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401.
Heavy metals in fly ash from municipal solid waste incinerators are present in high concentrations. Therefore fly ash must be treated as a hazardous material. On the other hand, it may be a potential source of heavy metals. Zinc, lead, cadmium, and copper can be relatively easily removed during the thermal treatment of fly ash, e.g. in the form of chlorides. In return, wet extraction methods could provide promising results for these elements including chromium and nickel. The aim of this study was to investigate and compare thermal and hydrometallurgical treatment of municipal solid waste fly ash. Thermal treatment of fly ash was performed in a rotary reactor at temperatures between 950 and 1050 °C and in a muffle oven at temperatures from 500 to 1200 °C. The removal more than 90% was reached by easy volatile heavy metals such as cadmium and lead and also by copper, however at higher temperature in the muffle oven. The alkaline (sodium hydroxide) and acid (sulphuric acid) leaching of the fly ash was carried out while the influence of temperature, time, concentration, and liquid/solid ratio were investigated. The combination of alkaline-acidic leaching enhanced the removal of, namely, zinc, chromium and nickel. 相似文献
402.
Esther del Val Juan Carlos Senar Juan Garrido-Fernández Manuel Jarén Antoni Borràs Josep Cabrera Juan José Negro 《Die Naturwissenschaften》2009,96(7):797-801
Carotenoids may provide numerous health benefits and are also responsible for the integumentary coloration of many bird species.
Despite their importance, many aspects of their metabolism are still poorly known, and even basic issues such as the anatomical
sites of conversion remain controversial. Recent studies suggest that the transformation of carotenoid pigments takes place
directly in the follicles during feather growth, even though the liver has been previously recognised as a storing organ for
these pigments with a certain potential for conversion. In this context, we analysed the carotenoid profile of plasma, liver,
skin and feathers of male Common Crossbills (Loxia curvirostra). Interestingly, the derivative feather pigment 3-hydroxy-echinenone was detected in the liver and in the bloodstream (i.e.
the necessary vehicle to transport metabolites to colourful peripheral tissues). Our results demonstrate for the first time
with empirical data that the liver may act as the main site for the synthesis of integumentary carotenoids. This finding contradicts
previous assumptions and raises the question of possible inter-specific differences in the site of carotenoid conversion in
birds. 相似文献
403.
The primary aim of our research was to investigate the applicability of activated sludge models (ASM) for aerobic thermophilic processes, especially autothermal thermophilic aerobic digestion (ATAD). The ASM3 model (Gujer et al., 1999) theoretically seems to be the most suitable, because storage plays an important role in a batch-feed cycle system like ATAD. The ASM3 model was extended with an activation step of the thermophilic organisms. This model was calibrated and verified by independent test results, demonstrating its ability to describe the process. The growth (microH = 26.04 day(-1)), storage (k(STO) = 20.39 day(-1)), hydrolysis (kH = 11.15 day(-1)) and decay rates (b 9H,O2) = 1.28 day(-1), b(STO,O2 = 1.10 day-1)) obtained from calibration are significantly higher at 55 degrees C than at mesophilic temperatures, justifying the faster metabolism at higher temperatures. An inert fraction of the biomass (characterized by the model parameter f(i) = 0.4) was found to be significantly greater than in the mesophilic case. This can be attributed to the lower diversity of the thermophilic species and thus to their narrower substrate spectra. 相似文献
404.
Martina Mackova Petra Prouzova Petr Stursa Edita Ryslava Ondrej Uhlik Katarina Beranova Jan Rezek Veronika Kurzawova Katerina Demnerova Tomas Macek 《Environmental science and pollution research international》2009,16(7):817-829
Purpose
Polychlorinated biphenyls (PCBs) represent a large group of recalcitrant environmental pollutants, differing in the number of chlorine atoms bound to biphenyl ring. Due to their excellent technological properties, PCBs were used as heat-transfer media, for filling transformers and condensers, as paint additives, etc. With increasing knowledge of their toxicity, transfer to food chains and accumulation in living organisms, their production ended in most countries in the 1970s and in 1984 in the former Czechoslovakia. But even a quarter of century after the PCB production ceased, from contaminated areas, the volatile PCBs evaporate and contaminate much larger areas even at very distant parts of the world. For this reason, PCBs still represent a global problem. The main method of PCB removal from contaminated environment is at present the expensive incineration at high temperatures. With the aim of finding effective alternative approaches, we are studying biological methods for PCB removal from the environment. In this paper, we summarise 10 years of studies using long-term PCB-contaminated soil from a dumpsite in South Bohemia, targeted for the use of plants (phytoremediation) and their cooperation with microorganisms in the root zone (rhizoremediation). 相似文献405.
406.
Summary. We investigated the hypothesis that aggregation signals produced by male webbing clothes moths (WCM), Tineola bisselliella (Hum.) (Lepidoptera: Tineidae), and close-range male attractant signals produced by females have a pheromonal basis, at least
in part. Gas chromatographic-electroantennographic detection (GC-EAD) and GC-mass spectrometric analyses of bioactive methanolic
extracts of male WCM disclosed three candidate pheromone components: hexadecanoic acid methyl ester (16:Ester), (Z)-9-hexadecenoic acid methyl ester (Z9—16:Ester), and octadecanoic acid methyl ester (18:Ester). In bioassay experiments in a large Plexiglas™ arena, a blend of
synthetic 16:Ester plus Z9—16:Ester was attractive to male and virgin (but not mated) female WCM; the 18:Ester was inactive.
GC-EAD analyses of pheromone gland extracts from female WCM revealed (E,Z)-2,13-octadecadienal (E2Z13—18:Ald) and (E,Z)-2,13-octadecadienol (E2Z13—18:OH) as candidate sex pheromone components. In arena bioassay experiments, 1—5 female equivalents of synthetic E2Z13—18:Ald (0.2 ng) and E2Z13—18:OH (0.1 ng) were more attractive to male WCM than were two virgin female WCM. We anticipate that the combination of
aggregation and sex pheromones, male-produced sonic aggregation signals, and habitat-derived semiochemicals will be highly
effective in attracting male and female WCM to commercial traps.
Received 12 January 2001; accepted 8 June 2001. 相似文献
407.
Dynamic Games in the Economics and Management of Pollution 总被引:1,自引:0,他引:1
Steffen Jørgensen Guiomar Martín-Herrán Georges Zaccour 《Environmental Modeling and Assessment》2010,15(6):433-467
The paper provides a survey of the literature which utilizes dynamic state-space games to formulate and analyze intertemporal,
many decision-maker problems in the economics and management of pollution. 相似文献
408.
R. Ballesteros J.J. Hernández L.L. Lyons 《Atmospheric environment (Oxford, England : 1994)》2010,44(7):930-938
The chemical speciation of the 16 polycyclic aromatic hydrocarbons associated to the particulate matter of conventional diesel fuel, rapeseed methyl esters, waste cooking oil methyl esters, waste cooking oil ethyl esters and their conventional fuel blends has been carried out. The speciation of these individual compounds was made by a combination of thermal extraction, solid phase micro-extraction and GC/MS analysis. This PAH speciation method was applied to a real samples obtained from a diesel engine under two different operating modes, urban and extraurban modes. The purpose of this work was to study the relationship between the amount, type and carcinogenic potency of polycyclic aromatic hydrocarbons in engine emissions and the multi-component biodiesel fuel composition. 相似文献
409.
Ariel Fernández 《Die Naturwissenschaften》1989,76(2):69-71
Helpful advice and discussions with Prof. M. Eigen are gratefully acknowledged. A conversation with Dr. Chr. Biebricher proved most useful. 相似文献
410.
Otávio José de Oliveira Camila Roberta Muniz Serra Pinheiro 《Journal of Cleaner Production》2009,17(9):883-885
Among the difficulties found in the implementation of ISO 14001 systems, resistance to change can always be found. It is mainly a consequence of the hurry to change, loss of focus, concentration of decision making at the level of top management, arbitrary imposition of objectives and results, faulty communication, and the absence of motivational and financial incentive for change.Therefore, the main objective of this paper is to present best practices with respect to the management of organizational change due to the implementation of ISO 14001 norms in two industrial companies in the Midwest region of the State of São Paulo – Brazil. 相似文献