首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
存世印谱中比较常见的一类病害是印蜕中印油老化导致的渗化问题。研究表明,印油渗化不仅会在印蜕四周形成黄色或棕色的油渍,而且会导致纸张pH值降低,影响印谱的长久保存。通过对印泥中常用的蓖麻油、菜籽油、茶油、调和印油等六种油脂进行模拟老化实验,发现油脂老化后普遍存在变色、pH值下降和渗化问题。采用气相色谱-质谱联用技术分析老化前后的油脂样品,发现油脂在老化过程中,不饱和脂肪酸含量降低,饱和脂肪酸占比增加,并形成了壬二酸等脂肪族羧酸。油脂老化过程中的成分变化,导致了变色、酸化、渗化等一系列问题。在印谱实物样品中也发现了饱和脂肪酸。在印谱的保护工作中,应对油脂的老化进行有针对性的处理。  相似文献   

2.
Analysis of absorbed organic molecules in groundstone could provide a valuable means to study resource use and processing in antiquity. The following study analyzed extracts from the surfaces of several central California milling tools to assess whether organic residues remained from prehistoric resource processing. It also sought to determine which source identification methods are likely to be successful at providing information about the type, or even the specific identify, of resources that were processed. Lipids (primarily fatty acids) were analyzed using GC–MS and the presence of phenolic compounds was assessed with UV-Vis spectroscopy. Milling surfaces were compared to previously broken surfaces from the same tool with the assumption that both surfaces had been exposed to similar post-depositional conditions. Results supported the presence of ancient residues in milling tools. A higher concentration of fatty acids was recovered from milling surfaces than paired broken surfaces. Furthermore, measurable amounts of azelaic acid (an oxidation product of some unsaturated fatty acids) were present in most milling surfaces, but not in broken surfaces. However, results also indicated that environmentally absorbed lipids formed a significant portion of the total lipid content. Thus, it is suggested that future analyses employ a biomarker approach, rather than criteria based on ratios of common fatty acids, to identify sources of organic residues in prehistoric milling tools.  相似文献   

3.
The partially mummified remains of a high-status female (ca. 1700 BP, Thessaloniki, Greece) were found inside a Roman-type marble sarcophagus containing a lead coffin. The individual was positioned on a wooden pallet, wrapped in bandages, and covered with a gold-embroidered purple silk cloth. Besides the clothes, remnants of soft tissue as well as the individual's original hair style and eyebrows were exceptionally well preserved. In addition to the macroscopic examination, microscopic and biochemical analyses were undertaken. Scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) analysis, and gas chromatography/mass spectrometry (GC/MS) were applied to examine the tissue preservation and probable mechanisms of mummification. The presence of chemical components, such as sesquiterpenes, triterpenoids, and diterpenoids, originating from coniferous and pistacia resins, myrrh, and other spices, verify ancient information on preparation methods of the dead in Greek and Roman times. These chemical components are thought to have played a prominent role in the mummification mechanism in this particular case. The potential effect of the lead coffin in the mummification process was also examined. Energy-dispersive X-ray analysis failed to detect lead penetration into the tissues, suggesting that the coffin played a limited role in the preservation of soft tissue.  相似文献   

4.
The presence of DNA has been demonstrated in the cell nuclei of an ancient Egyptian mummy fragment. When extracted, this DNA proved to be degraded to a considerable extent and chemically modified. However, the preservation of nucleic acids in this specimen suggests that applying recombinant DNA techniques to the study of ancient mummified tissues might prove to be a fruitful future area of research.  相似文献   

5.
Bones submitted to heat experience structural and chromatic modifications. In particular, heat-induced bone warping and thumbnail fractures have been linked to the burning of fleshed and green bones – where the soft tissues have been removed from the bones soon after death – in contrast to dry bones. Those have been suggested as indicators of the state of the individual before being burned thus allowing inferences about the funerary behaviour of archaeological populations. A large sample of 61 skeletons submitted to cremation has been examined for the presence of both of these heat-induced features. Although uncommon, bone warping and thumbnail fractures were present in some of the skeletons demonstrating that its presence is not restricted to the burning of non-dried bones as generally believed. Rather than being an indicator of the presence of bones with soft tissues, bone warping seems to be more of an indicator of the preservation of collagen–apatite links which can be maintained on dry bones with low collagen deterioration. In addition, our results also do not confirm thumbnail fractures as an exclusive sign of the burning of bones with soft tissues. As a result, these heat-induced changes should be used with caution when trying to infer about the pre-burning state of an individual.  相似文献   

6.
Fatty acids, typical to large herbivores, were isolated from a 7th century Byzantine sounding lead recovered from a shipwreck off Dor, an ancient anchorage in Northern Israel. The fatty acids survived by being sheltered in an anaerobic environment provided through a site formation process induced by the disintegrating wreck. Previously established identification criteria for fatty acids, absorbed in ceramics, were used to show that tallow was used in this navigational instrument in the Eastern Mediterranean during late antiquity.  相似文献   

7.
This paper narrates the history of the conservation of the human brain, tracking techniques of brain archiving from the first experiments in the preservation of soft tissue in spirits of alcohol to the latest refinements in cryogenic technology. It traces the changing social and legal conditions that permitted the collection of post mortem human tissue, as well as the increasingly sophisticated technologies that allowed for the preservation and storage of this material. This preliminary survey of brain archiving uses examples of specific collections in order to discuss changes in the techniques, goals and achievements of neural tissue collecting from the mid-eighteenth to the late twentieth centuries.  相似文献   

8.
This paper narrates the history of the conservation of the human brain, tracking techniques of brain archiving from the first experiments in the preservation of soft tissue in spirits of alcohol to the latest refinements in cryogenic technology. It traces the changing social and legal conditions that permitted the collection of post mortem human tissue, as well as the increasingly sophisticated technologies that allowed for the preservation and storage of this material. This preliminary survey of brain archiving uses examples of specific collections in order to discuss changes in the techniques, goals and achievements of neural tissue collecting from the mid-eighteenth to the late twentieth centuries.  相似文献   

9.
The corpse of a well‐preserved dog was recovered from a peat bog in the region of Burlage, Germany, in 1953. The dog, which dates to the 16th century, retained extensive soft tissue and fur on the postcranial body, although the head is skeletonised. Computed tomography was used to determine the extent of the preservation of the soft tissue, to determine sex and age and to attempt to identify trauma, pathology and potential cause of death. The analysis of the CT data indicated that the dog was an immature or adolescent male. Substantial soft tissue was preserved, including some internal organs. The entire skeleton was present, with the exception of the mandible and parts of the paws; all of the bones were flattened and some were distorted because of demineralisation in the peat. Partial disarticulation of the vertebral column was postmortem, although there was no further evidence of trauma or pathology on the skeleton or soft tissue. The cause of death could not be conclusively determined. To the knowledge of the authors, this dog represents the only known example of a complete historical nonhuman bog body with preserved soft tissue. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

10.
Historical towers, in particular medieval towers, are an important part of cultural heritage, and their preservation mandates monitoring and detailed analyses of vulnerability under seismic actions as well as of their long-term performance. Certain aspects of structural nature are linked to the masonry behavior as a unilateral material, and other are aspects related to the interaction with soft soil conditions. This study aims to contribute to the aspects of preservation by exploring the role of the soil-structure interaction in predicting the behavior of the structures, with specific reference to the well-documented case history of the medieval Ghirlandina Tower (Modena, Italy). A significant contribution comes from an experimental identification analysis, performed in the presence of ambient vibration. A novel finding is that the soil structure interaction cannot be neglected, in contrast to most published identification analyses that usually assume the structure to have rigid constraint at base.  相似文献   

11.
文化遗产的气味不仅反映了文物的历史信息,还对文化遗产自身产生持续性的影响,因此了解文化遗产的气味对其价值研究和当代保护都具有重要意义。本工作采用固相微萃取-气相色谱-质谱技术对中国国家博物馆藏《江友渚等七挖书画轴》天头用纸散发的气体进行了采集、分离和分析。结果表明:与纸张降解相关的标志物(如脂肪酸、醛、酮等)得到有效采集;而其他生物标记物(如沉香螺醇)的检出也反映了该书画轴的历史保存环境信息。此方法对该件书画轴的历史价值认知和科学保护具有重要作用。  相似文献   

12.
ω‐(o‐Alkylphenyl)alkanoic acids are known to form in vitro from triunsaturated fatty acids following protracted heating. These compounds have recently been identified in absorbed lipid extracts obtained from archaeological pottery vessels, providing a potentially valuable new class of indicator for the processing of commodities, such as marine oils, which contain high abundances of polyunsaturated fatty acids. Experiments were conducted to assess whether ω‐(o‐alkylphenyl)alkanoic acids form when pure compounds and complex triacylglycerol mixtures are heated with a fired clay. The results demonstrate that ω‐(o‐alkylphenyl)alkanoic acids are only produced following heating of unsaturated fatty acids (tri‐, di‐ and monounsaturated species) or complex unsaturated fatty acyl lipids at around 270°C. Heating saturated fatty acyl lipids does not yield ω‐(o‐alkylphenyl)alkanoic acids. Thus, when searching for evidence for the processing of marine derived animal fats in archaeological pottery vessels, it is essential that: ω‐(o‐alkylphenyl)alkanoic acids of carbon length C18 and C20 should be present, ideally with C22 also detectable (if only in trace abundances), together with at least one of the three isoprenoid fatty acids (phytanic, pristanic or 4,8,12‐tetramethyltridecanoic acid).  相似文献   

13.
Artificial mummification in ancient Egypt involved the application of chemicals to the body mostly for the purpose of preservation; others were applied for ritual aspects. Unguents were used also in everyday toilette. Here we report a type of material which was applied specifically to the hair, a fatty material used as a ‘hair gel’. Personal appearance was important to the ancient Egyptians so much so that in cases where the hair was styled the embalming process was adapted to preserve the hair style. This further ensured that the deceased’s individuality was retained in death, as it had been in life, and emphasises the importance of the hair in ancient Egyptian society.  相似文献   

14.
Little is known about what effects conservation treatments used to preserve human and animal hard and soft tissues have on DNA preservation. We have developed a method to assess quantitatively the extent of lesions or strand breakage caused by conservation treatments on short sequences of DNA in vitro. The method developed enables the determination of the percentage of DNA preserved following exposure to a conservation treatment solution relative to control samples, thereby allowing the direct comparison of treatments based upon their preserving/damaging effects on a DNA sequence. Forty-three chemicals commonly used in the preparation and/or conservation of human and/or animal remains were examined. We found that the majority were damaging, in particular and as expected, acidic treatments and treatments carried out at elevated temperatures. A few, primarily organic solvents, were not damaging. The approach we have adopted can be applied to screen other treatments either used in the past or for future conservation applications as they are developed to assess their effects on DNA. How these results should be interpreted in terms of conservation and sampling is also discussed.  相似文献   

15.
Fatty acids distribution and stable isotope ratios (bulk δ13C, δ15N and δ13C of individual fatty acids) of organic residues from 30 potsherds have been used to get further insights into the diet at the Late Neolithic (3384–3370 BC) site of Arbon Bleiche 3, Switzerland. The results are compared with modern equivalents of animal and vegetable fats, which may have been consumed in a mixed ecology community having agrarian, breeding, shepherd, gathering, hunting, and fishing activities. The used combined chemical and isotopic approach provides valuable information to complement archaeological indirect evidence about the dietary trends obtained from the analysis of faunal and plant remains. The small variations of the δ13C and δ15N values within the range expected for degraded animal and plant tissues, is consistent with the archaeological evidence of animals, whose subsistence was mainly based on C3 plants. The overall fatty acid composition and the stable carbon isotopic compositions of palmitic, stearic and oleic acids of the organic residues indicate that the studied Arbon Bleiche 3 sherds contain fat residues of plant and animal origin, most likely ruminant (bovine and ovine). In several vessels the presence of milk residues provides direct evidence for dairying during the late Neolithic in central Europe.  相似文献   

16.
皮革很容易劣化腐变,因此我国出土皮革文物数量很少。新疆、甘肃等北方地区出土的一些皮革文物,是研究古代人们生产生活的重要实物资料。为此,本研究探讨了出土干燥皮革文物发掘前和发掘后的劣变因素,并以新疆五堡墓地出土皮革文物的保护修复过程作为实例,对出土干燥皮革的保护方法和过程进行了阐述。在显微镜观察评估病害基础上,对皮革文物采取杀虫、加湿整形等处理。结果表明:干燥皮革劣变的内因主要是皮革本身的组成结构和鞣制方法,外因则主要是皮革出土前所处的土壤埋藏环境和出土后的大气保存环境,保护处理后的皮革恢复形状,可满足展览要求。本研究结果可为出土干燥皮革文物的保护研究提供参考。  相似文献   

17.
The study of organic residues in archaeological pottery has focused on fatty acids due to their relative stability and longevity. However, even these compounds are subject to degradation, which makes assignment of residues to original foods problematic. This paper suggests that the use of ratios of fatty acids that degrade at roughly the same rate can be useful to identify very general categories of foods. It compares independent information on pot function based on ethnography and engineering/technological studies to that reconstructed based on extracted fatty acid ratios. The results support the notion that Great Basin pots were used primarily to boil seeds and that pot shape and pot function were related.  相似文献   

18.
历史街区的基本特性及其保护原则   总被引:14,自引:0,他引:14  
杨新海 《人文地理》2005,20(5):48-50
论文首先分析了历史街区的三个基本特性:风貌的完整性和典型性、遗存的真实性和空间的功能性,并据此提出和阐述了历史街区保护应遵循的原则:全面保护原则、真实性保护原则、完善功能保护原则和渐进更新保护原则,以期对历史街区的保护实践有所裨益。  相似文献   

19.
The study investigated developmental defects of the dental hard tissues and postmortem changes in archaeological pig molars from Fais Island, Micronesia. The developmental defects of enamel were indicative of a disturbance of the secretory stage (accentuation of the incremental pattern, occurrence of Wilson bands and of hypoplastic defects) and the maturation stage of amelogenesis (hypomineralisation). Presence of coronal cementum in an M3 indicated a partial premature breakdown of the reduced enamel epithelium or a partial demise of the enamel organ earlier during tooth development. Developmental defects of dentine presented as accentuated Andresen lines and areas of interglobular dentine. The pattern of developmental defects in the studied molars and the fact that deciduous premolars of the pigs from Fais did not exhibit developmental defects on macroscopic inspection are consistent with the hypothesis that the tooth defects were caused by periods of severe nutritional stress occurring after weaning. Postmortem changes caused by microbial infiltration were recorded in dentine and cementum. A presumed case of soft tissue preservation in the form of presence of odontoblast processes was observed in an M1.  相似文献   

20.
The unifying nature of water on the preservation of organic archaeological and palaeoenvironmental source material within wet deposits is well recognized. It is also understood that, while the preservation of such deposits is fundamental towards our understanding of the past, in many areas de-watering through agricultural drainage and water abstraction is degrading them. Within the framework of preservation in situ such environments present considerable challenges. Fundamentally, the environmental dynamics of wetlands, not least of water, mean that they must be monitored carefully in order to understand the condition of the burial environment and thereby the likely preservation potential. This paper presents an approach to monitoring the saturation of the burial environment and modelling this data using a geographical information system (GIS). It demonstrates a method aimed at modelling the conditions of current preservation, and predictively modelling the conditions for long-term, in situ preservation in order to provide a baseline for resource management. It is shown that the quantification of saturation is possible and advantageous in the management of dynamic wetland environments.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号