Chinese Academy of Cultural Heritage

The rapid development of archaeology in China has led to the excavation of numerous fragmented porcelain artifacts, for which adhesive materials play a critical role in conservation and restoration. The long-term stability of these adhesives directly affects the structural safety and visual integrity of restored objects. In this study, four adhesives widely used in Chinese conservation practice-epoxy resin Hezhong AAA, epoxy resin Hongxing 509, acrylic resin Paraloid B-72, and cyanoacrylate adhesive 502-were systematically investigated through simulated cyclic aging experiments. A multi-analytical approach was employed, including ultra-depth-of-field microscopy, CIE Lab* colorimetric analysis, pencil hardness testing, and Fourier transform infrared spectroscopy (FTIR). The results reveal distinct aging behaviors among different adhesive types. Epoxy resin adhesives exhibit high initial hardness and pronounced hardening during aging, with coating hardness increasing from the B range to the H range after 15 aging cycles; however, they also show significant yellowing, with total color differences (ΔE) exceeding 10 and dominated by increases in the b* parameter. Paraloid B-72 maintains excellent color stability throughout aging, with ΔE values consistently below 2, although it shows limited thermal stability and delayed physical stabilization. The cyanoacrylate adhesive 502 demonstrates rapid curing and minimal discoloration but undergoes embrittlement and interfacial debonding during aging, indicating reduced long-term bonding reliability. By correlating macroscopic performance evolution with molecular-level chemical changes, this study elucidates the aging mechanisms of commonly used restoration adhesives and provides a scientific basis for adhesive selection, risk assessment, and long-term preservation strategies in porcelain conservation.

Cinnabar, also known in ancient times as vermilion or cinnabarite, is the red mineral pigment with the longest history of use and widest range of applications in Chinese history. Since prehistoric times, cinnabar has been extensively employed in burial practices—sprinkled in grave soil, applied to human bones, or spread across tomb floors—carrying significant religious and ceremonial significance. Simultaneously, its vivid color and stable properties made it indispensable in practical daily applications like painting, textile dyeing, document writing, and cosmetic adornment. Notably, major archaeological sites revealing extensive cinnabar usage are concentrated in the Central Plains regions along the Yellow and Yangtze rivers, while the primary mineral deposits of cinnabar are located in China's southwest. This geographical disparity between production and consumption raises a crucial question: How did cinnabar travel such distances to reach the Central Plains? What material exchange networks did this reflect? This paper delves into the ancient applications of cinnabar, examining recent scientific studies on its provenance through the analysis of both advancements and limitations in these methodologies.

Abstract. Murals constitute an invaluable component of cultural heritage, encapsulating profound artistic and historical significance. Hyperspectral remote sensing, as a non-destructive testing technique, offers an effective means for analysing and identifying mural pigments. We proposed a spectral unmixing method based on the negative logarithm of spectral reflectance, aimed at improving the accuracy of quantitative analysis for composite pigments in murals. We obtained three sets of mixed spectra: cinnabar-orpiment, azurite-orpiment, and azurite-malachite. The original reflectance was converted into negative logarithmic values, and linear models were applied for unmixing. Supervised unmixing was conducted in the experiment to evaluate the model’s precision, with the unmixing process carried out using known endmembers. The unmixing accuracy was quantified using the Root Mean Square Error, which compares the estimated abundances of all endmembers with actual values. Additionally, a comparison was made between the negative logarithmic transformation and the commonly used transformations of original reflectance, first derivative, and second derivative. The result show that the logarithmic hyperspace linear model simplifies spectral unmixing complexity, enhancing the accuracy of linear unmixing models in addressing mixed pigment unmixing problems. To validate the effectiveness of the proposed method for real murals, the improved model was applied to the hyperspectral data unmixing analysis of murals collected by the Yungang Academy, located in Shanxi Province, China. Experimental findings demonstrate that, compared to traditional methods, the improved unmixing approach more precisely represents the pigment distribution in the murals. This study offers new ideas and methods for the digital preservation and restoration of mural composite pigments.

Palm leaf manuscripts (PLMs), as invaluable organic cultural heritage, are prone to embrittlement. Clove oil (CO) has traditionally been used as a toughening agent, but its high volatility limits durability. Herein, we develop a novel material comprising CO-controlled release nanocapsules, prepared via Pickering emulsion templating and solvent evaporation, using cellulose nanowhiskers (CNW) as stabilizers and polymethyl methacrylate (PMMA) as the shell. This strategy reduces CO volatilization by more than 11-fold. Applied to simulated PLMs, the material causes no visible alteration while markedly enhancing tensile strength, fracture toughness, and elongation at break by 43.5%, 101.9%, and 57.8%, respectively. Furthermore, aging tests show that the novel material maintains enhanced mechanical properties of PLMs for 4 days, while CO alone loses them after 1 day. Characterizations demonstrate that the controlled CO release, together with CNW reinforcement, provides both enhanced performance and durability. This study presents a promising strategy for the preservation of PLMs.

Paper has become the world’s predominant writing medium since its invention. However, non-paper writing materials have also played a significant role in human civilization, serving purposes beyond mere text transmission. Despite their importance, research about craftmanship and utilization of these alternative materials remain limited. In this study, we employed non-destructive and micro-destructive analytical techniques—including THM-Py-GC/MS, p-XRF, ATR-FTIR, and hyperspectral imaging (HIS) to examine fragments excavated from Taklung Monastery in Tibet. Results identified birch bark as the writing material and revealed that ink was prominently gold (Au). This discovery reports a rare case of the utilization of gold ink on birch bark, offering valuable insights into 13th-century Tibetan writing material production. Furthermore, HIS enabled text extraction from the fragments. Combined with the unique excavation context, we suggest that birch bark also possesses religious significance. This study enhances our understanding of the diverse applications of writing materials of ancient Tibet.

Tunnel portal rocks in southern China, which are exposed to intense solar radiation and temperature fluctuations, are susceptible to thermal stress, which directly or indirectly affects the safety, stability, and normal use of a tunnel and its peripheral structures. Fractures act as conduits for solar radiation energy, converting it into thermal energy within the rock, thereby altering the thermal stress field. As formation mechanisms of rock, fractures are complex, and the nonlinear thermal conduction at fracture tips leads to thermal stress concentration. A parabolic shape function for the heat source and thermal stress at tips of rock fractures is herein proposed, and the thermal stress field of fractured rocks under solar radiation is obtained. The applicability of different fracture heat source functions for analyzing the effects of heat on rocks with varying thermodynamic properties is discussed. Compared with a linear heat source function, the thermal stress values of rock fracture tips are larger. The daily maximum σθmax increases by 8.14% when αc=0.05 based on the parabolic heat source function, providing more conservative results for the thermal stability analysis of fractured rock under solar radiation. Parabolic heat source functions are more reasonable for soft rocks with high thermal conductivity and low thermal deformation, while linear heat source functions are more appropriate for hard rocks. A parabolic heat source function is a typical function for analyzing the effects of heat on fractured rocks under solar radiation.

ABSTRACT The palace-style timber frame in the Tang dynasty is a typical ancient official timber structure in East Asia, has important historical and cultural value. The lateral performance of the puzuo layer formed by bracket sets and horizontal beams is very important for the seismic performance of the palace-style timber frame. In this paper, a scale test model of the puzuo layer is established, and quasi-static tests of horizontal reciprocating loading under different magnitude vertical loads are performed and a theoretical model was developed. The results show deformation characteristics in the test model, such as the bracket set rotation and S-shaped bending deformation of connection sections. The hysteretic loops under different magnitude vertical loads are fusiform and full, which indicates that the puzuo layer has good elastoplastic deformation and energy dissipation performance. The increase in vertical load can effectively improve the lateral resistance and energy dissipation capacity of the puzuo layer. Furthermore, a theoretical model is devised to delve into the deformation behaviors and hysteresis characteristics of the puzuo layer, as well as to elucidate the influence of vertical load variations on its lateral resistance. This research offers valuable insights for preserving timber structures featuring a puzuo layer.

The advent of the era of media convergence has broken down the barriers between traditional and emerging media, bringing profound changes to the marketing models of the cultural tourism industry. This paper explores the impact of media convergence on the development of the cultural tourism industry by analyzing its concepts and characteristics. It further delves into the application of diversified media channel integration, digital, and interactive marketing strategies. By building an integrated media matrix and fostering cross-industry collaborations, cultural tourism can maximize brand communication effectiveness, enhancing consumer engagement and loyalty. This study also examines typical domestic and international cases to summarize the successful experiences and practical paths of cultural tourism marketing strategies in the context of media convergence. The research suggests that the cultural tourism industry should continue to focus on media convergence trends, innovating marketing strategies to enhance market competitiveness and achieve a win-win situation for both cultural and economic benefits.