全文获取类型
收费全文 | 93922篇 |
免费 | 1229篇 |
国内免费 | 1102篇 |
专业分类
安全科学 | 3842篇 |
废物处理 | 3512篇 |
环保管理 | 14387篇 |
综合类 | 21119篇 |
基础理论 | 26755篇 |
环境理论 | 72篇 |
污染及防治 | 16153篇 |
评价与监测 | 5689篇 |
社会与环境 | 4141篇 |
灾害及防治 | 583篇 |
出版年
2022年 | 802篇 |
2021年 | 847篇 |
2020年 | 656篇 |
2019年 | 868篇 |
2018年 | 1227篇 |
2017年 | 1260篇 |
2016年 | 2204篇 |
2015年 | 1838篇 |
2014年 | 2567篇 |
2013年 | 9211篇 |
2012年 | 2367篇 |
2011年 | 2814篇 |
2010年 | 3351篇 |
2009年 | 3500篇 |
2008年 | 2425篇 |
2007年 | 2223篇 |
2006年 | 2538篇 |
2005年 | 2497篇 |
2004年 | 2772篇 |
2003年 | 2613篇 |
2002年 | 2163篇 |
2001年 | 2449篇 |
2000年 | 2041篇 |
1999年 | 1554篇 |
1998年 | 1376篇 |
1997年 | 1370篇 |
1996年 | 1504篇 |
1995年 | 1606篇 |
1994年 | 1487篇 |
1993年 | 1338篇 |
1992年 | 1337篇 |
1991年 | 1310篇 |
1990年 | 1253篇 |
1989年 | 1220篇 |
1988年 | 1065篇 |
1987年 | 1000篇 |
1986年 | 998篇 |
1985年 | 1066篇 |
1984年 | 1163篇 |
1983年 | 1170篇 |
1982年 | 1176篇 |
1981年 | 1099篇 |
1980年 | 938篇 |
1979年 | 935篇 |
1978年 | 830篇 |
1977年 | 721篇 |
1976年 | 639篇 |
1975年 | 610篇 |
1973年 | 652篇 |
1972年 | 648篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
73.
74.
工业革命以来,全球环境发生了前所未有的变化,将可能给地球系统带来灾难性后果,究其原因主要是由于人类活动造成的。人的行为深受意识的影响和制约,环境意识对于环境问题的产生和解决至关重要。本文选取上海、香港两个地区来分析公民对环境的关注度、公民的环保意识、环保行为以及公民对政府环境工作的看法和评价,研究公民对全球环境变化反应的区域差异,为政府制定相关环境保护政策提供理论依据。调查结果显示,上海、香港两地公民在很多环境闷题上具有共识。但是。在对手环境状况好转的期待值、参与环境保护活动的积极性、对人为因素主导力量的认识、环境保护与日常生活的切实关系、为环境保护的支付意愿、对于环境教育内容的认可度等方面存在着一定的差异。 相似文献
75.
76.
S. N. Goroshkevich 《Russian Journal of Ecology》2008,39(3):168-175
A statistical analysis of interannual variation in a set of vegetative and generative characters over 13 years has been performed to characterize the growth and seed production dynamics of the Siberian stone pine (Pinus sibirica Du Tour) in the southeast of the forest zone in western Siberia. The results have shown that the range of fluctuations in most of vegetative characters is ordinary and their distribution is close to normal. The range of fluctuations in many generative characters is enormous (from 0 to +∞), and the distribution of their values is usually skewed, with low values being recorded several times more frequently than high values. Most variable are the proportion of abortive cones and other characters that are determined mainly in the spring of the pollination year. These characters account for a very high level of variation in the total seed production. 相似文献
77.
Figueiredo AM Nogueira CA Saiki M Milian FM Domingos M 《Environmental pollution (Barking, Essex : 1987)》2007,145(1):279-292
Tillandsia usneoides L. is an epiphytic bromeliad plant able to absorb water and nutrients directly from the air. For this reason this species was selected to carry out a monitoring study of air pollution in the metropolitan region of S?o Paulo, Brazil. Five consecutive transplantation experiments (8 weeks each) were performed in 10 sites of the city, submitted to different sources of air pollution (industrial, vehicular), using plants collected from an unpolluted area. After exposure, trace metals were analyzed in the plant by instrumental neutron activation analysis. Traffic-related elements such as Zn and Ba presented high concentrations in exposure sites near to heavy traffic avenues (cars, buses and trucks) and may be associated to vehicular sources. For Zn and Co the highest contents were related to industrial zones and can be associated to the presence of anthropogenic emission sources. The rare earth elements, Fe and Rb, probably have soil particles as main source. 相似文献
78.
Paper waste – Recycling,incineration or landfilling? A review of existing life cycle assessments 总被引:1,自引:0,他引:1
A review of existing life cycle assessments (LCAs) on paper and cardboard waste has been undertaken. The objectives of the review were threefold. Firstly, to see whether a consistent message comes out of published LCA literature on optimum disposal or recycling solutions for this waste type. Such message has implications for current policy formulation on material recycling and disposal in the EU. Secondly, to identify key methodological issues of paper waste management LCAs, and enlighten the influence of such issues on the conclusions of the LCA studies. Thirdly, in light of the analysis made, to discuss whether it is at all valid to use the LCA methodology in its current development state to guide policy decisions on paper waste. A total of nine LCA studies containing altogether 73 scenarios were selected from a thorough, international literature search. The selected studies are LCAs including comparisons of different management options for waste paper. Despite claims of inconsistency, the LCAs reviewed illustrate the environmental benefits in recycling over incineration or landfill options, for paper and cardboard waste. This broad consensus was found despite differences in geographic location and definitions of the paper recycling/disposal systems studied. A systematic exploration of the LCA studies showed, however, important methodological pitfalls and sources of error, mainly concerning differences in the definition of the system boundaries. Fifteen key assumptions were identified that cover the three paper cycle system areas: raw materials and forestry, paper production, and disposal/recovery. It was found that the outcome of the individual LCA studies largely depended on the choices made in some of these assumptions, most specifically the ones concerning energy use and generation, and forestry. 相似文献
79.
80.
This research investigates whether species are perceived differently based on aesthetic and negativistic attitudes, and whether these and other attitudes, naturalistic activities, and gender predict support for the protection of threatened species. 228 undergraduate students completed a survey in which they rated pictures of 10 endangered species on aesthetic and negativistic attitudes, and support for protection. Findings showed that the two-striped garter snake, Ozark big-eared bat, and dolloff cave spider were conceptualized differently than other species, which may be the result of “irrational” fears linked to animal phobias, culture, and emotional reactions to pictures. The regression results support the common belief that aesthetics is an important determinant in perceptions of endangered species and that the importance of negativistic attitudes may be waning. Moralistic worldviews and attitudes toward landowner rights and the Endangered Species Act were significantly related to support for governmental protection of species. Surprisingly, naturalistic activities and gender were not significantly associated with support for governmental protection of species. In general, the results were consistent across both models. However, the amount of variance explained by aesthetic and negativistic attitudes was 23 percent higher in the other species models than in the bat, snake, and spider models. 相似文献