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881.
Significantly high radiation level and radionuclide concentration along Quilon beach area of coastal Kerala have been reported by several investigators. Detailed gamma radiation level survey was carried out using a portable scintillometer. Detailed studies on radionuclides concentration in different environmental matrices of high background areas were undertaken in the coastal areas of Karunagapalli, Kayankulam, Chavara, Neendakara and Kollam to study the distribution and enrichment of the radionuclides in the region. The absorbed gamma dose rates in air in high background area are in the range 43-17,400 nGyh−1. Gamma radiation level is found to be maximum at a distance of 20 m from the sea waterline in all beaches. The soil samples collected from different locations were analysed for primordial radionuclides by gamma spectrometry. The activity of primordial radionuclides was determined for the different size fractions of soil to study the enrichment pattern. The highest activity of 232Th and 226Ra was found to be enriched in 125-63 μ size fraction. The preferential accumulation of 40K was found in <63 μ fraction. The minimum 232Th activity was 30.2 Bq kg−1, found in 1000-500 μ particle size fraction at Kollam and maximum activity of 3250.4 Bq kg−1 was observed in grains of size 125-63 μ at Neendakara. The lowest 226Ra activity observed was 33.9 Bq kg−1 at Neendakara in grains of size 1000-500 μ and the highest activity observed was 482.6 Bq kg−1 in grains of size 125-63 μ in Neendakara. The highest 40K activity found was 1923 Bq kg−1 in grains of size <63 μ for a sample collected from Neendakara. A good correlation was observed between computed dose and measured dose in air. The correlation between 232Th and 226Ra was also moderately high. The results of these investigations are presented and discussed in this paper. 相似文献
882.
Carbon dioxide emissions have accelerated since the signing of the Kyoto Protocol. This discouraging development may partly
be blamed on accelerating world growth and on lags in policy instruments. However, it also raises serious question concerning
whether policies to reduce CO2 emissions are as effective as generally assumed. In recent years, a considerable number of studies have identified various
feedback mechanisms of climate policies that often erode, and occasionally reinforce, their effectiveness. These studies generally
focus on a few feedback mechanisms at a time, without capturing the entire effect. Partial accounting of policy feedbacks
is common in many climate scenarios. The IPCC, for example, only accounts for direct leakage and rebound effects. This article
attempts to map the aggregate effects of different types of climate policy feedback mechanisms in a cohesive framework. Controlling
feedback effects is essential if the policy measures are to make any difference on a global level. A general conclusion is
that aggregate policy feedback mechanisms tend to make current climate policies much less effective than is generally assumed.
In fact, various policy measures involve a definite risk of ‘backfiring’ and actually increasing CO2 emissions. This risk is particularly pronounced once effects of climate policies on the pace of innovation in climate technology
are considered. To stand any chance of controlling carbon emissions, it is imperative that feedback mechanisms are integrated
into emission scenarios, targets for emission reduction and implementation of climate policy. In many cases, this will reduce
the scope for subsidies to renewable energy sources, but increase the scope for other measures such as schemes to return carbon
dioxide to the ground and to mitigate emissions of greenhouse gases from wetlands and oceans. A framework that incorporates
policy feedback effects necessitates rethinking the design of the national and regional emission targets. This leads us to
a new way of formulating emission targets that include feedback effects, the global impact target. Once the full climate policy feedback mechanisms are accounted for, there are probably only three main routes in climate
policy that stand a chance of mitigating global warming: (a) returning carbon to the ground, (b) technological leaps in zero-emission
energy technology that make it profitable to leave much carbon in the ground even in Annex II countries and (c) international
agreements that make it more profitable to leave carbon in the ground or in forests. 相似文献
883.
E. Lombi D.P. Stevens M.J. McLaughlin 《Environmental pollution (Barking, Essex : 1987)》2010,158(6):2110-2116
Water treatment residuals (WTRs) are produced by the treatment of potable water with coagulating agents. Beneficial recycling in agriculture is hampered by the fact that WTRs contain potentially toxic contaminants (e.g. copper and aluminium) and they bind phosphorus strongly. These issues were investigated using a plant bioassay (Lactuca sativa), chemical extractions and an isotopic dilution technique. Two WTRs were applied to an acidic and a neutral pH soil at six rates. Reductions in plant growth in amended soils were due to WTR-induced P deficiency, rather than Al or Cu toxicity. The release of potentially toxic Al from WTRs was found to be mitigated by their alkaline nature and pH buffering capacity. However, acidification of WTRs was shown to release more soluble Al than soil naturally high in Al. Copper availability was relatively low in all treatments. However, the lability of WTR-Cu increased when the WTR was applied to the soil. 相似文献
884.
Pérez-Parada A González J Pareja L Geis-Asteggiante L Colazzo M Niell S Besil N González G Cesio V Heinzen H 《Journal of environmental science and health. Part. B》2010,45(8):796-803
In order to evaluate the extraction of pesticide residues that are transferred to the brew during mate drinking process of P.U.1 yerba mate leaves (Ilex paraguariensis), a special device to simulate the way in which mate is drunk in Uruguay was developed. The transfer to the brew of 12 organophosphates, 5 synthethic pyrethroids and one organochlorine pesticide from spiked samples was studied. The relationship between the transfer data thus obtained and physicochemical properties like water solubility (Ws), octanol-water coefficient (Kow) and Henry's constant (H) was evaluated. The extractability of the pesticide residues from yerba mate can be correlated with log Ws and log Kow. These transfer values allowed the calculation of ARLs (acceptable residue level) for the pesticides following Food and Agriculture Organization (FAO), World Health Organizaion (WHO) guidelines. These results can help the future establishment of maximum residue levels (MRLs). 相似文献
885.
886.
887.
S.P. McGrath C. Micó J.L. Stroud S. Fozard 《Environmental pollution (Barking, Essex : 1987)》2010,158(10):3085-3094
Four plant species (oilseed rape, Brassica napus L.; red clover, Trifolium pratense L.; ryegrass, Lolium perenne L.; and tomato, Lycopersicon esculentum L.) were tested on ten soils varying widely in soil properties to assess molybdenum (Mo) toxicity. A larger range (66-fold-609-fold) of added Mo concentrations resulting in 50% inhibition of yield (ED50) was found among soils than among plant species (2-fold-38-fold), which illustrated that the soils differed widely in the expression of Mo toxicity. Toxicity thresholds based on soil solution Mo narrowed the variation among soils compared to thresholds based on added Mo concentrations. We conclude that plant bioavailability of Mo in soil depends on Mo solubility, but this alone did not decrease the variability in observed toxicity enough to be used in risk assessment and that other soil properties influencing Mo toxicity to plants need to be considered. 相似文献
888.
Guan-yong Su Zi-shen Gao Yijun Yu Jia-chun Ge Si Wei Jian-fang Feng Feng-yan Liu John P. Giesy Hong-xia Yu 《Environmental science and pollution research international》2010,17(3):634-642
Background, aim, and scope
Polybrominated diphenyl ethers (PBDEs) and their metabolites are toxic to animals, and concentrations of the PBDEs metabolites can exceed those of the parent materials. But no information was available on concentrations of PBDEs metabolites in the lower Yangtze River in the region around Jiangsu Province of China, which is heavily urbanized and industrialized area. The aims of this study were to determine whether PBDEs and their methoxylated PBDEs (MeO-PBDEs) were accumulated in Coilia sp. in this area and to investigate the potential sources for these two kinds of brominated organic pollutants. 相似文献889.
Kärrman Anna Domingo José L. Llebaria Xavier Nadal Martí Bigas Esther van Bavel Bert Lindström Gunilla 《Environmental science and pollution research international》2010,17(3):750-758
Background, aim and scope
Perfluorinated compounds (PFCs) are global environmental pollutants that bioaccumulate in wildlife and humans. Laboratory experiments have revealed toxic effects such as delayed development, humoral suppression, and hepatotoxicity. Although numerous human blood levels have been reported, little is known about distribution in the human body. Knowledge about PFC distribution and accumulation in the human body is crucial to understanding uptake and subsequent effects as well as to conduct risk assessments. The present study reports PFC levels in human liver and breast milk from a general population living in Catalonia, Spain. Liver and milk levels are compared to previously reported levels in blood from the same geographic area as well as to other existing reports on human liver and milk levels in other countries. 相似文献890.
Hauke Reuter Ulrike Middelhoff Frieder Graef Richard Verhoeven Thomas Batz Martin Weis Gunther Schmidt Winfried Schröder Broder Breckling 《Environmental science and pollution research international》2010,17(8):1479-1490