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301.
Annual trends of a group of 66 volatile organic compounds (VOCs), containing 20 ozone precursors, were the aim of a sampling campaign carried out for a year in air at urban and industrial areas from Tarragona region. VOCs were determined by active collection on multisorbent tubes, followed by thermal desorption and gas chromatography–mass spectrometry. The analytical method was developed and validated, showing good levels of detection and quantification, recoveries, precision, and linearity for all the compounds in the range being studied. All the industrial and urban samples taken during the sampling campaign were similar in their qualitative composition. The most abundant compound in all urban and industrial sites was i-pentane, with concentrations between 15.2 and 202.1 μg m???3 in urban sites and between 1.3 and 98.6 μg m???3 in industrial sites. In urban sites, the following compounds in order of abundance were toluene, n-pentane, m,p-xylene, and o-xylene, with maximum levels of 150.6, 45.8, 42.3, and 31.7 μg m???3, respectively. In industrial sites, the most abundant compounds depended on the sampled site.  相似文献   
302.
Land cover mapping of the tropical savanna region in Brazil   总被引:1,自引:0,他引:1  
The Brazilian tropical savanna (Cerrado), encompassing more than 204 million hectares in the central part of the country, is the second richest biome in Brazil in terms of biodiversity and presents high land use pressure. The objective of this study was to map the land cover of the Cerrado biome based on the segmentation and visual interpretation of 170 Landsat Enhanced Thematic Mapper Plus satellite scenes acquired in 2002. The following land cover classes were discriminated: grasslands, shrublands, forestlands, croplands, pasturelands, reforestations, urban areas, and mining areas. The results showed that the remnant natural vegetation is still covering about 61% of the biome, however, on a highly asymmetrical basis. While natural physiognomies comprise 90% of the northern part of the biome, only 15% are left in its southern portions. Shrublands were the dominant natural land cover class, while pasturelands were the dominant land use class in the Cerrado biome. The final Cerrado’s land cover map confirmed the intensive land use pressure in this unique biome. This paper also showed that Landsat-like sensors can provide feasible land cover maps of Cerrado, although ancillary data are required to help image interpretation.  相似文献   
303.
An equation to estimate Hg concentrations of <4 μg/L in groundwaters of a polluted area in NE Italy was set out by using transplants of the aquatic moss Rhynchostegium riparioides as trace element bioaccumulators. The equation is derived from a previous mathematical model which was implemented under laboratory conditions. The work aimed at (1) checking the compliance of the uptake kinetics with the model, (2) improving/adapting the model for groundwater monitoring, (3) comparing the performances of two populations of moss collected from different sites, and (4) assessing the environmental impact of Hg contamination on a small river. The main factors affecting Hg uptake in the field were—as expected—water concentration and time of exposure, even though the uptake kinetics in the field were slightly different from those which were previously observed in the lab, since the redox environmental conditions influence the solubility of cationic Fe, which is a negative competitor of Hg2+. The equation was improved by including the variable ‘dissolved oxygen concentration’. A numerical parameter depending on the moss collection site was also provided, since the differences in uptake efficiency were observed between the two populations tested. Predicted Hg concentrations well fitted the values measured in situ (approximately ±50 %), while a notable underestimation was observed when the equation was used to predict Hg concentration in a neighbouring river (?96 %), probably due to the organic pollution which hampers metal uptake by mosses.  相似文献   
304.
The planetary importance of microbial function requires urgently that our knowledge and our exploitation ability is extended, therefore every occasion of bioprospecting is welcome. In this work, bioprospecting is presented from the perspective of the UMBRELLA project, whose main goal was to develop an integral approach for remediation of soil influenced by mining activity, by using microorganisms in association with plants. Accordingly, this work relies on the cultivable fraction of microbial biodiversity, native to six mining sites across Europe, different for geographical, climatic and geochemical characteristics but similar for suffering from chronic stress. The comparative analysis of the soil functional diversity, resulting from the metabolic profiling at community level (BIOLOG ECOPlates) and confirmed by the multivariate analysis, separates the six soils in two clusters, identifying soils characterised by low functional diversity and low metabolic activity. The microbial biodiversity falls into four major bacterial phyla: Actinobacteria, Proteobacteria, Firmicutes and Bacteroidetes, including a total of 47 genera and 99 species. In each soil, despite harsh conditions, metabolic capacity of nitrogen fixation and plant growth promotion were quite widespread, and most of the strains showed multiple resistances to heavy metals. At species-level, Shannon’s index (alpha diversity) and Sørensen's Similarity (beta diversity) indicates the sites are indeed diverse. Multivariate analysis of soil chemical factors and biodiversity identifies for each soil well-discriminating chemical factors and species, supporting the assumption that cultured biodiversity from the six mining sites presents, at phylum level, a convergence correlated to soil factors rather than to geographical factors while, at species level, reflects a remarkable local characterisation.  相似文献   
305.
Effective integrated water resources management (IWRM) and developments impacting on water resources are recognized as key components of environmentally sustainable development. Istanbul (Turkey) is a very large metropolitan city with a population of approximately 14 million. Istanbul is one of the 23 megacities (metropolitan areas with a population of more than 10 million) in the world and one of the most rapidly growing cities in Europe. The annual population growth is 2.8 %. The population growth in the city is almost twice the overall rate of the whole of Turkey, because of a large in-migration. The present study is a baseline assessment of IWRM of Istanbul and also provides a critical review of Istanbul’s future challenges. The assessment is part of an action on water governance (City Blueprints) in the context of the European Innovation Partnership on Water of the European Commission. The City Blueprint indicator approach and process have been applied as first step of gaining a better understanding of IWRM and the challenges ahead. This is done by using well-established and high-quality data sets, a relatively cost-effective online survey and a relatively simple questionnaire. Istanbul has set a good example to the challenges faced in water supply in megacities, where illegal settlements on watershed zones posed a threat to scarce water resources. Despite these enormous efforts, the projected future population growth and climate change in Istanbul will necessitate further major transitions towards sustainable IWRM. This holds for all aspects of the water cycle: water quality, water quantity, water supply and sanitation, coping with extreme weather events (floods and droughts), as well as for the protection of the sources of water, i.e. ecosystem conservation. Istanbul is a place where problems emerge and solutions need to be found. The time window available to do this is rapidly closing. As such, this review of IWRM of Istanbul confirms the conclusions of the World Economic Forum that water supply is one of the top three global risks for both the impact and likelihood. Our framework has been applied for nearly 40 cities, and the results for Istanbul are discussed in the broader context of recent initiatives on water governance and smart cities by the European Commission.  相似文献   
306.
The purpose of this article is to analyze the possible effects of job satisfaction on mental and physical health, happiness, subjective well-being and self-esteem. A total of 971 Portuguese-speaking adults participated in this study. Most participants reported high rates of satisfaction with their colleagues, the nature of their work and leadership, while reporting dissatisfaction with regard to salaries and promotions. Results indicated the existence of the protector effect of job satisfaction for health, happiness, subjective well-being and self-esteem, in addition to reinforcing the importance of maintaining a positive evaluation of one’s work. As a practical implication, the results may suggest that the effects of personnel management policies which emphasize job satisfaction could potentially lead to improvements in levels of health, happiness, subjective well-being and workers’ self-esteem, all of which are factors that can potentially improve organizational performance. The study also considered its limitations and the possibility for future investigation.  相似文献   
307.
Companies need to follow environmental laws as they affect their manufacturing systems, waste handling, and the management of soil on their properties to ensure that their properties are either improved or altered as little as possible. Thus, the objective of this study was to evaluate the use of energy dispersive X‐ray fluorescence spectrometry (EDXRF) to determine the concentrations of elements present in the soil at a manufacturer of products based on fiberglass where wastes from production activities have been deposited on the property.  相似文献   
308.
The purpose of this work was to study the efficiency of different treatments, based on the combination of O3, H2O2, and TiO2, on fresh surface water samples fortified with wild strains of Escherichia coli. Moreover, an exhaustive assessment of the influence of the different agents involved in the treatment has been carried out by kinetic modeling of E. coli inactivation results. The treatments studied were (i) ozonation (O3), (ii) the peroxone system (O3/0.04 mM H2O2), (iii) catalytic ozonation (O3/1 g/L TiO2), and (iv) a combined treatment of O3/1 g/L TiO2/0.04 mM H2O2. It was observed that the peroxone system achieved the highest levels of inactivation of E. coli, around 6.80 log after 10 min of contact time. Catalytic ozonation also obtained high levels of inactivation in a short period of time, reaching 6.22 log in 10 min. Both treatments, the peroxone system (O3/H2O2) and catalytic ozonation (O3/TiO2), produced a higher inactivation rate of E. coli than ozonation (4.97 log after 10 min). While the combination of ozone with hydrogen peroxide or titanium dioxide thus produces an increase in the inactivation yield of E. coli regarding ozonation, the O3/TiO2/H2O2 combination did not enhance the inactivation results. The fitting of experimental values to the corresponding equations through non-linear regression techniques was carried out with Microsoft® Excel GInaFiT software. The inactivation results of E. coli did not respond to linear functions, and it was necessary to use mathematical models able to describe certain deviations in the bacterial inactivation processes. In this case, the inactivation results fit with mathematical models based on the hypothesis that the bacteria population is divided into two different subgroups with different degrees of resistance to treatments, for instance biphasic and biphasic with shoulder models.
Graphical abstract ?
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309.

Background, aim, and scope  

Freshwater reservoirs can be impacted by several hazardous substances through inputs from agricultural activity, sewage discharges, and groundwater leaching and runoff. The water quality assessment is very important for implementation of the monitoring and remediation programs to minimize the risk promoted by hazardous substances in aquatic ecosystems. Evaluation of the degree of contamination of aquatic environments must not take in account only its chemical characterization but it must be complemented with biological assays, which determine potential toxic effects and allows an integrated evaluation of its effects in populations and aquatic ecosystem communities. The application of this type of strategy has clear advantages allowing a general evaluation of the effects from all the water components, including those due to unknown substances and synergic, antagonistic, or additive effects. There are only a few studies that reported ecotoxicological acute end points, for the assessment of surface water quality, and the relationship among toxicity results and the anthropogenic pollution sources and the seasonal period. The aim of this study was to assess the ecotoxicological characterization of the surface water from Alqueva reservoir (South of Portugal) and to evaluate the influence of anthropogenic sources of pollution and their seasonal variation in its toxicity. The construction of Alqueva reservoir was recently finished (2002) and, to our knowledge, an ecotoxicological assessment of its surface water has not been performed. Because of that, no information is available on the possible impact of pollutants on the biota. The surface water toxicity was assessed using acute and chronic bioassays. The results are to be used for developing a monitoring program, including biological methods.  相似文献   
310.
This paper discusses the results of biodegradability tests of natural fibers used by the automotive industry, namely: coir, coir with latex, and sisal. The biodegradation of coir, coir with latex, and of sisal fibers was determined by monitoring the production of carbon dioxide (CO2) (IBAMA—E.1.1.2, 1988) and fungal growth (DIN 53739, 1984). The contents of total extractives, lignin, holocellulose, ashes, carbon, nitrogen and hydrogen of the fibers under study were determined in order to ascertain their actual content and to understand the results of the biodegradation tests. The production of CO2 indicated low biodegradation, i.e., about 10% in mass, for all the materials after 45 days of testing; in other words, no material inhibited glucose degradation. However, the percentage of sisal fiber degradation was fourfold higher than that of coir with latex in the same period of aging. The fungal growth test showed a higher growth rate on sisal fibers, followed by coir without latex. In the case of coir with latex, we believe the fungal growth was not intense, because natural latex produces a bactericide or fungicide for its preservation during bleeding [1]. An evaluation of the materials after 90 days of aging tests revealed breaking of the fibers, particularly sisal and coir without latex, indicating fungal attack and biodegradation processes.  相似文献   
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