全文获取类型
收费全文 | 278篇 |
免费 | 5篇 |
国内免费 | 3篇 |
专业分类
安全科学 | 12篇 |
废物处理 | 3篇 |
环保管理 | 57篇 |
综合类 | 94篇 |
基础理论 | 45篇 |
污染及防治 | 52篇 |
评价与监测 | 11篇 |
社会与环境 | 12篇 |
出版年
2019年 | 7篇 |
2018年 | 4篇 |
2017年 | 4篇 |
2016年 | 3篇 |
2015年 | 4篇 |
2014年 | 4篇 |
2013年 | 13篇 |
2012年 | 10篇 |
2011年 | 18篇 |
2009年 | 12篇 |
2008年 | 6篇 |
2007年 | 11篇 |
2006年 | 10篇 |
2005年 | 11篇 |
2004年 | 5篇 |
2003年 | 10篇 |
2002年 | 3篇 |
2000年 | 6篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1996年 | 4篇 |
1995年 | 5篇 |
1994年 | 4篇 |
1992年 | 2篇 |
1991年 | 6篇 |
1989年 | 4篇 |
1988年 | 4篇 |
1987年 | 8篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1983年 | 4篇 |
1982年 | 6篇 |
1981年 | 3篇 |
1977年 | 5篇 |
1976年 | 3篇 |
1974年 | 5篇 |
1970年 | 2篇 |
1969年 | 2篇 |
1968年 | 5篇 |
1967年 | 3篇 |
1957年 | 3篇 |
1955年 | 3篇 |
1954年 | 4篇 |
1953年 | 2篇 |
1942年 | 3篇 |
1923年 | 2篇 |
1922年 | 2篇 |
1920年 | 9篇 |
1919年 | 2篇 |
1918年 | 2篇 |
排序方式: 共有286条查询结果,搜索用时 15 毫秒
111.
112.
Schlick-Steiner BC Steiner FM Höttinger H Nikiforov A Mistrik R Schafellner C Baier P Christian E 《Die Naturwissenschaften》2004,91(5):209-214
Deception is a crucial yet incompletely understood strategy of social parasites. In central Europe, the Mountain Alcon Blue, Maculinea rebeli, a highly endangered butterfly, parasitises several Myrmica ant species. Caterpillars gain access to host nests probably by faking the ants odour. We analysed gas chromatography–mass spectrometry data of body surface hydrocarbons of pre-adoption and hibernated larvae of Maculinea rebeli and of their host species Myrmica sabuleti and M. schencki. Data were ordinated by different methods, based on similarities in the relative quantities of compounds between chromatograms. The two Myrmica species exhibit species-specific profiles. The Maculinea rebeli pre-adoption larva has a complex profile that simultaneously contains species-specific substances of the two investigated host species. This evidence leads to the interpretation that, in central Europe, Maculinea rebeli is predisposed for multi-host use by the chemical signature of its pre-adoption larva. The Maculinea rebeli larva clearly does not rely on an intersection-odour of compounds common to all host ant species, but synthesises an aggregate-odour containing specific compounds of each of the investigated hosts. We term this previously unknown chemical strategy aggregate-odour multi-host mimicry.B.C. Schlick-Steiner and F.M. Steiner contributed equally to this work. 相似文献
113.
The hexagon model of color vision predicts that white flowers which reflect ultraviolet light resemble green foliage to a
bee's eye, whereas, according to other models of the bee color vision, UV-reflecting white is discriminable from foliage green.
The hexagon model is widely used in ecologically and evolutionary oriented literature, and the predicted similarity between
white and green has been recently presented as a well established fact (Waser and Chittka 1998). We show that bees detect
UV-reflecting white objects presented on a green background, a finding that is in disagreement with the predictions of the
hexagon model.
Received: 22 March 1999 / Accepted in revised form: 2 July 1999 相似文献
114.
Ulrich Helfenstein Ursula Ackermann-Liebrich Charlotte Braun-Fahrländer Hans Urs Wanner 《Environmental monitoring and assessment》1991,17(2-3):147-156
The purpose of the present statistical analysis was the assessment of the relation between time series of environmental factors and of frequencies of diseases of the respiratory system in pre-school children. During about one year, daily measurements of air pollutants and climatic variables were taken. During the same period of time two series of medical data were collected: (i) The daily relative number of pre-school children, exhibiting diseases of the respiratory tracts who either came to the outpatients' clinic of the children's hospital or were reported by paediatricians in Basle (ENTRIES). (ii) The daily relative frequency of symptoms of the respiratory tracts observed in a group of randomly selected pre-school children (SYMPTOMS).By means of transfer function models the relation between the two target variables and the explaining variables was analysed. Several practical problems did arise: Choice of the appropriate transformation of the different series, interpretation of the crosscorrelation function using different methods of prewhitening, time splitting and nonstationarity of the crosscorrelation structure. In particular, it was found that after prewhitening the crosscorrelation function between the explanatory series SO2 and the response series SYMPTOMS changes with time. While during the winter period an instantaneous relation between these two series (and to a lesser extent between NO2 and SYMPTOMS) was identified, no such relation was found for the other seasons. 相似文献
115.
Ralf Dillert Matthias Brandt Iris Fornefett Ulrike Siebers Detlef Bahnemann 《Chemosphere》1995,30(12):2333-2341
The photocatalytic degradation of 2,4,6-trinitrotoluene and ten other nitroaromatic compounds in aerated TiO2 suspensions has been studied. The following order of reactivity was observed: nitrotoluenes > nitrobenzene > dinitrotoluenes . dinitrobenzenes > 2,4,6-trinitrotoluene > 1,3,5-trinitrobenzene, which reflects the known influence of nitro groups towards the attack of electrophilic reagents on the aromatic molecule. 相似文献
116.
Three 14C-labelled polychloroalkanes (C12 and C16), representing low (23% Cl by weight), medium (51%), and highly (68%) chlorinated paraffin (CP) mixtures, were presented to rainbow trout via the water. The uptake in fat-rich tissues was positively correlated to the degree of chlorination of the preparations. Notably, all preparations gave rise to a high and selective uptake of radioactivity in the olfactory organ and gills. This selective radiolabelling may reflect a general ability of these organs to enrich xenobiotics from the surrounding water. The olfactory organ may be a hitherto unforseen target for toxic environmental pollutants in fish. 相似文献
117.
118.
119.
120.
The Science of Nature - 相似文献