全文获取类型
收费全文 | 8469篇 |
免费 | 64篇 |
国内免费 | 33篇 |
专业分类
安全科学 | 176篇 |
废物处理 | 411篇 |
环保管理 | 621篇 |
综合类 | 1644篇 |
基础理论 | 1926篇 |
环境理论 | 14篇 |
污染及防治 | 2680篇 |
评价与监测 | 613篇 |
社会与环境 | 457篇 |
灾害及防治 | 24篇 |
出版年
2023年 | 75篇 |
2022年 | 174篇 |
2021年 | 187篇 |
2020年 | 100篇 |
2019年 | 117篇 |
2018年 | 253篇 |
2017年 | 276篇 |
2016年 | 362篇 |
2015年 | 249篇 |
2014年 | 398篇 |
2013年 | 637篇 |
2012年 | 412篇 |
2011年 | 531篇 |
2010年 | 368篇 |
2009年 | 328篇 |
2008年 | 477篇 |
2007年 | 453篇 |
2006年 | 371篇 |
2005年 | 307篇 |
2004年 | 242篇 |
2003年 | 235篇 |
2002年 | 205篇 |
2001年 | 174篇 |
2000年 | 107篇 |
1999年 | 85篇 |
1998年 | 50篇 |
1997年 | 48篇 |
1996年 | 41篇 |
1995年 | 62篇 |
1994年 | 72篇 |
1993年 | 28篇 |
1992年 | 43篇 |
1991年 | 41篇 |
1990年 | 35篇 |
1989年 | 31篇 |
1986年 | 38篇 |
1984年 | 26篇 |
1983年 | 26篇 |
1982年 | 31篇 |
1966年 | 40篇 |
1965年 | 42篇 |
1964年 | 26篇 |
1963年 | 32篇 |
1962年 | 26篇 |
1961年 | 36篇 |
1960年 | 29篇 |
1959年 | 26篇 |
1958年 | 26篇 |
1957年 | 35篇 |
1956年 | 29篇 |
排序方式: 共有8566条查询结果,搜索用时 15 毫秒
21.
Schuller P Iroumé A Walling DE Mancilla HB Castillo A Trumper RE 《Journal of environmental quality》2006,35(5):1756-1763
Rapid and reliable methods for documenting soil erosion associated with forest harvest operations are needed to support the development of best management practices for soil and water conservation. To address this need, the potential for using 7Be measurements to estimate patterns and amounts of soil redistribution associated with individual post-harvest events was explored. The 7Be technique, which was originally developed for use on agricultural land, was employed to estimate soil redistribution associated with a period of heavy rainfall within a harvested forest area located in the Lake Region of Chile (39 degrees 44'7' S, 73 degrees 10'39' W; 22% slope; and mean annual rainfall 2300 mm yr(-1)). The results provided by the 7Be technique were validated against direct measurements of soil gain or loss during the same period obtained using erosion pins. The information produced by the two approaches was similar. The results of this study demonstrate the potential for using 7Be measurements to document event-based erosion in recently harvested forest areas. 相似文献
22.
Assessment of environmental changes in the Orinoco River delta 总被引:1,自引:0,他引:1
H. Echezuría J. Córdova M. González V. González J. Méndez C. Yanes 《Regional Environmental Change》2002,3(1-3):20-35
Major anthropogenic driven changes in the hydrologic and sedimentation patterns of the Orinoco River have had an impact on
environmental conditions in the delta. The abrupt water flow reduction from 3,600 to 200 m3 s–1 in one of its major distributaries resulting from dam construction forced its transformation from a fresh-water body into
a tidal channel with an increase in salinity level (as far as 100 km upstream) and with well-mixed water at the mouth and
estuarine connection to the Paria Gulf. Three different sectors along this distributary can be identified (indicated by the
Na/Cl ratio in the water). As a result, noticeable changes have occurred in the mangrove community which moved about 60 km
further upstream. The changes have also promoted the formation of new islands of sediment progradation at the mouth of this
distributary, where successional colonization and species replacement by different species of grasses and mangroves take place.
Electronic Publication 相似文献
23.
24.
Thierry Rousseau Nicole Laurent Christel Thauvin-Robinet Stéphanie Lionnais Christine Durand Laurence Faivre Paul Sagot 《黑龙江环境通报》2002,22(8):692-696
Fraser syndrome (MIM 219000) is a rare disorder of autosomal recessive inheritance, characterized by the association of cryptophthalmos, syndactyly and genital abnormalities. Here we report on two cases of Fraser syndrome (cryptophthalmos syndrome) in a non-consanguineous couple, with variable expression in echographic, clinical and autopsy findings. Furthermore, we highlight the difficulties in prenatal diagnosis of Fraser syndrome. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
25.
A. Migné D. Davoult N. Spilmont D. Menu G. Boucher J.-P. Gattuso H. Rybarczyk 《Marine Biology》2002,140(4):865-869
This paper describes a closed-chamber method for measuring CO2 fluxes in intertidal soft sediments during periods of emersion. The method relies on closed-circuit incubations of undisturbed sediment and measurement of CO2 exchanges using an infrared gas analyser. The method was assessed during field experiments, both in light and dark conditions, on an exposed sandy beach and in an estuary. The rates of gross community production measured under moderate irradiance (4.2 mg C m-2 h-1 on the exposed sandy beach and 35 mg C m-2 h-1 in the estuary) are in good agreement with rates reported in the literature. In conjunction with appropriate sampling strategies, this method can be useful for estimating and comparing production of intertidal areas or for assessing factors that influence production. 相似文献
26.
Branquinho C Serrano HC Pinto MJ Martins-Loução MA 《Environmental pollution (Barking, Essex : 1987)》2007,146(2):437-443
The several established criteria to define a hyperaccumulator plant were applied to a rare and endangered species, Plantago almogravensis, and to the 3rd most abundant element in the earth crust, Al. Using the most common criteria, P. almogravensis undoubtedly is an Al hyperaccumulator plant. If the recent proposed requirements were considered, most of them matching those for a plant to be used in phytoextraction, it can only be considered an unusual accumulator of Al. A discussion is made concerning the several criteria of a hyperaccumulator plant in order to include rare and endemic ones and abundant elements. In ecological terms, the enrichment in Al and Fe observed may account for the differences in the vegetation pattern. Due to the rarity and endangered nature of this plant, the contribution of this work is also relevant for the ecological understanding and the development of conservation options of this endemic species. 相似文献
27.
28.
Alletto L Benoit P Bergheaud V Coquet Y 《Environmental pollution (Barking, Essex : 1987)》2008,156(3):678-688
Laboratory studies were conducted to evaluate the effects of temperature and water pressure head on the degradation of the diketonitrile metabolite (DKN) of isoxaflutole during 84 d in samples collected in a loamy soil under conventional (CT) and conservation (MT) tillage systems. Soil temperature was the major factor controlling DKN degradation in the two tillage systems. The shortest half-lives (T1/2) were measured in the seedbed samples under MT at 25 °C and −33 cm water pressure head. We found that mouldboard ploughing under CT was responsible for the spatial variability of herbicide degradation properties, whereas under MT herbicide degradation was associated to the vertical distribution of organic matter. 相似文献
29.
Schröder W Hornsmann I Pesch R Schmidt G Markert B Fränzle S Wünschmann S Heidenreich H 《Environmental monitoring and assessment》2007,133(1-3):495-505
The study was conducted to test the hypothesis that the regional variability of nitrogen (N) and metal accumulations in terrestrial ecosystems are due to historical and recent ways of landuse. To this end, two regions of Central Europe were selected for investigation: the Weser-Ems Region (WER) and the Euro Region Nissa (ERN). They were assumed to have land use-specific accumulation profiles. Thus, the metal and N accumulations in both regions were examined by means of geostatistically based comparative moss analysis. The sampling and chemical analysis of mosses were conducted in accordance with the convenient guidelines and methods, respectively. The spatial representativity of the sampling sites was computed by means of a land classification which was calculated for Europe by means of classification trees and GIS-techniques. The differences of deposition loads were tested for statistical significance with regard to time and space. The measurement values corroborated the decline of metal accumulation observed since the beginning of the European Metals in Mosses Surveys in 1990. The metal loads of the mosses in the ERN exceeded those in the WER significantly. The opposite holds true for the N concentrations: those in the WER were significantly higher than those in the ERN. The reduction of emissions from power plants, factories and houses was strongly correlated with the decline of deposition and bioaccumulation of metals. As proved by the European Metals in Mosses Surveys, this tendency is due to successful environmental policies. But no such success could be verified by monitoring the accumulation of N in mosses. 相似文献
30.