全文获取类型
收费全文 | 2967篇 |
免费 | 15篇 |
国内免费 | 19篇 |
专业分类
安全科学 | 63篇 |
废物处理 | 166篇 |
环保管理 | 259篇 |
综合类 | 392篇 |
基础理论 | 635篇 |
环境理论 | 4篇 |
污染及防治 | 1016篇 |
评价与监测 | 261篇 |
社会与环境 | 198篇 |
灾害及防治 | 7篇 |
出版年
2023年 | 29篇 |
2022年 | 91篇 |
2021年 | 59篇 |
2020年 | 35篇 |
2019年 | 51篇 |
2018年 | 97篇 |
2017年 | 76篇 |
2016年 | 149篇 |
2015年 | 90篇 |
2014年 | 157篇 |
2013年 | 254篇 |
2012年 | 176篇 |
2011年 | 239篇 |
2010年 | 149篇 |
2009年 | 135篇 |
2008年 | 167篇 |
2007年 | 162篇 |
2006年 | 138篇 |
2005年 | 115篇 |
2004年 | 99篇 |
2003年 | 89篇 |
2002年 | 75篇 |
2001年 | 69篇 |
2000年 | 46篇 |
1999年 | 20篇 |
1998年 | 17篇 |
1997年 | 17篇 |
1996年 | 8篇 |
1995年 | 19篇 |
1994年 | 20篇 |
1993年 | 8篇 |
1992年 | 16篇 |
1991年 | 12篇 |
1990年 | 10篇 |
1989年 | 6篇 |
1988年 | 6篇 |
1987年 | 3篇 |
1985年 | 3篇 |
1983年 | 7篇 |
1982年 | 5篇 |
1980年 | 3篇 |
1965年 | 3篇 |
1964年 | 3篇 |
1962年 | 4篇 |
1961年 | 3篇 |
1960年 | 3篇 |
1958年 | 5篇 |
1957年 | 2篇 |
1956年 | 2篇 |
1940年 | 3篇 |
排序方式: 共有3001条查询结果,搜索用时 203 毫秒
1.
Francisco M. Baena-Moreno Mónica Rodríguez-Galán Fernando Vega Luis F. Vilches Benito Navarrete 《International Journal of Green Energy》2019,16(5):401-412
Biomethane production through biogas upgrading is a promising renewable energy for some industries which could be part of the equilibrium needed with fossil fuels consumption to achieve a sustainable society. This paper presents a comprehensive list of biogas upgrading technologies focused on carbon dioxide removal as well as recent advances reported by researcher with wide expertise in this topic. Additionally, an extensive costs–performance comparison among the technologies studied is discussed. Among the different alternatives, chemical scrubbing stood out to achieve high biomethane purities while cryogenic technologies proved to be effective against methane losses. Regarding the different costs, water scrubbing and membrane separation seem to be the most affordable techniques. 相似文献
2.
3.
Cornus stolonifera, Salix petiolaris, and Spiraea alba
clones already located within the corridor of an electrical power line. To
establish the efficiency of treatments, we examined the statistical
differences of growth traits between species and treatments.
An analysis of the effects of layering shows, after the first growth season,
differences for all growth traits in only one species, Spiraea alba.
After the second growth season, we observed the development of new aerial
stems. Layering favors horizontal expansion of shrubs over height
development. The third year after treatment, the effect of layering is
reduced except for Cornus stolonifera, which continuously increases,
as shown by the significant progression of the clone issued from the layer
even five years after treatments. With the cutting back technique, we
expected a distinct vertical growth of the shrubs at the expense of
increasing the crown diameter. This technique would be best associated with
the rejuvenation of clones, followed by a layering of new shoots to allow a
horizontal expansion of the shrubs. Therefore, the formation of a dense shrub
community by layering should be considered a valuable approach for the
biological control of undesirable trees in powerline rights-of-way. 相似文献
4.
F. Rincón-León G. Zurera-Cosano R. Moreno-Rojas M. Amaro-López 《Environmental monitoring and assessment》1993,27(3):193-200
The importance of eating habits and the number of fish sampled in the estimation of mercury environmental contamination through biological indicators was studied. The species used were one with piscivorous habits (Anguilla anguilla) and another with omnivorous habits (Ciprinus carpio). From one original sample for each species, randomized samples were generated using the subroutine GGSRS from the mathematics library IMSL, and later the statistical significance of Pearson's correlation coefficient for the relationship between fish weight and mercury concentrations in muscle was obtained for each random sample. The results show that the use of omnivorous species such as Ciprinus carpio as a biological indicator of contamination enables us to carry out estimations with a greater degree of confidence than when piscivorous species such as Anguilla anguilla are used. 相似文献
5.
Riviane R. Hora Claudie Doums Chantal Poteaux Renée Fénéron Jorge Valenzuela Jürgen Heinze Dominique Fresneau 《Behavioral ecology and sociobiology》2005,59(2):285-292
Social parasites exploit the worker force of colonies of other social insects to rear their own young. Social parasitism occurs in several Hymenoptera and is particularly common in several tribes of the ant subfamilies Myrmicinae and Formicinae. Here, we document the occurrence of miniaturized queens (microgynes) in colonies of Ectatomma tuberculatum, an ant belonging to the subfamily Ectatomminae. Behavioral observations and genetic analyses show that microgynes concentrate their reproductive efforts almost exclusively on the production of sexual offspring (microgynes and males), whereas the regular, large queens (macrogynes) produce workers in addition to sexuals. According to mitochondrial and nuclear markers, gene flow between microgynes and macrogynes is extremely limited. Whereas the co-occurrence of microgynes and macrogynes in the related species Ectatomma ruidum constitutes an intraspecific polymorphism associated with alternative dispersal tactics, microgynes found in colonies of E. tuberculatum appear to be a distinct species and to represent the first case of social parasitism in the poneromorph subfamilies of ants. 相似文献
6.
Fluxes of ions in precipitation, throughfall and stemflow in an urban forest in Kuala Lumpur, Malaysia 总被引:1,自引:0,他引:1
Radzi Abas M Ahmad-Shah A Nor Awang M 《Environmental pollution (Barking, Essex : 1987)》1992,75(2):209-213
A study was carried out to determine the chemical composition of bulk precipitation, throughfall and stemflow in an urban forest in Kuala Lumpur, Malaysia. The mean weekly rainfall recorded during the period of study was 63.2 mm. Throughfall, stemflow and canopy interception of incident precipitation were 77.1%, 1.2% and 21.7% respectively. Bulk precipitation, througfall and stemflow were acidic, the pH recorded being 4.37, 4.71 and 4.15 respectively. In all cases the dominant ions were NO3, SO4, Cl, NH4, K, Ca and Na. Of the ions studied Ca, K, Cl, SO4, Mg and Mn showed net increases in passing through the forest canopy, while NH4, Na, NO3, Zn, H and Fe showed net retention. This study shows that the urban environment of Kuala Lumpur contributes considerable amounts of materials to the atmosphere, as reflected by the high ionic contents in bulk precipitation, throughfall and stemflow. 相似文献
7.
Biaou Séverin Gouwakinnou Gerard Nounagnon Biaou Honoré Samadori Sorotori Tovihessi Marc Sèwanou Awessou Beranger Kohomlan Ahononga Fiacre Codjo Houéto Felix Ogoubiyi 《Environment, Development and Sustainability》2022,24(8):9885-9905
Environment, Development and Sustainability - Land use and land cover change (LULCC) is one of the problems that the world has been facing for the last few decades despite political attention.... 相似文献
8.
Shahpari Ghazal Sadeghi Hossein Ashena Malihe García-León David 《Environment, Development and Sustainability》2022,24(3):4110-4127
Environment, Development and Sustainability - In the last two decades, recurring drought becomes a challenge for Iran’s economy, which is located in a drought-prone area, and it has been... 相似文献
9.
Pleijel H Skärby L Wallin G Selldén G 《Environmental pollution (Barking, Essex : 1987)》1991,69(2-3):151-168
Spring wheat (Triticum aestivum L., cv. Drabant) was exposed to different concentrations of ozone in open-top chambers for two growing seasons, 1987 and 1988, at a site located in south-west Sweden. The chambers were placed in a field of commercially grown spring wheat. The treatments were charcoal-filtered air (CF), non-filtered air (NF) and non-filtered air plus extra ozone (NF(+)). In 1988, one additional ozone concentration (NF(++)) was used. Grain yield was affected by the ozone concentration of the air. Air filtration resulted in an increase in grain yield of about 7% in both years, compared to NF. The addition of ozone (NF(+), NF(++)) reduced grain yield and increased the content of crude protein of the grain in both years. Filtration of the air had no significant effect on the content of crude protein, compared to NF. The results showed a strong positive chamber effect on grain yield in the cold and wet summer of 1987. In 1988, there was no net chamber effect on grain yield. The relative differences between the CF, NF and NF(+) treatments with respect to grain yield were of the same magnitude in the two years, despite the very different weather conditions. 相似文献
10.
Energy-dispersive X-ray fluorescence systems as analytical tool for assessment of contaminated soils
To determine the heavy metal content in soil samples at contaminated locations, a static and time consuming procedure is used in most cases. Soil samples are collected and analyzed in the laboratory at high quality and high analytical costs. The demand by government and consultants for a more dynamic approach and by customers requiring performances in which analyses are performed in the field with immediate feedback of the analytical results, is growing. Especially during the follow-up of remediation projects or during the determination of the sampling strategy, field analyses are advisable. For this purpose four types of ED-XRF systems, ranging from portable up to high performance laboratory systems, have been evaluated. The evaluation criteria are based on the performance characteristics for all the ED-XRF systems such as limit of detection, accuracy and the measurement uncertainty on one hand, and also the influence of the sample pretreatment on the obtained results on the other hand. The study proved that the field portable system and the bench top system, placed in a mobile van, can be applied as field techniques, resulting in semi-quantitative analytical results. A limited homogenization of the analyzed sample significantly increases the representativeness of the soil sample. The ED-XRF systems can be differentiated by their limits of detection which are a factor of 10 to 20 higher for the portable system. The accuracy of the results and the measurement uncertainty also improved using the bench top system. Therefore, the selection criteria for applicability of both field systems are based on the required detection level and also the required accuracy of the results. 相似文献