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21.
Objectives. The present study sought to identify firefighters’ rated physical demands for the most frequently occurring work tasks and to determine if the ratings differed between full-time and part-time firefighters to help create a basis for the development of physical employment tests for firefighters. Methods. An extensive questionnaire was completed by 125 and 68 firefighters in 2000 and 2010, respectively. The data were analysed with the Mann-Whitney U test and binominal test and ranked on the basis of the responses in each category. Results. Significant differences were seen between the full- and part-time firefighters. The work tasks rated as the most physically strenuous in terms of aerobic fitness, muscle strength, work posture and body control by most respondents were smoke diving upstairs (carrying a hose), victim rescue in different ways, carrying a stretcher over terrain and pulling a hose. Conclusions. Physically strenuous work tasks should be included in the end-point performance variables used to select physical performance tests for firefighters. The part-time firefighters with no experience in several of the work tasks suggests that work-related exercises are important if both groups of firefighters are expected to do similar work.  相似文献   
22.
Two experiments examined whether differences in elevation of the terrain are encoded in cognitive maps of outdoor environments. In Experiment 1, two groups of subjects who had travelled a varying number of times between a set of locations made direct estimates in metres of the differences in elevation between the locations. The results showed that subjects in both groups had knowledge of elevation but those for whom the terrain was less familiar tended to exaggerate the differences. In Experiment 2, decision times were measured of responses to the question whether one location is below or above another one. Neither for subjects who were more, nor for subjects who were less familiar with the terrain, did the decision times vary with the distances between the locations, thus failing to support the hypothesis that differences in elevation are retrieved by a process of ‘mental travel’.  相似文献   
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Two representative samples of surficial marine sediments have been studied, one from the northern Baltic Proper and the other from the Gulf of Finland. Aliphatic hydrocarbons were determined by gas chromatography on a fused silica capillary column, and six polyaromatic hydrocarbons were determined by gas chromatography-mass fragmentography. Hydrocarbons were extracted with a benzene-methanol mixture and ultrasonic agitation. The aliphatic hydrocarbons were tentatively identified by their retention times. The polyaromatic hydrocarbons (PAHs) were identified on the basis of their retention times and mass fragmentograms by direct comparison with those of standard compounds. The aliphatic hydrocarbon contents ranged from 0,1 to 2,6 μg/g dry matter. In both samples there was a clear maximum at n-C17 and also a clear odd-carbon predominance. The PAH contents ranged from 4 to 120 ng/g dry matter. The PAH concentration was about 58 per cent higher in the sample from the Gulf of Finland than in the sample from the Baltic Proper.  相似文献   
25.
Objectives: The objective of this article is to assess the status of road safety in Asia and present accident and injury prevention strategies based on global road safety improvement experiences and discuss the way forward by indicating opportunities and countermeasures that could be implemented to achieve a new level of safety in Asia.

Methods: This study provides a review and analyses of data in the literature, including from the World Health Organization (WHO) and World Bank, and a review of lessons learned from best practices in high-income countries. In addition, an estimation of costs due to road transport injuries in Asia and review of future trends in road transport is provided.

Results: Data on the global and Asian road safety problem and status of prevention strategies in Asia as well as recommendations for future actions are discussed. The total number of deaths due to road accidents in the 24 Asian countries, encompassing 56% of the total world population, is 750,000 per year (statistics 2010). The total number of injuries is more than 50 million, of which 12% are hospital admissions. The loss to the economy in the 24 Asian countries is estimated to around US$800 billion or 3.6% of the gross domestic product (GDP).

Conclusions: This article clearly shows that road safety is causing large problems and high costs in Asia, with an enormous impact on the well-being of people, economy, and productivity. In many Asian low- and middle-income countries, the yearly number of fatalities and injuries is increasing. Vulnerable road users (pedestrians, cyclists, and motorcyclists combined) are particularly at risk. Road safety in Asia should be given rightful attention, including taking powerful, effective actions. This review stresses the need for reliable accident data, because there is considerable underreporting in the official statistics. Reliable accident data are imperative to determine evidence-based intervention strategies and monitor the success of these interventions and analyses. On the other hand, lack of good high-quality accident data should not be an excuse to postpone interventions. There are many opportunities for evidence-based transport safety improvements, including measures concerning the 5 key risk factors: speed, drunk driving, not wearing motorcycle helmets, not wearing seat belts, and not using child restraints in cars, as specified in the Decade of Action for Road Safety 2011–2020. In this commentary, a number of additional measures are proposed that are not covered in the Decade of Action Plan. These new measures include separate roads or lanes for pedestrians and cyclists; helmet wearing for e-bike riders; special attention to elderly persons in public transportation; introduction of emerging collision avoidance technologies, in particular automatic emergency braking (AEB) and alcohol locks; improved truck safety focusing on the other road user (including blind spot detection technology; underride protection at the front, rear, and side; and energy-absorbing fronts); and improvements in motorcycle safety concerning protective clothing, requirements for advanced braking systems, improved visibility of motorcycles by using daytime running lights, and better guardrails.  相似文献   

26.
Zinc (Zn) is a chemical element that has gained more attention lately owing to its possibility to form corrosive deposits in large boilers, such as Waste-to-Energy plants. Zn enters the boilers in many different forms and particularly in waste, the amount of Zn is hard to determine due to both the heterogeneity of waste in general but also due to the fact that little is yet published specifically about the Zn levels in waste. This study aimed to determine the Zn in Swedish waste fuels by taking regular samples from seven different and geographically separate waste combustion plants over a 12-month period. The analysis shows that there is a relation between the municipal solid waste (MSW) content and the Zn-content; high MSW-content gives lower Zn-content. This means that waste combustion plants with a higher share of industrial and commercial waste and/or building and demolition waste would have a higher share of Zn in the fuel. The study also shows that in Sweden, the geographic location of the plant does not have any effect on the Zn-content. Furthermore, it is concluded that different seasons appear not to affect the Zn concentrations significantly. In some plants there was a clear correlation between the Zn-content and the content of other trace metals.  相似文献   
27.
Empirical modeling of atmospheric deposition in mountainous landscapes.   总被引:1,自引:0,他引:1  
Atmospheric deposition has long been recognized as an important source of pollutants and nutrients to ecosystems. The need for reliable, spatially explicit estimates of total atmospheric deposition (wet + dry + cloud) is central, not only to air pollution effects researchers, but also for calculation of input-output budgets, and to decision makers faced with the challenge of assessing the efficacy of policy initiatives related to deposition. Although atmospheric deposition continues to represent a critical environmental and scientific issue, current estimates of total deposition have large uncertainties, particularly across heterogeneous landscapes such as montane regions. We developed an empirical modeling approach that predicts total deposition as a function of landscape features. We measured indices of total deposition to the landscapes of Acadia (121 km2) and Great Smoky Mountains (2074 km2) National Parks (USA). Using approximately 300-400 point measurements and corresponding landscape variables at each park, we constructed a statistical (general linear) model relating the deposition index to landscape variables measured in the field. The deposition indices ranged over an order of magnitude, and in response to vegetation type and elevation, which together explained approximately 40% of the variation in deposition. Then, using the independent landscape variables available in GIS data layers, we created a GIS-relevant statistical nitrogen (N) and sulfur (S) deposition model (LandMod). We applied this model to create park-wide maps of total deposition that were scaled to wet and dry deposition data from the closest national network monitoring stations. The resultant deposition maps showed high spatial heterogeneity and a four- to sixfold variation in "hot spots" and "cold spots" of N and S deposition ranging from 3 to 31 kg N x ha(-1) x yr(-1) and from 5 to 42 kg S x ha(-1) x yr(-1) across these park landscapes. Area-weighted deposition was found to be up to 70% greater than NADP plus CASTNET monitoring-station estimates together. Model-validation results suggest that the model slightly overestimates deposition for deciduous and coniferous forests at low elevation and underestimates deposition for high-elevation coniferous forests. The spatially explicit deposition estimates derived from LandMod are an improvement over what is currently available. Future research should test LandMod in other mountainous environments and refine it to account for (currently) unexplained variation in deposition.  相似文献   
28.
Transport and retardation of non-sorbing tritiated water and chloride and slightly sorbing sodium was studied in Syyry area SY-KR7 mica gneiss, in altered porous tonalite and in fresh tonalite. Experiments were performed using dynamic fracture and crushed rock column methods. Static batch method for sodium was introduced to compare retardation values from static and dynamic experiments. The 14C-PMMA method was used to study the pore structure of matrices. The pore aperture distribution was evaluated from Hg-porosimetry determinations and the surface areas were determined using the B.E.T. method. The flow characteristics and transport behavior of tracers were interpreted using a numerical compartment model for dispersion. The effect of matrix diffusion was calculated using an analytical solution to the advection-matrix diffusion problem in which surface retardation was taken into account. Radionuclide transport behavior in rock fractures was explained on the basis of rock structure.  相似文献   
29.
A new method is described, which gives quantitative information on levels and spatial distributions of porosity in the matrix of rock in the sub-mm- to cm-scale. Migration pathways can be identified and visualized. The method employs impregnation of dried rock samples by 14C-labelled methylmethacrylate (MMA), radiation polymerization, autoradiography and digital image processing. Infiltration and diffusion processes can be quenched by polymerization and the resulting profiles studied easily.  相似文献   
30.
That a memory representation of the spatial layout of a large-scale environment may be acquired very fast was shown in two experiments in which subjects (48 undergraduates and high-school students) were taken on tours through a residential area with which they were unfamiliar. Memory for the path traversed was almost perfect after the first trial, as indicated by almost perfect recall of the order in which a number of designated landmarks had been passed. Memory for the locations of the same landmarks appeared to reach an asymptotic level after the second of three trials. The memory representation of the locations were however not perfectly accurate, thus the asymptotic level might have been an acquisition plateau. The rate of acquisition was slightly faster for subjects driven in a car slowly through the area than for those who walked the same path. Men tended to improve slightly faster than women if they were driven by car but there were no other sex differences. Finally, the acquired memory representation appeared to be resistant to forgetting. Re-learning after a one-week retention interval was faster and rate of learning was not negatively affected whether the trials were massed or distributed with one week in between. The results are discussed in terms of hypotheses concerning the order in which different types of information about spatial layouts (landmarks, paths, and locations) are acquired. The bearing of the results on the question of why memory representations of the spatial layout are often found to be distorted is also discussed.  相似文献   
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