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151.
Santos MA  Pacheco M  Ahmad I 《Chemosphere》2006,63(5):794-801
The effect of bleached kraft pulp mill effluent (BKPME) persistent compounds on phagocyte activities and its organ-specific influence in gill, kidney and liver was studied in European eel (Anguilla anguilla L.). Eels were caged and plunged at 3 different sites-50 m (site 1), 100 m (site 2) and 2,000 m (site 3) away from the end of the closed BKPME discharging channel for 8 and 48 h. Gill, head kidney and peritoneum phagocytes oxidative burst activity (OBA) was measured by the nitroblue tetrazolium reduction assay whereas lipid peroxidation (LPO) in eel gill, kidney and liver was measured by thiobarbituric acid reaction. A significant gill OBA induction was found at 8h on site 2, and on sites 1, 2 and 3 at 48 h exposure. However, in head kidney and peritoneal exudate phagocytes, OBA induction was significant only at sites 2 and 3 after 48 h exposure. In those particular sites, a significant increase in gill, kidney and liver LPO was measured that is assumed to result from OBA induction. Considering OBA and LPO, gill is the most affected tissue compared to kidney and liver. Gill vulnerability towards peroxidative damage was demonstrated at 8h on site 2 and at 48 h on sites 1, 2 and 3, whereas in kidney was observed at sites 2 and 3 only at 48 h. Liver LPO increased at site 2 only after 48 h exposure. Our results demonstrate that the OBA activation pattern in gill and kidney is associated with the induced peroxidative damage extent in those organ, together with water pollution the exposure route, resulting from previous BKPME effluent sediment contamination which may affect the activation pattern of circulating fish phagocytes.  相似文献   
152.
The successful application of electrochemical technology, employing a dimensionally stable anode (DSA((R))), for the remediation of wastewater from the oil extraction industry has been demonstrated. Samples from the oil-water separation box of an effluent treatment plant were submitted to voltammetry, chronoamperometry and electrolysis studies using a DSA anode of nominal composition Ti/Ru(0.34)Ti(0.66)O(2). Electrolysis of the oily wastewater lead to a time-dependent reduction in chemical oxygen demand (COD) in the sample that could be attributed to: (i) the direct oxidation of oil components at the electrode, by the metal oxide itself or by OH() radicals available at the electrode surface, (ii) the indirect oxidation of oil components by intermediate oxidising agents formed in parallel reactions (ex. ClO(-)), and (iii) the aggregation of suspended oil droplets by electroflotation. The largest reduction (57%) in COD was obtained following electrolysis of an oily sample for 70 h at 50 degrees C with a current density of 100 mA cm(-2). The stability of DSA electrodes for use in oily wastewater remediation has been assessed.  相似文献   
153.
Gravato C  Teles M  Oliveira M  Santos MA 《Chemosphere》2006,65(10):1821-1830
Fish are exposed in the aquatic ecosystems to different classes of pollutants. Polycyclic aromatic hydrocarbons (PAHs) and heavy metals represent two important classes of aquatic contaminants. Thus, one lot of European eels (Anguilla anguilla L.) was pre-exposed during 24 h to 2.7 microM beta-naphthoflavone (BNF; a PAH-like compound), and subsequently exposed during 24 h to 0, 1 and 2.5 microM copper (Cu). Additionally, another lot not pre-exposed to BNF was exposed to the same Cu concentrations. BNF pre-exposure promoted a significant increase in liver ethoxyresorufin O-deethylase (EROD) activity, but did not change the other responses investigated in eels. On the other hand, both Cu concentrations did not modify the liver EROD activity either in eels pre-exposed to BNF or not. Liver total cytochrome P450 was increased in eels exposed to Cu 2.5 microM, being significantly only in eels not pre-exposed to BNF. Free sulfhydryl group content was decreased by 1 and 2.5 microM in eels pre-exposed to BNF or not pre-exposed, being significant at 2.5 microM Cu in eels not pre-exposed compared to its control. Liver total glutathione (TG), reduced glutathione (GSH) and GSH/oxidized glutathione (GSSG) levels were slightly decreased by 1 and 2.5 microM Cu in eels pre-exposed to BNF, whereas a slight tendency to increase was observed in eels not pre-exposed. Thus, liver TG and GSH significantly decreased in 2.5 microM Cu BNF pre-exposed eels compared to eels not pre-exposed to BNF. Liver glutathione reductase and catalase activities were significantly inhibited by 1 and 2.5 microM Cu in eels pre-exposed to BNF, concomitantly with a slight liver glutathione peroxidase tendency to decrease. Lipid peroxidation was significantly increased by 1 microM Cu in eels either pre-exposed or not pre-exposed to BNF. Liver H(2)O(2) was significantly increased by 1 microM Cu in eels pre-exposed to BNF. Liver DNA integrity was significantly decreased by 1 and 2.5 microM Cu in eels pre-exposed to BNF. The oxidative stress and genotoxic effects induced by Cu in eels pre-exposed to BNF revealed that the metal effects are potentiated by previous exposure to BNF.  相似文献   
154.
This paper provides the first quantitative information on mercury in soil, coastal sediment, and in characteristic organisms of terrestrial and shallow coastal marine ecosystems from Admiralty Bay (King George Island, Antarctica). As expected for a remote area, mercury content is low in abiotic components of the ecosystem, and probably similar to natural levels. Mercury also occurs in very low concentrations in the vegetation, invertebrates and fish. These low mercury levels may be due to sulphide formation in reducing sediments of this environment. Higher concentrations of mercury occurred in bird feathers and mammal hair, indicating biomagnification. This was not found for Zinc. These results may be useful as a reference background to detect future inputs of trace elements in this remote area of the earth. Terrestrial vegetation and bird feathers are suggested as target regional biomonitors.  相似文献   
155.
The concentration of biogenic amines and free amino acids was studied in 102 Portuguese wines and 18 musts from Alentejo demarcated (D.O.C.) regions. Most wines were commercial, except for 38 monovarietals obtained by micro vinification. Musts from the varieties used to produce the latter wines were also studied. Both biogenic amines and free amino acids were analyzed by HPLC using fluorescence detection for their o-phthalaldehyde/fluorenylmethyl chloroformate (OPA/FMOC) derivatives. The most significant amines (average 10.8 mg/L for histamine+tyramine in red, and 7.4 mg/L for white wines) were found to be present at low levels and, although no important relationship between each individual biogenic amine could be obtained, the total amine content depends significantly on the assimilable amino acid content in wine.  相似文献   
156.
Nowadays, the world faces unprecedented challenges in social, environmental and economical dimensions, in which the industrial design has showed an important contribution with solutions that provide positive answers regarding these problems. In particular, due to its relevance, the automotive industry confronts a moment of crises, and based on the ecodesign of products it has been transforming the challenges in opportunities. In this context, the use of natural fiber composites, produced in developing countries, have presented several social, environmental and economical advantages to design “green” automotive components. Thus, this work through LCA method demonstrates the possibility to use natural fibers through a case study design which investigates the environmental improvements related to the replacement of glass fibers for natural jute fibers, to produce a structural frontal bonnet of an off-road vehicle (Buggy). Results pointed out the advantages of applying jute fiber composites in Buggy enclosures.  相似文献   
157.
This study aimed to assess the influence of excess iron on the capacity of accumulation of this heavy metal, mineral composition, and growth of Setaria parviflora and Paspalum urvillei. Seedlings were submitted to 0.009; 1; 2; 4; and 7 mM of Fe-EDTA. In both species there was an increase in the concentration of Fe, Zn, P, and Ca and a decrease in Mn, K, and Mg in the iron plaque. Both species accumulated more iron in roots. In the shoots, S. parviflora showed higher iron content, except at 7 mM. Iron altered the contents of Fe, Cu, K, and Mg in roots, and of Fe, Mn, Zn, N, P, K, Ca, and Mg in shoots. The two species tolerated high iron concentrations and accumulated high content of this element in both shoots and roots. The iron did not reduce their growth. Both species are indicated for studies aiming restoration of iron-contaminated areas.  相似文献   
158.

We report a small hawk-like diurnal bird from the early Oligocene (30–31 million years ago) of Poland. Aviraptor longicrus, n. gen. et sp. is of a size comparable with the smallest extant Accipitridae. The new species is characterized by very long legs, which, together with the small size, suggest an avivorous (bird-eating) feeding behavior. Overall, the new species resembles extant sparrowhawks (Accipiter spp.) in the length proportions of the major limb bones, even though some features indicate that it convergently acquired an Accipiter-like morphology. Most specialized avivores amongst extant accipitrids belong to the taxon Accipiter and predominantly predate small forest passerines; the smallest Accipiter species also hunts hummingbirds. Occurrence of a possibly avivorous raptor in the early Oligocene of Europe is particularly notable because A. longicrus coexisted with the earliest Northern Hemispheric passerines and modern-type hummingbirds. We therefore hypothesize that the diversification of these birds towards the early Oligocene may have triggered the evolution of small-sized avivorous raptors, and the new fossil may exemplify one of the earliest examples of avian predator/prey coevolution.

  相似文献   
159.
An important alternative for sustainable use of tucunaré stocks and improvement in fishermen welfare in Balbina reservoir, Central Amazon, would be to train commercial fisherman to also become tourist guides for sport fishing. In this study, we modeled fishermen response to this question, in order to evaluate the acceptance of such an idea. Thus, we surveyed 47 fishermen, who currently comprise approximately 75% of the total fishermen population. This survey was implemented during December of 2001 and January of 2002. We used a probity analysis to run two models. The first model includes the variables: family size, school level, fishing time, residence time and boat ownership. On the other hand, the second model includes the number of children under and above eight years old but not the family size. Both models are significant and the most relevant variables are: fishing time (years of participation of fisherman is in the activity) and residence time (length of residency of particular fishermen live at the village nearby the reservoir).  相似文献   
160.
This paper is focused on novel utilizations of raw materials and technologies for manufacturing lightweight metallic reservoirs. The objective is to develop an environmental friendly technology for producing gas and liquid storage reservoirs that ensures a more efficient utilization of raw materials and a better end-of-life management of products than other technologies currently used to fabricate metallic reservoirs.The proposed technology utilizes previously engineered single-stage nosing of thin-walled tubes using sacrificial (expendable) mandrels to develop a multi-stage process that makes use of recyclable mandrels for producing lightweight, axisymmetric, seamless reservoirs. Recyclable mandrels are cast from low melting point alloys, possess the ability to continuously adapt its shape to that of the preforms and are easily removed by melting, while leaving the reservoir intact, at the end of the process.The prospects for eliminating the welding routes commonly used in the fabrication of reservoirs and for remelting and recycling the mandrels, results in significant economic and time savings and offers potential for opening new markets for the production of low-cost seamless reservoirs.The presentation is supported by experimentation and numerical modelling based on independently determined mechanical properties of the materials with the purpose of understanding the deformation mechanics and identifying the major operating parameters of the proposed technology.  相似文献   
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