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21.
With considerable evidence demonstrating the intrinsic importance of weather and climate for tourist decision-making, the projected redistribution of climatic resources as a result of climate change is anticipated to have important consequences for temporal and spatial patterns of tourism demand. Some of the world's leading coastal tourism destinations (Mediterranean and Caribbean) have been identified as becoming ‘too hot’ for tourism. However, the microclimates of coastal tourism areas have not been considered by such assessments. With a focus on thermo-physiologically relevant climatic parameters, this paper examines the adaptive range of microclimatic conditions available in two coastal resort settings in the Caribbean islands of Barbados and Tobago. Recorded weather parameters include air temperature, black globe temperature, relative humidity, and wind speed. The microclimatic results, which are presented using the Universal Thermal Climate Index (UTCI), show that hourly thermal conditions can range up to 4 °C in different outdoor areas of the resort property (beach, garden, pool, cabana). This is salient in terms of characterizing tourism destinations for climate change assessments, as the results reveal that thermal conditions can vary at the micro-scale of a coastal resort, with the ability for tourists to attain thermally comfortable conditions within a single resort property. When a location becomes thermally uncomfortable (i.e. too hot), tourists can change their location (e.g. move from the pool to the beach), providing an onsite adaptive range between 1 °C and 4 °C. The results also demonstrate that thermo-physiologically relevant climatic parameters provide a more precise estimate of the available range of thermal comfort than is inferred from ambient temperature alone. The findings are discussed in the context of tourists’ climatic preferences and reveal that the microclimatic conditions recorded in this study (UTCI 29–36 °C) are well within tourists’ preferred thermal conditions and do not exceed tourists’ thermal thresholds for coastal tourism.  相似文献   
22.
The burial and pore fluid pressure history of fluorite ore deposits is reconstructed: (i) at Hammam Zriba–Djebel Guebli along the eastern margin of the Tunisian Atlas; and (ii) at Koh‐i‐Maran within the northern part of the Kirthar Range in Pakistan. Both the deposits are hosted by Late Jurassic carbonate reservoirs, unconformably overlain by Late Cretaceous seals. Microthermometric analyses on aqueous and petroleum fluid inclusions with pressure–volume–temperature–composition (PVTX) modeling of hydrocarbon fluid isochores are integrated with kinematics and thermal 2D basin modeling in order to determine the age of mineralization. The results suggest a Cenozoic age for the fluorite mineralization and a dual fluid migration model for both ore deposits. The PVTX modeling indicates that the initial stage of fluorite cementation at Hammam Zriba occurred under fluid pressures of 115 ± 5 bars and at a temperature close to 130°C. At Koh‐i‐Maran, the F3 geodic fluorite mineralization developed under hydrostatic pressures of 200 ± 10 bars, and at temperatures of 125–130°C. The late increase in temperature recorded in the F3 fluorites can be accounted for by rapid rise of hotter fluids (up to 190°C) along open fractures, resulting from hydraulic fracturing of overpressured sedimentary layers.  相似文献   
23.
Here we present a database of responses by South African agate and chalcedony to heat treatment. This will assist analyses of heated stone tools not only in South African archaeological sites, but wherever heated agate and chalcedony pieces were knapped. The minerals are abundant worldwide. To replicate potential heating methods during the Stone Age we placed some minerals in a wood fire, some under coals, and others were buried in sediments beneath fires. Thermal responses include lustrous flaked surfaces, pot lid fractures, semi-circular internal fractures, rough internal surfaces, and crazing. Aerobic heating is implied by pot lid fractures. To explain the thermal responses we analyzed the minerals using X-ray fluorescence, Raman spectroscopy, and carbon and sulfur analyses. Our chalcedony contains more water and impurities than agate, making it more vulnerable to thermal damage. Our method of combining field experiments with chemical analyses has global applications even though we expect that mineral components of agate and chalcedony will vary slightly in different parts of the world.  相似文献   
24.
釉陶器在埋藏过程中,受物理及化学等因素的影响,会产生各种病害,釉层剥离是常见的病害之一。为了更深入地了解唐代釉陶器釉层剥离的原因并为以后的保护提供科学依据,对陕西、河南地区四个遗址出土的唐代釉陶器样品进行了显微观察、成分检测、热膨胀系数分析和吸水率测试。结果显示,四个遗址中,釉面保存相对完整且剥离现象较少的是巩县黄冶窑,而铜川黄堡窑、西安醴泉坊窑和乾县懿德太子墓釉陶器釉层剥离较为严重。进一步研究表明,釉陶器胎釉热膨胀系数不匹配和胎体烧结程度过低(因此造成吸水率过高)是影响釉陶器釉层剥离的主要内在因素。研究结果可为釉陶器的后续保护工作奠定基础。  相似文献   
25.
都市圈发展的新背景、新趋势及其规划响应   总被引:3,自引:0,他引:3  
薛俊菲 《人文地理》2008,23(3):35-39
随着经济全球化的深入发展,城市之间的竞争日益加剧,城市发展越来越呈现出区域化特征,大都市成为了世界城市和城市化发展的主流。在这样的新背景之下,都市圈发展呈现出一些新的趋势,中心性进一步强化并出现多中心的新形式,空间扩散广域化并日趋连绵成片,区域进一步融合并且跨界发展明显。世界各主要都市圈的规划纷纷对这些新形势做出了响应,即以全球性、整体性的视角来审视都市圈发展所面临的问题,致力于形成多中心的空间结构,促进产业扩散与转移,对交通进行网络化整合,并建立类似都市圈政府的机构对都市圈规划进行管理。这些良好的经验可以作为我国都市圈理论研究和规划实践的有益借鉴。  相似文献   
26.
ABSTRACT

In 1983, David Braun proposed that a shift from thicker- to thinner-walled cooking vessels in the midwestern United States was triggered by an increased dietary reliance on starchy grains (Braun 1983). Drawing on well-established principles of materials science (Van Vlack 1964), he suggested that, compared to thicker-walled vessels, thinner-walled ones would have been more thermally efficient and less likely to break from thermal shock. These attributes, he suggested, would have been advantageous for preparing seeds and grains that require lengthy cooking periods. Although consistent with materials science principles, Braun’s proposition has never been tested. In this paper, we present results of experiments undertaken to evaluate the relative cooking efficiency of thin- versus thick-walled vessels and consider the implications of these findings for understanding traditional ceramic technologies.  相似文献   
27.
The thermal histories of archaeological cereal grains have been explored with electron spin resonance spectroscopy by a quantitative study of pyrolysis-induced radical carbon. Comparison with modern samples of heated cereal grain has shown that the g value of the radical carbon signal is characteristic of exposure to a previous maximum temperature, and studies of other signal parameters suggest that further information, such as the duration of previous heating, may be deduced from such studies. The proposed method offers the possibility of quantitatively rigorous measurement in archaeological studies of cultural and technological processes that previously relied upon subjective assessment.  相似文献   
28.
The hypothesis that Kohout thermal convection may have induced the massive dolomitization of the 60 m thick lowest more reefal unit in well Unda [top of Great Bahama Bank (GBB)] is evaluated through numerical modelling. A two‐dimensional (2‐D) section, including lithological and petrophysical data, together with datings for the sediments of the GBB, was used in the basin model TEMISPACK to reconstruct the history of the whole platform, with a focus on the reef unit. Simulations showed that during high sea‐level periods, Kohout convection is a valid mechanism in the settings of the GBB, although the convection cell remains flat in most cases because of high permeability anisotropy. This mechanism induces rapid fluid flow in the superficial as well as in the deeper parts of the platform, with velocities of at least two orders of magnitude higher than with compaction alone. Lithology appears as a strong control of fluid circulations at the margin scale through the permeability anisotropy, for which a critical value lies between values of 10 and 100. The reefal unit in Unda is part of a larger area determined by the lithologic distribution, in which flow velocities are significantly higher than in the rest of the platform. These velocities are high enough to bring the magnesium necessary to precipitate the observed amounts of dolomite, within durations in agreement with the available time of post‐reef deposition high sea level(s). However, neither fluid flow pattern nor flow velocities are able to explain the preferential massive dolomitization of the lower reef unit and the complete absence of dolomite in the upper one.  相似文献   
29.
The application of chemical geothermometry to shallow groundwaters or spring discharge assumes that there is minimal mixing or re-equilibration of water as it travels from depth to the surface. In this study, we examine the potential for mixing and re-equilibration by examining heat and fluid flow along crustal-scale faults in tectonic geothermal systems. Numerical modeling results indicate that maximum in situ temperatures could be under-predicted by up to 30% due to mixing of fluids that enter the fault at different depths. This, coupled with the depression of isotherms by downward groundwater flow in the hanging wall, could cause underestimates of maximum circulation depth of greater than 80% in extreme cases. Kinetics does not favor re-equilibration in the shallower portions of faults due to low temperatures and higher fluid velocities. However, in areas of deeper circulation or higher heat flow such reactions are possible.  相似文献   
30.
Pulsed thermography has been applied to the quantitative characterization of the insertions of two ancient bronzes, the Boxer at Rest and the Hellenistic Prince. The analysis of the thermographic signal time dependence performed by a specifically developed model enabled the evaluation of the insertions’ thickness and of elements which could provide indications about the procedure followed for their insertion. This could be achieved by exploiting a semi-empirical relation establishing the thermal diffusivity dependence on the total effective weighted concentration of Sn and Pb atoms obtained from the analysis of the values determined on samples containing different concentrations of Sn and Pb.  相似文献   
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