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21.
A human skull, buried about 2500 years ago in a Bronze Age cemetery at Jinggouzi, a site of an important ethnic group in ancient China, appeared to have characteristics of fibrous dysplasia. The CT images indicated a reduction in bone density and relatively homogeneous lesions. More features were revealed using CT reconstruction techniques. Lesions seen in low‐magnification images using a 3D deep‐field microscope had an irregular honeycomb‐like structure. At higher magnification, the trabeculae morphology and the gaps between the trabeculae were irregular and varied in size and shape. Paraffin‐embedded specimens stained with HE showed trabeculae with tortuous irregular arrangements varying in shape and width. The irregular trabeculae of woven bone has been described as having fibrous dysplasia. Molecular analysis of the GNAS gene indicated no mutation. This provides a non‐invasive approach for us to make more comprehensive diagnoses and to assist research into ancient human diseases.  相似文献   
22.
许多出土饱水木质文物因其降解严重、含水率较高,容易在脱水过程中出现不可逆的收缩变形以及开裂现象,从而遭到严重破坏。因此,饱水木质文物脱水方法的研究是文物保护工作中的重要课题。为探究风冷冷冻法对饱水木质文物脱水的效果,以一批无法复原的出土饱水木质文物为研究对象,在对其材种、含水率、基本密度及化学成分进行了测定和分析后,使用一台风冷电冰箱在-18℃条件下对样品进行了风冷干燥脱水处理,记录脱水时间和脱水效果,并分析了该方法的传质传热特点,证明了风冷干燥法用于饱水木质文物的脱水干燥能够取得良好效果,并且具有对文物干预小、适用性广、操作简便、成本低廉等优点,为饱水木质文物的脱水处理提供了一种新的思路。  相似文献   
23.
一个行业的职业道德准则对该行业秩序的发展及其法制的完善都具有重要意义。《国际博物馆协会博物馆职业道德准则》作为博物馆行业的最低道德标准和兼采各国经验总结而成的国际性道德准则,对博物馆行业国际秩序的发展发挥着重要影响,对于一国文物、博物馆法制的完善也有积极意义。当前我国尚未真正建立起切实有效的博物馆行业自律系统,现行法制也不能完全满足博物馆事业发展的需要。以《国际博物馆协会博物馆职业道德准则》为参照,完善博物馆行业治理体系,是我国博物馆事业发展的必要选择。  相似文献   
24.
Capillary trapping is a physical mechanism by which carbon dioxide (CO2) is naturally immobilized in the pore spaces of aquifer rocks during geologic carbon sequestration operations, and thus a key aspect of estimating geologic storage potential. Here, we studied capillary trapping of supercritical carbon dioxide (scCO2), and the effect of initial scCO2 saturation and flow rate on the storage/trapping potential of Berea sandstone. We performed two‐phase, scCO2‐brine displacements in two samples, each subject to four sequential drainage–imbibition core‐flooding cycles to quantify end‐point saturations of scCO2 with the aid of micro‐ and macro‐computed tomography imaging. From these experiments, we found that between 51% and 75% of the initial CO2 injected can be left behind after the brine injection. We also observed that the initial scCO2 saturation influenced the residual scCO2 saturation to a greater extent than the rate of brine injection under the experimental conditions examined. In spite of differences in the experimental conditions tested, as well as those reported in the literature, initial and residual saturations were found to follow a consistent relationship.  相似文献   
25.
L. Jiang  W. Pan  C. Cai  L. Jia  L. Pan  T. Wang  H. Li  S. Chen  Y. Chen 《Geofluids》2015,15(3):483-498
Permian hydrothermal activity in the Tarim Basin may have been responsible for the invasion of hot brines into Ordovician carbonate reservoirs. Studies have been undertaken to explain the origin and geochemical characteristics of the diagenetic fluid present during this hydrothermal event although there is no consensus on it. We present a genetic model resulting from the study of δ13C, δ18O, δ34S, and 87Sr/86Sr isotope values and fluid inclusions (FIs) from fracture‐ and vug‐filling calcite, saddle dolomite, fluorite, barite, quartz, and anhydrite from Ordovician outcrops in northwest (NW) Tarim Basin and subsurface cores in Central Tarim Basin. The presence of hydrothermal fluid was confirmed by minerals with fluid inclusion homogenization temperatures being >10°C higher than the paleo‐formation burial temperatures both in the NW Tarim and in the Central Tarim areas. The mixing of hot (>200°C), high‐salinity (>24 wt% NaCl), 87Sr‐rich (up to 0.7104) hydrothermal fluid with cool (60–100°C), low‐salinity (0 to 3.5 wt% NaCl), also 87Sr‐rich (up to 0.7010) meteoric water in the Ordovician unit was supported by the salinity of fluid inclusions, and δ13C, δ18O, and 87Sr/86Sr isotopic values of the diagenetic minerals. Up‐migrated hydrothermal fluids from the deeper Cambrian strata may have contributed to the hot brine with high sulfate concentrations which promoted thermochemical sulfate reduction (TSR) in the Ordovician, resulting in the formation of 12C‐rich (δ13C as low as ?13.8‰) calcite and 34S‐rich (δ34S values from 21.4‰ to 29.7‰) H2S, pyrite, and elemental sulfur. Hydrothermal fluid mixing with fresh water in Ordovician strata in Tarim Basin was facilitated by deep‐seated faults and up‐reaching faults due to the pervasive Permian magmatic activity. Collectively, fluid mixing, hydrothermal dolomitization, TSR, and faulting may have locally dissolved the host carbonates and increased the reservoir porosity and permeability, which has significant implications for hydrocarbon exploration.  相似文献   
26.
Bayesian statistics has now demonstrated its strong utility in archaeology, specifically through software that conditions radiocarbon data. Only recently has this technology been applied within Maya archaeology, however, in part because the Maya calendar provides a much greater resolution in dating archaeological events than is possible with radiocarbon data. The Long Count in particular allows for the assignment of some events relative to each other, accurate to the day. In this paper, a new approach is presented to incorporate robust records of both in the same Bayesian analysis through the OxCal software. The results do call for a reconsideration of the earliest radiocarbon studies in the Maya area from the 1960s, as well as the latest attempts to corroborate the currently popular calendar correlation known as the GMT. This new study demonstrates the value of the approach and corroborates the 1σ accuracy of the GMT, while at the same time opening up the possibility of revision by 20 or more years.  相似文献   
27.
The grounds of 51 post‐Byzantine icons (Eastern Orthodox panel paintings) were studied by means of analytical techniques. The artefacts cover the period from the mid‐15th to the mid‐19th century and originate mainly from western (Epirus and the Ionian Islands) and southern Greece (Crete). The findings are examined in the light of technical recipes from related areas and eras, while special insights are gained from the exploration of a gypsum processing recipe by Dionysius of Fourna. A spectrum of ground fabrication practices that is richer than that reported so far or can be deduced from surviving Greek recipes is documented; three instances of ‘grosso‐sottile’ type grounds and a case of ‘inverse grosso‐sottile’ ground are among the reported novel, for post‐Byzantine icons, findings. Moreover, a case of an early icon restoration intervention is documented.  相似文献   
28.
The Akko 1 shipwreck was an Egyptian armed vessel, built at the beginning of the 19th century. A wooden saw handle and a box containing iron nails and two split pins were discovered towards the stern. Given their function, location and context, these were part of the ship's carpenter's tools and accessories. A methodology was developed for conducting systematic metallurgical analysis in order to understand the manufacturing process of the surviving ironwork items, as well as to enlarge our knowledge regarding ironworking technologies during the early 19th century. Such methodology may assist in the future understanding of the technological evolution of similar wrought‐iron objects. The results demonstrated that the artefacts have a wrought‐iron heterogeneous microstructure and were manufactured by hot‐working prior to surface hardening by pack carburization.  相似文献   
29.
为了探索一种适宜的遗址文物保存方式,在四季分明,气候变化较为剧烈的西北地区的文物遗址环境区,达到最大程度保护遗址文物的目的,通过对开放式的秦始皇兵马俑博物馆一号坑遗址环境的建筑结构、温度和相对湿度变化及大气颗粒物进行分析监测,并与封闭式汉阳陵博物馆外葬坑的结果进行对比研究,发现单从环境温湿度恒定、阻挡室外颗粒污染物和气态污染物的角度来讲,封闭式的汉阳陵博物馆存在明显的优势。但依然不能阻止温湿度的季节间波动和室外空气污染物渗入的威胁,同时还要预防室内污染的发生,并且出现玻璃护围内部结露,文物大面积返碱等问题,并不能很好解决文物良好保存和观展目的。所以依旧需要探索一种适宜的遗址文物保存方式,既能保持文物保存环境的温湿度的相对稳定和洁净,又能缓解全封闭玻璃护围内部结露,文物大面积返碱等问题,最大程度延长遗址文物的寿命的同时,满足观众参观的需求。本对比研究结果可为今后的设计提供参考。  相似文献   
30.
The oldest extant musical instruments in the world are stone chimes. This music was created by the ‘eight tones’ that could be produced by these ‘stone’ voices. Although many of these stone chimes have been unearthed from sites predating the Spring and Autumn Period and the Warring States Period in China, their discussion in archaeological reports is usually not very thorough. In this paper, the ancient and modern samples are analysed from the point of view of lithology. The aim is to explore how the ancients chose to make these stones, and to check that the type of stone from which these ancient Chinese stone chimes are made is actually those recorded in previous studies. The results show that most of the ancient stone chimes in China are made of limestone. These chimes required a material with a single, homogeneous and compact mineral composition. Lingbi chimes (a kind of ‘lithophone’ produced in Lingbi county, China, are pure in composition and have a fine microcrystalline structure, which is the best choice for making stone chimes. This paper makes a systematic study of the lithology of Chinese stone chimes. The results supplement a significant lacuna in the study of ‘lithophone’ and ancient stone instruments both in China and on a more global scale.  相似文献   
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