Abstract:The east gate wall of the outer city of the Shimao site has suffered from serious outward deformation and is facing the risk of collapse. In order to protect it scientifically, the stability and reinforcement methods for the wall were studied. The weathering reduction coefficient was proposed to characterize the degree of weathering of the mortar joint. The discrete element method was used to establish the wall model and verify its effectiveness. The deformation and stability of the wall under weathering were studied by the strength reduction method, and the weathering degree of the wall and the mechanical parameters of the mortar joint were determined by the inversion analysis method. The results show that the main cause of wall deformation and instability was the decrease of mortar joint strength. Under the action of earth pressure, the wall failure presented a slip-overturning mode. At present, the wall is in an understable state with the weathering coefficient of 0.45-0.48, mortar joint strength cohesion of 21 kPa and internal friction angle of 14°, respectively. On this basis, two reinforcement methods—grouting and lateral supporting—were proposed and compared, to finally obtain good results. The research results could provide a reference for the follow-up reinforcement and protection of the city wall of the Shimao site.

Abstract:The cultural layer of the Jingtoushan site dates back about 7 800-8 300 years, approximately 1 000 years prior to the Hemudu culture. As a prehistoric shell mound site that has never been discovered in previous archaeological work in Zhejiang region, the Jingtoushan site was selected as one of the top ten new archaeological discoveries in 2020. The cultural accumulation of the Jingtoushan site is 5-10 m below the sea level and is covered with thick saturated marine sedimentary silt. The cultural remains include ash pits and food storage pits, shell deposits, utensil processing and food processing sites, etc. The relics unearthed from the site include more than 100 wooden objects such as oars, handles and pestles, as well as more than ten woven fabric such as mats, baskets, pack baskets, fish covers, fans, fishing nets and fine ropes. The woven fabric are made from reeds, awn grass, bamboo and other raw materials, and are scattered in the marine silt along with various relics. Due to various factors in the burial environment, the woven fabric have undergone severe degradation, resulting in structural decay and fragility and reduced mechanical strength, posing significant challenges for safe separation and extraction. Taking the cohesive soil of the Jingtoushan site as the research object, various analysis methods such as X-ray diffraction, potentiometric titration and ion chromatography were used to analyze the mineral composition and contents of the site soil, the content of organic matters and humic substances such as humic acid and fulvic acid, as well as the ion contents and pH value of the soil impregnation solution. The analysis results indicate that the soil at the site is alkaline, with similar X-ray diffraction peaks, mineral composition and contents, and high contents of organic matter and soluble salts. The presence of iron oxides in soil clay minerals, as well as humic substances such as humic acid and fulvic acid in organic matters, are important soil binding substances, causing the soil texture of the site to be cohesive and difficult to disperse, which is not conducive to the separation and extraction of fragile woven fabric. In order to safely separate and extract fragile woven fabric, it is necessary to convert organic or inorganic soil binding substances in the soil to reduce the binding effect on soil particles. Organic binding substances in soil can be treated with oxidants or alkaline solutions to make the organic matters in the soil to be oxidized and decomposed or converted into soluble salts, thereby achieving the dispersion of cohesive soil. However, this method of decomposing and transforming soil organic matters through oxidants or alkaline solutions, while completing soil dispersion, will inevitably bring potential harm to fragile woven fabric. In addition to humic organic binding substances such as humic acid and fulvic acid, there are also inorganic binding substances present in the form of iron oxides in cohesive soils. In the pre-study of soil dispersion methods, HRP with (O, O) as the coordinating atom was selected as a complexing agent for the Fe element, and the inorganic binding substances in the form of iron oxides were complexed and transformed at the room temperature. The research results indicate that under mild conditions, 30 mmol/L HRP could effectively disperse cohesive soil. This dispersion method could provide a reference for the separation and extraction of woven fabric unearthed from the Jingtoushan site and other similar sites.

Abstract:Under the persistent action of weathering factors, the microstructure of earthen sites continues to deteriorate, leading eventually to the development of macro diseases. The variation of microstructural characteristics reflects the inherent weathering degree of soil materials. In order to study the correlation between deterioration and the micro-pore structure of the Suoyang earthen site, a low temperature-liquid nitrogen adsorption test was conducted on soil specimens sampled from the city wall in different directions at the site for the determination of specific surface area, pore volume and pore size distribution characteristics, and the fractal dimension of the specimens was calculated based on the FHH fractal model. The research data show that Suoyang soils demonstrated a high deviation rate in specific surface area, and obvious difference in specific surface area of the specimens in different directions. The soils were mainly the micropores with a high coefficient of variation in pore volume and large dispersion degree, corresponding to weathering difference between them. The pore morphology included slit, wedge, “ink bottle”, tubular hole, and other complex forms. The pores less than 2.765 nm were mostly closed pores. In combination with the fractal dimension, it is found the soil specimens featured obvious fractal characteristics, irregular pore space structure, strong heterogeneity and large surface roughness. The fractal dimension had a certain correlation with the weathering or deterioration degree. The quantitative characterization of soil pores is of importance for the evaluation of weathering and deterioration of earthen sites.

Abstract:The ancient bonding materials on pottery are closely related to the repair process of pottery, and are one of the reflections of the level of pottery making in society at that time. In this study, we conducted a scientific and technological analysis on an ancient adhesive used for pottery buildings unearthed from the Han Dynasty cliff tombs at Baozishan, Xinjin District, Chengdu. The inorganic and organic components of the adhesive were investigated respectively using scanning electron microscopy-energy dispersive spectrometry (SEM-EDS), X-ray diffraction (XRD), laser particle size analysis, Fourier transform infrared spectrometry (FTIR) and gas chromatography-mass spectrometry (GC-MS). The results show that the particle state, size and composition of the adhesive were similar to those of clay particles, so it is inferred that its main inorganic component was clay. The characteristic peaks of FTIR spectrum at the wave numbers 3 431 cm-1, 1 670 cm-1 and 1 419 cm-1 were consistent with the amide group. The result of amino acid analysis shows that its organic component contained a protein binder, a mixture of animal glue and egg. The organic mixed materials had a higher viscosity to make up for a single material, and the clay could increase the density of hydrogen bonds in the system and played a filling role. The synergistic effect of each component in the adhesive is the reason for its high adhesion and certain stability. However, due to its poor durability and incompatibility with the overall style of pottery, it is speculated that the material was a temporary adhesive. In addition, its composition and use were very similar to those of the ancient adhesive used for the Qin Terra-Cotta Warriors, which shows the inheritance and evolution of the burial system and pottery-making techniques of the Qin Dynasty in the Han Dynasties. The research results provide information for the study of the history of pottery restoration in China, and also provide a scientific basis for the conservation and restoration of contemporary pottery.

Abstract:In order to explore the aging mechanism of leather relics under the influence of light, in this study, we used artificially-aged modern vegetable-tanned sheepskin as the simulation samples, and carried out Fourier transform infrared spectrometry, scanning electron microscopy, atomic force microscopy, colorimetric analysis and thermogravimetric analysis to explore the micro and macro changes in the aging process of the samples. The results show that light caused the oxidation of amino acids and tannins in leather, seen by the appearance of a characteristic carbonyl peak at 1 715 cm-1. The carbonyl index increased with the extension of light time and thus could be used as a quantitative index of the degree of leather oxidation. Oxidation of aromatic amino acids and vegetable tannins could cause leather discoloration, and a prediction model of color difference changing with light time could be obtained by fitting. When the hydrogen bonds broke under the action of light, the intramolecular random curling content of collagen increased to 33.14%. This proved the unwinding of the triple helix structure of collagen, an increase of molecular disorder, a decrease of stability, and the release of part of the crystalline water. In addition, the moisture and lipids in the leather were lost under the light, which made the fibers shrink and curl, and the gap between fibers increased. At the same time, stress was generated, which gradually accumulated and caused the deformation of the leather surface.

Abstract:In order to conduct in-depth research on the historical and cultural significance of the Qinglongshan site in Yiliang, 12 samples from the wooden components of unearthed weapons were identified and analyzed. The identification results show that there were 7 kinds of wood, namely Pinus sp., Castanopsis sp., Photinia sp., Alangium sp., Chukrasia sp., Phoebe sp. and Poaceae bamboo, used for the wooden components of the weapons. According to the characteristics of these kinds of wood, the ancients chose the ones with lower density and better toughness for arrow shafts, and the ones with high hardness, high density, impact resistance and good stability for long handled weapon rods. Actual bamboo weapon handles were found in Yunnan region for the first time in our study, and it is speculated that they were made of composite bamboo materials. In addition, through the analysis of coexisting ecological factors of wood, the ancient climate environment around the site was preliminarily revealed to have an average annual temperature of approximately 13.3℃ to 18.7℃ and an average annual precipitation of approximately 868 mm to 1 363 mm. These results provide a basis for the conservation and restoration of weapons unearthed in the future, as well as clues for the study of the materials used for wooden components of weapons and regarding the climate environment during the ancient period of Yunnan.

Abstract:Neoteric and modern Chinese traditional ink-sticks were used as the research objects in our work. The main body and the gold-decorated part of the ink-sticks were characterized using various methods including elemental analysis, X-ray fluorescence (XRF) spectrometry, thermogravimetric analysis (TGA), transmission electron microscopy (TEM), dynamic light scattering (DLS) analysis and static contact angle testing. The properties and performance characteristics of these traditional ink-sticks were systematically studied in terms of elemental composition, component ratio of soot, glue and other additives, microscopic morphology and monodisperse size of ink particles, aggregation state and size of ink particles, hydrophilicity and hydrophobicity of ink-stick surfaces. The results demonstrate that different ink-sticks had certain regularity in elemental composition, composition ratio, microscopic size, aggregation and dispersion state of ink particles, and surface hydrophilicity and hydrophobicity. The basic testing and analysis of physical-chemical properties of ink-sticks could provide data support for the scientific database of Chinese traditional ink-sticks. Moreover, the research on the specific correlation and differences could be related to the ink-making process and ink quality, providing not only a scientific basis for the use, preservation and identification of ink, but also a reference for the writing effect of ink.

Abstract:Fengguo Temple in Yixian County, Liaoning Province, is in the first batch of national key cultural relic protection units, and the existing Yuan Dynasty murals in the Great Buddha’s Hall are exquisite in picture and rich in content and are of high artistic and historical value. However, under the influences of natural and human factors over the past nearly one thousand years, these exquisite murals have different degrees of disease, among which flocculent contaminants have strong particularity, and the harm to the murals is especially serious. Our experiments took this kind of disease as the research object. First, it was judged that the range of distribution of contaminants on the surface of the murals was extremely large, which was seriously harmful to the preservation of the murals. Then, the methods of infrared spectrometry, energy spectrometry and X-ray fluorescence analysis were used to determine that the two flocculent contaminants unique to the mural surface were moth cocoon silk and spider silk. Finally, through environmental monitoring and review on relevant historical data, it was speculated that the reasons for their occurrence should be closely related to the environment of preservation and historical restoration. The accumulation of flocculent contaminants can do foreseeable and continuous harm to the surface of the murals, so cleaning up and prevention is extremely urgent. For the first time, a systematic analysis of flocculent contaminants of temple murals was conducted, with the aim of comprehensively revealing the characteristics and causes of flocculent contaminants on the surface of Yuan Dynasty murals in the Great Buddha’ Hall of Fengguo Temple. This work provides examples for research on the surface contaminants of temple murals and a certain theoretical basis for the exploration of targeted methods for cleaning and preventing contaminants on the surface of murals.

Abstract:The activities of animals on the surfaces of murals and painted sculptures often result in fecal pollution hard to remove, which affects the aesthetic value and tends to cause various types of deterioration. Trogopterus xanthipes and Sciurotamias davidianus are two kinds of squirrels that live in and around the Maijishan Grottoes all the year round. Their brownish-black solid and liquid excrement is widely distributed on the grottoes, shotcreted cliff, surface of the trestle path and inner part of beam holes. This study is aimed at identifying screen cleaning agents and techniques for the restoration of polluted areas. This was done by coating the tested zone with biological enzymes and surfactants combined with 4% absorbent resin (SAP). The results show that the area of cleaning with artificial saliva displayed the maximum color difference, which was significantly different from the control area (the color difference values were 8.311 ± 0.798 CIELab units, P＜0.05) and the greatest clearing rate (59.6%), which acted as an ideal cleaning agent. The species repellent experiment was carried out based on the above results. Metal spikes, capsaicin and ultrasonic avoidance devices were used for conducting on-site repellent experiments of the noxious animals. Using infrared camera monitoring, it was found that the repellent effects of the three measures were different:metal spikes had an intense effect on Sciurotamias davidianus, and they could not move within the range of the spikes after deployment; Trogopterus xanthipes showed sensitivity to capsaicin, and there was an obvious decrease in the maximum duration of activity and average daily activity frequency after spraying. The ultrasonic repellent device had a certain repellent effect at the early stage of installation, but later both of the species showed adaptability. Therefore, a reasonable combination of measures should be selected depending on the animal species. The results of this study provide a scientific basis and practical guidance for cleaning animal excrement and repelling harmful species active at similar cultural heritage sites.

Abstract:This work aimed to evaluate the effectiveness and long-term performance of mold disease control methods during relocation of murals from the tomb of Han Xiu, and to study the causes of mold diseases as well as the prevention and control measures used in the current restoration stage. The characteristics of mold diseases were analyzed using ultra depth-of-field microscopy. The community composition of fungi was identified using molecular techniques. In addition, the influences of mold control methods during relocation on the development and succession of microflora in the restoration stage was explored by combining the mold identification results in the relocation stage and the monitoring data of the preservation environment. The following results were obtained:the 11 strains isolated from the mold samples in the restoration stage belonged to Penicillium and Cladosporium; compared with the relocation stage, the diversity of molds on the mural surfaces was significantly reduced, and the composition of the dominant fungus Penicillium was also significantly different. The results also show the effective inhibition by clotrimazole and other anti-mold agents on the growth of Aspergillus, Fusarium and Alternaria, and the adaptability and selectivity of Penicillium fungi to the environment. The action of mold metabolites on the mural body caused mildew pollution, discoloration, disruption and other diseases of the murals. In addition, Penicillium mycelium had deeply entered into the interior, causing great harm to the stability of the mural structure. Therefore, it is recommended to classify and clean the yellow and black molds on the surfaces, screen mildew prevention agents and develop environmental control of exhibition cases promptly, to achieve long-term prevention and control of mold diseases of the murals from the tomb of Han Xiu.

Abstract:In different eras and regions, and by different institutions, various sci-tech conservation and restoration techniques have been successively implemented for ancient architectural color paintings in China. However, there is a lack of comparative studies on the historical evolution of sci-tech conservation and restoration and the evaluation of effects. It is urgently needed to establish a scientific, objective and practical evaluation system for the conservation and restoration of ancient architectural color paintings in China. This study is part of the self-funded project “Research on the Historical Evolution and Effect Evaluation of Sci-Tech Conservation of Color Paintings” by the Key Scientific Research Base of the National Cultural Heritage Administration. The study involves detailed investigations of 10 typical ancient architectural color paintings nationwide, which have undergone conservation for at least five years and have relatively complete preliminary data. Based on the investigation results, five types of conservation materials were selected for laboratory simulation tests to evaluate their reinforcement performances for the pigment layer. This study aims to provide reliable practical cases, and experimental data supports for the selection of conservation materials for ancient architectural color paintings, thus offering new references and insights to cultural heritage conservation and related material evaluation.

Abstract:In order to reveal the process of lacquering a Guqin (Chinese zither) and to understand the characteristics of its production, several analytical tools (optical microscopy, scanning electron microscopy-energy dispersive spectrometry, micro-Raman spectrometry and infrared microscopy) were used to observe, detect and analyze the surface, bottom and cross section of the lacquer film fragments encountered during the restoration of Gong Chengjun’s Zhongni-style Guqin. The results show that the lacquer film of the Guqin included a lacquer layer, a lacquer ash layer and a wrapping layer. Abundant materials were used for the lacquer film, which was very thick. The upper part of the lacquer layer was black and the lower one red, the colorant was vermilion and the film forming components of both were lacquer. The lacquer ash layer included the bottom, middle and the surface ash parts. There was little difference in particle size between the bottom and middle ones, and the surface one was the finest. Furthermore, the surface of each part of the ash layer was not polished after lacquering. The bottom ash part was composed of copper alloy, Cornu Cervi Degelatinatum, anhydrite and lacquer. The middle ash part was composed of Cornu Cervi Degelatinatum, anhydrite, lacquer and nearly ellipsoidal particles. These particles, a mixture of silicon dioxide, iron oxide and a very small amount of anatase titanium dioxide, were prepared in advance and then used for the production of the middle ash layer. The surface ash layer was composed of anhydrite and lacquer. The process of making the wrapping layer was to paint a mixture of anhydrite and lacquer, then lay the cloth, and finally paint a mixture of anhydrite and lacquer again. The fabric used in the wrapping layer may be ko-hemp cloth. Dry oil was added into all the lacquer which was used in the Guqin. Based on a comprehensive analysis of the results, the layered structure, material composition and lacquering process characteristics of the lacquer film of the Guqin were understood. It is speculated that the sound of the Guqin is suppressed and short, that the tone is fine and tight, and that the Guqin was restored during the period of the Republic of China.

Abstract:Wooden cultural relics from the Archaeological Site of the Wooden Watergate of Nanyue Kingdom and the Eastern Han Dynasty foundation site thereon have suffered from a variety of diseases. To investigate the contributing factors of these diseases, different methods (polarized light microscopy, Fourier transform infrared spectrometry, ion chromatography and X-ray diffraction) were employed to test and analyze the relics, stagnant water and salts. Disease surveying and environmental monitoring were implemented as well. The microscopic characteristics of the relics indicated that the wood was from Glyptostrobus pensilis (Chinese swamp cypress) and that the cell walls had been corroded by bacteria. The FT-IR spectra show that the characteristic peak of hemicellulose had disappeared and those of cellulose and lignin had diminished or become degenerative. The salt crystals were raw plaster demonstrated by the FT-IR and XRD results, and Ca²⁺ and SO^2-₄ were the dominant ions in the stagnant water as confirmed by ion chromatography, which illustrated that the ions had migrated to the relic surface with seepage and turned to salts. There was a significant positive correlation (P<0.01) between the groundwater and the level wood moisture content in the western region (top), western region (bottom) and south region (top). The wood moisture contents were mostly lower than 30% and kept changing. All the above results indicate that groundwater had not only infiltrated into the relics to cause wetting, but also affected the change of wood moisture content. When the wood moisture content was lower than 30%, the wooden fibers would swell and shrink leading to fissures, but being excessively high would promote the breeding of bacteria, leading to microbial damage. Salts brought by groundwater further exacerbated the development of fissures. Eventually, affected by all the above diseases, the relics rotted away in part. This study provides a theoretical support for the subsequent conservation and restoration of the relics.

Abstract:The study of the mechanism of corrosion of ancient bronze is an important prerequisite for its conservation and restoration. Over the past few decades, compared with the corrosion products of copper and lead, the understanding and research on tin corrosion products in the field of cultural relic conservation have been relatively insufficient and unsystematic. This article reviews research achievements in the formation process, as well as characteristics and characterization methods for tin corrosion products in different fields. We first summarize the transformation process of tin-formed corrosion products. Generally, the bivalent hydrated oxide SnO·nH₂O is formed first after the corrosion of tin in bronze, and the tetravalent oxide SnO₂·nH₂O is partially formed under oxidizing conditions, resulting in a complex hydrated oxide—SnO_x·nH₂O. Then cassiterite (SnO₂) is formed after further oxidization and dehydration. Due to the long and complex dehydration process in the natural environment, the tin corrosion products show an amorphous-nanocrystalline gel state externally. We then review some special properties of tin corrosion products. The first property is that the crystallinity is low—it is often difficult for the methods commonly used for cultural relic analysis (such as XRD and Raman spectrometry) to collect signals of tin corrosion products in bronze, or the signals are weak, mainly because they are in the transition stage from being amorphous to crystalline. The second property is in-situ deposition—copper and lead in bronze often migrate outwards after corrosion, while tin is corroded and deposits in situ, which is also the reason why some bronze objects suffer from severe corrosion, but the “tin rich patina” can retain the original state of the objects. The third property is high electrical resistivity—the formation and deposition of tin corrosion products can polarize the original anode and inhibit the corrosion of the anode metal matrix; however, the corrosion product film on bronze is not uniform and dense. The fourth property is the ability to exchange ions—the order in which tin corrosion products adsorb cations in alkaline environments is Al³⁺>Ba²⁺>Na⁺, and the order in which anions are adsorbed in weakly acidic environments is PO3-₄>Br->Cl-. This may provide an explanation for the deposition of elements such as Fe and Al in the “tin rich patina” and the pyromorphite in the rust layer of bronze in Sichuan and Chongqing regions. The fifth property is the overlapping lattice structure with the Cu-Sn δ phase boundary, which can inhibit the corrosion of tin corrosion products and copper on the Cu-Sn δ phase boundary, thereby inhibiting the corrosion of metals—this coincidence can well explain the local corrosion resistance phenomenon of Heiqigu copper mirrors and mercury bronze mirrors. Subsequently, we review the application of XRD, Raman spectrometry, XPS and other analytical methods in the characterization of tin corrosion products in bronze, verifying their low crystallinity. This also reflects the shift in understanding of tin corrosion products in bronze from early tin dioxide to hydrated oxides with partial amorphous characteristics and an approximate cassiterite structure. Finally, based on a review of the research results of tin corrosion products in different environments, this article introduces and compares the corrosion models of bronze in different environments. In the atmospheric environment, outdoor bronze exhibits the deposition of cuprous oxide and tin corrosion products on the surface, and divalent copper corrosion products migrate to lower areas under the influence of rainwater erosion. In the oxygen-rich marine environment, tin in bronze often forms hydrated oxides containing chlorine in the early stages of corrosion, and then undergoes dechlorination and dehydration to transform into hydroxycassiterite and tin dioxide. In anaerobic marine mud zones, bronze is mainly affected by sulfate reducing bacteria to form sulfides of copper and tin. In the soil environment, “chloride corrosion” damages the substrate of bronze in the form of inward invasion of chloride ions, causing cyclic corrosion called “bronze disease” and forming powdery rust, and “chloride-free corrosion” occurs in the form of cation diffusion. Under specific conditions, Cu in the substrate continuously passes through the tin corrosion layer and flows outwards, causing the bronze strength to decrease and become “fragile”.

Abstract:Earthen sites are an important part of cultural heritage in China, and more and more scholars have focused on and participated in their conservation. In order to clarify the research progress of the conservation work for earthen sites in China in the past 30 years and to predict the future research trends, the method of bibliometrics combined with two types of literature visualization analysis software—VOSviewer and CiteSpace—were used to analyze 331 papers of CNKI from 1990 to 2021. The results show that the number of published papers on the conservation of earthen sites presents a rising trend in recent 30 years. Currently, academic teams with the characteristic of “small concentration and large dispersion” have been formed. There has developed a relatively complete research network, the topics of which include deterioration, reinforcement materials, anchorage technology, stability, conservation conception, etc. The research on the conservation of earthen sites in the past 30 years can be divided into three stages:1) exploration of the concept of earthen site conservation and construction of theoretical frameworks; 2) research on the conservation materials and technologies for earthen sites; 3) research on the deterioration mechanism of earthen sites. The main research trends corresponding to the three major research topics are as follows:1) improving the deterioration classification and quantitative grading of earthen sites; 2) building systemic evaluation of the conservation materials and technologies for earthen sites; 3) conducting research on mechanisms of deterioration under multi-field coupling, as well as quantifying physical and mathematical models of deterioration and developing forecasting models with multidisciplinary references.

Abstract:After analyzing the traditional restoration techniques for ceramics in China, and drawing on the Western concept of “identifiable” cultural relic restoration, this study presents a new restoration method for ceramics called the “downgrading method”, which pioneers the treatment of restoration by reducing the original tone in filling the layer, imitating the glaze and painting color. With the restoration of two Ming official porcelain wares unearthed from the Jingdezhen Imperial Kiln site as examples, the implementation process and results of the “downgrading method” are described and analyzed in detail. These provide a through demonstration of this method for the conservation and restoration of ceramic cultural relics in China.

Abstract:An important part of a field survey is to clarify the influence of long-term changes in solar radiation on stone cultural relics when the deterioration mechanism of the stone is discussed. So far, most of the relevant surveys and studies could only be carried out by establishing environmental monitoring stations. Hemispherical photography is a quick way to measure the sky view factor and is widely used in disciplines such as ecology. Through two case studies of field surveys on conserving stone cultural relics in Japan and China, the hemispherical photography method has proved to be effective in selecting the locations for environmental monitoring devices, determining the effects of solar altitude variation on the stone cultural relics, and comparing long-term changes in the exposure of stone cultural relics to solar radiation at different locations. The method is convenient, economical, and efficient. As an auxiliary means, it can be used more for the preliminary measurement and data analysis of the selection of environmental monitoring devices and determining the effects of solar radiation during field surveys on stone cultural relics.

Abstract:Bonding in the restoration of pottery cultural relics is an old and constantly updated subject. The properties of both pottery wares and adhesives should be taken into account when selecting adhesives for the restoration of pottery cultural relics. Individual differences of pottery exist at each stage of production, including the differences in the composition of clay and non-clay, and in the content of aluminum silicate in clay, as well as in firing temperatures and atmospheres. Ancient Chinese pottery developed around the composition of pottery and the change of firing temperature, so there were many kinds of pottery with a long history of using bonding materials. In the past 30 years, with regard to pottery bonding, more attention has been paid to the detection and research on adhesive properties. The frequency of use and basic properties of commonly used adhesives during the period are of guiding significance. Thermoplastic and thermosetting resin adhesives involving polymer adhesives have different main properties due to differences in linear structure and three-dimensional network structure:thermoplastic adhesives have smaller tensile strength and are reversible after bonding; thermosetting adhesives, the opposite is true for the agent. The good bonding mechanical properties, durability and reversibility of the adhesive are necessary conditions for selecting a suitable adhesive for ceramic cultural relics; the curing time, temperature conditions, shrinkage rate, etc. of the adhesive are direct factors that affect the bonding process. It is necessary to take into account a variety of factors, combine the performance summary of adhesives, select suitable adhesives, collect bonding information, detect bonding effects in stages, and insist on multi-disciplinary cooperation, etc., in order to promote in-depth research and progress of adhesive applications.

Abstract:The conservation, restoration and identification of paper cultural relics require analyses of the composition and age of paper and writing/inking materials. With more and more importance attached to the preservation of paper cultural relics, non-destructive and micro-destructive analysis technologies have gained more attention, compared to destructive analysis. This article describes a variety of relevant technologies for non-destructive and micro-destructive analysis of paper cultural relics, including atomic force microscopy, confocal micro-Raman spectrometry, X-ray photoelectron spectrometry, fiber-optic reflectance spectrometry, terahertz spectrometry, micro-computed tomography, surface desorption atmospheric pressure chemical ionization mass spectrometry, time-of-flight secondary ion mass spectrometry, pyrolysis-gas chromatography/mass spectrometry, accelerator mass spectrometry, near-infrared spectrometry combined with chemometrics (principal component analysis) or artificial intelligence algorithms (convolutional neural networks), and other technologies. The article also provides a perspective on the development of raw material identification, dye component analysis, and dating of paper cultural relics. Research on paper cultural relics involves multiple disciplines, and through the integration of these analytical technologies and practical work, the enhancement of academic exchange, and the promotion of relevant standard research, it will strongly contribute to the rapid development of methods for the preservation, restoration and identification of paper cultural relics.