全文获取类型
收费全文 | 1574篇 |
免费 | 5篇 |
国内免费 | 7篇 |
专业分类
安全科学 | 10篇 |
废物处理 | 71篇 |
环保管理 | 80篇 |
综合类 | 523篇 |
基础理论 | 363篇 |
污染及防治 | 364篇 |
评价与监测 | 97篇 |
社会与环境 | 68篇 |
灾害及防治 | 10篇 |
出版年
2017年 | 15篇 |
2016年 | 20篇 |
2014年 | 21篇 |
2013年 | 70篇 |
2012年 | 22篇 |
2011年 | 45篇 |
2010年 | 44篇 |
2009年 | 48篇 |
2008年 | 66篇 |
2007年 | 51篇 |
2006年 | 46篇 |
2005年 | 45篇 |
2004年 | 41篇 |
2003年 | 37篇 |
2002年 | 48篇 |
2001年 | 60篇 |
2000年 | 54篇 |
1999年 | 34篇 |
1998年 | 20篇 |
1997年 | 30篇 |
1996年 | 28篇 |
1995年 | 30篇 |
1994年 | 28篇 |
1993年 | 26篇 |
1992年 | 19篇 |
1991年 | 36篇 |
1990年 | 50篇 |
1989年 | 23篇 |
1988年 | 27篇 |
1987年 | 20篇 |
1985年 | 21篇 |
1984年 | 21篇 |
1983年 | 16篇 |
1982年 | 30篇 |
1979年 | 18篇 |
1978年 | 13篇 |
1977年 | 15篇 |
1976年 | 13篇 |
1974年 | 17篇 |
1972年 | 17篇 |
1971年 | 12篇 |
1969年 | 11篇 |
1968年 | 12篇 |
1967年 | 23篇 |
1966年 | 19篇 |
1965年 | 13篇 |
1964年 | 12篇 |
1962年 | 13篇 |
1958年 | 14篇 |
1957年 | 12篇 |
排序方式: 共有1586条查询结果,搜索用时 31 毫秒
431.
432.
433.
434.
435.
436.
G. Gal M.R. Hipsey A. Parparov U. Wagner V. Makler T. Zohary 《Ecological modelling》2009,220(13-14):1697-1718
The need for scientifically based management of lakes, as key water resources, requires the establishment of quantitative relationships between in-lake processes responsible for water quality (WQ) and the intensity of major management measures (MM, e.g. nutrient loading). In this paper, we estimate the impact of potential changes in nutrient loading on the Lake Kinneret ecosystem. Following validation of the model against a comprehensive dataset, we applied an approach that goes beyond scenario testing by linking the lake ecosystem model DYRESM–CAEDYM with a set of ecosystem variables included in a pre-assessed system of water quality indices. The emergent properties of the ecosystem predicted from the model simulations were also compared with lake data as a form of indirect validation of the model. Model output, in good agreement with lake data, indicated differential effects of nitrogen and phosphorus nutrient loading on concentrations, and major in-lake fluxes, of TN and TP, and dynamics and algal community structure. Both model output and lake data indicated a strong relationship between nitrogen loading and in-lake TN values. This relationship is not apparent for phosphorus and only a weak relationship exists between phosphorus loading and in-lake TP. The modeling results, expressed in terms of water quality, allowed establishment of critical/threshold values for the nutrient loads. Implementation of the ecological modeling supplemented with the quantified set of WQ indices allowed us to take a step towards establishment of the association between permissible ranges for water quality and major management measures, i.e. towards sustainable management. 相似文献
437.
Biodiversity,ecohydrology, threat status and conservation priority of the freshwater fishes of river Gomti,a tributary of river Ganga (India) 总被引:1,自引:1,他引:0
Extensive surveys were conducted to explore the diversity of fishes, distribution patterns, abundance, threat, and habitat
status in the upper, middle, and lower stretch of river Gomti, a tributary of river Ganga. Altogether 56 fish species belonging
to 20 families and 42 genera were collected from various sampling sites. Of the 56 species, five belong to the ‘endangered’
(EN) category and 11 belong to the vulnerable (VU) category. Six major categories of habitat were identified and pattern of
fish assemblage and dominant genera in each habitat studied. Considerable differences were observed in the fish species richness
and relative abundance (RA) of the species in the different sampling sites of river Gomti. Shannon–Wiener biodiversity index
has been calculated for the fishes indicating considerable variation (p < 0.05) across the river. Apart from Indian Major Carps (Labeo rohita, Catla catla, Cirrhinus mrigala), Chitala chitala, Notopterus notopterus, Ompok pabda, O. bimaculatus, Labeo bata, L. calbasu, Cirrhinus reba, Channa marulius, Bagarius bagarius, and Clupisoma garua were the important species. All the species have been reported for the first time in this river. Indiscriminate catch, poisoning,
using of fine mesh sized nets, dumping of sewage, siltation, water abstraction, changing land use pattern, decreased water
discharge, and exotic species threaten the fish diversity. Urgent need exists for taking up research on the priority fish
species and their habitat. Restoration measures have been proposed based on ecosystem scale approach for fish biodiversity
conservation. 相似文献
438.
439.
440.
U.G. Yasantha Abeysundara Sandhya Babel Mongkut Piantanakulchai 《Journal of Cleaner Production》2009,17(2):231-238
This paper presents a method to facilitate the decision-making process in selecting sustainable floors (elements) for buildings in Sri Lanka, taking into consideration environmental, economic and social assessments of materials used for these elements. Two types of elements are selected for this study, namely, tile and vinyl tile. Environmental burdens associated with these elements are analyzed in terms of embodied energy and environmental impacts that are relevant to Sri Lanka, such as global warming, acidification and nutrient enrichment. Economic analysis is based on market prices and affordability of materials. Factors considered for the social analysis are thermal comfort, good interior (aesthetics), ability to construct fast, strength and durability. It was found that tile elements are superior to vinyl tile elements on environmental scores if processes of complete life cycle of these elements are taken into account. On social score also, tile elements (104.8) are better than vinyl tile elements (51.15). But on economic score, vinyl tile elements are better. These scores are presented in a matrix which will help in selecting sustainable floor coverings for buildings. 相似文献