Abstract:Most of the jade artifacts unearthed from Fuquanshan site in Qingpu District of Shanghai have not been tested scientifically. In this study, six jade artifacts of Songze culture and 478 jade artifacts of Liangzhu culture were microscopically observed and nondestructively analyzed using Fourier transform infrared (FTIR), portable X-ray fluorescence (pXRF) and Raman spectrometry. The results show that jade artifacts of Songze culture are made of tremolite, serpentine and fluorite, while those of Liangzhu culture are made of tremolite, serpentine, quartz, illite, fluorite, steatite and turquoise. It is confirmed that some tremolite samples have graphite inclusions, and the Sr contents of all tremolite samples are lower than 50 μg/g, which is inconsistent with the known Meiling jade from Jiangsu Province. It is also revealed that the tremolite jades and serpentine jades both have two genetic types—ultrabasic rock type and marble type, indicating that the jade materials used from Songze to Liangzhu periods have the characteristics of multiple sources. This finding provides an important new material for the comprehensive understanding of the development of prehistoric cultures in south China from the perspective of jade use.

Abstract:Changsha kiln was a famous export kiln during the Tang Dynasty. Products with the monochrome transparent lime glaze were fired in its early stage and later developed into those with the polychrome transparent or opaque lime glaze. At the time, Changsha kiln became famous and clearly reflected the cultural exchanges between China and foreign countries. The opaque glaze, especially the opaque white glaze, which was widely used in Changsha kiln, provided an important glaze layer for its color paintings. In view of this, we took some Changsha kiln porcelain pieces unearthed from Tongguan kiln and Huangsipu sites as the research samples and tested their bodies and glazes by means of energy dispersive X-ray fluorescence (EDXRF) spectrometry, optical microscopy (OM), scanning electron microscopy (SEM) and spectrophotometry. In our study, raw materials for the bodies and glazes, glaze opacification mechanism and reasons for the rise of opaque glaze products of Changsha kiln are discussed. These provide a scientific basis for the comprehensive understanding of the source of the glaze-making technology for Changsha kiln opaque glaze porcelains.

Abstract:Proteinaceous binding media, including animal glue, egg white, egg yolk and porcine blood, were widely used for organic cultural relics in China. Gas chromatography/mass spectrometry (GC/MS) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) are often used for their identification. According to literature reviews, marker compounds of animal glue and egg yolk are relatively clear, but those of egg white and porcine blood are still controversial. However, there is no further subdivision of animal glue in the literature, and marker compounds of egg yolk are consistent with other materials commonly used for ancient organic objects, such as wax, oil and lacquer, which makes it difficult to identify egg yolk in complex ancient objects. In our study, thermally assisted hydrolysis-methylation pyrolysis-gas chromatography/mass spectrometry (THM-Py-GC/MS) was used to analyze six kinds of proteinaceous binding media—bone glue, hide glue, fish maw glue, egg white, egg yolk and porcine blood—which were commonly used for ancient murals, paintings and other cultural relics. Their spectra were analyzed according to the RAdICAL system developed by the Getty Conservation Institute, and their characteristic pyrolysis products were also summarized. The results show that 1) pyrroles, especially pyrrole, diketodipyrrole and diketopiperazines can be used as recognition components of bone glue and hide glue; 2) besides pyrroles mentioned above, recognition components of fish maw glue also include cholesterols; 3) indoles, blood/egg white marker compounds, prolines and trimethyl phosphate are recognition components of egg white and porcine blood, and cholesterol compounds are also recognition components of porcine blood in addition to the above four kinds of compounds; 4) recognition components of egg yolk are trimethyl phosphate, egg yolk marker and cholesterols. According to this method and data interpretation, the six common proteinaceous binding materials in cultural relics were successfully recognized and distinguished, which gives support to solving archaeological problems and conserving cultural relics. Finally, principal component analysis (PCA) was used to interpret data of the six proteinaceous binding materials and a piece of film from a sculpture of Avalokitesvara Bodhisattva of Longshan Temple in Anhai County, Quanzhou, Fujian Province. It was determined that the proteinaceous materials of the film were animal glue (bone glue or hide glue) and egg white. In our study, PCA was used to interpret THM-Py-GC/MS data and presented a credible result in the field of archaeometry and cultural relic conservation. This study, to a certain extent, has solved the problem of identifying proteinaceous binding media in organic cultural objects. Six kinds of proteinaceous binding media were successfully identified using THM-Py-GC/MS, and their data were reinterpreted using PCA. Visual classification of the six kinds of proteinaceous binding media was realized. The methods were successfully applied to an ancient Bodhisattva sculpture, providing a new opportunity for their development.

Abstract:In order to reveal the compositions of pigments and adhesives used for polychrome clay sculptures of the Liao Dynasty in Huayan Temple in Datong, we carried out comprehensive analysis of typical polychrome samples. Digital microscopy, scanning electron microscopy-energy dispersive spectrometry (SEM-EDS) and micro-Raman spectrometry were used for pigment analysis. The results show that the red pigments are mainly lead red (Pb₃O₄) and cinnabar (HgS), the green ones mainly malachite [Cu₂CO₃(OH)₂] and atacamite [Cu₂(OH)₃Cl] (these two samples were mixed with two different pigments in similar colors), the blue one is azurite [Cu₃(CO₃)₂(OH)₂], the yellow one orpiment (As₂S₃) and the gold area mainly composed of gold(Au). The composition of adhesives in polychrome samples was detected by Fourier transform infrared (FTIR) spectrometry and thermally assisted hydrolysis and methylation-pyrolysis-gas chromatography/mass spectrometry (THM-Py-GC/MS). The results show that the main adhesives for the gold area are heat-bodied tung oil and glue protein, indicating the existence of the traditional painting technique of “gilding”. For the other color (red, green, blue and yellow) areas, only glue protein is used as adhesives.

Abstract:Sculptures are not only a historical record of social development, the display of people’s aesthetic sentiment and spiritual life, but also a symbol and carrier of advanced cultures. As modern artworks, copper sculptures have been collected by more and more museums due to their historical, cultural, aesthetic, technological and era value. Corrosion products may sometimes be produced on sculptures after years, which may affect the beauty of artworks or further damage sculptures. Therefore, it is necessary to identify corrosion products and then take suitable methods to remove them. The corrosion products includes not only inorganic copper salts, but also some organic copper salts caused by volatile organic compounds. This complexity poses great challenges for analytical detection and result analysis. Corrosion products of a copper sculpture collected by the National Museum of China were analyzed using several methods, including 3D video ultra-depth-of-field microscopy, scanning electron microscopy coupled with energy dispersive X-ray spectrometry (SEM-EDS), micro-Raman spectrometry and microscopic Fourier transform infrared (micro-FTIR) spectrometry. The corrosion products observed under an optical microscope are mainly light blue and blue. The SEM-EDS results show that there is no chloride element in the corrosion products of the copper sculptures. Accordig to the results of Raman and micro-FTIR spectrometry, it can be determined that the corrosion products are chalconatronite [Na₂Cu(CO₃)₂·3H₂O] and sodium copper formate hydroxide oxide hydrate [Cu₄Na₄O(HCOO)₈(OH)₂·4H₂O] which is rarely seen in domestic reports on copper corrosion products. It is of great significance for understanding the corrosion products of copper cultural relics. Scientific detection methods and analysis results provide important information and guidance for investigating the causes of formation of corrosion products and making proposals for the conservation of copper sculptures. Analysis of the preservation conditions and storage environment of the copper sculpture revealed that the sculptures was generally displayed or stored without independent cabinet. On the copper sculpture, there are stains which may be residues from cleaning. It is known that Cu₄Na₄O(HCOO)₈(OH)₂·4H₂O can be synthesized by storing chalconatronite in a desiccator with a formaldehyde/formic acid-rich atmosphere. Therefore, it can also be inferred that formaldehyde/formic acid exists in the exhibition or storage environment of the sculpture. The volatile organic compounds in the collection environment mainly come from the release of building materials and wood materials. In the warehouse, the bottom of the cabinet where the copper sculpture is stored is covered with wooden boards, which are the source of the release of volatile organic compounds such as formic acid and acetic acid. The above are reasons for the formation of corrosion products on the sculpture. In order to prevent the small corrosion produts from further corroding and damaging the sculpture, physical methods will be used to remove the corrosion products. In addition to keeping clean and controlling the temperatures and humidity inside and outside the storage places of copper sculptures, they should be kept away from acidic substances and items such as wooden objects that release acidic gases easily, so as to prevent harmful gases from adversely affecting cultural relics.

Abstract:As one of the main diseases of ancient murals, soot pollution has seriously affected their artistic value and visual appearance. In view of the soot diseases of grotto and temple murals, we prepared mildly, moderately and heavily sooted test blocks using simulation techniques, and conducted soot-cleaning experiments with Carbomer gel, agar gel and gellan gum. The morphology, cementation state and cleaning efficiency of soot stains were analyzed using microscopic observation, profile analysis and Fourier transform infrared (FTIR) spectrometry. The results show that the three kinds of gel materials had better cleaning effects on mildly and moderately sooted test blocks and could relieve heavy soot to certain degrees, turning dark brown pollution into light grey. Among the three, Carbomer gel has the best cleaning effect. After observing interfaces with a portable microscope, we found that 1) black and brown stain particles were densely distributed in the uncleaned area, and that stain particles in the cleaned area were greatly reduced; 2) in contrast, after cleaning, small amounts of stain particles and pigment particles were alternately distributed in the uncoated murals, and the coated murals were free of stains except for only a few small brown bubble structures on the surface of the heavily sooted test blocks (the natural colors of pigments can be completely recovered, and the brightness of murals can be greatly improved). In addition, there was no gel residue on the wall paintings according to FTIR analysis. However, the soot-cleaning effect is affected by many coupling factors, such as whether a mural has a coating, degrees of aging, concurrent vulnerability to diseases, types of soot or burning, degrees of combination between soot stains and mural pigments, and differences between fuel media that lead to sooting. At present, cleaning with gel is only suitable for soot of coated murals and non-heavy soot of uncoated murals. This study may provide a reference for the cleaning of soot diseases of ancient murals.

Abstract:Grottoes are widely distributed in Gansu Province and most of them were excavated in sandstone. Due to long-term influences of natural environment, the surfaces of sandstone grottoes have been seriously weathered, with some areas even becoming powdery. Therefore, prevention and control of weathering of sandstone grottoes will become an important research direction. This study paid attention to the typical weathering disease of sandstone in Beishiku Temple. We selected seven kinds of prevention materials including 0.5% hydroxymethyl cellulose, 5% sandstone reinforcement material, 1.5% silicone-modified acrylic acid, 1.5% acrylic acid, 20% nano-SiO₂,10% tetraethyl orthosilicate and 3% potassium silicate. Based on laboratory tests of the weathering prevention performances of these materials (the macro- and micro-characteristics before and after reinforcement were qualitatively described, and chromaticity, volume change rate, wave velocity, surface hardness, compressive strength, air permeability and water absorption were used as quantitative evaluation indexes of reinforcement), we finally selected sandstone reinforcement material, silicone-modified acrylic acid, nano-SiO₂, potassium silicate and tetraethyl orthosilicate as recommended materials. The results provide basic research data for the research and application of weathering prevention technology for Beishiku Temple.

Abstract:Characters recorded in ancient calligraphy and painting works are precious historical information, and the extraction and recognition of faded characters is the basis for the excavation and display of historical value. This paper proposes for the first time a method for the automatic extraction and recognition of characters of faded texts in ancient calligraphy and painting works based on the combination of the spectral enhancement index and LeNet-5:utilizing the advantages of nondestructive hyperspectral-imaging detection and a wide spectral range to acquire hyperspectral data from ancient calligraphy and painting works, analyze the spectral characteristics of texts and backgrounds and construct handwriting enhancement indexes, so as to realize the enhancement of faded texts in ancient calligraphy and painting works; constructing the LeNet-5 convolution neural network which uses a handwritten Chinese character set for training to automatically recognize the binary image of the extracted text. Finally, some faded characters in the painting, Lun Dao Tu, by Zhang Shibao (1805—1878), a famous artist in the Qing Dynasty, were used as examples to verify the proposed approach. The accuracy of character recognition is 70.8%. The results show that the method proposed in this paper can effectively improve the intelligentization of extraction and recognition of faded characters in ancient calligraphy and painting works.

Abstract:Fragile remains with complex overlapping are often encountered in archaeological excavations and are difficult to extract. This paper takes, as an example, the left wheel remains of the No.5 chariot from CMK2 at Gujun site in Xingtang County, Hebei Province, for introducing a method for the extraction of large fragile remains using the technology of temporary consolidation with menthol and rigid support. Through careful excavation and pre-detection, wheel body reinforcement, temporary consolidation with menthol, rigid bracing addition, overall extraction, back cleaning and reinforcement, front cleaning conservation and other technical processes, the left wheel remains were successfully extracted and conserved. Among these processes, excavation technology, rigid support technology and menthol as a temporary consolidant play key roles. This study provides a technical reference for the overall extraction and conservation of such large-plane fragile remains.

Abstract:The HDI trimer is a chemical reinforcement material for paper. In order to evaluate its safety for the reinforcement of handwriting on paper relics, we selected handwriting materials, Chinese ink, carbon ink, blue-black ink, pure blue ink, red ink and pencil, which are commonly seen in paper files. We noted the color changes before and after reinforcement and the diffusion of the handwriting materials. We also compared the HDI trimer with other reinforcement materials such as chitosan, carboxymethyl cellulose and a gelatin-glycerin solution. In addition, we did a comprehensive analysis of its durability according to the resistances to acid, alkali, oxidation and dry heat aging, and also further investigated the effects of conservation on handwriting. The results show that 1) the HDI trimer performs better than other reinforcement materials in terms of safety; 2) with regard to durability, the HDI trimer has good conservation effects on handwriting materials of Chinese ink and carbon ink, but relatively poorer conservation effects on those of blue-black ink, pure blue ink, red ink and pencil. In addition, in order to achieve ideal reinforcement effects, appropriate mass fractions of the reinforcement material should be chosen according to the characteristics of different writing materials.

Abstract:Nanshan Temple in Taizhou was once a royal temple but now is a historical and cultural site protected at the provincial level in Jiangsu. In 2019, Nanjing Museum designed a protection scheme for ancient architectural polychrome paintings in the Great Buddha’s Hall of Nanshan Temple. In this study, the paintings were tested and analyzed for the first time since the foundation of the People’s Republic of China. Small amounts of pigments were scraped as samples for a series of observations and analysis, including ultra-depth-of-field microscopy, X-ray diffraction (XRD), scanning electron microscopy-energy dispersive spectrometry (SEM-EDS) and Raman spectrometry. The results show that the red pigment is cinnabar, the blue one ultramarine blue, the green one lavendulan and the white one limestone. The detection and analysis results provide important information for the research on high-grade temple buildings in Jiangsu Province.

Abstract:Wood and paper materials are the main sources of organic acids in the air of museums. Released volatile organic acids include formic acid, acetic acid, propionic acid, butyric acid, valeric acid and other short-chain organic acids. These organic acid gases will lead to the corrosion of bronze relics, surface weathering of lead utensils, corrosion and embrittlement of enamel and pottery, deterioration of silk fibers, and shortening of paper life. In our study, a method based on ion chromatography for the simultaneous determination of formic acid, acetic acid, propionic acid, butyric acid and valeric acid in the air of museum was established. Using ultrapure water as an absorbent with the volume of 10 mL, air samples were collected by the active sampling method at a flow rate of 400 mL/min. A 5 mmol/L KOH eluent was used for isocratic elution, and concentrations of the five volatile organic acids could be determined simultaneously within 9 min. The results show that in the linear range of 0.05~0.5 μg/mL, correlation coefficients of formate, acetate, propionate, butyrate and valerate were higher than 0.995, detection limits were 0.001~0.009 μg/mL and quantitation limits were 0.004~0.030 μg/mL. Recoveries of the five organic acids were 91.4%~107.4%. Concentration ranges of formic acid and acetic acid detected in Warehouse A were 36.40~85.44 μg/m³ and 274.42~312.11 μg/m³, respectively, and concentration ranges of formic acid, acetic acid and propionic acid detected in Warehouse B were 18.66~34.00 μg/m³,123.53~152.55 μg/m³ and 15.80~24.48 μg/m³, respectively. This method has the advantages of simple sampling, no sample pretreatment, short detection time and low cost, which is suitable for the daily detection in museums.

Abstract:This paper is a literature review that traces the development and technical characteristics of the winding machine. The winding machine can be designated as manual and electric according to its transmission mode, and as vertical and the horizontal according to its mechanical structure. Limited by technical conditions, the early winding machine featured complex mechanical structures, low weaving accuracy, heavy weight and inconvenience for carrying, which restricted its use environment. Using the 3D modeling technology to design the winding machine structure and optimizing the configuration of mechanical materials in combination with the principles of mechanical mechanics, this research resulted in an improved winding machine. It has the advantages of simple operation, high weaving accuracy, stable operation and convenient movement and transport, so as to meet the needs of textile cultural relic conservation under complex conditions.

Abstract:Tremolite-actinolite jade is an outstanding representative of traditional Chinese culture and its conservation and inheritance are worthy of attention. In this paper, influences of human behavior before jade burial and natural alteration processes after jade burial are organically combined, and disease characteristics and formation mechanisms, restoration and protection strategies of tremolite-actinolite jade are systematically sorted out. The results show that the disease characteristics of unearthed jade artifacts mainly include ten types:four types, including cracking, peeling, breaking and incompleteness, can be caused by human behavior; five types, including surface contamination, surface crusting, holing, powdering and detachment of composite materials, are caused by natural alteration; the phenomenon of discoloration can be caused by human behavior or natural alteration separately or both jointly. Restoration of unearthed jade artifacts should follow the principle of minimal intervention, with restorers doing as little as possible to them. For artifacts suffering from serious holing, powdering or detachment of composite materials, reinforcement is recommended to maintain their basic shapes. Preventive conservation of unearthed jade artifacts requires setting medium to high humidity conditions, avoiding ultraviolet light during exhibition and packaging with non-acidic materials during storage. The purpose of this work is to closely combine conservation and archaeological work, not only for jade conservation, but also for jade archaeology, which in turn contributes to the inheritance of such precious cultural heritage.

Abstract:China is located between the Pacific Rim seismic zone and the Eurasian seismic zone, thus damage of cultural relics caused by earthquakes has occurred from time to time. In recent years, many developments have been achieved in terms of earthquake prevention technology for cultural relics, and integrated earthquake prevention systems have also been successfully applied in some museums. However, in general, risk prevention and emergency management are relatively weak. The use of inappropriate prevention approaches, lack of daily management and emergency capacity have been found in some museums. Therefore, it is very necessary to establish an earthquake emergency management system for cultural relics, in which the emergency plan is particularly important. By establishing an earthquake emergency management system, the awareness, emergency capacity and prevention approaches of museums can be improved so as to further protect cultural relics.

Abstract:Known as the “fourth milestone” in the development of ancient Chinese ceramics, the emergence of white porcelain broke the dominance of celadon and laid a foundation for the firing of color-glazed porcelain in later generations. However, the question of the origin of white porcelain has long been unresolved. Early white porcelain with uneven color distribution between blue and white is a transitional variety during the period when white porcelain was created. Therefore, scientifically defining “early white porcelain” has a direct bearing on the study of the origin of white porcelain. On the basis of related research on early white porcelain, we analyzed the problems in the scientific research on the whiteness of ancient ceramic glazes and suggested that the test method for whiteness of domestic ceramics in the light industry standard should be adopted to calculate the whiteness of ancient ceramics, so that the whiteness data published by different researchers can be compared with one another. In addition, it was proposed to use parameters of chromaticity, raw materials and firing processes as important indicators to distinguish early white porcelain from celadon, which provides new methods and ideas for the study of the origin of white porcelain.