Abstract:Archaeological timbers were desalinated and then stabilized and consolidated with polyethylene glycol (PEG) after being excavated from Kuahuqiao Sites. However, due to darkening after conservation, the archaeological timbers needed to be re-conserved. In the process of re-conservation, a solution of 1,2-dimethyl-3-hydroxy-4(1H)-pyridone was selected for desalting and decolorizing, PEG was used as a stabilizing and consolidating agent, and the vacuum freezing method was used for dehydration and drying. The re-conservation has achieved good results. The dimension and shape of the archaeological wood remain unchanged, the color is more natural, and the wood texture is clear and visible.

Abstract:Water is one of the main factors causing the deterioration of brick and stone cultural heritages. Thus, clarifying the distribution and movement pattern of water inside these objects has been an important task in conservation studies. Though microwave technology shows good prospects for detecting the moisture content of these materials, it has not been widely adopted in this field. Based on this, our paper first introduces the theoretical foundation of microwave technology and the related devices. The Yuhuang Temple in Shanxi Province was then chosen as a site for measurement of the moisture content of brick and stone material, both in the laboratory and in situ. The results show that microwave technology can accurately reveal the spatial distribution of moisture inside the object, and thus can play an important role in researching the causes of various diseases. In addition, compared to some other nondestructive testing technologies, microwave technology is more advantageous in detecting the moisture content of the material. Thus it is worthy of being studied and applied by cultural heritage researchers and conservators.

Abstract:Hyperspectral imaging can acquire information on the surfaces of cultural relics in a contactless and nondestructive way. Processing and analysis of the information is very helpful for the discovery and restoration of painted patterns on the surfaces of cultural relics. Based on damage to the painted patterns on the No. 2 Qin bronze chariot unearthed from the Emperor Qinshihuang’s Mausoleum Site, we propose a digital restoration method combining hyperspectral imaging and computer image technology. On one hand, the near-infrared hyperspectral image was used to detect and recover the edges of the patterns which are difficult to recognize; on the other hand, the spectra of the unknown pigments on the painted patterns were matched with those in an established standard library of mineral pigments to identify the type of pigments (realgar 1, azurite 5, malachite 1, yellow lead and lead white, etc.) used in the painting of the bronze chariot. The results show that the method can obtain a complete digital restoration image of the painted patterns, which can provide favorable support for further research on the bronze chariot and its application.

Abstract:The study of linear features plays an important role in the field of mural protection and restoration. However, due to the natural environment or other factors, murals often suffer from many diseases which make identification of their linear features difficult. Therefore, in this study, a method combining minimum noise fraction (MNF) and Haar wavelet transform was proposed to enhance the linear features using hyperspectral images of murals. Firstly, MNF transformation was carried out on the hyperspectral images, and then the top 10 bands were selected for inverse MNF transformation for reconstruction to reduce noise of the hyperspectral image. Secondly, true color bands of the reconstructed image were transformed into a gray image, which was decomposed by Haar wavelet in the next step. Then the optimal band of the image after MNF was chosen by using the maximum average gradient algorithm. It was transformed into two parts—a low-frequency signal and high-frequency signal—by the same Haar wavelet as above. After that, this low-frequency signal part was fused with the low-frequency signal part from the gray image decomposition to get the optimized low-frequency signal. The reconstructed gray image above is considered to be the optimized high-frequency signal. Finally, the optimized low and high frequency signals were transformed inversely to the resultant image by the Haar wavelet. Comparison of the original gray image and resulting enhancement by principal component analysis, verifies the effectiveness of the linear feature enhancement method proposed.

Abstract:Ancient Chinese timber structures include mainly post and lintel and column and tie construction systems, the structural arrangement and connection joints of which are obviously different from those of modern timber structures. In order to improve the engineering practicability of structural calculations and the structural safety assessment of ancient Chinese timber buildings, simplified calculation methods were advanced. The mechanical performances of common timber rafters, common timber purlins, three-purlin beams and five-purlin beams were studied. In addition, based on the analysis of dynamic characteristics of some typical timber structures, approximate calculation models for the basic structural natural periods of these typical timber structures were proposed. These results may provide a basis and reference for structural calculations, structural safety assessments and strengthening designs of ancient Chinese timber structures.

Abstract:According to the analysis of chemical and mineral components of building mortars from the Ming Dynasty to the Republic of China, some masonry and plastering mortar is dolomitic lime or magnesium lime, and the content of MgO ranges from 5% to 26%. In particular, all mortar samples from the Great Wall belong to dolomitic lime. Compared with calcium lime, dolomitic lime boasts higher strength, lower water absorption, lower shrinkage and better workability; therefore it is more frost-resistant than calcium lime. In addition, the temperature and energy required for calcining dolomitic lime is lower than that required for high-calcium lime. It is recommended that further research on dolomitic lime be carried out systematically in China, and that it includes the type and distribution of raw material, calcination temperature, slaking, optimal formulation and technologies for restoration, etc. At the same time, it is suggested that further research also be carried out on the durability of dolomitic lime under atmospheric industrial pollution, as well as the conservation and restoration technologies for dolomitic lime-related architectural heritages.

Abstract:Faience is a kind of ancient ceramic product which was widely found in many areas. Chinese faience appeared in the Western Zhou Dynasty (1046 BCE—771 BCE). Wanfunao Site is located in Yichang, Hubei Province. The radiocarbon dating results of a series of samples show that Wanfunao Site dates mostly to the Western Zhou Dynasty. The faience beads have been excavated from Tomb M8 of the site. In this work, some of the faience beads were chosen as samples for study. Scanning electron microscopy with energy dispersive spectrometry (SEM-EDS) were applied to the analyses of microstructure and composition. The results show that some of the faience beads may have been manufactured locally in China, but for the others of these samples, because of corrosion, the flux in the glaze was below the detection limit. Based on the previously-published scientific research on faience products in the Western Zhou Dynasty and combined with relevant evidence of archaeological excavation, from the perspective of the way faience products were used, this research attempts to explore the role that faience products played in the progress of ancient spiritual civilization and the development of faience products in China.

Abstract:In our study, energy dispersive X-ray fluorescence (EDXRF) spectrometry, confocal laser Raman microspectrometry (LRS), optical coherence tomography (OCT) and optical microscopy (OM) were combined to analyze seven glass eye beads unearthed in ancient Qufu City of the State of Lu, Shandong Province. The chemical compositions, mineral phases, surface physical structures and microstructures, glass types, manufacturing techniques, provenances and functions of the glass eye beads were determined. The results obtained show that they were made in the state of Chu and then transported to the State of Lu as luxury goods. These eye beads are physical evidence of exchanges and contacts between the States of Lu and Chu.

Abstract:Inlaid objects of the Qing Dynasty are numerous and varied, and glass is one of the important materials for inlays. In this study, we analyzed the composition and manufacturing techniques of six glass inlays on a Qing Dynasty jade-inlaid hanging screen with a red sandalwood frame from the Palace Museum. Micro-area X-ray fluorescence spectrometry, scanning electron microscopy, micro-Raman spectrometry and laser-induced breakdown spectrometry were applied to the analyses of composition and microstructure. The results show that the samples belong to the K₂O-CaO-SiO₂ system. SiO₂ is introduced with quartz as the glass matrix, K₂O is introduced with niter as the flux and CaO has two main sources: calcite and fluorite. Dark blue glass is colored with cobalt, light blue glass is colored with copper and blue-green glass has copper and iron as its coloring agents. The opacifier for the four glass inlays is CaF₂. Lead-tin yellow is both the coloring agent and opacifier of yellow glass inlays. According to microscopic appearances and archives, it is considered that these glass inlays were made through secondary processing which adopted the traditional jade-manufacturing technique on the glass block.

Abstract:Some cases of scientific analysis of cultural relics based on a novel X-ray fluorescence analysis technology—scanning macro-X-ray fluorescence imaging technology (MA-XRF)—are introduced in this paper. A brief overview of development history of the methodology is given, and advantages of this methodology are discussed in relation to characteristics of different types of cultural relics. This paper also introduces several typical study cases conducted at the Palace Museum using this method for its collection of cultural relics. The purpose and significance of this research is to introduce applicable cases to the field of cultural relic conservation, point out the advantages of this technology and provide a reference for further development and application in the future.

Abstract:In our work, we examined over 20 Zhou Dynasty bronze objects including vessels, weapons, farm implements and tools unearthed at the Guangfulin Site in Shanghai. Metallographic microscopy and X-ray fluorescence spectrometry (XRF) were used to analyze the metallographic structure and composition of the alloys. The results were significant in revealing the methods of cast bronze fabrication and processing technology at that time. Based on this work, the methods of alloy composition, casting technology and diffusion of bronze in Shanghai before the Qin Dynasty are reviewed and summarized. It is expected that this work will provide more information for the future research on the development of prehistoric and pre-Qin cultures in southern China.

Abstract:A great number of polychrome potteries (Canglou) were excavated from Han Dynasty tombs at Macun and Baizhuang in Jiaozuo. The polychrome potteries contain abundant information relevant to studies of the history and ancient culture of China. Polarized light microscopy was used to identify pigments, and X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM) and thermal dilatometry, etc. were applied to analyze the composition, elements present, microscopic structure and phases of fragment samples. The results show that the pigments were mainly carbon black, bone white, cinnabar, iron oxide red and ultramarine, etc. The fragment samples were fired using local clay. They are sand-up potteries and the pottery structure is closely-grained. This study provides a lot of information for future conservation and restoration studies.

Abstract:According to the main diseases of the ontology of the site of Kizilgaha Beacon Tower, the OKIO-Ⅱ grating three-dimensional scanning system was used to monitor the characteristics of high-precision disease changes 8 times for 14 months. From the monitoring data, it was found that the annual shrinkage of the site body is relatively large. The north facade suffers the largest shrinkage and the most serious weathering, followed by the west facade; the south facade has the smallest shrinkage. The effect of gully erosion shrinkage on water flow is smaller than that of weathering, and the disease characteristics are as follows: the erosion amount along the central line is large while that of the gully sides is small; the erosion amount on the top is large while that of the bottom is small. The development rate of etching disease ranks the first. The deep shrinkage in the etching area changes greatly at both ends and the change in the middle is small. Fracture disease expansion is small, but most is transverse expansion while a few show transverse shrinkage phenomena. The overall trend is expansion. At present, the main diseases developed at the site have not affected the overall stability of the site, and the research provides an effective data support for the selection of site protection measures.

Abstract:In order to ascertain the hygrothermal environment of the middle hall building of Longju Temple, the temperature and relative humidity in building spaces were measured by a monitoring system based on Internet of Things technology. The spatial-temporal distribution of temperature and the relative humidity were analyzed. The characteristics of the hygrothermal environment were then evaluated. The influence on cultural relics was also considered. The results show that the building has good buffering and isolating effects against changes of external temperature and humidity, but that the internal hygrothermal environment is not conducive to the preservation of cultural relics due to high relative humidity and great fluctuation of humidity. Therefore, controlling humidity is the key to preventive conservation of cultural relics. The hygrothermal environment is the main cause of mildew on and other damage to the murals and it also threatens the structural safety of the bamboo-woven clay wall. These research results could enrich the hygrothermal environment understanding of ancient wooden buildings with bamboo-woven clay wall and provide a basis for understanding the causes of mural damage and wall structural problems.

Abstract:In order to fully understand the air pollution characteristics and sources of pollutants in the site area of Jinsha Site Museum, PM2.5 and VOCs levels in the atmosphere inside and outside the Site Protection Hall were observed in the fall of 2019, and their respective chemical components were comprehensively analyzed. The results show that 1) the atmospheres inside and outside the Jinsha Site Museum’s Site Protection Hall were both severely polluted by PM2.5, with their average mass concentrations of 77.0 and 94.6 μg/m³, respectively; 2) the difference between day and night levels indoors was significantly larger than that outdoors due to the degree of human activity; 3) the concentrations of OM, NO-₃ and SO2-₄ were higher outdoors than indoors, while the concentrations of NH⁺₄ and typical crustal elements (K⁺,Mg²⁺ and Ca²⁺) were higher indoors than outdoors; 4) indoor and outdoor PM2.5 levels were respectively alkaline and acidic due to the influence of their chemical compositions; 5) crustal elements dominated, with their indoor and outdoor proportions reaching 82.8% and 84.4%, respectively; 6) according to the analysis of the enrichment factor, it was found that the elements of Cu (outdoor), Ag, Cd and Sb had reached a severe enrichment; 7) the indoor and outdoor concentrations of VOCs were almost the same, 81.2×10-9 and 81.3×10-9, respectively, alkanes, contributing the most, accounting for 44% and 46%, respectively; 8) the outdoor concentrations of VOCs, derived from artificial sources such as motor vehicles, industrial solvent coatings, fuel volatilization and biomass combustion, were significantly higher than indoor concentrations. These research results were of a great significance for a comprehensive understanding of the air quality in the site area of Jinsha Site Museum, the high-quality preservation of earthen site and the cultural relics therein, and the provision of a quality visiting environment.

Abstract:Quantitative judgment, description and comparison of color are important contents in cultural relics and archaeology. Color measurement can quickly, accurately and non-destructively obtain the color data on research objects and analyze it to get more information. At present, color measurement has been widely used in the practical work of archaeological science and conservation. This paper combines domestic and foreign literature to review the application and research status of color measurement methods in cultural relics and archaeology. It is found that color measurement can effectively help solve the following problems: determination of the coloring mechanisms and production processes for cultural relics, evaluation of the effect of cleaning cultural relics and measuring the color stability of conservational materials, and analysis of the influence of environment on the color of cultural relics. With improvement and development of colorimetric theories and methods, as well as combination with other analytical techniques and methods, optimized colorimetric measurement conditions can be developed. In addition, the color appearance model of the cultural relics by calculation and processing of color data and the digital color management system will play a greater role in cultural relics and archaeology.