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981.
Rämö K Kanerva T Nikula S Ojanperä K Manninen S 《Environmental pollution (Barking, Essex : 1987)》2006,144(1):101-111
We studied the effects of relatively low levels of O(3) (40-50 ppb) and CO(2)-enrichment (+100 ppm) on a northern European lowland hay meadow during the summers 2002-2004 using open-top chambers (OTCs) and ground-planted mesocosms. Ozone reduced the aboveground biomass of the community (up to 40%), and four out of seven species (Campanula rotundifolia, Fragaria vesca, Trifolium medium, Vicia cracca) showed either significant growth reduction and/or visible injuries under elevated O(3). However, the reductions in aboveground biomass were not reflected as changes in the dominance of different functional groups or in the total community root biomass. Elevated CO(2) did not amend the detrimental effects of O(3) on aboveground biomass. Elevated CO(2) alone had only minor effects. An O(3)-induced reduction in the aboveground biomass and N pool of the community are likely to have important consequences in the nutrient cycling of the ecosystem. 相似文献
982.
Sediment phosphorus extractants for phosphorus-31 nuclear magnetic resonance analysis: a quantitative evaluation 总被引:2,自引:0,他引:2
Ahlgren J De Brabandere H Reitzel K Rydin E Gogoll A Waldebäck M 《Journal of environmental quality》2007,36(3):892-898
The influence of pre-extractant, extractant, and post-extractant on total extracted amounts of P and organic P compound groups measured with 31P nuclear magnetic resonance (31P-NMR) in lacustrine sediment was examined. The main extractants investigated were sodium hydroxide (NaOH) and sodium hydroxide ethylenediaminetetraacetic acid (NaOH-EDTA) with bicarbonate buffered dithionite (BD) or EDTA as pre-extractants. Post extractions were conducted using either NaOH or NaOH-EDTA, depending on the main extractant. Results showed that the most efficient combination of extractants for total P yield was NaOH with EDTA as pre-extractant, yielding almost 50% more than the second best procedure. The P compound groups varying the most between the different extraction procedures were polyphosphates and pyrophosphates. NaOH with BD as pre-extractant was the most efficient combination for these compound groups. 相似文献
983.
S. Toller E. Kärrman J.P. Gustafsson Y. Magnusson 《Waste management (New York, N.Y.)》2009,29(7):2071-2077
Incineration ashes may be treated either as a waste to be dumped in landfill, or as a resource that is suitable for re-use. In order to choose the best management scenario, knowledge is needed on the potential environmental impact that may be expected, including not only local, but also regional and global impact. In this study, A life cycle assessment (LCA) based approach was outlined for environmental assessment of incinerator residue utilisation, in which leaching of trace elements as well as other emissions to air and water and the use of resources were regarded as constituting the potential environmental impact from the system studied. Case studies were performed for two selected ash types, bottom ash from municipal solid waste incineration (MSWI) and wood fly ash. The MSWI bottom ash was assumed to be suitable for road construction or as drainage material in landfill, whereas the wood fly ash was assumed to be suitable for road construction or as a nutrient resource to be recycled on forest land after biofuel harvesting. Different types of potential environmental impact predominated in the activities of the system and the use of natural resources and the trace element leaching were identified as being relatively important for the scenarios compared. The scenarios differed in use of resources and energy, whereas there is a potential for trace element leaching regardless of how the material is managed. Utilising MSWI bottom ash in road construction and recycling of wood ash on forest land saved more natural resources and energy than when these materials were managed according to the other scenarios investigated, including dumping in landfill. 相似文献
984.
Markus Hengstschläger Dieter Bettelheim Regina Drahonsky Josef Deutinger Gerhard Bernaschek 《黑龙江环境通报》2001,21(6):477-480
Marker chromosomes are supernumerary chromosomes of unknown origin and are seldom found in prenatal diagnosis. Application of fluorescent in situ hybridization (FISH) allows the identification of the chromosomal origin of markers. Estimation of the risk of an abnormal phenotype outcome can be enabled by collecting data on phenotypes associated with markers of the same chromosomal origin. So far only very few cases of prenatal diagnosis of de novo supernumerary markers derived from chromosome 16 have been reported. Here the prenatal diagnosis of a de novo supernumerary marker chromosome 16 is described and the relevant literature discussed. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
985.
986.
987.
Immobilization: A Revolution in Traditional Brewing 总被引:1,自引:0,他引:1
988.
A case of prenatal diagnosis of an overgrowth syndrome at 30 weeks of gestation is reported. The diagnosis was suggested on the basis of increased fetal growth from 16 weeks onwards, advanced bone age, and characteristic facial features such as hypertelorism, broad forehead and small chin. The fetus presented at 12 weeks with a markedly increased nuchal translucency thickness and generalized skin edema, but normal karyotype. Serial ultrasound scans revealed brain abnormalities including mild unilateral ventriculomegaly and a cyst in the cavum septi pellucidi. The pregnancy was terminated at the parents' request at 32 weeks of gestation and postmortem examination confirmed the prenatal findings. This case demonstrates the possibility of prenatal diagnosis of early overgrowth syndromes and highlights the dilemma arising from the prenatal diagnosis of a non-lethal condition associated with an uncertain prognosis and poorly documented in utero. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
989.
990.
Summary Changes in the density of beech scale infestation (Cryptococcus fagisuga) of a mature beech stand (Fagus sylvatica) were investigated after gap-cutting in limed and unlimed areas bordering on the gaps and in untreated areas over a 5-year period. Parallelly the concentrations of sucrose, protein amino acids, and procyanidins were examined in the inner and outer bark of non-infested beech trees and beeches infested by beech scale.Irrespective of liming in the areas bordering on the gaps the proportion of beech trees with increasing beech scale infestation was significantly higher, the proportion of beeches with diminishing infestation was significantly lower than in the untreated control areas. Trees with the same infestation tendency occurred in clusters.Physiological defence reactions in the inner and outer bark of the infested beech trees were registrated as an increase in the procyanidin content and a decrease in the protein amino acid content. A change in the outer bark—inner bark—ratio of the infested beech trees showed a transfer of compounds between the inner and outer bark. During the period of observation long-lasting shifts occurred in the pattern of compounds of the bark irrespective of actual infestation intensity. 相似文献