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11.
Changes in resource use over time can provide insight into technological choice and the extent of long-term stability in cultural practices. In this paper we re-evaluate the evidence for a marked demographic shift at the inception of the Early Iron Age at Troy by applying a robust macroscale analysis of changing ceramic resource use over the Late Bronze and Iron Age. We use a combination of new and legacy analytical datasets (NAA and XRF), from excavated ceramics, to evaluate the potential compositional range of local resources (based on comparisons with sediments from within a 10 km site radius). Results show a clear distinction between sediment-defined local and non-local ceramic compositional groups. Two discrete local ceramic resources have been previously identified and we confirm a third local resource for a major class of EIA handmade wares and cooking pots. This third source appears to derive from a residual resource on the Troy peninsula (rather than adjacent alluvial valleys). The presence of a group of large and heavy pithoi among the non-local groups raises questions about their regional or maritime origin.  相似文献   
12.
An experimental study on half-scale brick-masonry models with different strengthening and retrofitting measures has been studied under cyclic loading in a quasi-static test facility. The strengthening measures undertaken for the studies axe the horizontal bond beam at the lintel and sill level with a combination of vertical reinforcement at corners and openings. The retrofitting measures studied are grouting with epoxy-sand-mortar and cement-grout-injection with welded wire mesh in the cracked region. The tests reveal that the horizontal bond beam at lintel level with vertical reinforcement is effective in reducing the cracking above the lintel level. The insertion of an additional sill-band signi-ficantly reduces the cracking in walls. The epoxy-sand-mortar techniques for retrofitting of cracked regions prove to be effective enough to restore the initial strength, stiffness and deformation capacity. Although specimen retrofitted with cement-grout-injection with welded wire mesh is effective to regain the ultimate strength yet the brittle failure is observed as the specimen is stressed beyond the elastic limit.  相似文献   
13.
易溶盐富集是陕西西安大雁塔砖体表面风化、结构破坏、强度衰减的主要原因。为分析盐害对大雁塔砖体结构、强度的影响机理,采用以饱和硫酸钠溶液为介质,对大雁塔砖体进行易溶盐结晶循环模拟劣化试验。在Na2SO4反复结晶、溶解过程中,测定试样的质量、波速及单轴抗压强度等指标,分析其变化规律。结果表明,在盐害作用下,试验砖体表现出与塔体表面类似的风化破坏现象;Na2SO4晶体在试样孔隙内不断发育,晶体挤压效应导致孔隙率增大,内部结构破损;质量、波速、单轴抗压强度随循环的次数呈先增加后减小的变化规律。砖体对盐害耐受力约为砖体质量的0.5%。  相似文献   
14.
土遗址锚杆锚固质量一直是土遗址加固工程中关注的重点问题。目前,土遗址领域均采用具有破坏性的拉拔试验对其进行检测。基于土遗址的文物属性,本研究尝试利用无损检测技术评价土遗址加固用玻璃纤维锚杆的锚固质量。通过锚杆无损检测仪与拉拔仪分别对甘肃省红沙堡遗址与永泰城址加固工程中的玻璃纤维锚杆锚固系统进行检测。比较实际测量杆长与仪器测量杆长结果,得出杆长指标可以判断无损检测仪所测结果的真实性。无损检测仪得出的检测波形衰减规律显著,对比相应锚杆的拉拔试验的评价结果,证实了声频应力波法在土遗址玻璃纤维锚杆锚固系统无损检测中的适用性。本研究结果将为评价土遗址加固用玻璃纤维锚杆锚固质量提供可靠的依据。  相似文献   
15.
旅游业与我国经济增长关系的实证分析   总被引:18,自引:1,他引:18  
杨勇 《旅游科学》2006,20(2):40-46
旅游业与国民经济增长之间的关系一直是有关学者研究的对象,这也导致了对旅游业地位的不同认识。本文利用历史数据对改革开放以来中国居民旅游消费支出与经济增长之间的关系作出判断,认为我国旅游业与经济增长之间并不存在稳定的因果关系。文章对产生这种现象的原因进行了分析,并提出了相关政策建议。  相似文献   
16.
This article presents the results of an experimental study on the rotational behavior of degraded Chinese traditional mortise-tenon joints with different degradation types and different degradation degrees. Six joint specimens degraded through artificially simulated method, were tested by reversed cyclic loading, from which the moment-rotation curves were obtained. The results indicated that the rotational behavior of these joints is semi-rigid, the hysteretic curve shapes of degraded joints are same to that of joint without degradation. The maximum moment, yield moment, and initial rotational stiffness of degraded joints decreases as the degraded degree increases, whose empirical degradation relationships were obtained based on the test data. A hysteretic model for degraded traditional mortise tenon joints was proposed. Experimental results were used to validate the proposed hysteretic model. Good agreement between predictions and tests was observed.  相似文献   
17.
In this article, we provide practical and straightforward guidance for the selection and sampling of shipwreck timbers for dendrochronological research. We outline sampling strategies and present informative figures that illustrate how to proceed in a variety of scenarios that archaeologists regularly encounter. However, in order to fully exploit the potential of tree‐ring research on these objects, we would urge archaeologists to involve dendrochronologists during the project planning phase to carefully plan and conduct adequate sampling of shipwreck assemblages.  相似文献   
18.
The Algarve region in southern Portugal has one of the most significant rammed earth construction legacies in the country. This construction method is characterized by its high susceptibility to water damage and external renderings are essential to the longevity of these constructions. This study collects and organizes data that provides the basis for the conservation and repair of renderings. Five earth buildings from western Algarve were selected to represent this heritage and its diversity of composition and susceptibility to water damage. Some of their commonest anomalies result from the interaction between the earth substrate and the traditional external renderings, given their distinct characteristics and behavior. The selected sample is described and the mechanical strength of the rammed earth walls and their renderings are evaluated through in situ tests. Samples of the external renderings and earth substrate of the five buildings comprising the sample were also collected and characterized in the laboratory. The characteristics of these two materials and their behavior as an assembly were analyzed. The results of the in situ and laboratory tests are compared and the viability of using a method based on in situ tests for the wider characterization of the type of construction under analysis evaluated.  相似文献   
19.
20.
Sampling of geothermal fluids presents some problems not encountered when sampling surface and nonthermal ground waters. Specific collection techniques are required to obtain representative samples because of the elevated temperature and boiling of these fluids, the effect of exposing them to the atmosphere and cooling of the samples. Sample treatment during collection depends on the analytical method to be used. When sampling wet‐steam wells, both the liquid and the vapour fractions should be collected at the same fluid separation pressure. When sampling fumarole steam, maximum information is obtained if the total discharge is collected into a single container without separating the gas and the steam condensate fractions. Silica polymerization affects the solution pH. The only way to obtain reliable pH measurement of a water sample supersaturated with respect to amorphous silica is to measure it on site, before the onset of polymerization. This paper provides an outline of the geothermal sampling techniques and analytical methods currently in use in Iceland. Sampling of hot‐water and wet‐steam wells is described, as is sampling of hot springs, fumaroles and gas bubbling through hot‐spring waters. Detailed procedures are given for the analysis of total carbonate carbon and total sulphide sulphur in geothermal water and steam condensate samples.  相似文献   
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