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251.
Policy indicators applied at a national scale can have considerable financial impact for resource allocations to individual counties, especially if there are extreme local factors. This article develops arid explores a new measure of population dispersal and sparsity and discusses the impact of this indicator in a variety of locations, by using GIS techniques.  相似文献   
252.
This paper describes the recent economic history of the Scottish economy and uses a synthesised theory of labour market segmentation and the dual economy to identify the origins of the relative decline of Scottish industry and labour over the period, critically evaluating the role of the SDA and of government policy in general. Incorporating the impacts of takeover and merger of indigenous companies, the promotion of the branch plant economy, the selective effects of emigration and training schemes, and the reliance on small and medium sized companies to regenerate the economies of city‐regions, an analysis based on the importance of the centre‐periphery relations of monopoly capitalism for the Scottish economy is undertaken.  相似文献   
253.
The promotion of renewable energy during the last decade did not result in widescale application of the technology. In many cases, technologies were promoted before they were commercially viable or were inappropriately selected for the particular end-use application. In other cases, a lack of local technical expertise and support infrastructure was absent to sustain the technology once it had been placed in the field. There was also a loss of donor interest and funding for renewables concomitant with the decline in oil prices. This paper attempts to summarize lessons learned from this decade of experience with renewable energy and to offer criteria and suggestions for future activities in transferring renewable energy technology.  相似文献   
254.
The physical and chemical qualities of the process effluent and the tailings dam wastewater of AngloGold-Ashanti Limited, a gold mining company in Ghana, were studied from June to September, 2010. The process effluent from the gold extraction plant contains high amounts of suspended solids and is therefore highly turbid. Arsenic, copper and cyanide were identified as the major pollutants in the process effluent with average concentrations of 10.0, 3.1 and 21.6 mg?L?1, respectively. Arsenic, copper, iron and free cyanide (CN?) concentrations in the process effluent exceeded the Ghana EPA discharge limits; therefore, it is necessary to treat the process effluent before it can be discharged into the environment. Principal component analysis of the data indicated that the process effluent characteristics were influenced by the gold extraction process as well as the nature of the gold-bearing ore processed. No significant correlation was observed between the wastewater characteristics themselves, except for the dissolved oxygen and the biochemical oxygen demand. The process effluent is fed to the Sansu tailings dam, which removes 99.9 % of the total suspended solids and 99.7 % of the turbidity; but copper, arsenic and cyanide concentrations were still high. The effluent produced can be classified as inorganic with a high load of non-biodegradable compounds. It was noted that, though the Sansu tailings dam stores the polluted effluent from the gold extraction plant, there will still be serious environmental problems in the event of failure of the dam.  相似文献   
255.
Abstract

Artificially contaminated (spiked) natural soils were solidified/stabilized using various combinations of commonly used additives, such as lime, cement, fly ash, activated carbon, and silica fume. The effectiveness of the solidification/stabilization (S/S) processes was evaluated based on experimental findings from compaction testing, unconfined compressive shear strength, and X-ray diffraction (XRD). Correlations of limited reliability between unconfined compressive strength and penetrometer and torvane measurements were derived. Results from XRD experiments indicated that certain organic contaminants (i.e., naphthalene and pyrene) might impact the S/S processes for a given combination of additives. The type and amount of organic contaminants also affected the pozzolanic reactions. Specifically, the absence or small peak intensity of pozzolanic product XRD patterns for a given combination of additives was a good indication that the type and the amount of organic contaminant present inhibited pozzolanic reactions. This phenomenon was tested and confirmed for actual field-contaminated samples.  相似文献   
256.
257.
A case study of the Yorkshire Derwent (UK) catchment is used to illustrate an integrated approach for assessing the viability of policy options for reducing diffuse nitrate losses to waterbodies. For a range of options, modeling methods for simulating river nitrate levels are combined with techniques for estimating the economic costs to agriculture of modifying those levels. By incorporating spatially explicit data and information on catchment residence times (which may span many decades particularly in areas of groundwater discharge) a method is developed for efficient spatial targeting of measures, for example, to the most at-risk freshwater environments. Combining hydrological and economic findings, the analysis reveals that, in terms of cost-effectiveness, the ranking of options is highly sensitive to both (i) whether or not specific stretches of river within a catchment are regarded as a priority for protection, and (ii) the criterion of nitrate concentration deemed most appropriate as an indicator of the health of the environment. Therefore, given the focus under European legislation upon ecological status of freshwaters, these conclusions highlight the need to improve understanding of mechanistic linkages between the chemical and biological dynamics of aquatic systems.  相似文献   
258.
With a changing climate and increased urbanisation, the occurrence and the impact of flooding is expected to increase significantly. Floods can bring pathogens into homes and cause lingering damp and microbial growth in buildings, with the level of growth and persistence dependent on the volume and chemical and biological content of the flood water, the properties of the contaminating microbes, and the surrounding environmental conditions, including the restoration time and methods, the heat and moisture transport properties of the envelope design, and the ability of the construction material to sustain the microbial growth. The public health risk will depend on the interaction of these complex processes and the vulnerability and susceptibility of occupants in the affected areas. After the 2007 floods in the UK, the Pitt review noted that there is lack of relevant scientific evidence and consistency with regard to the management and treatment of flooded homes, which not only put the local population at risk but also caused unnecessary delays in the restoration effort. Understanding the drying behaviour of flooded buildings in the UK building stock under different scenarios, and the ability of microbial contaminants to grow, persist, and produce toxins within these buildings can help inform recovery efforts. To contribute to future flood management, this paper proposes the use of building simulations and biological models to predict the risk of microbial contamination in typical UK buildings. We review the state of the art with regard to biological contamination following flooding, relevant building simulation, simulation-linked microbial modelling, and current practical considerations in flood remediation. Using the city of London as an example, a methodology is proposed that uses GIS as a platform to integrate drying models and microbial risk models with the local building stock and flood models. The integrated tool will help local governments, health authorities, insurance companies and residents to better understand, prepare for and manage a large-scale flood in urban environments.  相似文献   
259.
Metal oxide nanomaterials have exhibited toxicity to a variety of aquatic organisms, especially microbes and invertebrates. To date, few studies have evaluated the toxicity of metal oxide nanomaterials on aquatic vertebrates. Therefore, this study examined effects of ZnO, TiO2, Fe2O3, and CuO nanomaterials (20-100 nm) on amphibians utilizing the Frog Embryo Teratogenesis Assay Xenopus (FETAX) protocol, a 96 h exposure with daily solution exchanges. Nanomaterials were dispersed in reconstituted moderately hard test medium. These exposures did not increase mortality in static renewal exposures containing up to 1000 mg L−1 for TiO2, Fe2O3, CuO, and ZnO, but did induce developmental abnormalities. Gastrointestinal, spinal, and other abnormalities were observed in CuO and ZnO nanomaterial exposures at concentrations as low as 3.16 mg L−1 (ZnO). An EC50 of 10.3 mg L−1 ZnO was observed for total malformations. The minimum concentration to inhibit growth of tadpoles exposed to CuO or ZnO nanomaterials was 10 mg L−1. The results indicate that select nanomaterials can negatively affect amphibians during development. Evaluation of nanomaterial exposure on vertebrate organisms are imperative to responsible production and introduction of nanomaterials in everyday products to ensure human and environmental safety.  相似文献   
260.

Problem

U.S. teenaged and young-adult drivers' elevated rates of fatal traffic crash involvement typically are attributed to biological and developmental risk-taking associated with young age. However, young drivers differ from older ones along several sociodemographic dimensions, including higher poverty rates and greater concentration in poorer areas, which may contribute to their risks.

Method

Using Fatality Analysis Reporting System, Census, and Federal Highway Administration data for 1994-2007, bivariate and multivariate regression analyses were conducted of fatal motor-vehicle crash involvements per 100 million miles driven by driver age (16 through 74) and state along with 14 driver-, vehicle-, and state-level variables.

Results

Driver age was not a significant predictor of fatal crash risk once several factors associated with high poverty status (more occupants per vehicle, smaller vehicle size, older vehicle age, lower state per-capita income, lower state population density, more motor-vehicle driving, and lower education levels) were controlled. These risk factors were significantly associated with each other and with higher crash involvement among adult drivers as well.

Summary and Discussion

The strong association between fatal crash risk and environments of poverty as operationalized by substandard vehicle and driving conditions suggests a major overlooked traffic safety factor particularly affecting young drivers.  相似文献   
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