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Shazhou, China

Zhang H.-Y.,Lanzhou University | Yan G.-S.,Lanzhou University | Wang X.-D.,Dunhuang Academy
Journal of Zhejiang University: Science A | Year: 2012

Moisture adsorption-desorption tests (MATs) were conducted on simulated mural plaster specimens under different air temperatures (ATs) and relative humidity (RH) to investigate the possible effect of seasonal alteration and visitors' breath on the deterioration of Mogao Grottoes, Dunhuang, China. Saturated salt solutions were used to maintain a constant RH, and plant growth cabinets were used to maintain a constant or varying temperature in the simulation test. The weight of specimen was periodically measured to determine the adsorbed or desorbed moisture. Test data illustrate that the desorption process is far quicker than the adsorption one, indicating that it is possible to inhibit the disadvantage effect from visitors, such as shortening the staying time in caves. In case of high humidity, an accumulated moisture adsorption was found to correspond to the varying temperature. On the other hand, in case of low humidity, accumulated moisture desorption corresponded. Test data imply that opening caves more often to visitors in humid seasons should be avoided so as to prevent continuous wetting of wall paintings. © 2012 Zhejiang University and Springer-Verlag Berlin Heidelberg.

Liang H.,Nottingham Trent University | Lucian A.,Nottingham Trent University | Lange R.,Nottingham Trent University | Cheung C.S.,Nottingham Trent University | Su B.,Dunhuang Academy
ISPRS Journal of Photogrammetry and Remote Sensing | Year: 2014

PRISMS (Portable Remote Imaging System for Multispectral Scanning) is designed for in situ, simultaneous high resolution spectral and 3D topographic imaging of wall paintings and other large surfaces. In particular, it can image at transverse resolutions of tens of microns remotely from distances of tens of metres, making high resolution imaging possible from a fixed position on the ground for areas at heights that is difficult to access. The spectral imaging system is fully automated giving 3D topographic mapping at millimetre accuracy as a by-product of the image focusing process. PRISMS is the first imaging device capable of both 3D mapping and spectral imaging simultaneously without additional distance measuring devices. Examples from applications of PRISMS to wall paintings at a UNESCO site in the Gobi desert are presented to demonstrate the potential of the instrument for large scale 3D spectral imaging, revealing faded writing and material identification. © 2014 International Society for Photogrammetry and Remote Sensing, Inc. (ISPRS).

Lu Z.,Microsoft | Luo W.,Microsoft | Luo W.,Chinese University of Hong Kong | Sun Z.,Dunhuang Academy | And 2 more authors.
Journal of Computing and Cultural Heritage | Year: 2012

This article describes recent field work undertaken by Microsoft Research Asia and the Dunhuang Academy to capture highresolution images of Buddhist art at the UNESCO world heritage site, the Mogao Caves. This project is intended as a feasibility study examining the use of a digital large-format gigapixel camera to capture high-resolution images in a cultural heritage setting. In particular, we report on the current challenges faced by the Dunhuang Academy in their imaging efforts and how the use of a digital large-format camera can improve the quality of the imaging process while reducing time and effort. We also describe lessons learned from this field study as well as remaining challenges inherent to such projects. © 2012 ACM.

Wei G.-F.,Zhejiang University | Wei G.-F.,Anhui University | Zhang B.-J.,Zhejiang University | Yang F.-W.,Zhejiang University | And 3 more authors.
Yantu Lixue/Rock and Soil Mechanics | Year: 2012

On the basis of preparation and characterization of calcium-based hydraulic consolidant, this paper makes a preliminary study of consolidation conservation of historical earthen sites under moisture circumstance. Analytic results of scanning electron microscope and X-ray diffractometry show that Ca(OH) 2 are transformed into a kind of acicular secondary CaO with diameter 50 nm and length 200 nm after being calcined, and this nano-sized secondary CaO are transformed into oval plate-like Ca(OH) 2 with size 200-300 nm after being slaked. Meanwhile, research results indicate that calcium hydroxide crystals undergo both substantial size reduction and clear morphological change, developing nanometer, plate-like and acicular crystals upon aging. Results of consolidation experiment of moist earthen samples reveal that permeabilities of nanometer lime-alcohol dispersions are superior to that of analytically pure Ca(OH) 2-alcohol dispersions, and consolidation effects of calcium-based hydraulic consolidant are obvious. It is possible that calcium-based hydraulic consolidant will become a new consolidation material used for conservation of historical earthen sites under moisture circumstance.

Liu S.,CAS Shanghai Institute of Optics and fine Mechanics | Su B.-M.,Dunhuang Academy | Li Q.-H.,CAS Shanghai Institute of Optics and fine Mechanics | Gan F.-X.,CAS Shanghai Institute of Optics and fine Mechanics
Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis | Year: 2015

The authors tried to find a method for quantitative analysis using pXRF without solid bulk stone/jade reference samples. 24 nephrite samples were selected, 17 samples were calibration samples and the other 7 are test samples. All the nephrite samples were analyzed by Proton induced X-ray emission spectroscopy (PIXE) quantitatively. Based on the PIXE results of calibration samples, calibration curves were created for the interested components/elements and used to analyze the test samples quantitatively; then, the qualitative spectrum of all nephrite samples were obtained by pXRF. According to the PIXE results and qualitative spectrum of calibration samples, partial least square method (PLS) was used for quantitative analysis of test samples. Finally, the results of test samples obtained by calibration method, PLS method and PIXE were compared to each other. The accuracy of calibration curve method and PLS method was estimated. The result indicates that the PLS method is the alternate method for quantitative analysis of stone/jade samples. ©, 2015, Science Press. All right reserved.

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