Abstract:A showcase provides an isolated space for the exhibition and preservation of cultural relics. The tightness of a showcase affects the control of the micro-environment within the showcase. Good tightness can reduce permeation of the external pollutants, buffer humidity fluctuations, improve the effects of passive conditioning agents such as humidity controls and absorbent materials, and increase the effectiveness of purification within one power cycle. Therefore, tightness is one of the most important factors to evaluate for a showcase. To measure the exchange rate between air inside and outside of a showcase, a method to detect tightness of showcase using tracer gases was developed. Carbon dioxide and ethylene as tracer gases in terms of convenience, safety, and data quality were evaluated. The results showed that the values of the two tracer gases had a certain correlation and both tracer gases can be used to detect the tightness of a showcase. Detection with carbon dioxide was more convenient, because one can use a portable instrument that records data in real time, but because carbon dioxide is denser than air, it sank to the bottom of showcases. Relative humidity was also found to impact the detection results when carbon dioxide was used as the tracer gas. Carbon dioxide as the tracer gas was used to measure the tightness of a number of showcases. The experiments showed that the air exchange rates of different showcases varied from 0.1 times a day to 37 times a day and that the use of carbon dioxide as a tracer gas provides a simple method to evaluate the tightness of showcases.

Abstract:Many seriously weathered stone components have been found in the JianFu Palace of the Forbidden City. To evaluate the state of preservation of these stone components, the scratch width, resilience, water diffusion rate, surface and transmission wave speeds of the stone components in the JianFu Palace were tested selectively. The survey data were compared with those obtained with fresh stones. From these studies it has been shown that those stone components have weathered badly and that protective treatment will be needed. The environmental factors affecting weathering of the stone components in the JianFu Palace were also tested and analyzed. The relationship between environmental and preservation conditions of stone component is discussed and the data obtained provided theoretical support for deterioration analysis and conservation operation.

Abstract:Microorganisms are a major concern in preservation and exhibition of ancient mural paintings. Their identification is a major step leading toward better conservation. Compared with traditional methods, molecular biologybased techniques directly analyze the genetic materials of the microorganisms, avoiding the culturing process and providing a fast and comprehensive method for the identification of major pathogens. Molecular biological techniques were used to detect microorganisms in two tombs built in the 5th century in North China. Pseudonocardia species as the main pathogens was identified. Results provided important information for planning the treatment and prevention of mural damage caused by microorganisms.

Abstract:Tomb M29 at Hanjiawan Village, Changan District, Xian, is a typical brick grave, composing a long sloping passage, alcoves, courtyard, doors, corridors and the brick burial chamber. Its murals are found between the passage and the corridor, depict dragons, tigers, attendants etc., and enrich understanding of murals in the tombs of the middle to late Tang Dynasty. In preparation for protection of the murals, Xray diffraction (XRD), scanning electron microscopeenergy dispersive Xray (SEMEDX) and MicroRaman spectroscopy was used to analyze the structures and pigments of the murals. Results showed that to paint the murals, a layer of earth mixed with grass was first applied to the walls, which was then covered with a layer of lime, onto which the mural was painted. The major color is black, for which carbon black was used as colorant.

Abstract:Efflorescence often appears on the city wall of Xian, forming large areas of white crystalline salts. Efflorescence causes cosmetic damage and can reduce the mechanical strength of the bricks, which leads to peeling and powdering, and even threatens the stability and safety of the wall. To investigate the cause of efflorescence, the crystalline salt was analyzed using XRD.The results showed that the major components are NaCl, NaNO₃, Na₂SO₄·10H₂O, and Na₂SO₄. Based on groundwater and rainfall data for the Xian area, the major cause of efflorescence is the introduction of soluble salts from construction materials, groundwater and rainfall. A conservation method against efflorescence was developed, first removing the surface salts with multiple layers of paper, following by sterilization and insulation.

Abstract:Red sandstone, as a building material, plays a vital role in the history of Guangdong province. Many red sandstone cultural relics had significant historical, scientific and artistic value are preserved in Dongguan city. Most of these relics are outdoor sites, and therefore had serious deterioration problems due to various causes. Currently, conservation efforts for these cultural relics have not been deployed effectively. A survey of the preservation status of these red sandstone cultural relics was made using scientific analytical methods such as Xray diffraction (XRD) to study the deterioration mechanism of those red sandstone sites. The results suggest that the main factors causing deterioration of red sandstone relics are water (precipitation, acid rain and capillary water) and soluble salts. This conclusion provides a reliable basis for future projects on conservation of red sandstone cultural relics.

Abstract:Huashan rock paintings represent the most important materials for studying the social history and culture of ancient Baiyue people in China. Analysis of the binding media is crucial to understanding the painting process, pigment exfoliation, pigment fading and the eventual treatment of deterioration of the Huanshan rock paintings. Microscope, infrared and microRaman spectroscopy and gas chromatographymass spectrometry (GCMS) were employed to analyze the binding media used in Huashan rock painting. The analysis showed the binding media of pigment was vegetal material. Pigment samples contained calcium oxalate, which indicates the usage of binding media came from plant resources.

Abstract:The paleodose of pottery comprises the equivalent dose Q and a superlinearity correction I. For the purpose of measuring the paleodose accurately and calculating the error of paleodose correctly, the linear regression method was used to calculate the equivalent dose and the superlinearity correction for 10 pieces of pottery. The errors in various methods were analyzed. The results indicate that linear regression method is more accurate than the currently used normal method for calculating pottery paleodoses. Comparison of the errors calculated with different methods showed that the method averaging after linear regression is better than other methods in calculating paleodose errors. This study is important for improving the accuracy of paleodose measurements and calculating paleodose errors correctly. It makes paleodose measurement conforms to statistical laws.

Abstract:Large quantities of polychrome pottery were excavated from a Han Dynasty tomb in Xiangshan (Xiang Mountain), Qingzhou of Shandong Province. To decide how best to preserve these relics, based on their states of deterioration, the white salts on the surfaces and the bodies of the polychrome pottery objects were studied by Xray diffraction (XRD) and polarized light microscopy ( PLM). These studies showed that the salts are mostly calcium carbonate and calcium sulphate. The body of the polychrome pottery is composed of sand and clay. The clay used is a product of longterm weathering of a clay mineral. The analytical results revealed the production process includes mostly modeling, supported with modeling and sculpturing. The mechanism of deterioration is also discussed based on the results. The surface weathering of the pottery results from the broken chemical bonds within the mica minerals and damage due to the soluble salts from the preservation environment. This research provides important information for conservation and restoration of polychrome pottery.

Abstract:To improve the antiphotoageing property of B72, a hindered amine light stabilizer having a high molecular weight, H622, was selected to modify B72. The color change, weight loss and other parameters of the ageing process were monitored and the photostabilization mechanism was investigated. The experiment results showed that stability of the modified material was greatly enhanced after modification with the hindered amine light stabilizer H622. The infrared spectrum, contact angle, weight-loss, hardness and other parameters of the modified material changed much less than did B72 itself after aging. Moreover, the color change of the modified material was negligible after about 500 hours of ageing. It is proposed that the mechanism of stabilization involves absorption of light by the hindered amine and generation of nitroxyl radicals, which can trap free radicals produced by degradation of B72, resulting in inhibition of the B72 degradation reaction.Therefore, it seems practical to modify B72 with hindered amine light stabilizer H622, thus providing a new method to extend the lifespan of B72.

Abstract:The Nanyue kings mausoleum in Guangzhou and the Chu kings mausoleum at Lion Mountain of Xuzhou are the two of the most important sites, having the largest numbers of unearthed jadewares from Han dynasty burial grounds in China. The silk and gold threaded jade suits from these two mausoleums are the most important jadewares buried with the dead in the southern and central parts of China. The authors compared the mineral materials and technological characteristics of the jade suits from the two mausoleums by direct observation, microscope, environmental scanning electron microscopy (ESEM), and infrared and Raman spectroscopy. The results show that the raw materials of most of the jade suits in both mausoleums are nephrite jade. But based on current jade colour and texture, the jade materials from the Chu king mausoleum are of much better quality than those in the Nanyue king mausoleum; the latter appeared to have multiple origins. The so-called “pseudojade” from the Nanyue king mausoleum were likely from western Guangdong. The cutting traces and marks on the jadeware from the Nanyue king mausoleum suggest that the jade-carving tools of the Nanyue kingdom were nearly the best available at that time, or there was some material exchange between Nanyue area and Central plain. Furthermore, the possibility cant be excluded that all or parts of the jade suits from the Nanyue king mausoleum were locally carved. The authors propose that different cutting-craft systems coexisted in the Han Dynasty and that the obvious difference between the jade suits, in terms of technological features, from the two mausoleums indicates that these jade suits were possibly made by different cutting-craft systems

Abstract:In order to determine the mineral composition and source of composite glass beads (eyebeads) unearthed at the Shahe Town Tomb in the Changping District of Beijing, Xray diffraction (XRD), laser Raman Spectroscopy (LRS) and portable energydispersive Xray fluorescence analysis（PXRF）were used to nondestructively measure the structural and chemical compositions of the matrix and of the body of the glass balls. The results indicate that the matrix of the dragonfly glass balla belongs to the Na₂OCaOSiO₂ type of glass, and Cu and Co are the major coloring elements. Based on the fact that the cobalt component has a relatively high percentage of iron but a low percentage of manganese, and that comparison with similar domestic and foreign beads, we conclude that these three beads are likely imported. The tomb was built during the Qing Dynasty. The owner of the tomb may have acquired these beads though collection or other sources and used them as funerary objects.

Abstract:To understand the formation of corrosion on a Western Zhou Dynasty bronze excavated from tomb M24 in Ouhai, Zhejiang province, scanning electron microscopy (SEM), Xray fluorescence spectroscopy (XRF), Xray diffraction (XRD), high performance ion chromatography(HPIC) and other instruments were used to analyze the corrosion products of the bronze sword and the soil around its burial site. The results show that the bronze sward is severely corroded. Copper has been lost and the major corrosion products are Sn compounds. By measuring corrosion potential and determining the potential-pH of the CuH₂O system the progress of corrosion of this bronze can be deduced. These results will provide useful information for similar relics.

Abstract:When the gold inlaid bronze chariot and harness ornaments were unearthed from Mao mausoleums, they were heavily covered by rust and it was hard to see their patterns. This conservation project was initiated in accordance with preservation principles and operational methods. Taking into account the current condition of preservation of these relics, chemicals were first applied to soften the surface, and then mechanical methods were used to get rid of rust. Subsequently water was used to deepclean the objects, the relics were soaked in benzotriazole（BTA） solvent and finally organic polymers were applied on the surface for protection. The relics were preserved effectively and their historical, artistic and research values were restored. This conservation practice shows that all conservation work should be designed according to the unique conditions of each object in order to achieve the desired goal. The methods used and technique employed provide reference information for treatment of similar relics.

Abstract:Because of the tomb environment and preservation conditions after excavation, the bronze relics are subject to varying degrees of damage. The surfaces of many bronze relics are usually covered with various types of corrosion products. Many of them are already damaged or deformed when excavated, and some are even fragmented and beyond recognition. A scientific conservation and restoration plan is needed to avoid further damage. A damaged bronze ding with a hanging squama design was excavacted from Dabuzhishan (Mountain Dabuzi, Lixian (Li country) of Gansu province. Sample analysis, surface cleaning, restoration of cementation, inhibition and surface sealing protection were carried out. After treatment, the object became a complete piece which have a clear decorative design and balanced color, and achieved the desired result.

Abstract:In order to restore a bronze cowrie-container having tiger-handles and an eightyak design, from the Shanghai Museum, a device for correcting its shape was designed to restore it according to deformation features of the container. During the shapecorrection process, the device efficiently corrected the shape. The device provides good support when forces were applied on the container, thus avoiding fracture of the container. This shape correction device is easy to use and has good prospects for restoration of other objects.

Abstract:To solve the problem of a shortage of ancient repair paper, the China National Preservation and Conservation Center for Ancient Book launched a task for the production of custommade repair paper for ancient books. The custom-made paper replicates ancient papers and is manufactured in the original production region as the ancient paper was, and use traditional crafts such as limewater immersion and sunlight bleaching. After two years of efforts, a variety of bamboo, bast and Xuan paper have been produced. Testing indicates that these papers meet quality requirements. This article reviews various categories of ancient paper, their classification and quality requirements. The advantages and disadvantages of using traditional crafts compared with modern handmade papers are discussed. Test results show that these custom-made papers are suitable for repairing ancient books.

Abstract:The cobalt coloring materials used throughout Chinese history include pigments, glass and ceramic glazes. Smalt and cobalt blue are historical pigments. The application of cobalt blue glass may have started during the Western Han Dynasty. The use of cobalt blue ceramic glazes started with glaze bead of pottery body during the Warring States period and further developed into several types in tri-colored glazed pottery during the Tang Dynasty. Both domestic cobalt ore materials and imported Smalt materials were used. Contaminating components in the ore, e.g., Mn, Fe, Ni, As and Bi, will affect the quality of cobalt coloring materials.