全文获取类型
收费全文 | 349篇 |
免费 | 3篇 |
国内免费 | 2篇 |
专业分类
安全科学 | 13篇 |
废物处理 | 10篇 |
环保管理 | 37篇 |
综合类 | 20篇 |
基础理论 | 78篇 |
污染及防治 | 120篇 |
评价与监测 | 51篇 |
社会与环境 | 25篇 |
出版年
2023年 | 7篇 |
2022年 | 15篇 |
2021年 | 16篇 |
2020年 | 7篇 |
2019年 | 8篇 |
2018年 | 18篇 |
2017年 | 11篇 |
2016年 | 35篇 |
2015年 | 15篇 |
2014年 | 29篇 |
2013年 | 32篇 |
2012年 | 19篇 |
2011年 | 27篇 |
2010年 | 16篇 |
2009年 | 8篇 |
2008年 | 19篇 |
2007年 | 19篇 |
2006年 | 10篇 |
2005年 | 6篇 |
2004年 | 4篇 |
2003年 | 4篇 |
2002年 | 3篇 |
2001年 | 5篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1979年 | 2篇 |
1976年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有354条查询结果,搜索用时 187 毫秒
231.
Zamora-Briseño Jesús Alejandro Améndola-Pimenta Monica Ortega-Rosas Daniel Antonio Pereira-Santana Alejandro Hernández-Velázquez Ioreni Margarita González-Penagos Carlos Eduardo Pérez-Vega Juan Antonio del Río-García Marcela Árcega-Cabrera Flor Rodríguez-Canul Rossanna 《Environmental science and pollution research international》2021,28(26):34309-34327
Environmental Science and Pollution Research - Crude oil is one of the most widespread pollutants released into the marine environment, and native species have provided useful information about the... 相似文献
232.
This research addresses the need to improve our knowledge on the demand for national forests for recreation and offers an in-depth data analysis supported by the complementary use of count data and ordered models. From a policy-making perspective, while count data models enable the estimation of monetary welfare measures, ordered models allow for the wider use of the database and provide a more flexible analysis of data. The main purpose of this article is to analyse the individual forest recreation demand and to derive a measure of its current use value. To allow a more complete analysis of the forest recreation demand structure the econometric approach supplements the use of count data models with ordered category models using data obtained by means of an on-site survey in the Bussaco National Forest (Portugal). Overall, both models reveal that travel cost and substitute prices are important explanatory variables, visits are a normal good and demographic variables seem to have no influence on demand. In particular, estimated price and income elasticities of demand are quite low. Accordingly, it is possible to argue that travel cost (price) in isolation may be expected to have a low impact on visitation levels. 相似文献
233.
234.
235.
Rogelio Cruz-Martínez Adolfo Etchegaray Saulo Molina-Giraldo Belen Nieto-Castro Enrique Gil Guevara Joaquin Bustillos Miguel Martínez-Rodríguez Alma Gámez-Varela Daniel Saldivar-Rodríguez Erendira Chávez-González Rodolfo Keller Ricardo Russo Eduardo Yepez-García Fausto Coronel-Cruz Johnatan Torres-Torres Alejandro Rojas-Macedo Daniel Ibarra-Ríos Ricardo Ordorica-Flores Jaime Nieto-Zermeño Manuel Alcocer-Alcocer 《黑龙江环境通报》2019,39(7):519-526
236.
Luke Beesley Eduardo Moreno-Jiménez Nicholas Lepp 《Environmental pollution (Barking, Essex : 1987)》2010,158(1):155-160
Three methods for predicting element mobility in soils have been applied to an iron-rich soil, contaminated with arsenic, cadmium and zinc. Soils were collected from 0 to 30 cm, 30 to 70 cm and 70 to 100 cm depths in the field and soil pore water was collected at different depths from an adjacent 100 cm deep trench. Sequential extraction and a column leaching test in the laboratory were compared to element concentrations in pore water sampled directly from the field. Arsenic showed low extractability, low leachability and occurred at low concentrations in pore water samples. Cadmium and zinc were more labile and present in higher concentrations in pore water, increasing with soil depth. Pore water sampling gave the best indication of short term element mobility when field conditions were taken into account, but further extraction and leaching procedures produced a fuller picture of element dynamics, revealing highly labile Cd deep in the soil profile. 相似文献
237.
Formaldehyde, acetaldehyde, acetone, propanal, butanal, 2-butenal, 3-methylbutanal, hexanal, benzaldehyde, 2-methylbenzaldehyde, and 2,5-dimethylbenzaldehyde were measured during six spring days at downtown Santiago de Chile. Measurements were performed 24h/day and averaged over three hour periods. The averages of the maxima (ppbv) were, formaldehyde: 3.9+/-1.4; butanal: 3.3+/-3.4; acetaldehyde: 3.0+/-0.9; acetone: 2.4+/-1.0; 2-butenal: 0.56+/-0.52; propanal: 0.46+/-0.21; benzaldehyde: 0.34+/-0.3; 3-butanal: 0.11+/-0.05; hexanal: 0.11+/-0.08; 2-methylbenzaldehyde: 0.08+/-0.05; 2,5-dimethylbenzaldehyde: 0.05+/-0.03. Aliphatic aldehydes (C1-C3) are strongly correlated among them and weakly with primary (toluene) and secondary (ozone plus nitrogen dioxide or PAN) pollutants. In particular, the correlation between acetaldehyde and propanal values remains even if diurnal and nocturnal data are considered separately, indicating similar sources. All these aldehydes present maxima values in the morning (9-12h) and minima at night (0-3h). The best correlation is observed when butanal and 2-butenal data are considered (r=0.99, butanal/2-butenal=6.2). These compounds present maxima values during the 3-6h period, with minima values in the 0-3h period. These data imply a strong pre-dawn emission. Other aldehydes show different daily profiles, suggesting unrelated origins. Formaldehyde is the aldehyde whose concentration values best correlate with the levels of oxidants. The contribution of primary emissions and photochemical processes to formaldehyde concentrations were estimated by using a multiple regression. This treatment indicates that (32+/-16)% of measured values arise from direct emissions, while (79+/-23)% is attributable to secondary formation. 相似文献
238.
There are difficulties in quantifying and characterising the organic matter (OM) in soils that contain significant amounts of partially oxidised char or charcoal materials. The anthropogenic black carbon (BC), such as that found in the Terra Preta de índio soils of the Amazon region, is a good example of the OM that is difficult to analyse in such soils. 13C direct polarisation/magic angle spinning (DP/MAS) at high MAS frequency, 1H-13C cross polarisation (CP)/MAS with total suppression of spinning sidebands (TOSS), and chemical shift anisotropy (CSA) filter nuclear magnetic resonance techniques have been applied successfully for quantifying the different components of OM. However, because pyrogenic materials present strong local magnetic susceptibility heterogeneities, the use of CSA-filter and TOSS make the pulse sequences very sensitive to imperfections in the π pulses. In this study, the DP/MAS pulse sequence was replaced by a CP with a radio frequency ramp—variable amplitude CP (VACP)—VACP/MAS pulse sequence, and composite π pulses were used in the CSA-filter and TOSS pulse sequences. In that way, the component functionalities in a humic acid from a BC soil were successfully determined. The spectrometer time needed was greatly decreased by employing this VACP/MAS technique. This development provides an accurate method for characterising BC-rich samples from different origins. 相似文献
239.
Derval dos Santos Rosa Maria Regina Calil Cristina das Graças Fassina Guedes Carlos Eduardo O. Santos 《Journal of Polymers and the Environment》2001,9(3):109-113
The biodegradability of poly--hydroxybutyrate and poly--caprolactone in soil compostage before and after irradiation of the polymers for 192, 425, and 600 h in a Weather-Ometer was examined. The biodegradability tests were done in soil compostage at pH 7.0, 9.0, and 11.0 to assess the influence of this parameter on degradation. The rate of degradation was directly proportional to the soil alkalinity. Poly--hydroxybutyrate showed the greatest weight loss and aging in a Weather-Ometer did not significantly increase the biodegradation, except when the polymer was aged for 425 h and buried in soil compostage of pH 11.0. 相似文献
240.
Godoy JM de Oliveira MS de Almeida CE de Carvalho ZL da Silva ER Fernandes Fda C Pitanga FL Danelon OM 《Journal of environmental radioactivity》2008,99(4):631-640
Twenty ropes with 400 Perna perna mussels seeds (3 cm shell size) were set-up on floating structures at Cabo Frio Island, Arraial do Cabo, approximately 100 km northeast of Rio de Janeiro city. A rope was taken out on a monthly basis, and the shell sizes of 100 seeds were measured. The haemolymph of 10 male and 10 female individuals was taken, and the same individuals were separated for 210Po/210Pb determination. After one year of monthly sampling, no clear correlation was observed between the 210Po concentration, mussel's age and weight. A mean 210Po concentration of 155 Bq kg(-1) wet weight basis, was obtained, which is comparable with data reported in the literature. The radiation dose did not have any observable effect on the micronuclei frequency and DNA breaks in the mussels. This was probably due to the low dose rate, 0.02 mGy d(-1), in comparison with the suggested potential dose limit of 10 mGy d(-1). 相似文献