全文获取类型
收费全文 | 188篇 |
免费 | 5篇 |
国内免费 | 3篇 |
专业分类
安全科学 | 2篇 |
废物处理 | 11篇 |
环保管理 | 19篇 |
综合类 | 23篇 |
基础理论 | 46篇 |
污染及防治 | 64篇 |
评价与监测 | 16篇 |
社会与环境 | 15篇 |
出版年
2023年 | 6篇 |
2022年 | 5篇 |
2021年 | 7篇 |
2020年 | 8篇 |
2019年 | 4篇 |
2018年 | 11篇 |
2017年 | 12篇 |
2016年 | 13篇 |
2015年 | 5篇 |
2014年 | 5篇 |
2013年 | 18篇 |
2012年 | 17篇 |
2011年 | 16篇 |
2010年 | 10篇 |
2009年 | 16篇 |
2008年 | 11篇 |
2007年 | 10篇 |
2006年 | 5篇 |
2005年 | 5篇 |
2004年 | 2篇 |
2003年 | 3篇 |
2002年 | 3篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1991年 | 1篇 |
排序方式: 共有196条查询结果,搜索用时 15 毫秒
191.
Modeling Habitat Suitability for Complex Species Distributions by Environmental-Distance Geometric Mean 总被引:1,自引:1,他引:0
This paper presents a new habitat suitability modeling method whose main properties are as follows: (1) It is based on the density of observation points in the environmental space, which enables it to fit complex distributions (e.g. nongaussian, bimodal, asymmetrical, etc.). (2) This density is modeled by computing the geometric mean to all observation points, which we show to be a good trade-off between goodness of fit and prediction power. (3) It does not need any absence information, which is generally difficult to collect and of dubious reliability. (4) The environmental space is represented either by an expert-selection of standardized variables or the axes of a factor analysis [in this paper we used the Ecological Niche Factor Analysis (ENFA)].We first explain the details of the geometric mean algorithm and then we apply it to the bearded vulture (Gypaetus barbatus) habitat in the Swiss Alps. The results are compared to those obtained by the median algorithm and tested by jack-knife cross-validation. We also discuss other related algorithms (BIOCLIM, HABITAT, and DOMAIN). All these analyses were implemented into and performed with the ecology-oriented GIS software BIOMAPPER 2.0.The results show the geometric mean to perform better than the median algorithm, as it produces a tighter fit to the bimodal distribution of the bearded vulture in the environmental space. However, the median algorithm being quicker, it could be preferred when modeling more usual distribution. 相似文献
192.
Alexandre Roulin 《Die Naturwissenschaften》2009,96(3):375-382
Identifying the factors that mediate covariation between an ornament and other phenotypic attributes is important to determine
the signaling function of ornaments. Sign and magnitude of a covariation may vary across environments if the expression of
the ornament or of its linked genes regulating correlated phenotypes is condition-dependent. I investigated in the barn owl
Tyto alba whether sign and magnitude of covariation between body mass and two heritable melanin-based plumage ornaments change with
food supply, along the reproductive cycle and from the morning to the evening. Using a dataset of 1,848 measurements of body
mass in 336 breeding females, I found that females displaying large black spots were heavier than conspecifics with smaller
spots in the afternoon (i.e., a long time after the last feeding) but not in the morning (i.e., a short time after the last
feeding). This is consistent with the recently proposed hypothesis that eumelanin-based ornaments are associated with the
ability to maintain energy balance between food intake and energy expenditure. Thus, covariation between melanin-based coloration
and body mass can be detected only under specific conditions potentially explaining why it has been reported in only ten out
of 28 vertebrate species. The proposition that ornamented individuals achieve a higher fitness than drab conspecifics only
in specific environments should be tested for other ornaments. 相似文献
193.
Radhouani H Igrejas G Pinto L Gonçalves A Coelho C Rodrigues J Poeta P 《Journal of environmental monitoring : JEM》2011,13(8):2227-2233
Antimicrobial resistance and the mechanisms implicated were studied in 54 enterococci recovered from 57 seagull fecal samples. Almost 78% of the recovered enterococci showed resistance against one or more antibiotics and these isolates were identified to the species level. E. faecium was the most prevalent species (52.4%). High percentages of erythromycin and tetracycline resistances were found among our isolates (95.2%), and lower percentages were identified to other antibiotics. Most of the tetracycline-resistant strains carried the tet(M) and/or tet(L) genes. Genes associated with Tn916/Tn1545 and/or Tn5397 transposons were detected in 45% of tetracycline-resistant isolates. The erm(B) gene was detected in 65% of erythromycin-resistant isolates. The vat(D) and vat(E) genes were present in 5.9% and 11.8% of quinupristin/dalfopristin-resistant isolates, respectively. The ant(6)-Ia gene was identified in 57.1% of streptomycin-resistant isolates. All nine kanamycin-resistant isolates carried the aph(3)'-IIIa gene. The cat(A) gene was found in two chloramphenicol-resistant isolates. Seagulls should be considered a risk species for spreading in the environment antimicrobial resistant enterococci and can serve as a sentinel for antibiotic pressure from the surrounding farm and urban setting. 相似文献
194.
Effects of Coffee Management Intensity on Composition, Structure, and Regeneration Status of Ethiopian Moist Evergreen Afromontane Forests 总被引:1,自引:0,他引:1
Kitessa Hundera Raf Aerts Alexandre Fontaine Maarten Van Mechelen Pieter Gijbels Olivier Honnay Bart Muys 《Environmental management》2013,51(3):801-809
The effect of arabica coffee management intensity on composition, structure, and regeneration of moist evergreen Afromontane forests was studied in three traditional coffee-management systems of southwest Ethiopia: semiplantation coffee, semiforest coffee, and forest coffee. Vegetation and environmental data were collected in 84 plots from forests varying in intensity of coffee management. After controlling for environmental variation (altitude, aspect, slope, soil nutrient availability, and soil depth), differences in woody species composition, forest structure, and regeneration potential among management systems were compared using one way analysis of variance. The study showed that intensification of forest coffee cultivation to maximize coffee production negatively affects diversity and structure of Ethiopian moist evergreen Afromontane forests. Intensification of coffee productivity starts with the conversion of forest coffee to semiforest coffee, which has significant negative effects on tree seedling abundance. Further intensification leads to the conversion of semiforest to semiplantation coffee, causing significant diversity losses and the collapse of forest structure (decrease of stem density, basal area, crown closure, crown cover, and dominant tree height). Our study underlines the need for shade certification schemes to include variables other than canopy cover and that the loss of species diversity in intensively managed coffee systems may jeopardize the sustainability of coffee production itself through the decrease of ecosystem resilience and disruption of ecosystem services related to coffee yield, such as pollination and pest control. 相似文献
195.
Diório Alexandre Díaz-Angulo Jennyfer Castellanos Reynel M. Gomes Ana I. Bergamasco Rosângela Vieira Marcelo Fernandes Dezotti Márcia Mueses Miguel Angel Machuca-Martinez Fiderman Vilar Vítor J. P. 《Environmental science and pollution research international》2022,29(28):42120-42129
Environmental Science and Pollution Research - This work aims to integrate several hydrogen peroxide (H2O2) activation mechanisms, photolysis (UVC irradiation), chemical electron transfer (TiO2-P25... 相似文献
196.
Davis Lodinikki Lemoy Aragão Walessa Alana Bragança de Oliveira Lopes Géssica Eiró Luciana Guimaraes Freire Alexandre Rodrigues Prado Felippe Bevilacqua Rossi Ana Cláudia da Silva Cruz Allan das Graças Fernandes Dantas Kelly Albuquerque Alan Rodrigo Leal Paz Simone Patricia Aranha Angélica Rômulo Simões Lima Rafael Rodrigues 《Environmental science and pollution research international》2022,29(10):13930-13940
Environmental Science and Pollution Research - There are a few data relating to the effects of lead (Pb) exposure on the alveolar bone, which has very distinct morphophysiological characteristics... 相似文献