912 resultados para Recreation centers.
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We synthesize some powder phosphors of CaF2:Ce3+ under different reaction conditions, find three luminous centres, and demonstrate that each luminous centre is formed with different charge compensation procedures.
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With the method of high temperature solid state reaction and stockbarger, we synthesized a series of powder phosphors of KMgF3-Ce3+, KMg1-alphaMalphaF3-Ce3+(M = Be2+, Ca2+) and the single crystal of KMgF3-Ce3+. We tested their excitation and emission spectra, found two emission centers in KMgF3-Ce3+ and demonstrated that they resulted from different charge compensating ways. By the structural analysis on KMgF3-Ce-3+ from a four-cycle diffractometer and spectral analysis on KMg1-alphaMalphaF3-Ce3+(M = Be2+, Ca2+), we deduced that Ce3+ ion only.substituted K+ site in KMgF3.
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Eu3+ ion was adopted as a probe to detect the probability of entrance of alkali elements into the crystal lattice of MgO, CaO and La2O3 by means of its characteristic emission. Based on the experimental data it is concluded that Li+ and Na+ ions can substitute Mg2+ and Ca2+ ions and only a small amount of K+ ion can enter into the lattice of CaO. Whilst Li+ ion can not enter into the lattice of lanthana. The conclusion of this investigation is in good agreement with that obtained by Lunsford by ESR studies.
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How should funding agencies enable researchers to explore high-risk but potentially high-reward science? One model that appears to work is the NSF-funded synthesis center, an incubator for community-led, innovative science.
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© 2015 Human Kinetics, Inc.Background: Young children's physical activity (PA) is influenced by their child care environment. This study assessed PA practices in centers from Massachusetts (MA) and Rhode Island (RI), compared them to best practice recommendations, and assessed differences between states and center profit status. We also assessed weather-related practices. Methods: Sixty percent of MA and 54% of RI directors returned a survey, for a total of 254. Recommendations were 1) daily outdoor play, 2) providing outdoor play area, 3) limiting fixed play structures, 4) variety of portable play equipment, and 5) providing indoor play area. We fit multivariable linear regression models to examine adjusted associations between state, profit status, PA, and weather-related practices. Results: MA did not differ from RI in meeting PA recommendations (β = 0.03; 0.15, 0.21; P = .72), but MA centers scored higher on weather-related practices (β = 0.47; 0.16, 0.79; P = .004). For-profit centers had lower PA scores compared with nonprofits (β = -0.20; 95% CI: -0.38, -0.02; P = .03), but they did not differ for weather (β = 0.12; -0.19, 0.44; P = .44). Conclusions: More MA centers allowed children outside in light rain or snow. For-profit centers had more equipment-both fixed and portable. Results from this study may help inform interventions to increase PA in children.
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The relatively new recreational pursuit of coasteering, which has developed in the St David's area of Pembrokeshire, appears to be expanding rapidly. The majority of local commercial recreation providers (outdoor pursuit centers etc.) now appear to offer this pursuit. The majority of the rocky coastlines where it takes place lie within Pembrokeshire Marine Special Area of Conservation (SAC), and are also Sites of Special Scientific Interest (SSSI). No assessment has yet been undertaken of coasteering's potential impact on the intertidal habitats. Therefore the Countryside Council for Wales (CCW) commissioned the Marine Life Information Network (MarLIN) to undertake a desk study of the likely environmental effects of coasteering on rocky intertidal habitats within the Pembrokeshire marine SAC. The desk study was based on a review of the available literature, and in particular the effects of trampling on rocky intertidal communities. Communities (as biotopes) within the Pembrokeshire marine SAC likely to be exposed to coasteering activities were identified from Phase I biotope data for the area, provided by CCW. Where possible, existing research by MarLIN into the intolerance, recoverability and sensitivity of the biotopes identified, was used to identify their potential vulnerability to trampling. The literature review revealed that: - foliose canopy forming algae (e.g. fucoids) were particularly intolerant and sensitive to trampling impacts; - trampling damaged erect coralline turfs, barnacles, and resulted in an increase in bare space; in some cases paths across the shore were visible; - on brown algae dominated shores, understorey algae could suffer due to increased desiccation but algal turf species, opportunists and gastropod grazers (e.g. limpets) could increase in abundance as an indirect effect of trampling, and that - trampling impacts resulted from physical contact and wear and were dependant on the intensity, duration, and frequency of trampling, and even the type of footwear used. A total of 19 intolerant rocky intertidal biotopes were identified as potentially vulnerable to trampling and hence coasteering within the Pembrokeshire marine SAC, of which six are of Welsh importance and eight are nationally rare or scarce. Trampling is a highly localized impact and it was not possible to identify biotopes, and hence communities, actually impacted by coasteering activities in the Pembrokeshire marine SAC. In addition, the majority of the literature addresses the impacts of trampling on wave sheltered or moderately exposed brown algal dominated shores, while coasteering occurs on more wave exposed, steeply inclined shores. Therefore, direct survey of the routes used by coasteering groups within the Pembrokeshire marine SAC is required to identify the intensity, duration and frequency of trampling impact, together with the communities impacted. Given the paucity of data concerning trampling effects in the rocky intertidal in the UK, a survey of the impacts of coasteering would provide an opportunity to examine the effects of trampling and visitor use in steep rocky, wave exposed shores. The report recognizes the potential to engage coasteerers in contributing to the development of strategies for minimizing adverse impacts, recording impacts and collecting information of use in identifying climate change and the occurrence of non-native species.
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In this study we show that forest areas contribute significantly to the estimated benefits from om outdoor recreation in Northern Ireland. Secondly we provide empirical evidence of the gains in the statistical efficiency of both benefit and parameter estimates obtained by analysing follow-up responses with Double Bounded interval data analysis. As these gains are considerable, it is clearly worth considering this method in CVM survey design even when moderately large sample sizes are used. Finally we demonstrate that estimates of means and medians of WTP distributions for access to forest recreation show plausible magnitude, are consistent with previous UK studies, and converge across parametric and non-parametic methods of estimation.
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An iron prophyrin complex has been immobilized on the surfaces of platinum, silver, and indium doped-tin oxide coated glass by using the poly(gamma-ethyl L-glutamate)-N-(3-aminopropyl)imidazole derivative 1 as a linking agent, thus allowing-the surface-enhanced resonance Raman and UV-VIS absorption spectra and electrochemical properties of the porphyrin to be studied in solvents in which it is not normally soluble.