全文获取类型
收费全文 | 594篇 |
免费 | 6篇 |
国内免费 | 9篇 |
专业分类
安全科学 | 16篇 |
废物处理 | 25篇 |
环保管理 | 60篇 |
综合类 | 70篇 |
基础理论 | 129篇 |
污染及防治 | 227篇 |
评价与监测 | 45篇 |
社会与环境 | 34篇 |
灾害及防治 | 3篇 |
出版年
2023年 | 9篇 |
2022年 | 13篇 |
2021年 | 15篇 |
2020年 | 6篇 |
2019年 | 17篇 |
2018年 | 21篇 |
2017年 | 16篇 |
2016年 | 21篇 |
2015年 | 14篇 |
2014年 | 41篇 |
2013年 | 57篇 |
2012年 | 48篇 |
2011年 | 49篇 |
2010年 | 30篇 |
2009年 | 31篇 |
2008年 | 35篇 |
2007年 | 42篇 |
2006年 | 24篇 |
2005年 | 25篇 |
2004年 | 17篇 |
2003年 | 14篇 |
2002年 | 10篇 |
2001年 | 7篇 |
2000年 | 13篇 |
1999年 | 5篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 5篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有609条查询结果,搜索用时 31 毫秒
281.
Soil carbon storage in silvopastoral systems and a treeless pasture in northwestern Spain 总被引:2,自引:0,他引:2
Howlett DS Mosquera-Losada MR Nair PK Nair VD Rigueiro-Rodríguez A 《Journal of environmental quality》2011,40(3):825-832
Soil particle size and land management practices are known to have considerable influence on carbon (C) storage in soils, but such information is lacking for silvopastoral systems in Spain. This study quantified the amounts of soil C stored at various depths to 100 cm under silvopastoral plots of radiata pine ( D. Don) and birch ( Roth) in comparison to treeless pasture in Galicia, Spain. Soils were fractionated into three size classes (<53, 53-250, and 250-2000 μm), and C stored in them and in the whole (nonfractionated) soil was determined. Overall, the C stock to 1 m ranged from 80.9 to 176.9 Mg ha in these soils. Up to 1 m depth, 78.82% of C was found in the 0- to 25-cm soil depth, with 12.9, 4.92, and 3.36% in the 25- to 50-, 50- to 75-, and 75- to 100-cm depths, respectively. Soils under birch at 0 to 25 cm stored more C in the 250- to 2000-μm size class as compared with those under radiata pine; at that depth, pasture had more C than pine silvopasture in the smaller soil fractions (<53 and 53-250 μm). In the 75- to 100-cm depth, there was significantly more storage of C in the 250- to 2000-μm fraction in both silvopastures as compared with the pasture. The higher storage of soil C in larger fraction size in lower soil depths of silvopasture suggests that planting of trees into traditional agricultural landscapes will promote longer-term storage of C in the soil. 相似文献
282.
Osma JF Toca-Herrera JL Rodríguez-Couto S 《Journal of environmental management》2011,92(11):2907-2912
In this paper the cost of producing the enzyme laccase by the white-rot fungus Trametes pubescens under both submerged (SmF) and solid-state fermentation (SSF) conditions was studied. The fungus was cultured using more than 45 culture medium compositions. The cost of production was estimated by analyzing the cost of the culture medium, the cost of equipment and the operating costs. The cost of the culture medium represented, in all cases, the highest contribution to the total cost, while, the cost of equipment was significantly low, representing less than 2% of the total costs. The cultivation under SSF conditions presented a final cost 50-fold lower than the one obtained when culturing under SmF conditions at flask scale. In addition, the laccase production under SSF conditions in tray bioreactors reduced the final cost 4-fold compared to the one obtained under SSF conditions at flask scale, obtaining a final price of 0.04 cent €/U. 相似文献
283.
��lvaro S��nchez Rodr��guez Zoraida Sosa Ferrera Jos�� Juan Santana Rodr��guez 《Environmental Chemistry Letters》2011,9(2):203-208
An analytical procedure was developed to allow for the study of the levels of concentration of biocides in the various different
ports on the island of Gran Canaria, The Canary Islands. The analytes studied were extracted from water samples using solid-phase
extraction and then determined by high-performance liquid chromatography using a diode array detector. The relative standard
deviations of the developed procedure were under 12%. Recoveries over 85% and limits of detection between 0.007 and 0.4 μg/L
were obtained for all the analytes. The method was applied to the analysis of sea water samples from the ports and marinas
on the island of Gran Canaria. 相似文献
284.
Delgado-Alvarez Carolina Guadalupe Ruelas-Inzunza Jorge Osuna-Martínez Carmen Cristina Bergés-Tiznado Magdalena Elizabeth Escobar-Sánchez Ofelia Ocampo-Rodríguez Pedro Octavio Soto-Romero Karen Lizbeth Garzón-Raygoza Nancy Lorena Aguilar-Júarez Marisela Osuna-López José Isidro Frías-Espericueta Martín 《Environmental science and pollution research international》2021,28(9):10909-10917
Environmental Science and Pollution Research - Mercury and selenium concentrations and Se:Hg molar ratio in edible muscle and hepatopancreas of the crab Callinectes arcuatus from coastal lagoons of... 相似文献
285.
286.
Francisco E. Fontúrbel Marcela Franco Mariano A. Rodríguez-Cabal M. Daniela Rivarola Guillermo C. Amico 《Die Naturwissenschaften》2012,99(11):873-881
Dromiciops gliroides is an arboreal marsupial found in the temperate forests of South America (36–43 °S). This species is the sole extant representative of the order Microbiotheria, and is a key seed disperser of many native plant species, including the keystone mistletoe Tristerix corymbosus. Here, we synthesized the current knowledge on the ecological aspects of this species, and compared the available information from Argentina and Chile. Population density (23?±?2 (mean ± SE) individual/ha) and home range (1.6?±?0.6?ha) appear to be relatively similar across a marked ecological gradient in the mainland, but lower densities (7?±?2 individual/ha) and smaller home ranges (0.26?±?0.04?ha) were detected at island sites. We detected regional variation in body condition in Chile, but there were no significant differences across a wider E-W gradient. Movement patterns fit a random walk model; such behavior might have important consequences in shaping plant’s spatial patterns. Although our data suggest that D. gliroides is more tolerant to habitat disturbance than previously thought, its incapability to disperse across non-forested areas suggests that the rapid rate of habitat loss and fragmentation that characterizes southern temperate forests likely poses a serious threat to this species. These ecological similarities are surprising given that forests studied receive dramatically different rainfall and correspond to distinct forest types. The evidence synthetized here dispels some of the myths about this species but also stresses the need for more comprehensive ecological studies across its distribution range. 相似文献
287.
288.
289.
Cristina Quintas-Soriano Dainee M. Gibson Jodi S. Brandt María D. Lpez-Rodríguez Javier Cabello Pedro A. Aguilera Antonio J. Castro 《Ambio》2021,50(1):150
Conservation easements are the fastest growing private conservation strategy in the United States. However, mechanisms to assess private land conservation as well as their support by the general public are not well understood. This study uses the ecosystem services framework for assessing existing private lands in Idaho and identifies areas for future conservation easements. Using conservation targets of the land trust as a guide for selecting ecosystem services, we (a) mapped the spatial delivery of conservation targets across public and private lands, (b) explored public awareness in terms of social importance and vulnerability, and (c) mapped future priority areas by characterizing conservation bundles. We found that public lands provided the highest levels of conservation targets, and we found no difference in conservation target provision between private areas and conservation easements. The spatial characterization of conservation target bundles identified potential future priority areas for conservation easements, which can guide planning of land trust conservation efforts.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01323-x) contains supplementary material, which is available to authorized users. 相似文献
290.
Cristina Gutiérrez Maria T. García Ignacio Gracia Antonio de Lucas Juan F. Rodríguez 《Journal of Material Cycles and Waste Management》2012,14(4):308-316
Polystyrene (PS) is currently used as packaging, insulating and storing material in various industrial or domestic fields. As a result, a large quantity of PS wastes is produced. Plastic wastes are not usually biodegradable, so it is necessary to suggest a technology to recycle them. Landfills and incineration are reasonably cheap methods but are not environmentally acceptable, therefore, alternative methods for polymer recycling are required. The general purpose of PS foam recycling is to recover a more compact polymeric material without degradation. Dissolution with terpenic solvents is presented here as an efficient and cheap alternative that is developed at room temperature; among the oils studied, limonene was selected because of its intermediate solubility and its abundance. The solvent removal is possible thanks to supercritical technology that provides a high solubility in limonene and almost a complete PS insolubility at moderated pressures (77?bar) and low temperatures (30?°C). Thus, based on the results of thermogravimetric and chromatographic analysis, we propose that.supercritical antisolvent precipitation is an ideal technique for carrying out the separation of PS and limonene, providing a recycled polymer with a reduced volume, almost completely free of solvent and without degradation of the polymeric chains. 相似文献