Abstract:Copper-based cultural relics exhibit a variety of corrosion products. In addition to the well-known “bronze disease” and other chlorine-containing corrosion products, the occurrence of sodium-containing double salt corrosion products in recent years has also attracted widespread attention. In this study, a variety of laboratory analysis methods were used to examine corrosion products on multiple copper-based artifacts. In combination with relevant literature, several common Cu-Na corrosion products were summarized, including chalconatronite [Na₂Cu(CO₃)₂·3H₂O], sodium copper formate hydroxide oxide hydrate [Cu₄Na₄O(HCOO)₈(H₂O)₄(OH)₂], sodium copper carbonate acetate , and others. The causes of their formation and the sources of sodium were classified, including casting processes, burial environments, usage conditions, conservation treatments, and material interactions in composite artifacts. This provides support for improved conservation and preservation of cultural relics. For the first time, ion introduction during modern metal casting processes is discussed as a potential factor that can lead to corrosion under certain conditions, and the mechanism of its formation is further elaborated. A blue-purple corrosion product, juangodoyite [Na₂Cu(CO₃)₂] was identified for the first time by Raman spectrometry, and its formation mechanism was discussed.

Abstract:As the largest and best-preserved wooden ancient vessel of the Qing Dynasty in China, the Yangtze River Estuary No.2 shipwreck carries rich marine archaeological and historical-cultural value, making its conservation work of great importance and urgency. In this study, X-ray detection and analysis were employed to clarify the distribution characteristics of iron nails within the wood. By combining high-throughput microbial sequencing, genomics and metabolomics technologies, the structural and functional characteristics of the pathogenic microbial community on the ship hull were analyzed, and the results indicated that the deterioration of the wooden hull might contribute to various mechanisms such as iron oxidation, acidic metabolite production, and cellulase secretion. The results of genomic analysis showed that the bacterial community was dominated by the core dominant genera Acidovorax and Hydrogenophaga, while the fungal community was mainly composed of the saprophytic genera Fusarium and Trichoderma. Functional prediction and metabolite identification revealed that the bacterial community’s core metabolic pathways focus on carbohydrate and amino acid metabolism, with a rich diversity of organic acid compounds in metabolites, additionally iron ion transport and redox-related pathways were enriched in severely corroded samples. The fungal community exhibits a clear dominance of saprophytic types, forming a synergistic degradation effect with pathogenic types. These findings preliminarily elucidate the molecular biological mechanisms of iron component corrosion and microbial synergistic interactions, providing a scientific basis for investigating the degradation mechanisms of the Yangtze River Estuary No.2 shipwreck.

Abstract:The corrosion and deterioration of iron cultural relics in museum collections, under the coupled effects of multiple factors, pose a severe challenge for cultural heritage conservation. This study systematically quantified the synergistic corrosion effects of environmental factors, including temperature, humidity, SO₂, NO₂, O₃, HCOOH, and Cl- on iron cultural relics through simulated exposure experiments. A hybrid prediction model was developed based on a Random Forest (RF)-Long Short-Term Memory (LSTM) network. This study introduced a “Corrosion Index (IP)” to correlate environmental stress with the condition of cultural relics. By combining feature engineering of a temperature-humidity interaction term (T_RH) and a pollutant synergy term (SO₂_RH), the approach enabled accurate time-segmented prediction of the corrosion rate (60-day prediction R²=0.940). Feature importance analysis identified Cl- as the core risk factor (with a long-term contribution of 0.32), while the temperature-humidity synergy (T_RH) consistently dominated the corrosion process (contribution of 0.28 ± 0.03). Based on corrosion kinetic thresholds, a four-tier risk classification model was established, and a graphical user interface (GUI) supporting real-time assessment was developed, providing technical support for the preventive conservation of museum iron art culture relics.

Abstract:Bagan retains pagodas from various historic periods in Myanmar. Due to long-term exposure to open-air condition, large areas of black contaminants have formed on the mortar surfaces of these pagodas. To investigate the impact of black contaminants on the mortar, we identified the types of black contaminants and measured the parameters including temperature, moisture content, water absorption, surface hardness and ultrasonic intensity for mortar with black contaminants and for normal mortar. Comparison of these parameters shows that the black contaminants are biological crusts. Mortar affected by black contaminants exhibits the higher temperature, higher moisture content, greater water absorption, lower surface hardness, and increased efflorescence compared to normal mortar. These results indicate that that black contaminants have not only affected the appearance of the pagodas but also reduced the mechanical strength and weakened the resistance to weathering of the mortar. This study could provide a basis for the removal of black contaminants.

Abstract:This study focuses on the cleaning methods for gilt copper ornaments from the Buddhist pagoda in the Hall of Mental Cultivation of the Palace Museum. Preliminary scientific analysis revealed the presence of black deposits and cuprous oxide corrosion on the surfaces of the ornaments. Based on condition assessment, phased cleaning experiments were designed to systematically compare the effectiveness of two different carriers:paper pulp poultice and agar gel. In the first phase, 2A solution and non-ionic surfactants were applied through both carriers to remove surface deposits. In the second phase, three chelating agents (EDTA, citric acid, and potassium sodium tartrate) were applied through both carriers to remove corrosion products. The results demonstrate that the agar gel carrier method offered advantages in cleaning effectiveness, controllability, and environmental performance, providing scientific guidance for developing cleaning protocols for gilt copper cultural relics.

Abstract:Reconstructive overall relocation represents an innovative conservation model for tomb murals. Its core lies in completing key procedures at the archaeological site, including penetration reinforcement of the mural body, fabrication of a transition layer, and replacement of supports for weight reduction, thereby ensuring the safe relocation and exhibition of the cultural relics. This approach maximizes the preservation of original structural and material information while achieving effective weight reduction, addressing the fundamental challenge of relocating large-scale mural tombs. Within this framework, the scientific screening of on-site conservation materials is critically important, as it directly affects the stability of the mural structure, including the pigment layer, lime plaster layer, and overall tomb integrity. Currently, research on the overall relocation of tomb murals has predominantly focused on condition surveys and indoor conservation, with limited attention to the scientific screening of on-site conservation materials. This study focuses on the Mongol Empire-Yuan Dynasty mural tomb at Dong’er Village, Pucheng County, Shaanxi Province, addressing key technical challenges encountered during the reconstructive overall relocation process, including the fragility of the lime plaster layer and the need to dismantle and replace the original supporting bricks. Using portable detection equipment, scientific material screening and effectiveness evaluation were conducted at the archaeological site. Operational indicators including permeability, chromatic aberration, hardness, adhesion-detachment rate, gluing phenomenon, and curing phenomenon were employed to systematically evaluate penetration reinforcement materials (PVB, PVAc, AC33, B72, nanolime, and their combinations) and support materials (combinations of chemical fiber cloth, carbon fiber cloth, glass fiber cloth with AC33 slurry and epoxy resin). These indicators were specifically selected for their practicality in field conditions and their ability to provide quantitative data for material comparison. Simultaneously, a sclerometer was used to quantitatively characterize the reinforcement effects of three key conservation procedures:penetration reinforcement, transition layer fabrication, and support replacement. The results demonstrate that B72 exhibits a penetration volume of 1.51-3.76 mL/cm³, a hardness increase rate of 100.68%, and an adhesion-detachment reduction rate of 91.67%, indicating optimal comprehensive performance as a penetration reinforcement material for the lime layer. In comparison, PVB showed insufficient penetration, AC33 exhibited excessive color change and slow curing, and nanolime combinations required up to 12 days for complete curing, making them impractical for on-site work schedules. Epoxy resin penetrates glass fiber cloth evenly, exhibits high strength after curing and adheres strongly to the honeycomb aluminum core, making it the optimal support material combination. Following the three key conservation procedures, the average hardness of the mural structure increased from 103 HLC in the original lime layer to 589 HLC in the epoxy glass fiber cloth layer, with gradually decreasing hardness dispersion, indicating significantly enhanced structural hardness and improved uniformity. The integrity, safety, and stability of the tomb murals were effectively guaranteed. This study establishes a rapid screening and effectiveness evaluation methodology for mural conservation materials applicable to archaeological sites. It innovatively applies the combination of epoxy resin and glass fiber cloth, a fiber-reinforced composite material, together with a honeycomb aluminum core to the mural support structure. This enhances the scientific and standardized quality of reconstructive overall relocation work and provides an important reference for the conservation of similar cultural heritage, particularly for large-scale architectural remains requiring structural reinforcement and relocation.

Abstract:Yuan Dynasty painted sculpture fragments housed in Yongle Palace, Shanxi, are invaluable material evidence for studying the materials and techniques used in the creation of clay-based painted sculptures from the early Yuan period. To enrich the scientific research repository on the materials and techniques for Yuan Dynasty clay sculptures, this study employed a multi-technique analytical strategy to sample, examine, and analyze these fragments. The results indicate that the primary framework of Yongle Palace Yuan sculptures is made of cypress wood. The sculpting clay is differentiated into coarse and fine layers:the coarse clay layer uses wheat straw and wheat husks as reinforcing materials, while the fine clay layer employs cotton and hemp fibers. The painted layers exhibit multiple superimposed pigment layers, as well as techniques such as gilding and raised paste gilding. The base coat for painting process is generally white, over which colors such as pink, blue, and green are applied, whereas the base coat for gilding is typically red. The Yuan Dynasty sculptures in Sanqing Hall of Yongle Palace follow the traditional Shanxi regional technique paradigm for clay sculptures:wooden framework; rough shaping with coarse clay; refined detailing with fine clay; painting and gilding. The paper found in the fine clay layer of some individual fragments is likely the result of later refurbishments or local repairs. This research provides critical reference materials for the authentic restoration of the Yuan Dynasty painted sculptures in Sanqing Hall of Yongle Palace.

Abstract:The white pottery remains found at the Qianjiaping site provide an important way to explore prehistoric cultural exchanges between the middle reaches of the Yangtze River and the area around the Pearl River estuary, as well as the external transmission path of the Gaomiao culture. To explore the origin of raw materials and firing process characteristics of the white pottery of the Qianjiaping site, the chemical composition, phase composition, microstructure, firing temperature, physical properties, and other aspects of 32 white pottery samples unearthed from the Qianjiaping site were analyzed. The main instruments used include an energy-dispersive X-ray fluorescence spectrometer, an X-ray diffractometer and an optical thermal expansion instrument. The results show that these white potteries can be divided into three types based on the raw materials used for pottery making. The first type contains high aluminum content, the second type contains high magnesium content, and the third type is white coated pottery with a body made of ordinary fusible clay and a surface coating made of high aluminum clay. The analysis of the composition of both high magnesium and high aluminum white potteries indicate that the white pottery from the Qianjiaping site exhibits differences compared to those from other Gaomiao cultural sites. This indicates that most of the white potteries at this time were likely fired locally. The results of the firing temperature tests show that the average firing temperatures of high magnesium white pottery, white coated pottery and red pottery are similar, and lower than that of high aluminum white pottery. At this time, all the pottery types were fired in kilns.

Abstract:A large number of potteries dating from the Southern Song to the Ming and Qing Dynasties were unearthed from the Yuanhetang ancient kiln site group in Suzhou. This study selected potteries and soil samples for scientific analysis. Density measurement, petrographic observation, X-ray fluorescence spectrometry, X-ray diffraction, thermomechanical analysis, and Raman spectrometry were used to examine their basic properties, body compositions, phase compositions and firing temperatures. The results show that these potteries were made from common fusible clay with relatively high iron content and exhibit good physical properties. The pottery bodies are fine and uniform, and are classified as clay potteries. The firing temperature ranges between 950℃ and 1 050℃, indicating that they belong to the high-temperature category. The firing atmosphere was predominantly reducing, with well-developed carburization techniques. This study reveals the unique techniques and high-quality characteristics of pottery production in this region from a technological perspective, and demonstrates the continuous refinement and development of pottery craftsmanship in the Suzhou area. It provides additional information and supporting data for the discovery, identification, and study of the ancient Pingjiang kiln.

Abstract:i>Yingzao Fashi, compiled by Li Jie during the Northern Song Dynasty, is the earliest and most comprehensive extant text in China on the manufacturing techniques for bricks and tiles. It provides detailed records of specifications and production methods, serving as a crucial reference for the study of ancient brick and tile making. The Sui-Tang Luoyang City was initially constructed in 605 AD, the first year of the Daye reign of Emperor Yang of the Sui Dynasty, and remained in use from the Sui and Tang Dynasties through the Northern Song Dynasty, spanning more than 500 years. It is the ancient city with the longest duration of use among all the ancient cities constructed in China before the compilation of Yingzao Fashi. With its massive scale, the Sui-Tang Luoyang City was one of the largest capitals in the world at the time and holds significant importance in the history of ancient Chinese capital architecture. The unearthed brick and tile components from the Zhengpingfang site served as building materials for high-grade architectural complexes in the Sui-Tang Luoyang City. Their manufacturing techniques possess significant historical, cultural and technological research value, and they provide important material evidence to corroborate textual records on ancient brick and tile production. First, we conducted a comprehensive assessment of the morphological characteristics of the brick and tile samples unearthed from the Zhengpingfang area of the Sui-Tang Luoyang City, including color, specifications, preservation status, and traces of craftsmanship. Subsequently, scientific analysis of composition, physical properties, and microstructure were carried out using instruments such as wavelength-dispersive X-ray fluorescence (WDXRF) spectrometry, X-ray diffraction (XRD), polarized light microscopy, and thermal dilatometry. The results are summarized in three aspects as follows. 1) The clay raw material used for the bricks and tiles are fusible clays, sourced locally but not from a single origin. Based on the compositional similarities between brick and tile materials from the Guozijian (Imperial Academy) area and from the kiln area, the kilns at Zhengpingfang were likely dedicated to producing building components for nearby structures, such as the Guozijian within the Zhengpingfang area, reflecting a close relationship between brick and tile kilns and the surrounding constructions. 2) The firing techniques were relatively mature, with an average firing temperature of 1042°C. The mineral composition is primarily quartz and feldspar, with no mullite detected. 3) By integrating morphological and physical data of the unearthed bricks and tiles with textual records in Yingzao Fashi on specifications, grades, and manufacturing techniques, the overall technical features of the bricks and tiles unearthed at Zhengpingfang in the Sui-Tang Luoyang City are consistent with the manufacturing techniques and specifications documented in Yingzao Fashi. This demonstrates continuity in brick and tile production from the Tang to the Song Dynasties to a certain extent. This study clarifies the historical and scientific value of the ceramic bricks and tiles unearthed at the Zhengpingfang area of the Sui-Tang Luoyang City, identifies their raw material sources and manufacturing techniques, and confirms their technical inheritance. These findings could provide a scientific basis for further research on the evolution and development of ceramic brick and tile manufacturing techniques in China.

Abstract:Pingcheng (present-day Datong, Shanxi) served as the capital of the Northern Wei Dynasty from 398 to 494 AD and emerged as a pivotal center of politics, economy, culture, and ethnic integration in Northern China during that period. Glazed pottery embedded with glass represents an innovative exploration of glazed ceramic decoration techniques by Northern Wei artisans. Combining the technical characteristics of both glazed pottery and glass, such artifacts are exceptionally rare in the history of Chinese ceramics and constitute important material evidence for studying technological transmission and cultural interaction. However, due to the limited number of excavated examples, these artifacts have received relatively little attention in academic research, and systematic research remains lacking. This study focuses on eight pieces of glazed pottery embedded with glass unearthed from tombs in the Datong region, including the tomb of Sima Jinlong and Tomb M36 of the Erdianchang Cemetery. Four representative samples were selected for systematic analysis using ultra depth-of-field 3D microscopy (20×-1 000× observation) and scanning electron microscopy with energy dispersive X-ray spectrometry (SEM-EDS) under low vacuum conditions at an accelerating voltage of 20 kV. The analyses targeted the microstructure, chemical composition, raw material formulations, and manufacturing techniques of the ceramic bodies, glaze layers, and embedded glass. Additionally, the cultural origins of the artifacts were explored through their morphological features. The results indicate that the ceramic bodies are typical high-iron, low-firing clays from Northern China, with ions of iron as the primary colorant, resulting in red or gray-black body colors depending on the firing atmosphere. The glaze belongs to a low-temperature lead glaze system (PbO-SiO₂-Al₂O₃) with PbO content of 50%-60%, producing yellowish-brown or blackish-brown due to ions of iron. The glaze slip incorporates clay similar to that used for the ceramic bodies. The embedded glass can be classified into two compositional systems:v-Na-Ca-Pb and v-Na-Al-Pb. After removing PbO and normalizing the composition, the soda-lime glass of the former system exhibits high-magnesium characteristics (MgO content:5.1%-6.1%), suggesting that its raw materials may have originated locally in Pingcheng. In contrast, the soda-alumina glass of the latter system (Al₂O₃ content:11.3%-13.2%) shows a composition highly similar to Indo-Pacific trade beads (abbreviated as Indo-Pacific beads), implying that it was produced by re-melting such beads with the addition of lead as a flux. Of particular significance, the locally embedded copper-red glass (colored by Cu⁰ or Cu₂O) on Sample dx-M562 (a ewer with a ram’s head spout) pushes back the emergence of copper-red glaze technology in China from the traditionally accepted Tang Dynasty to the Northern Wei period. Furthermore, diopside crystals are commonly precipitated at the interface between the glass and glaze layers, and traces of glass melt flow due to gravity are observed on the glaze surfaces of some samples. These observations indicate that the glass was embedded after the glazed pottery had been fired and cooled. The manufacturing process can be summarized as follows:forming the pottery body; applying raised geometric patterns (Sample ybdd-M74:2 was likely bisque-fired first); applying the glaze overall; kiln firing; and embedding molten glass after cooling. In terms of decoration, the practice of inlaying glass within pearl chain patterns (Lianzhuwen) clearly imitates the style of gem-inlaid gold and silverware from the Persian Sasanian Empire, which was introduced to Pingcheng via the Silk Road. Meanwhile, the ram’s head motif on dx-M562 incorporates elements from similar vessels popular during the Eastern Jin Dynasty. This study systematically reveals, for the first time, the raw material systems and manufacturing techniques of Northern Wei glazed pottery embedded with glass. It clarifies their multicultural origins and fills a gap in the research on ancient composite pottery-and-glass technology. The findings provide key scientific evidence for material and cultural exchanges along the Silk Road. The new discovery regarding the origin of copper-red glaze technology revises existing understandings in the history of Chinese ceramics and holds significant academic value.

Abstract:A set of exquisite cardboard water-and-land paintings in the collection of Qingdao Museum was investigated to determine their materials and production techniques. X-ray diffraction (XRD), scanning electron microscopy-energy dispersive spectrometry (SEM-EDS), optical microscopy (OM), paper fiber measurement, energy dispersive X-ray fluorescence spectrometry (EDXRF) and laser confocal microscopy Raman spectrometry (LCMR) were used for scientific analysis. The results show that both the central paper and the backing board paper are made of bamboo fibers. The backing board consists of 13 layers of bamboo paper, supplemented with soil, lime, and other materials to increase thickness, enhance mechanical strength, and improve moisture absorption properties. The pigments include inorganic materials such as cinnabar, lead white, and malachite, as well as the organic material from Garcinia and the synthetic pigment of Prussian blue. This study reveals the materials and manufacturing techniques for the paintings, as well as their artistic style and function, reflecting the integration of Chinese and Western elements during the late Qing Dynasty. It provides important empirical evidence for the comprehensive study of cardboard water-and-land paintings of the Qing Dynasty, and offers a scientific basis for the conservation and restoration of similar cultural relics.

Abstract:Palm leaf manuscripts, as a critical component of cultural heritage, hold immense historical and cultural significance, particularly in South Asia and Southeast Asia. Despite their historical importance, these manuscripts are highly susceptible to environmental factors such as relative humidity (RH), which can significantly influence their physical, mechanical, and chemical properties over time. This study aims to investigate the effects of varying RH levels on the aging behavior of palm leaf manuscripts to identify optimal conditions for their long-term preservation. In this study, palm leaf samples were prepared using traditional methods involving leaves of Corypha umbraculifera L., which were boiled, dried, flattened, and refined. Accelerated aging experiments were conducted at five controlled RH levels (10%, 30%, 50%, 70% and 90%) over 100 days at 25℃. A combination of advanced analytical techniques, including dynamic vapor sorption (DVS), thermomechanical analysis (TMA), Fourier transform infrared spectrometry (FTIR), scanning electron microscopy (SEM), and gloss measurement, was employed to assess the morphological, chemical, and mechanical changes of the manuscripts under these conditions. The findings demonstrate that both excessively dry and highly humid conditions adversely affect the preservation of palm leaf manuscripts. Under low RH conditions (10% and 30%), the samples exhibited significant surface cracking and shrinkage, which severely compromised their mechanical properties, such as hardness and flexural strength. The cracking was particularly severe at 10% RH, leading to irreversible structural damage. Conversely, high RH conditions (70% and 90%) promoted mold growth on the samples, causing substantial changes in appearance, including discoloration and loss of gloss. Mold growth also resulted in increased hygroscopicity and accelerated chemical degradation of cellulose and hemicellulose, as evidenced by diminished characteristic peaks in the FTIR spectra. These chemical alterations correlated with a marked decline in mechanical properties of the manuscripts, including a substantial reduction in flexural strength and modulus. In contrast, samples aged at 50% RH exhibited minimal changes across all parameters. The manuscripts retained their original morphological, chemical, and mechanical characteristics, with no significant alteration in surface appearance, color, gloss, or structural integrity. The mechanical properties, including flexural strength and modulus, showed negligible deterioration, highlighting the stability of the material under these conditions. These results suggest that 50% RH is an optimal condition for the preservation of palm leaf manuscripts, as it effectively balances the risks of desiccation and mold-induced degradation. The study also elucidates the underlying mechanisms of manuscript degradation under varying RH conditions. Low RH environments induce moisture loss, which leads to internal stresses and subsequent surface cracking. These physical damages are accompanied by a loss of flexibility and mechanical strength, rendering the manuscripts brittle and vulnerable to further deterioration. In high RH environments, microbial activity is intensified, with mold producing organic acids and enzymes that accelerate the hydrolytic degradation of cellulose and hemicellulose. This dual process of physical and biochemical degradation severely compromises the manuscripts’ preservation. Furthermore, the research highlights the significance of maintaining stable environmental conditions for preventive conservation. The integration of advanced analytical techniques, such as DVS for hygroscopic behavior analysis and TMA for mechanical performance evaluation, provides a robust methodological framework for assessing the impact of environmental factors on organic cultural heritage. Unlike previous studies primarily focusing on visual and morphological changes, this research delves into the chemical mechanisms of degradation, offering a comprehensive understanding of how relative humidity influences the aging of palm leaf manuscripts. The findings of this study have broader implications for the conservation of organic cultural heritage materials. The identification of 50% RH as the optimal preservation condition offers practical guidance for the storage and display of palm leaf manuscripts in museums, libraries, and archives. By emphasizing the interplay between environmental factors and material properties, this research provides critical data for the formulation of evidence-based conservation strategies. In conclusion, the study underscores the necessity of precise environmental control for the preservation of palm leaf manuscripts. Both excessively low and high RH levels pose significant risks to their longevity, highlighting the importance of maintaining a stable and moderate RH environment. While 50% RH has been identified as the optimal condition, future research should explore the combined effects of temperature, pollutants, and other environmental factors to develop a more comprehensive understanding of the long-term preservation requirements for palm leaf manuscripts.

Abstract:To protect valuable cultural heritage such as paper-based documents, researchers at home and abroad have carried out large-scale deacidification studies. Due to the unique characteristics of neoteric and modern Chinese paper-based documents, which differ from those of foreign literatures, and the large number of documents with varying degrees of acidification, a study was conducted on the adsorption behavior of 54 documents. The pH value and paper tightness (D) of documents before processing were selected as classification factors, and the documents were classified and matched with different deacidification solutions. Using self-developed deacidification equipment, the bound documents were deacidified through an impregnation process with independent intellectual property rights. The pressure of the impregnation deacidification system was determined to be 0.5 atm, and continuous deacidification for 30 minutes improved the deacidification effect. After immersion, pulsating drying was used, and the system pressure was controlled at 60 Pa. After about 2.5 hours, the adsorption capacity of the deacidification solution in the documents was reduced to no more than 10% of the net weight of the documents, and the documents could basically recover their initial weight. The documents were treated using an integrated process of classification, impregnation and drying. It was verified that for the deacidified paper, the pH value of was 7.5-9.5, and the alkali reserve was 1.0%-3.5% (calculated as calcium carbonate). The paper performance was enhanced.

Abstract:Focusing on the printing blocks of The Qianlong Tripitaka from the Capital Museum, China, this study employed a suite of multi-dimensional digital imaging measures, including photography, infrared and ultraviolet photography, microscopic imaging, three-dimensional imaging and spectral imaging, to acquire image data. Specifically: the standard camera captured baseline images of the blocks; the infrared and ultraviolet camera documented large-scale deterioration patterns; the optical microscope recorded fine details such as cracks and engraving features; the electron microscope analyzed the extent of wood aging; the computed tomography (CT) scanner revealed the internal wood structure; the 3D laser scanner generated three-dimensional models; and the hyperspectral imager identified concealed information on the blocks. By integrating these approaches, comprehensive multi-dimensional digital imagery of the printing blocks was obtained, laying a foundation for the subsequent development of a digital archive and enabling their innovative and practical utilization.

Abstract:This study conducted a micro-analysis of the paper samples from the “Lake” volume copy of The Yongle Canon, which was repatriated from France. The methods employed included surface microscopy and fiber staining microscopy. The results show that the mounting paper of the bookmark is made from Broussonetia papyrifera bark. The spine paper and the inner cardboard of the cover primarily consist of a mixture of Broussonetia papyrifera bark and bamboo, with a lesser proportion of bamboo. The guard sheet primarily consists of Edgeworthia chrysantha bark and bamboo, with a minor proportion of bamboo. The remaining paper in the textual reconstruction list for the lost part of The Yongle Canon mainly comprises bamboo materials. The remaining paper fragments of the main text consist of a mixture of Broussonetia papyrifera bark and bamboo, with bamboo exceeding Broussonetia papyrifera bark in proportion. These findings, obtained through experimental methods, provide the first detailed revelation of the paper materials used in The Yongle Canon, confirming the complexity of its paper composition. The study offers a valuable reference for subsequent scientific conservation, restoration, and research efforts.

Abstract:i>Qinggaoni is a common material in archaeological explorations. The practice of placing Qinggaoni in burial pits for sealing purposes originated in the Neolithic Age, gained popularity in the Shang Dynasty, prevailed from the Zhou to Han Dynasties, and reached its peak in the Qin and Han Dynasties. However, relatively few studies have focused on Qinggaoni, especially on humus, which affects the structural properties of Qinggaoni. In this study, a synchronous laser diffraction and dynamic image particle analyzer (LDPA), a scanning electron microscope equipped with an energy dispersive spectrometer (SEM-EDS) and a Fourier transform infrared spectrometer (FTIR) were used to analyze the particle size, micromorphology, composition and humus properties of the Qinggaoni samples excavated from different sites in the Lanling Tashan tombs, Shandong Province. The results show that the inorganic minerals present in the Qinggaoni mainly include quartz, albite, muscovite, hydroxy-iron oxide, ferrihydrite and biotite. These minerals have a large specific surface area and surface charge, and they were combined with humin (which has a high content in organic humus and is closely bound to minerals) and humic acid (which has colloidal properties) to form a stable inorganic-organic complex. Among the samples, those from Tomb M166 show a large specific surface area and broader particle size distribution. Microorganisms such as Bacillus cereus are also enriched on the surface, providing favorable conditions for the formation of humus in the paste.

Abstract:In 2022, a bronze mirror with an inscription was unearthed from a tomb at Yaozhuang, Liuhe District, Nanjing, dating to the late Ming and early Qing Dynasties. This mirror was originally from Japan and introduced into China through commercial exchange. The mirror is fragmented and lacks a handle, and its decorative surface is covered with a layer of silver white material, resembling a “mercury shower”. To understand the production process, composition, and preservation status of the silver white coating on the mirror surface, microscopic observation, Raman spectrometry, and scanning electron microscopy-energy dispersive spectrometry (SEM-EDS) were used for analysis. The results show that the mirror was cast from a copper-tin-lead ternary alloy, and the silver white substance on the surface is cassiterite, formed through long-term corrosion in the burial environment. The bronze mirror is severely corroded, and the body has been basically mineralized.

Abstract:Cultural heritage embodies profound historical, artistic and scientific significance. Protecting and inheriting cultural heritage as well as uncovering their inherent values, presents a great challenge faced by contemporary cultural relic conservation practitioners. However, owing to the complexity, diversity, and value of cultural heritage, applications such as disease identification, quantitative analysis, deterioration prediction, and virtual restoration often suffer from low efficiency and insufficient levels of automation and intelligence. In addition, conventional data processing techniques struggle to address the nonlinear and heterogeneous characteristics of cultural heritage data, thereby limiting their effectiveness in complex application scenarios. Deep learning, as an emerging technological approach, provides new solutions to these challenges. This paper reviews the application of deep learning in cultural heritage disease research from 2017 to 2024. Using bibliometric methods, it outlines developmental stages and trends and identifies key research hotspots. The results indicate that the period from 2020 to 2024 witnessed rapid growth, with a significant increase in the number of publications on related topics. In terms of geographical contributions, China and Italy have demonstrated particularly strong academic influence and contribution. At the data source level, digital images serve as the core foundation, while spectral analysis and radiographic imaging data, which contain rich material and structural information, have also become research priorities. In terms of model applications, Convolutional Neural Networks (CNNs) and Generative Adversarial Networks (GANs) are the most commonly employed models. Regarding application targets, deep learning technologies have been applied to various types of cultural heritage, including buildings, calligraphy and paintings, murals, earthen painted artifacts, and stone relics. Based on these findings, the main challenges and future development directions in this research field are discussed from four perspectives:1) data—improving the quality and quantity of samples; 2) models—enhancing performance, generalization ability, and interpretability; 3) applications—extending technologies to areas such as disease mechanism analysis and dynamic deterioration prediction; and 4) standards—establishing unified industry standards, data-sharing platforms, and adaptive evaluation metrics. This study provides a theoretical foundation and practical references for future research and contributes to advancing the intelligent development of cultural relic conservation.