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491.
This article deals comprehensively with factors which influence attitudes to the placement of high-voltage overhead transmission lines (HVOTLs). It employs an analytical schema which links the initial stimulus of the power lines' proposal in an area to Background and Socio-economic independent variables and a set of mediating variables. From a survey of 600 residents in three different domiciliary settings in Queensland, Australia, results indicate an absence of positive attitudes and, at best, neutral ones to HVOTL placement. By multinomial logistic regression, the study probes the grounds behind negativity and extreme negativity, uncovering direct links between these attitudes and certain of the variables included in the analytical schema.  相似文献   
492.
We present a multi-model ensemble study for the Baltic Sea, and investigate the combined impact of changing climate, external nutrient supply, and fisheries on the marine ecosystem. The applied regional climate system model contains state-of-the-art component models for the atmosphere, sea ice, ocean, land surface, terrestrial and marine biogeochemistry, and marine food-web. Time-dependent scenario simulations for the period 1960–2100 are performed and uncertainties of future projections are estimated. In addition, reconstructions since 1850 are carried out to evaluate the models sensitivity to external stressors on long time scales. Information from scenario simulations are used to support decision-makers and stakeholders and to raise awareness of climate change, environmental problems, and possible abatement strategies among the general public using geovisualization. It is concluded that the study results are relevant for the Baltic Sea Action Plan of the Helsinki Commission.  相似文献   
493.
Indoor plants can remove volatile organic compounds (VOCs) from the air. The majority of knowledge comes from laboratory studies where results cannot directly be transferred to real-life settings. The aim of this study was to develop an experimental test system to assess VOC removal by indoor plants which allows for an improved real-life simulation. Parameters such as relative humidity, air exchange rate and VOC concentration are controlled and can be varied to simulate different real-life settings. For example, toluene diffusion through a needle gave concentrations in the range of 0.10–2.35 μg/L with deviations from theoretical values of 3.2–10.5 %. Overall, the system proved to be functional for the assessment of VOC removal by indoor plants with Hedera helix reaching a toluene removal rate of up to 66.5 μg/m2/h. The mode of toluene exposure (semi-dynamic or dynamic) had a significant influence on the removal rate obtained by H. helix.  相似文献   
494.
Connectivity is key for understanding how ecological systems respond to the challenges of land-use change and habitat fragmentation. Structural and functional connectivity are both established concepts in ecology, but the temporal component of connectivity deserves more attention. Whereas functional connectivity is often associated with spatial patterns (spatial functional connectivity), temporal functional connectivity relates to the persistence of organisms in time, in the same place. Both temporal and spatial processes determine biodiversity responses to changes in landscape structure, and it is therefore necessary that all aspects of connectivity are considered together. In this perspective, we use a case study to outline why we believe that both the spatial and temporal components of functional connectivity are important for understanding biodiversity patterns in the present-day landscape, and how they can also help us to make better-informed decisions about conserving and restoring landscapes and improving resilience to future change.  相似文献   
495.
In regions with high livestock densities, the usage of antibiotics and metals for veterinary purposes or as growth promoters poses a risk in manured soils. We investigated to which degree the concentrations and depth distributions of Cu, Zn, Cr and As could be used as a tracer to discover contaminations with sulfonamides, tetracyclines and fluoroquinolones. Besides, we estimated the potential vertical translocation of antibiotics and compared the results to measured data. In the peri-urban region of Beijing, China, soil was sampled from agricultural fields and a dry riverbed contaminated by organic waste disposal. The antibiotic concentrations reached 110 μg kg?1 sulfamethazine, 111 μg kg?1 chlortetracycline and 62 μg kg?1 enrofloxacin in the topsoil of agricultural fields. Intriguingly, total concentrations of Cu, Zn, Cr and As were smaller than 65, 130, 36 and 10 mg kg?1 in surface soil, respectively, therewith fulfilling Chinese quality standards. Correlations between sulfamethazine concentrations and Cu or Zn suggest that in regions with high manure applications, one might use the frequently existing monitoring data for metals to identify potential pollution hotspots for antibiotics in topsoils. In the subsoils, we found sulfamethazine down to ≥2 m depth on agricultural sites and down to ≥4 m depth in the riverbed. As no translocation of metals was observed, subsoil antibiotic contamination could not be predicted from metal data. Nevertheless, sulfonamide stocks in the subsoil could be estimated with an accuracy of 35–200 % from fertilisation data and potential leaching rates. While this may not be sufficient for precise prediction of antibiotic exposure, it may very well be useful for the pre-identification of risk hotspots for subsequent in-depth assessment studies.  相似文献   
496.
The study was designed to investigate the content and distribution of selected heavy metals (As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Fe, Pb and Zn) in samples of fruticose macrolichen Usnea antarctica from James Ross Island. A special emphasis was devoted to mercury and its species (elemental mercury and methylmercury). It was found that mercury contents were relatively high (up to 2.73 mg kg?1 dry weight) compared to other parts of the Antarctic Peninsula region, while the concentrations of most other elements were within reported ranges. Mercury contents in lichens originating from the interior were higher than those from the coast, which is probably the result of local microclimate conditions. Similar trends were observed for Hg0 and MeHg+, whose contents were up to 0.14 and 0.098 mg kg?1 dry weight, respectively. While mercury did not show a significant correlation with any other element, the mutual correlation of some litophile elements probably refers to the influence on thalli of resuspended weathered material. The influence of habitat and environmental conditions could play an essential role in the bioaccumulation of contaminants rather than just the simple presence of sources. Thus, the study of the thalli of this species can bring a new perspective on the interpretation of contaminant accumulation in lichens of the polar region.  相似文献   
497.
The purpose of the present study was to find out the sources of mercury and arsenic pollution of water in the industrial area of Peshawar, the capital of Khyber Pakhtunkhwa, Pakistan. Samples of effluents, mud, and water were collected from the target area (industrial area of Peshawar), the area of water supply source, and from the less polluted area, the Lower Dir district, as the control. Hg was determined by the cold vapor generation technique, while arsenic was determined using the electrothermal atomic absorption technique. Data of the water from the industrial area were compared with that of the source area, control area, as well as with the WHO and some international drinking water quality standards. The results show that some parameters, i.e., TDS, DO, pH, and hardness, were more than the permissible limits. Textile and glass industries were found to be the major sources of Hg and As pollution. Downstream dilution of these contaminants was also observed.  相似文献   
498.
The area of the Black Triangle has been exposed to extreme levels of acid deposition in the twentieth century. The chemical weathering of sandstones found within the Black Triangle became well-known phenomenon. Infiltration of acid rain solutions into the sandstone represents the main input of salt components into the sandstone. The infiltrated solutions–sandstone percolates–react with sandstone matrix and previously deposited materials such as salt efflorescence. Acidic sandstone percolates pH?3.2–4.8 found at ten sites within the National Park Bohemian Switzerland contained high Al-tot (0.8–10 mg?L?1) concentrations and high concentrations of anions SO4 (5–66 mg?L?1) and NO3 (2–42 mg?L?1). A high proportion (50–98 %) of Al-tot concentration in acid percolates was represented by toxic reactive Aln+. Chemical equilibrium modeling indicated as the most abundant Al species Al3+, AlSO4 +, and AlF2+. The remaining 2–50 % of Al-tot concentration was present in the form of complexes with dissolved organic matter Al-org. Mobilization and transport of Al from the upper zones of sandstone causes chemical weathering and sandstone structure deterioration. The most acidic percolates contained the highest concentrations of dissolved organic material (estimated up to 42 mg?L?1) suggesting the contribution of vegetation on sandstone weathering processes. Very low concentrations of Al-tot in springs at BSNP suggest that Al mobilized in unsaturated zone is transported deeper into the sandstone. This process of mobilization could represent a threat for the water quality small-perched aquifers.  相似文献   
499.
Impacts of urbanization on aquatic ecosystems are intensifying as urban sprawl spreads across the global land base. The urban stream syndrome (USS) identifies “symptoms” associated with urban development including changes in biotic communities, hydrology, water chemistry, and channel morphology. Direct relationships between road density (as surrogate of urbanization) and indicators of the USS were identified for streams in the Toronto region. Significant negative relationships were revealed between road density and biological (fish and benthic macroinvertebrate) richness, diversity, and fish Index of Biotic Integrity scores. Significant positive relationships were found between road density and tolerant fish/benthic macroinvertbrates, benthos Family Biotic Index scores, mean summer stream temperature, stream flashiness, and several water quality variables. Analysis of biological data showed that only four fish species and a reduced number of benthic macroinvertebrate families remained at the most urbanized sites. Road density was found to be a major determinant in both the fish and benthic macroinvertebrate community structure.  相似文献   
500.
The aim of this study is to summarise the determination of concentrations of microcystins (MCs) in muscle and liver of freshwater fish species caught in stagnant waters of the Czech Republic. Within the years 2007–2009, 351 muscle samples and 291 liver samples of 16 freshwater fish species derived from four fishponds, and four water reservoirs were analysed. MCs were detected in 53 liver samples. The highest concentrations of microcystins were determined in liver samples of carnivorous fish species; 50.3 ng/g of fresh weight (FW) in perch (Perca fluviatilis) and 22.7 ng/g FW in pikeperch (Sander lucioperca). MCs in liver were detected in other five fish species; asp (Aspius aspius), pike (Esox lucius), common carp (Cyprinus carpio), grass carp (Ctenopharyngodon idella) and European eel (Anguilla anguilla). Concentrations of MCs in liver of nine fish species (European bream, whitefish, tench, silver carp, European catfish, roach, chub, crucian carp and rudd) were below the detection limit of 1.2–5.4 ng/g FW for different MC congeners. However, the concentrations of MCs in all muscle samples were below the detection limit. The assessment of MCs concentrations might be influenced by the detection method used. Due to the concentrations of MCs being below the detection limit in muscle samples of all fish species analysed, it seems that there might be a low potential threat for human health in case of fish muscle consumption.  相似文献   
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