Abstract:In our work, we tried to reveal the mechanisms of weathering and erosion of ancient bricks using X-ray diffraction (XRD) analysis, X-ray fluorescence (XRF) spectrometry and scanning electron microscopy (SEM) for microstructure analysis, mercury porosimetry to test the properties of pores, and thermodynamics software, HSC, to characterize chemical reactions in bricks. The results of the study indicate that 1) for ancient building bricks within a certain height near the ground, underground water and ions are continuously transferred to the upper part and the surface through the capillary network inside the wall bricks and the pressure generated due to the crystallization of soluble salts and freezing of water are the main factors causing the weathering and destruction of bricks; 2) in areas with high levels of NO_x and SO₂ in the air, and frequent acid rain, acidic substances in the air are carried into the surface of bricks where they then react to form new salts. The crystallization, dissolution and loss of these salts are also non-negligible factors leading to the destruction of ancient bricks, especially those that cannot be penetrated by groundwater. This work provides a scientific theoretical basis for efforts to protect ancient bricks.

Abstract:Based on the model of a single-story place house made according to Ying Zao Fa Shi of the Song Dynasty, we have developed a 3D beam-spring finite element model which takes into account the sliding of column root, the semi-rigid connection of mortise-tenon joints and shock isolation of Dou-gong. Using this model, the seismic analysis results were in good agreement with the experimental result made in a shaking table test. The criteria for determining the relative displacement of the column root sliding and the maximum story drift angle were proposed and the two kinds of mechanisms were studied using incremental dynamic analysis (IDA) method. The results show that the wooden structure of the ancient building was not prone to collapse due to column root sliding under ordinary seismic waves, but that story collapse was the mechanism most likely to be involved under long-period seismic waves. Compared with ordinary seismic waves, ancient wooden buildings were more affected by long-period seismic waves.

Abstract:In this study, we reviewed historical literature on modern Chinese reinforced concrete structures in order to find appropriate structural calculation methods for such structures built from 1912 to 1949. After obtaining the original structural calculation methods for beams of modern Chinese reinforced concrete buildings, we also carried out a comparative study using the original and the contemporary calculation methods, including the methods for calculation of flexural capacity and shear capacity of concrete beams. According to the comparative calculation analysis, without considering earthquake load, when the longitudinal reinforcement ratio is 1%-2%, the calculation values of flexural capacity in the current codes are 3.61-4.02 times those in the earlier codes; when the stirrup ratio is 0.1%-1%, the calculation values of shear capacity in the current codes are 1.61-2.41 times those in the previous codes; when the bent-up reinforcement ratio is 0.5%-1.5%, the calculation values of shear capacity in the current codes are 2.03-2.36 times those in the previous codes.

Abstract:In order to comprehensively understand the craftsmanship of a Guqin and also to provide a scientific basis for its restoration and conservation, we analyzed lacquer film and silk string fragments of a Guqin named “Yu Quan” made by Zhu Yuan, a famous expert of Guqin in the Yuan Dynasty. Utilizing various analytical methods, including stereomicroscopy, electron probe analysis, Fourier transform infrared spectrometry (FTIR), pyrolysis gas chromatography-mass spectrometry etc., we studied the micro-morphology, stratified structure, composition and lacquering technique of the Guqin. The results show that the body of the Guqin is made up of a wood body layer, a lacquer ash layer, a primer layer and a color lacquer layer. The application of the primer layer connects well the lacquer ash layer and the lacquer film layer. During the Guqin-making process, a lacquering technique utilizing a grey-painted lacquer was used to enhance the Guqin’s mechanical and waterproofing properties and also improve its playing effect. The main material of the lacquer ash layer is bone ash. FTIR showed that the strings were made from animal fibers. Furthermore, ESCAPE identification of organic matters showed that the lacquer film was composed of lacquer liquid, dry oil and starch. The lacquer liquid was probably derived from urushiol from lacquer trees (e.g., Rhus verniciflua, Rhus succedanea and Melanorrhoea sp.). The application of modern analytical instrumentation reveals hidden information contained in the Guqin to a certain extent. This research provides information on the preservation state, material composition, stratified structure and lacquering technique of the Guqin, and can be used to guide the scientific conservation and restoration of other unearthed lacquerware.

Abstract:The fragments collected from a middle- to late-Qing Dynasty kingfisher blue crown with dragon and phoenix were analyzed by various methods, including 3D video microscopy, scanning electron microscopy-energy dispersive spectrometry (SEM-EDS) and Fourier transform infrared (FTIR), to investigate the materials and craftsmanship of the kingfisher blue crown. According to the analytical results, the materials of the crown contained mainly metal and wood, and copper or silver, or a Cu-Ag alloy, with gilding on the metal surface was used for metal matrix. Sky blue and dark blue kingfisher feathers were cut to form some patterns and were glued onto the matrix. Animal glue was used as the adhesive agent between the metal or wood and the kingfisher feathers. In order to reduce production costs and the weight of the crown, fewer precious metals, such as gold, were used. In fact, traditional techniques, such as filigree, gold threads, and gilding were employed in the crown-making. The results of this research provide scientific support for understanding the materials and techniques used for traditional handmade crafts in China.

Abstract:The bronzes unearthed from Tomb M35 and M36 at Chenzhuang Site of Gaoqing County, Shandong Province, exhibit special corrosion phenomena, specifically black rust. Analysis of the corrosion products on these bronzes show that 1) the soluble sulfate content of the soil of the two tombs is very high; 2) the content of sulfur in the bronzes is very high; 3) the black rust is a compound of copper and sulfur; 4) the shiny particles are well-crystallized forms of copper and sulfur and the grains are parallel plate-shaped aggregates; 5) there is a lot of “copper” present, and the microstructures of the pure copper particles and the pure copper sheet are the same as that of compound of copper and sulfur; 6) the green tone and green rust spots on the bronzes ware were caused by the crystallization of sulfate minerals; 7) a copper-tin alloy is contained in the yellow white and gray white rust on the surface of matrix and 8) chloride ions are rarely detected in bronzes.

Abstract:Many traditional painting and calligraphy works have blurred and defective seals, but there has been no good way to extract and identify these seals. This paper reports a method of collecting spectrum-image information from blurred seals in calligraphy and painting works using hyperspectral image system. The minimum noise fraction (MNF) rotation was used to process spectral image data, which improved the recognition of blurred seals. The results show that this method can effectively extract the information from the blurred seals, contributing to the research on the value and authenticity of calligraphy and painting cultural relics in a scientific and effective way.

Abstract:The laser cleaning method has the advantages of high efficiency,safety and controllability.In our work, laser cleaning was used to remove contaminants on the surface of murals. First, the optimum laser cleaning threshold and damage threshold were determined via simulation experiments. Then within the range of above thresholds, different laser energy densities and auxiliary measures were selected, depending on the different contaminants on the murals, in order to perform laser cleaning experiments on mural samples. Finally, the effective device parameters were obtained. The cleaning effect was also evaluated using microscopic examination and chromaticity measurement during the cleaning experiments. The experiments confirmed that laser cleaning was effective on removing some of the contaminants on mural samples and defined the optimum working parameters of the laser device. This work should provide a useful reference for practical application of laser cleaning to murals.

Abstract:Kesi (silk tapestry), decorative silk fabric once used by the imperial household and appreciated in ancient China, is a valuable kind of cultural relic. However, silk is prone to embrittlement and discoloration due to environmental influences, which creates a challenge for identification of dyes. In our study, a Kesi hanging panel with a Chinese character of “Chang” hung in Dun Ben Dian of Yu Qing Gong in the Palace Museum, was analyzed by ultra-high performance liquid chromatography combined with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) assisted with the natural products database of UNIFI. The dyes of different colored fibers of the Kesi object were extracted using an optimized two-step method and analyzed using UPLC-QTOF-MS. By searching the natural products database, we quickly determined that the yellow character of “Chang” was dyed with amur cork tree, that the red character of “Mian” was dyed with both safflower and amur cork tree, and that the blue backing fiber and the cyan backing paper were dyed with indigo. This method facilitates the identification of dyes, and thus provides scientific evidence to guide restoration, exhibition and conservation of relics.

Abstract:Ancient Chinese paintings and calligraphy in museums are vulnerable to contamination or degradation caused by microorganisms. A comprehensive investigation of microbial disease information can contribute to the development of relevant protection measures. In our work, we purified black and red stains from a Chinese painting named Mu Niu Tu collected in Chuzhou Museum and identified bacteria and fungi by 16S rRNA and ITS gene sequencing. The enzymatic activities of cultivated bacteria and fungi were also measured using biochemical tests. The results show that 13 strains of bacteria and fungi separated from stain samples belong mainly to the genera, Bacillus, Schizophyllum and Rhizopus. The enzymatic activity tests indicate that esterase, lipase and N-acetyl-β-glucosaminidase were most involved in biodeterioration. The results provide relevant data support for the research on the mechanism of microbial damage to Chinese paintings and calligraphy in museums.

Abstract:Introduced in the Han Dynasty and commonly used in the Tang Dynasty, amber had been valued by ancient Chinese people because of its decorative and medicinal properties. In ancient China, amber was mainly imported, so the analysis of amber provenance may reflect the cultural exchanges at that time. So far in China, only privately-collected amber has been identified and no scientific analysis of archaeological amber reported. In our study, through infrared spectral analysis and comparison of the infrared spectra of amber from Fushun, Myanmar and the Baltic region, we found that a red ornament from one Tang Dynasty tomb (AD819) of a low-rank official at Guanghuacun Street in Chengdu was amber which probably came from the Baltic coast and was transferred to Sichuan through ancient Rome and other ancient cultural centers. The use of amber by low-rank officials reflects the prevalence of amber, flourishing international trade and cultural exchanges in the Tang Dynasty.

Abstract:In order to more effectively carry out desalination as a conservation treatment for a great number of ceramic relics from the Ming Dynasty shipwreck, Nan’ao Ⅰ, samples from three different kiln systems of Nan’ao Ⅰwere selected as research objects. We tested and analyzed the clay bodies, and compared the results of four different desalination methods (soaking in still water at ambient temperature, soaking in heated still water, soaking in water with ultrasonication and soaking in heated water with ultrasonication) with eleven parameters. It was found that compared with desalination by soaking at normal temperature, the rate was greatly increased using the other three methods that employed heating or ultrasonication. However, as the temperature rose or the ultrasonic frequency increased, the desalination rate did not increase significantly. Furthermore, the ultrasonic waves had adverse effects on the glaze surface and the clay body of these fragile cultural relics. Based on these observations, we proposed desalination parameters for the ceramic relics from the three kiln systems, with the aim of providing support for the safe and effective desalination of the more than 20,000 pieces of ceramic relics from Nan’ao Ⅰ. This work also provides a reference for the conservation of ceramic relics from other shipwrecks.

Abstract:The Suspended Reclining Buddha, a huge stone statue created in the late Tang Dynasty, possesses highly historical, artistic, scientific and religious values. However, the current state of preservation is poor due to the existence of pigment fall-off, soaking powder, flaking and other diseases. Therefore, urgent conservation and restoration is needed. In order to understand the composition and structure of pigment layers on the Suspended Reclining Buddha, pigment samples were analyzed using a variety of methods including metallographic microscopy, X-ray fluorescence spectrometry, X-ray powder diffraction, scanning electron microscopy-energy dispersive spectrometry and Raman spectrometry. The results indicate:1) the red pigment is hematite and red lead; 2) the blue pigment is ultramarine; 3) the green pigment is atacamite; 4) the cyan pigment is cornwallite; 5) the white pigment is anglesite; 6) some parts of the statue are covered with gold leaf and 7) the statue has been repainted many times.

Abstract:The structural characteristics of Jansal Palace in Tibet and its method of analysis are discussed in this paper. The responses of the structure under static load and under earthquake action are also shown. The methodology in this research is different from that of other studies mainly in that 1) the walls are considered in the calculation model; 2) the shapes of columns and walls are considered; 3) the timber purlins are transferred into slabs and 4) defects of members are considered. The results show that Jansal Palace in Tibet is stable under the static loads, but many of its members could not withstand earthquake action. In an earthquake, the wooden members with insufficient stiffness would vibrate first. The weakest part of the structure is the four-column portion in the center. These columns have a large slenderness ratio, thus a large deformation of these columns may destroy the whole structure. The difference in displacement between the columns and the walls is obvious, as they do not coordinate with each other. Additionally, the beam-column joints cannot withstand earthquake action, in the case of columns with deformation defects, which is important in ensuring protection of the building.

Abstract:X-ray photography is a type of X-ray imaging (photographic) technique. Known as Roentgen rays, X-rays are not visible to naked eye and can penetrate objects and expose photographic films. The penetrating power of X-ray to different substances is different. The grayscale imaged on the film is closely related to the material, density and thickness of objects. Therefore, the final result is a clearly defined white and black image. In our study, the architectural paintings selected have deep implications and utilized complicated techniques, and therefore have great research value. However, much of the key information about them has been lost because the paintings were smeared and painted over. With the help of X-ray photography, the patterns of the color paintings hidden under the top paint layers can be brought to light again. This method complements other repair methods, making possible the perfect restoration of color paintings hidden under the top paint layer.