全文获取类型
收费全文 | 740篇 |
免费 | 16篇 |
国内免费 | 7篇 |
专业分类
安全科学 | 27篇 |
废物处理 | 30篇 |
环保管理 | 173篇 |
综合类 | 85篇 |
基础理论 | 171篇 |
污染及防治 | 169篇 |
评价与监测 | 51篇 |
社会与环境 | 51篇 |
灾害及防治 | 6篇 |
出版年
2022年 | 8篇 |
2021年 | 14篇 |
2020年 | 11篇 |
2019年 | 11篇 |
2018年 | 19篇 |
2017年 | 20篇 |
2016年 | 18篇 |
2015年 | 20篇 |
2014年 | 16篇 |
2013年 | 82篇 |
2012年 | 30篇 |
2011年 | 42篇 |
2010年 | 24篇 |
2009年 | 24篇 |
2008年 | 41篇 |
2007年 | 48篇 |
2006年 | 35篇 |
2005年 | 18篇 |
2004年 | 19篇 |
2003年 | 38篇 |
2002年 | 24篇 |
2001年 | 10篇 |
2000年 | 13篇 |
1999年 | 5篇 |
1998年 | 10篇 |
1997年 | 9篇 |
1996年 | 9篇 |
1995年 | 8篇 |
1994年 | 18篇 |
1993年 | 11篇 |
1992年 | 4篇 |
1991年 | 6篇 |
1990年 | 10篇 |
1989年 | 4篇 |
1988年 | 5篇 |
1986年 | 6篇 |
1985年 | 9篇 |
1984年 | 6篇 |
1983年 | 12篇 |
1982年 | 10篇 |
1981年 | 7篇 |
1980年 | 7篇 |
1979年 | 6篇 |
1978年 | 5篇 |
1977年 | 4篇 |
1976年 | 1篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1971年 | 2篇 |
排序方式: 共有763条查询结果,搜索用时 15 毫秒
511.
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
512.
513.
Mariela Pajuelo Karen A. Bjorndal Kimberly J. Reich Michael D. Arendt Alan B. Bolten 《Marine Biology》2012,159(6):1255-1267
Most studies on the foraging ecology of loggerhead turtles (Caretta caretta) have focused on adult females and juveniles. Little is known about the foraging patterns of adult male loggerheads. We analyzed
tissues for carbon and nitrogen stable isotopes (δ13C and δ15N) from 29 adult male loggerheads tracked with satellite transmitters from one breeding area in Florida, USA, to evaluate
their foraging habitats in the Northwest Atlantic (NWA). Our study revealed large variations in δ13C and δ15N and a correlation between both δ13C and δ15N and the latitude to which the loggerheads traveled after the mating season, thus reflecting a geographic pattern in the
isotopic signatures. Variation in δ13C and δ15N can be explained by differences in food web baseline isotopic signatures rather than differences in loggerhead trophic levels.
Stable isotope analysis may help elucidate residency and migration patterns and identify foraging sea turtle subpopulations
in the NWA due to the isotopically distinct habitats used by these highly migratory organisms. 相似文献
514.
The aboveground net primary productivity (ANPP) of grass communities in grasslands and savannas is primarily determined by precipitation quantity. Recent research, motivated by predictions of changes in the distribution of rainfall events by global climate change models, indicates that ANPP may be affected by rainfall distribution as much as by annual totals. Grazing and community composition are also known to affect grassland ANPP. The manner in which interactions between rainfall distribution, grazing, and community composition affect the relationship between precipitation and ANPP represents a critical knowledge gap. The effects of community composition and grazing on aboveground growth responses to intraseasonal variation in water availability were investigated at seven grassland sites with a nonselective clipping experiment. The aboveground growth of the dominant C4 species at each site was measured at regular intervals for 2-3 growing seasons in the presence or absence of regular defoliation. In the absence of defoliation, there was a general lack of synchrony of intraseasonal growth among co-occurring species. Variation in growth rates was high and was only partially explained by variation in rainfall. Regular defoliation increased growth synchrony at all sites, but changes in growth responses to rainfall varied between sites. These results suggest that community composition will be important in determining ANPP-precipitation relationships under conditions of altered rainfall distribution. However this effect appears to be a result of species responding differently to soil water or other resources rather than to rainfall per se. Grazing may override the effects of community composition by reducing differences in growth patterns between species and has the potential to weaken precipitation controls on ANPP. 相似文献
515.
Krystyna Piotrowska Deborah Edwards Alan Mitch Ralph C. Dougherty 《Die Naturwissenschaften》1980,67(9):442-445
Experiments are reported in which three prochiral organic reactions were conducted in the presence of a ca. 1T magnetic field which was oriented with reference to the earth's geometric axes. The sign and magnitude of the rotation varied with the macroscopic orientation of the magnetic field and the time that the reaction was performed. Control measurements were in accord with expectations. The fact that the sign of the observed optical rotation of the product was reversed for all three reported reactions when the magnetic field was reversed for reactions conducted on the same day suggests that either the observed asymmetric synthesis was due to the reactions being conducted in a chiral physical field or extremely unusual stochastic processes were involved. 相似文献
516.
517.
Alan W. Gertler William G. Coulombe John G. Watson John L. Bowen Richard T. Egami Stan Marsh 《Environmental monitoring and assessment》1993,24(1):13-25
The USEPA replaced TSP with PM10 as the National Ambient Air Quality Standard for particulate matter. The commercially available PM10 sampler is a high-volume model using quartz fiber filters. In certain investigations, such as source apportionment studies, chemical analysis of the filter is necessary, however, many analyses cannot be run on quartz filters. An alternate filter such as Teflon is amenable to XRF and ion chemical analyses but is not amenable to analysis for carbon. To overcome these problems DRI constructed a medium-volume PM10 sampler that is capable of collecting particulates on both Teflon and quartz fiber filters simultaneously. This paper describes the design of the DRI medium-volume PM10 sampler, discusses a method for determining equivalence of two samplers, the results of applying the method to test the equivalence of the medium-volume sampler and a commerical high-volume sampler, and examines differences between PM10 and TSP measurements in a southwestern desert. 相似文献
518.
519.
Leaf surface chemicals stimulating oviposition byPieris rapae (Lepidoptera: Pieridae) on cabbage 总被引:3,自引:0,他引:3
Summary The chemical stimulation of oviposition byPieris rapae on cabbage was investigated by leaf washing and extraction. Isolation of the stimulant by various chromatographic techniques was monitored by a bioassay using Sieva bean as a surrogate host plant. Cold water, chloroform, or chloroform followed by cold water washes failed to release the stimulant from leaf surfaces. Boiling water or chloroform followed by methanol was required. The most active stimulatory compound was identified as 3-indolylmethyl glucosinolate (glucobrassicin). Other glucosinolates were identified as sinigrin, which was only slightly active, and glucoiberin, which was completely inactive as a stimulant. The significance of the selective response ofP. rapae andP. brassicae to different glucosinolates and the implications of the binding of polar allelochemicals to leaf surfaces is discussed with respect to host utilization and perception mechanisms of pierids. 相似文献
520.