Abstract:This paper presents lead isotopic analysis results for bronze objects from several Lower Xiajiadian culture sites and one Gaotaishan culture site. It is revealed that, except for two objects, lead isotope data of the bronzes from four Lower Xiajiadian cultural sites are quite close to each other. It is suggested that the resources of bronze objects from the four Lower Xiajiadian culture sites were most likely to be from the Dajing polymetallic deposit. It is also inferred that the bronze object with a high lead content from Dashanqian Site might be related to the Liaoning Huanren Polymetallic deposit in terms of its lead resource. The source of the raw material for an unalloyed copper object from Erdaojingzi Site is different from that of Dajing, a finding that needs further investigation in the future. The test results from Wanliu Site show that it has the characteristics of high radiogenic lead, which indicates that it had some relationship with other archaeological cultures of the same period.

Abstract:In our study, ultra-depth video microscopy, X-ray fluorescence spectrometry (XRF), ion chromatography (IC), Raman spectrometry (Raman) and scanning electron microscopy with energy dispersive spectrometry mapping (SEM-EDS mapping) were applied to analyze the corrosion on six representative samples of bronzes excavated from Yejiashan Cemetery of the early Western Zhou Dynasty. The results show that the burial environment of most tombs in Yejiashan Cemetery is neutral to weakly acid and low in chlorine, which protected bronzes from corrosion. The structures of the corrosion products are complicated, consistent with the results from the water-corrosion imitating experiments. The only tomb having an alkaline and rich-chlorine environment is M46. The powdery corrosion products of the sample from this tomb contains harmful corrosion belonging to the type Ⅱ “coarse surface”, which suggests that some effective measures should be taken to protect bronzes from this tomb. This study combines Raman spectrometry and SEM-EDS mapping analysis to indicate the corrosion layers of ancient Chinese bronzes; the results show that the methods could be applied to investigate the corrosion layer structure of bronzes quickly, efficiently and specifically.

Abstract:In order to compare the rust removal effects of commonly-used reagents for iron artifacts and to provide suggestions for the selection of reagents during iron artifact conservation, we carried out experimental studies using phosphoric acid, citric acid, tartaric acid and Na₂EDTA. Various kinds of samples such as rust powder, rust fragments, cast iron sheets and rusted cast iron sheets were used to quantitatively study the rust removal efficiency of the reagents and their corrosiveness to the iron substrate. The results show that 1) each of the reagents causes strong corrosion on the iron substrate, and that the corrosion rate is much higher than the rust removal rate but can be reduced by the addition of inhibitors; 2) among these reagents, phosphoric acid has the strongest ability to remove rust and it works well on both powder and fragment samples, but excessive amounts of phosphoric acid are needed to ensure the continuous rust removal, since a small amount of phosphoric acid has a passivation effect; 3) citric acid, tartaric acid and Na₂EDTA can dissolve the rust powder to some extent, but their efficiencies for rust removal from rusted fragments are very low. Consequently, phosphoric acid with a corrosion inhibitor is a suitable rust removal reagent in the conservation of iron artifacts.

Abstract:At present, research on purple octagonal column-shaped cultural relics unearthed in China is mainly concentrated on materials and production processes, and there are relatively fewer systematic discussions of their sources and functions. In our work, we used ultra-depth 3D video microscopy, polarized light microscopy, X-ray fluorescence spectrometry (XRF), X-ray diffractometry (XRD), laser Raman spectrometry and other analytical methods, to explore the surface characteristics, particle shape, material composition, production process and other information of a purple octagonal column artifact unearthed from a Qin tomb of the Warring States Period at Hejia Village of Zhouling Town. Based on our results, we discuss the possible source and evolution of the octagonal prism shape, the source of the materials, functional uses, etc. The results show that the purple octagonal prism has a microscopic morphology of purple and yellow crystal particles, and the main component is Chinese purple (copper barium silicate), which is presumed to have been fired twice to three times. Based on thorough literature review, it is speculated that the shape of the octagonal prism was greatly influenced by the native Chinese Taoist culture, and its main function is oral or congested. This work represents a significant reference for the systematic study of purple octagonal prisms unearthed in China.

Abstract:Paraloid B72 is widely used as a consolidation and sealing material for the conservation and restoration of cultural relics at home and abroad. However, there is almost no relevant discussion of proportions and scope of application as adhesives in the process of bonding, filling and coating-painting of ceramics. This article describes material properties and preparation methods of B72, and proposes standard of application proportions, the scope of application and formulations with talc for use as adhesives in the process of bonding, filling and coating-painting of ceramics, based on tests of set and working time and application conditions with different proportions of B72 in acetone. It provides simple, efficient and available application cases of B72 for conservators.

Abstract:The mortise-and-tenon joint is a main structure widely used in traditional Chinese wooden furniture. The material of antique wood furniture is perishable and prone to swelling after water absorption. Furthermore, mortise-and-tenon joints have diverse geometric features, which result in complex local stress states that may cause the tenon to be easily fractured or pulled out. To solve these problems, for Ming and Qing furniture collected in Shanghai Museum, relevant repair schemes were proposed according to the type of damage to the furniture. Then, the mechanical principle in the existing repair scheme of mortise-and-tenon joint and its rationality were elaborated on by continuum mechanical analysis, numerical simulation and performance tests. Finally, based on the mechanical model developed, the existing repair scheme used in the museum was optimized.

Abstract:Water content is one of the most commonly-used physical parameters to assess the deterioration of waterlogged archaeological wood. Currently, popular methods for the determination of water content include the drying method, the resistance method, near-infrared spectrometry, etc. However, these methods are either destructive or not applicable due to determination ranges. In order to find a non-destructive method suitable for the determination of water content of waterlogged archeological wood, relationships among water content, wet density and ash content of waterlogged wood were established in our study. Accordingly, we put forward a convenient method, called the “solution density method” to determine water content. Samples unearthed in Tianchang, Huaibei and other places were tested using this method. It was found that the data from this method, compared with standard values (obtained using dry method) were quite close (relative error within 10%), which demonstrates its reliability. A further study showed that the more the wood had deteriorated, the smaller the relative error was, indicating that this non-destructive method is more suitable for waterlogged wood with serious degradation.

Abstract:A hyperspectral imaging system was used to extract image information from three seals with low recognition and serious picture coincidence in Shanghai Museum’s Qing Ming Shang He Tu. The problem of low recognition of one seal was solved by minimum noise fraction (MNF). For the other two seals, the problem of high coincidence with the picture was minimized by band clipping combined with MNF, which effectively separated the seals from the picture and achieved satisfactory effects. The results show that MNF can effectively improve the identification of the blurred seal and also effectively separate the seals from the picture when combined with the corresponding band clipping processing.

Abstract:Soluble salts are an important cause of the weathering of stone relics. Accumulation and migration of soluble salts is inseparable from water. Salts in the top soil layer of Yungang Grottoes are an important source of the interior salts of Yungang stone relics. Therefore, it is of great significance to study the distribution characteristics of water and salts in the top soil layer of grottoes for the goal of reducing the accumulation of soluble salts in stone relics in the future. In our work, the saturated permeability coefficient, water content, void ratio and soluble salt content of soils at different depths and different locations in the top of Yungang Grottoes were systematically analyzed and tested. The distribution characteristics of water and salts in the top soil layer of Yungang Grottoes were studied in combination with the slope and vegetation coverage ratio at the sampling locations. The results show that 1) the higher the vegetation coverage ratio, the higher the water content of soil samples; 2) the larger the slope, the lower the water content of soil samples and 3) the void ratio and the saturated permeability coefficient show a linear relationship. The vegetation coverage ratio, slope and permeability are the main factors affecting the distribution of water and salts in the top soil layer of grottoes.

Abstract:Based on the investigation and study of the architectural form of Baiju Tower, we analyzed the stability of its coupled structure with both mountain body distinguishing the two situations of tall and low mountain body embedded in the tower body under gravity action and gravity and seismic coupling conditions respectively, on the basis of the Mohr-Coulomb constitutive model of rock and soil and finite element analysis technology. The following conclusions are drawn:under the action of self-weight, the overall structure safety satisfies with a high safety and stability coefficient; the stiffness of Baiju Tower is high, and the whole structure system belongs to the aseismic favorable system; the basic frequency mode of the whole structure of Baiju Temple prefers inclined model; under the action of 7 degrees (basic acceleration 0.15 g), the seismic stability of the two models is good; the main structure of the higher mountain model is basically in a safe state under 8 degree (basic acceleration 0.3 g) earthquakes, and that of the lower mountain model does not meet the requirements of stability; the model of the higher mountain body has higher safety level and stability than that of the lower mountain body model.

Abstract:Identification of species of wood components is the basic work for maintenance and protection of ancient wooden architectural objects. Our research was conducted in order to provide a basis for the selection of tree species to support the needs of renovation and protection of the hall of Zhilin Temple in Jianshui County, and also to understand the characteristics of wood culture, to identify species and to investigate the allocation of wood components in the hall. Seven hundred wood samples were identified using the methods of slicing, microscopic photography, macroscopic and microscopic characteristics analysis, etc. The results show that in the hall of Zhilin Temple, four genera of wood, namely Pinus sp., Cyclobalanopsis sp., Erythrophleum sp. and Schima sp., were used for various components. In addition, through the analysis of wood component allocation, it is found that selection of material for the hall of Zhilin Temple reached a high level, showing not only the time of construction but also the characteristics of repair.

Abstract:A lacquer inkslab is a special kind of inkslab. Both the lacquer wood inkslab and the lacquer sand inkslab are examples of it and show different technological characteristics. In the early stages, the lacquering process of lacquer inkslab was relatively simple, but in the Ming and Qing Dynasties, the lacquer sand inkslab reached the peak of its development. We carried out research on a lacquer inkslab unearthed from the tomb of Zhu Ran of the Three Kingdoms Period using micro computed tomography (CT), Raman and infrared spectrometry, etc., to explore the ancient lacquer inkslab technology. The results show that the lacquer was applied directly on the wooden body, that the exterior color of the inkslab hall and the inkslab box is the natural color of the lacquer, and that the red pigment on the edge of the inkslab hall is cinnabar. No abrasive particles, such as emery or quartz powder, were found in the lacquer layer of the inkslab hall. The inkslab was recorded as a “lacquer sand inkslab” in the archaeological report; however, the technology of lacquer sand inkslab can be found only in documents of the Ming and Qing Dynasties, and typically the inkslab hall is composed of lacquer and abrasive particles. Therefore, more suitably, the inkslab from the tomb of Zhu Ran should be called a lacquer inkslab. The experimental results of this research could provide a reference for the study of inkslabs of the two Han Dynasties.

Abstract:Conservation and restoration of cultural relics often produce gaseous and dust pollutants which do harm to human health and pose hazards to the safety of heritage objects. A professional, scientific and applicable ventilation system is the best measure for pollution control. Because of their specificity and complexity, the ventilation requirements of conservation facilities are totally different from those typically encountered by civil engineers. Thus problems often occur in museum constructional engineering due to the lack of relevant experience. In this paper, technology and design ideas and key parameters of ventilation systems for conservation facilities are discussed based on the standards of laboratory and experience of relevant projects. It could be helpful to other museum construction projects.

Abstract:Modern instrumentation and analytical methods can provide disease information and evaluate effects of conservation on leather cultural relics, providing scientific bases for their conservation and restoration. This paper introduces the characteristics and advantages of some analytical technologies and methods, including surface, spectral, and thermal analysis, and combinations of these, as well as their respective applications in the conservation of leather cultural relics. The primary goals of this work are to conduct a systematic and comprehensive study of leather cultural relics, qualitatively and quantitatively investigate the effects of environmental factors on the physical and chemical properties and microstructures of leather cultural relics from both macro and micro perspectives, create a testing database and a standard disease gallery and establish an effect evaluation system in terms of deterioration and disease prevention and control of leather cultural relics to guide future development and show trends.

Abstract:Bassanite (CaSO₄·0.5H₂O) is a kind of common traditional material used in cultural relic restoration. It has been applied to the restoration of cultural relics, either as a single component or in mixtures with other materials and shown its applicability to cultural relics with a variety of textures. The methods of application of CaSO₄·0.5H₂O, either as a single component or mixed with other materials, to cultural relics restoration were analyzed. The methods involving mixed materials can be divided into six types. In view of the appearance of high strength CaSO₄·0.5H₂O and other new materials, the development trend of CaSO₄·0.5H₂O are also prospected.