Abstract:The growth of molds on the surfaces of polychrome cultural relics will cause serious damage to cultural relics by changing the color and appearance and destroying the overall stability. An important method to prevent and control the mold damage is to use fungicides. Previous studies have found that different strains have different sensitivities to specific fungicides, and the concentration is not always the same. Therefore, in the face of complex and diverse molds in the actual conservation work for cultural relics, how does one select effective fungicides and adopt appropriate concentrations for mildew-proof treatments？ This has become the bottleneck problem of using fungicides to prevent polychrome cultural relics from being mildewed.In order to explore the methods for selecting the types and concentrations of fungicides for polychrome cultural relics, 12 kinds of fungicides, including isothiazolinone, tebuconazole, natamycin, clotrimazole, benzalkonium chloride, dichlorophenol, cinnamon essential oil, clove essential oil, thyme essential oil, basil essential oil, benzimidazole and nanosilver were selected, and five common molds found in polychrome cultural relics, including Penicillium chrysogenum, Aspergillus versicolor, Cladosporium sp., Alternaria alternata,and Aspergillus japonicus were used as the fungi being studied. The performances of these fungicides were systematically evaluated from the aspects of their antifungal activity, drug sensitivity, color change, antifungal effect and long-term effectiveness. In addition, a preliminary fungal control evaluation method system for the prevention and control of typical molds in polychrome cultural relics was developed:1) measuring the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of the fungicides using 96-well plates for preliminary screening and also to determine whether the mold was resistant to the fungicide (according to MBC≥32MIC); 2) judging whether the fungicides will change the colors of polychrome cultural relics based on color difference values (ΔE); 3) using the spore germination rate to calculate the semi-maximum effective concentration of the fungicide (EC₅₀) and measuring the size of inhibition zone to evaluate the anti-mildew effect of the fungicides; 4) calculating the concentration of culturable fungi through the polychromy simulation experiments that monitor the long-term antifungal effect. The experimental results showed that, according to the constructed evaluation system, the fungicides (and their concentrations) with good antifungal effects and long-term effectiveness against the above five common molds were screened:0.15% isothiazolinone and tebuconazole, 2% benzalkonium chloride, cinnamon essential oil and clotrimazole. Moreover, benzalkonium chloride had strong long-term antifungal effects on the five molds. However, 0.2% natamycin caused color changes in some pigments. The fungicides were selected according to a number of indicators, and an innovative program and method system for evaluating the performance of fungicides with multiple parameters was constructed for the first time. These could fill the lack of current method systems for scientific evaluation of fungicides for polychrome cultural relics. This work provides a theoretical basis for the prevention and control of molds in polychrome cultural relics, and can have important guiding significance for the conservation of cultural heritage.

Abstract:The leather obtained through the traditional technique of “cleaning leather”, used for shadow puppets, possesses unique characteristics, such as a hard texture, resistance to bending, good transparency, and a high concentration of hydrophilic groups, setting it apart from typical soft leather. However, the conservation of shadow puppet artifacts made from this kind of leather has received limited attention in academia, with many studies even incorrectly equating the leather used for these artifacts with regular tanned leather, thereby overlooking its distinct material properties. Therefore, this study employed shadow puppet leather as a standard sample, subjecting it to controlled artificial aging processes and conducting assessments through microscopic observation, performance testing, and infrared spectrometry. This method explores the specific characteristics of environmental factors in the deterioration of leather. This study introduces two innovations:1) it proposes a method suitable for quantitatively assessing the aging and degradation of shadow puppet leather—a method characterized by small sample size, ease of operation, and cost-effectiveness; 2) based on this method, the practical assessment of shadow puppet leather demonstrates that even without the effects of tanning, the leather retains a significant degree of chemical stability through the mechanical leather-making process only.

Abstract:One of the most common diseases in seal impressions books is ink oil permeation caused by the aging of ink oil. Some research shows that ink oil permeation can not only form yellow or brown oil stains around seals, but also reduce the pH values of paper, which affects the long-term preservation of seal impressions books. Through a simulated aging experiment using six kinds of oils commonly used in the red ink paste, it was found that there were many problems, such as discoloration, pH value decrease and oil permeation after aging. GC-MS was used to analyze the oil samples before and after aging, and the result show that the content of unsaturated fatty acids was reduced and aliphatic carboxylic acids such as azelaic acid were formed during the aging process. The compositional changes in the aging process of oil lead to a series of problems such as discoloration, acidification and permeation. For the conservation of seal impressions books, targeted treatments against the aging of oil should be carried out.

Abstract:The plum blossom jade plate paper (Meihuayubanjian) is a kind of famous Qing Dynasty court coating processed paper. In this study, a white Meihuayubanjian collected in the Palace Museum was analyzed using multiple scientific approaches:1) light-transmissive photography was carried out to observe painting traces during powder application—the width of the brush tool was about 5 cm; 2) 3D video microscopy was used to observe the details of gold painting on the paper—the width of gold fragments ranged from 0.8 μm to 12 μm; 3) using optical microscopy, it was found that the paper was made from bark fiber and bamboo fiber; 4) Fourier transform infrared (FTIR) spectrometry revealed that the coating material on the paper surface was lead white pigment; 5) the ice-plum pattern and the seal were scanned using large-area X-ray fluorescence (XRF) imaging spectrometry, which showed that the main elements in the seal were Hg, Fe and Ca; 6) micro-area XRF spectrometry showed that two kinds of mud gold with different purities were used. Based on these results, the craft for making Meihuayubanjian was restored, and the replica sample made had the same material and similar appearance to the relic.

Abstract:In terms of the uses of urushi for architectural decoration and finishing in Northern China, the partitions of the Bower of Ancient Catalpa (Gu Hua Xuan) are an exceptional example. Typical samples from the objects were analyzed using various methods, such as optical microscopy, immunofluorescence staining analysis, X-ray fluorescence (XRF) spectrometry, scanning electron microscopy-energy dispersive spectrometry (SEM-EDS) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). In combination with literature on traditional lacquering and Qing Dynasty historical archives, the organic and inorganic materials, manufacturing techniques and repair history of the decoration were comprehensively described. For the partitions of the Bower of Ancient Catalpa, decorative layers of eight generations have been preserved. The initial materials of the coating are Chinese urushi mixed with tung oil. Black lacquer in different periods was obtained by adding carbon black and iron salt, respectively. For the original painting, the decoration layer followed a complete process:ground—fabric lining—plaster—black lacquer—colored lacquer—gold decoration; the method of repainting was relatively simplified and the original “homogeneous gold foil” was changed to two types of gold foils with different colors.

Abstract:Eye glass beads are the most typical type of glass artifacts from the Spring and Autumn Period and the Warring States Period to the Han Dynasties in ancient China. They played a crucial role in cultural exchanges and technological dissemination between China and foreign countries, as well as in the origination and evolution of ancient Chinese glass technology. A large number of glass artifacts dated from the Warring States Period have been unearthed in Hunan Province, with more than 200 eye glass beads alone. Many scholars have paid attention to and conducted various studies on the glass products unearthed in Hunan Province over the past decades; however, there is still a lack of specialized scientific characterization and research on eye glass beads in general. The Chu State was one of the key regions for the origination and development of ancient glass technology in ancient China, as well as for technological and cultural exchanges. Hunan Province, located in the core area of the Chu State, is of great significance to the study of the status of Hunan in the origination and development of glass handicraft technology during the Warring States Period. In order to scientifically reveal the chemical composition systems, manufacturing techniques, provenances and cultural exchanges of eye glass beads dated to the Warring States Period unearthed in Hunan Province, eleven typical eye glass beads from Changsha, Changde and Hengyang of this period were selected for scientific analysis. A portable energy dispersive X-ray fluorescence spectrometer and a 3D digital microscopic system were used for non-destructive analysis of the chemical composition, surface and cross-sectional micro-structures. Based on a combination of the obtained scientific information with previous relevant research results, this study discusses and determines the flux system, manufacturing techniques and provenance of this batch of eye glass beads.  Based on these results, it was found that the laminated inlay manufacturing technique was used for all the eleven eye glass beads. The matrix was first produced, and then inlaid with different glass strips or slices during the incomplete solidification state. In terms of the chemical composition system, the eleven eye glass beads belong to three systems:soda-lime silicate glass, lead-barium silicate glass and potash-lime silicate glass. Among them, three eye glass beads are natron sub-type soda-lime glass, and the one flat eye glass bead is plant-ash sub-type soda-lime glass. Both the two types of glass beads were probably produced in Egypt or eastern Mediterranean area, and were then transported into Hunan via the land Silk Road. Another three eye glass beads are lead-barium glass, and the remaining four beads are potash-lime glass. Both of the types are typical native Chinese glasses during the Warring States Period. These seven eye glass beads were produced by local craftsmen in the Chu State using two characteristic native Chinese formulas. However, they also drew on and imitated the shape and laminated inlay manufacturing technique of eye glass beads imported from abroad. At the same time, the potash-lime glass beads were also influenced by the technology of traditional Chinese potash-rich faience beads, demonstrating the exquisite craftsmanship and boundless creativity of ancient Chinese artisans. The research in this article, to a certain extent, scientifically reveals the main flux system and manufacturing techniques of typical eye glass beads unearthed in Hunan Province dated to the Warring States Period, and explores the possible provenances of these glass beads. The results could provide a valuable perspective on the development level of glass handicraft technology in the Chu State and surrounding areas during the Warring States Period, as well as on regional and Sino-foreign exchanges.

Abstract:A large number of different kinds of colored gemstone artifacts of the Ming Dynasty have been unearthed in China, but the vast majority of colored gemstones did not originate in China. In our work, we analyzed a sapphire inlaid on a gold crown with seven phoenixes and three dragons excavated from the Yang tomb in Bozhou of the Ming Dynasty using an integrated study of trace elements and internal inclusion characteristics, in order to investigate the provenance of the sapphire. In situ analysis of trace elements by LA-ICP-MS reveals that the sample is characterized by low Fe and Ga contents and high Mg content with a low Ga/Mg ratio, which is consistent with the sapphire of metamorphic origin and excluded from magmatic origin deposits. The internal inclusions of the sample were observed and compared with those of other samples from different metamorphogenic sapphire provenances, and it was found that they were more similar to those of Myanmar and Madagascar sapphires. Finally, in combination with the historical records of the discovery and mining of sapphire deposits in different regions, the comprehensive research and analysis led to the conclusion that the ore for this sapphire artifact most likely came from the Myanmar mines. This study could provide some scientific basis for exploring the provenances of colored gemstone artifacts represented by sapphires of ancient China.

Abstract:The Yue kiln began firing mature porcelain in the Eastern Han Dynasty, and fired celadon was its main product until the Song Dynasties. The Housi’ao kiln site, located on the west bank of the middle part of Shanglin Lake at Qiaotou Town, Cixi, Zhejiang Province, is the core kiln site among the Shanglin Lake Yue kiln sites. From October 2015 to January 2017, Zhejiang Provincial Institute of Cultural Relics and Archaeology, Underwater Cultural Heritage Conservation Center of the National Cultural Heritage Administration, Ningbo Municipal Institute of Cultural Relics and Archaeology, and Cixi Cultural Relics Management Committee Office carried out inspections of the Housi’ao kiln site. The archaeological excavation and exploration work was conducted on the underwater remains of Shanglin Lake, including the kiln site itself. A large number of exquisite Yue kiln celadon objects (including Mi’se porcelain) of the late Tang Dynasty and Five Dynasties were unearthed. This excavation clarified the basic appearance and production techniques used for Mi’se porcelain in the late Tang and the Five-Dynasty periods (represented by the Housi’ao kiln site), basic layout of the Mi’se porcelain kiln site, and provenance of the Mi’se porcelain unearthed from the underground palace of Famen Temple (Tang Dynasty) and the Qians’ cemetery (Wuyue Kingdom in the Five Dynasties). Among these issues, the reasons for the color difference between unearthed Mi’se porcelain and ordinary celadon have been a matter of long-term concern. The academic community has also carried out a lot of research work based on scientific and technological analysis and archaeological excavation data. The results show that there is no obvious difference in the chemical composition of glaze between Mi’se porcelain and ordinary celadon, but the glaze color of Mi’se porcelain is greener than that of ordinary celadon. The main reason may be that Mi’se porcelain was fired through a unique firing process with porcelain saggers and rim sealing using glaze; however, there is still a lack of experimental verification. It can be seen that from the perspective of experimental archaeology, based on the scientific and technological testing and analytical data of Mi’se porcelain and ordinary celadon, a process simulation experiment is very necessary to verify whether this kind of firing process was the key reason for the firing of Mi’se porcelain and to determine what kind of impact it could have. Based on scientific and technological analysis data of Tang and Five-Dynasty Mi’se porcelain and ordinary celadon unearthed from the Housi’ao Yue kiln site at Shanglin Lake, local sedimentary clay and plant ash, etc. were used as the main raw materials to carry out a process simulation study on Mi’se porcelain. The focus is on comparative analysis of the effects of different types of saggers (ordinary one vs. porcelain one) and firing methods (glazed sealing vs. unglazed sealing) on the color of celadon glaze. The chromaticity of the simulated fired celadon glaze and the valence state of the coloring element Fe were determined and analyzed using a variety of instruments, such as colorimeter and photoelectron spectrometer, and the function and mechanism of the method of sealing the rims of porcelain saggers with glaze to fire Mi’se porcelain were discussed. The study found that: 1) The chromaticity analysis results of 14 celadon samples analyzed in the experiment show that the glaze color of celadon fired using porcelain saggers sealed with glaze was more uniform and greenish, regardless of whether it was covered with ordinary saggers or not. Their values of a* were from -3.18 to -2.01, and their values of b* were from 13.80 to 17.28, which were significantly lower than the values of a* (from -1.49 to -1.21) and b* (from 18.16 to 20.48) of ordinary sagger-fired celadon glaze. This is consistent with the color pattern of Mi’se porcelain glazes in the Tang Dynasty compared to ordinary celadon glazes. 2) The results of photoelectron spectrometry of 7 celadon samples show that the Fe²⁺/Fe³⁺ ratio of celadon glazes fired using porcelain saggers sealed with glaze was 2.80, which was significantly higher than 0.57 of celadon glazes fired in ordinary saggers. This is consistent with the Fe²⁺/Fe³⁺ ratio of Mi’se porcelain glazes in the Tang Dynasty compared to ordinary celadon glaze. 3) The comprehensive simulation experiment and scientific and technological analysis can effectively verify that the main reason why the appearance of Yue kiln Mi’se porcelain is different from ordinary celadon is that it adopted a unique firing process—sealing the rims of porcelain saggers with glaze. Especially during the cooling stage, the sintered porcelain sagger with its rims sealed can play a good role in maintaining the reducing atmosphere in the sagger, and to a large extent, it can avoid secondary oxidation of the glaze surface caused by external air re-entering the sagger during the cooling process, which is conducive to the color development of celadon glaze and the color stability of batch products.

Abstract:In order to alleviate the developmental problems due to water damage, microorganisms and other diseases caused by the local collapse of the Vajra Sutra Cave, the 3D printing technology was used to repair collapsed areas:a photosensitive resin was selected as the printing material for restored parts with a hollow structure; the light field and temperature field simulation design for the restored parts reduced the solar radiation intensity into the cave to 50%-56% that of direct sunlight, and the amplitude of temperature fluctuation was reduced from 6.6℃ to 1.9℃; S8801 was used to coat the inner and outer surfaces with the result that the main performance retention rates of S8801 after aging experiments were greater than 90%, and the basalt fiber and glass fiber were used to enhance the inner surface. After multiple rainfall observations, it was found that the problem of rainwater backtracking in the Vajra Sutra Cave in Longmen Grottoes had been effectively alleviated. This work laid a foundation for the combination of 3D printing technology and restoration of immovable stone cultural relics.

Abstract:In the conservation and restoration of cultural relics, paper needs to be decolorized to remove some stubborn stains and mildew. Six different types of decolorizers were selected to explore the effects of the decolorizing treatment on the physical and chemical properties of several traditional hand-made paper samples (such as rice paper, leather paper and bamboo paper) after aging. It was revealed that there were great differences in the effects of various decolorizers on the durability of different paper types. Both oxidizing and reducing decolorizers influenced the physical and chemical properties of the paper samples. Different decolorizers have diverse effects on the long-term durability of paper. In general, decolorizers with strong oxidation can cause serious damage to fiber materials, and reducing decolorization has limited influences on the physical and chemical properties of paper. In the process of necessary decolorization of paper relics, selecting the appropriate decolorizer according to the characteristics of paper itself can effectively reduce the damage.

Abstract:A scraping knife has been developed to better match modern silk threads with the warp and weft lines of silk cultural relics during the restoration of ancient silk paintings, in response to the different requirements for materials and mounting of ancient and modern times and various types of diseases. This knife is formed by a line or a surface with eight points as the scraping state, which can avoid the drawbacks of the commonly used tools for silk painting restoration, such as horseshoe knives and art knives, which have a small inclination angle force point and are difficult to control and can easily damage the painting core. Although this silk scraping knife has played a good role in restoring a Ming Dynasty silk painting, the scientific applications of Su Mounting technique as an intangible cultural heritage still needs to be continuously explored.

Abstract:A family cemetery of the Yuan Dynasty was discovered in Yanta District of Xi’an, and represents one of the important new archaeological discoveries in Shaanxi Province. Residual murals of Tombs M38 and M40 were damaged but brightly colored, still basically retaining the structural information of the pigment layer. In order to understand the mural pigment types of the two Yuan tombs, cross-sectional analysis, microscopic infrared spectrometry, micro-Raman spectrometry, and scanning electron microscopy-energy dispersive spectrometry (SEM-EDS) were used for scientific analysis. The results show that the pigments include mineral pigments and organic dyes:red pigments include red lead, cinnabar and iron red; the black one carbon black; the white one calcite; the green one malachite; blue ones azurite and indigo. The mural of Tomb M38 has a ground layer, but that of Tomb M40 does not. The application of indigo found this time is another use case following the murals of Han Xiu’s tomb of the Tang Dynasty in Xi’an, providing new information for the use of indigo as a painting material for Yuan Dynasty murals. The research results could also provide an important reference for the subsequent conservation and restoration of the murals in the two Yuan Dynasty tombs.

Abstract:Wood preservation is a highly professional job. Due to the lack of professional equipment in remote areas of Tibet, special treatment technologies and efficient detection measures are needed to ensure the effects. Penetration and retention are two important parameters used to evaluate the preservative effects:retention can be acquired via calculation; penetration generally needs to be tested using instruments in the lab. The invention of the portable X-ray fluorescence (pXRF) spectrometer enables work which used to be carried out in the laboratory to be completed on site. The instrument determines the penetration by detecting metal elements contained in a preservative; this method features fast detection and simple operation. This study could provide a reference for the quality control of wood anti-corrosion and insect-proof projects for Tibetan temples in remote areas.

Abstract:Plaster disruption, called the “cancer” of murals, is one of the most serious diseases of murals. Since the formation of plaster disruption is influenced by many factors, the related treatment and prevention are severely restricted by the indefinite mechanism of formation, lack of repair materials, and difficulty of repair methods. This paper systematically reviews previous research on the cause and mechanism of formation of plaster disruption, reinforcement and plaster repair materials, as well as conservation and restoration methods for different salts. Also, the experiences gained during the restoration of murals suffering from plaster disruption are objectively evaluated in this paper. We hope this article will provide systematic technological and practical references for the prevention and treatment of plaster disruption of ancient murals.

Abstract:The concept and applications of “inclusion” during the modern iron- and steel-making processes provide advanced support for the research on ancient iron and steel materials. The analysis of inclusions in ancient iron and steel materials has become an indispensable part of the research on archaeometallurgy. This article first combs the mechanisms of inclusion generation in different ancient chemical and physical metallurgical processes, and then summarizes the characterization methods for ancient inclusions and their applications. In summary, ancient inclusion research of western researchers is more focused on quantitative statistical analysis based on various component characteristics; methods for identifying the origins of inclusions have been established. By contrast, ancient inclusion research of Chinese scholars relies on qualitative judgment methods to establish inclusion-assisted methods for iron cultural relic process identification. How to enrich experimental analysis methods and extract more information from materials are two problems which need to be solved. In the future, modern metallurgical analysis methods could be used to understand the characteristics of inclusions in ancient iron and steel products from many aspects, laying a foundation to solve subsequent archaeological problems.

Abstract:Preventive conservation of museum cultural relics has made significant progress in China over the past more than twenty years of systematic research and application practice. In recent years, Shanghai Museum has introduced the concept of risk management into preventive conservation to reduce risk and to ensure the safety of cultural relics, through a clear process of establishing the context, risk assessment, risk treatment and monitoring and review. In this paper, two temporary exhibitions at Shanghai Museum are used as examples to elaborate on the application practice and to provide some thoughts on the preventive conservation and risk management of museum cultural relics from the perspectives of statistical analysis of environmental data, humidity threshold setting, selection of regulation strategies, assessment of the environmental safety of materials, and sealing performance of museum showcases.

Abstract:Since 1952, tomb murals that were removed and moved to museums have faced many risks in the processes of restoration, collection, display, transportation and research. What can be seen is moderate and even severe corrosion damage, such as extra-covering, color changing, powdering and falling off of the paint layer, detachment of the plaster layer, deformation of the support layer, etc. Thus there is urgent basic work to be done to sort out and investigate the risk factors that lead to the deterioration and damage of mural collections at this stage. Starting from the perspective of mural conservation, and fully considering the fragility of the mural itself, this article identifies potential uncertainties in collection management as clear risk factors. Targeted preventive measures are proposed to slow down the aging of mural collections and to avoid risks, and also to provide references for strengthening collection conservation and zero-risk management.

Abstract:Textile archaeology has a history of about one hundred years, but textile archaeometry is a new research field, among which, the analysis and detection of ancient dyes can provide important information such as the sources of natural dyes, related dyeing methods, and even the production locations and time of textile relics, so as to provide a scientific basis for the restoration and conservation of ancient cultural relics, and to help us understand the color culture of ancient textiles and clothing. According to the color, ancient dyes can be divided into red, blue and yellow dyes. In red dyes, the more common plant dyes are Carthamus tinctorius L., Caesalpinia sappan L. and Rubia cordifolia L.; the animal dyes are Dactylopius coccus Costa, Kermes vermillio and Kerria lacca. The blue dye, usually indigo, is mainly obtained from indigo-containing plants, and Strobilanthes cusia, Indigofera tinctoria, Polygonum tinctorium and Isatis tinctoria are among those which were used historically in China. Yellow dyes mainly include Cotinus coggygria Scop., Sophora japonica Linn., Phellodendron amurense Rupr. and Curcuma longa L. At present, the methods used for analysis and detection of ancient dyes mainly include fiber optic reflectance spectrometry (FORS), fluorescence spectrometry (FS), high performance liquid chromatography-mass spectrometry (HPLC-MS) and surface-enhanced Raman spectrometry (SERS). These methods have their own characteristics, providing scientific support for the study of natural dyes from textile relics.