4):285-297
Floods were by far the most damaging type of natural disasters during the 1990s, in terms of both human impacts and socio-economic losses. Vulnerability to flooding disasters around the world is almost always differentiated by the socio-economic conditions of different income groups in the disaster area. In general, the poorer the income group (or the country) the more vulnerable it is likely to be to the adverse impacts of floods. The article argues that Bangladesh is the world's most flood-prone developing country in terms of the relative socio-economic impacts of floods. While conventional flood control strategies tend to be based on structural engineering approaches—such as the construction of large-scale embankments, diversion canals and dams—this article argues that more emphasis should be given to alternative, non-structural measures. The main lesson from recent flooding disasters in Bangladesh is that, in the absence of expensive structural measures, many non-structural ones can go a long way towards reducing vulnerability to and mitigating the impacts of floods. 相似文献
983.
From open access to access by all: restating challenges in designing groundwater management in Andhra Pradesh, India 总被引:1,自引:1,他引:0
In a village-based watershed in Andhra Pradesh, India, it is increasingly difficult for users to access and extract groundwater for irrigation: a 'pumping race' is taking place. A move from groundwater development towards groundwater management is required, with a new perspective on options for change. Through a study of borewell technology and groundwater use, and considering new local developments in electricity supply and participatory resource management, the article argues that groundwater is a resource with 'instructions for use'. The technological dimensions of groundwater irrigation urge its study as a socio-technical process in order to design sustainable and equitable groundwater management. 相似文献
984.
985.
Almost all the issues of sustainable development in China relate to natural resources. Sustainable development as one of the most important strategies has been incorporated into all the actions related to the planning and management of natural resources in China. This paper gives an overview of the contributions of natural resources and the challenges facing the natural resource sectors. It contributes a series of proposals on the planning and management of natural resources. It also outlines the general framework of the planning system for natural resources and summarizes the Great Survey of Natural Resources Program that the Ministry of Land and Resources is implementing. 相似文献
986.
Craig L. Shafer 《Environmental management》1999,23(1):49-73
/ This review will trace the evolution of beyond boundary/buffer zone thinking and policy responses in the US National Park Service (NPS); address buffer zone science, benefits, and limitations; examine pertinent legal and social concerns; highlight some agency attempts to create buffer zone-like areas; and propose highlights of a protected area strategy, with buffer zones and corridors as one component. Some findings follow. The need to expand national parks to accommodate large ungulate movement began in the late 1800s, but the recognition that such land was also needed to thwart human impacts such as poaching surfaced in the 1930s. External park buffer zone recommendations by 1930s park scientists were not implemented, and other related adopted policy forgotten, supporting the belief that great insight can be discovered in forgotten institutional history. Buffer zones can remedy some impacts but not others, but their benefits are multiple and underappreciated. The science of buffer zones is very immature and deserves more attention. A present primary obstacle to creating park buffer zones and connecting corridors is a social climate opposing federal initiatives that may intrude on the rights of private landowners. Some proactive NPS bufferlike activity examples are reviewed, but there were none where permanent, complete, effective nonlegislated park buffer zones, derived from nonfederal property, circumscribed large natural area parks. The need for buffer zones and corridors may be a symptom of inadequate regional planning. Options to create buffer zones from private and federal land are outlined. A comprehensive, overall protected area strategy must include more than just buffer zones, with highlights provided. Because optimal regional planning for US national parks is now thwarted by land-use politics, American society must soon decide what is most crucial to future well-being. KEY WORDS: Buffer zone; Reserve; Boundary; Policy; Planning 相似文献
987.
石油烃类污染物在地下水中自然衰减特性 总被引:14,自引:0,他引:14
污染物在地下水中的自然衰减是目前解决地下水污染问题的一个重要的研究领域,是地下水污染生物修复的基础课题,本文以地下水中的常见污染物石油烃为对象,着重阐述该物在地下水中的自然衰减特性。根据所获取的国内外资料,介绍了其自然衰减的三种动力学方程:Monod动力学方程,一级衰减动力学方程和瞬时反应动力学方程,并且对于石油烃的自然衰减速率进行了详细的描述,为以后的研究提供参考。 相似文献
988.
城市生物多样性问题及保护对策探讨 总被引:5,自引:0,他引:5
结合秦皇岛市的实际,对城市生物多样性现状和特点、生物多样性保护存在的问题进行了讨论,并提出了城市生物多样性保护的对策。 相似文献
989.
本文通过对临潼区自然生态环境和资源利用现状进行评价,提出该区生态农业的发展模式及生态农业建设主要任务,以达到持续、高效、合理地利用区内各种资源。 相似文献
990.
Concentrations of the natural radionuclides 238U, 226Ra, 232Th and 40K have been measured by γ-ray spectrometry in 796 topsoil samples from the Pearl River Delta Zone (PRDZ) of Guangdong, China. The mean concentrations for 238U, 226Ra, 232Th and 40K were found to be 140 ± 37 Bq kg−1, 134 ± 41 Bq kg−1, 187 ± 80 Bq kg−1 and 680 ± 203 Bq kg−1 dry mass, respectively. These values were all higher than the mean values in soil for China and the world. Outdoor air-absorbed dose rates, calculated from activity concentrations of 226Ra, 232Th and 40K, ranged from 86 to 237 nGy h−1, with a mean value of 165 ± 46 nGy h−1. The corresponding annual outdoor effective dose rate per person was estimated to be between 0.11 and 0.29 mSv y−1, with a mean value of 0.20 ± 0.06 mSv y−1, which was also higher than the world mean value of 0.07 mSv y−1. The radium equivalent activity (Raeq) and the external hazard index (Ir) resulted from the natural radionuclides in soil, were also calculated and found to vary from 230 to 676 Bq kg−1 and from 0.6 to 1.8, respectively. The Raeq and the Ir in all the investigated regions were up to 75% higher than the set limits of 370 Bq kg−1 and 1.0, respectively. 相似文献