Conservation Institute of Dunhuang Academy

Dunhuang, China

Conservation Institute of Dunhuang Academy

Dunhuang, China

Time filter

Source Type

Zhang D.,Shanghai JiaoTong University | Wang T.,Shanghai JiaoTong University | Wang X.,Conservation Institute of Dunhuang Academy | Wang X.,National Research Center for Conservation of Ancient Wall Paintings | And 2 more authors.
Engineering Geology | Year: 2012

As a new kind of inorganic reinforced material, potassium silicate can greatly improve the mechanical strength and the anti-wind erosion ability of ruins' soil in arid areas after being reinforced. The research developed a test device and test method of determining the thermal conductivity of earthen ruins' soil. The disturbed soil taken from the site of Jiaohe Ruins was made into soil specimens, and then, to study the reinforcement effect PS has on the thermal conductivity of ruins' soil by a thermal conductivity determination test and a laboratory model test. Test analysis showed that the thermal conductivity of PS reinforced specimens was reduced, furthermore, the larger the PS concentration, the smaller the thermal conductivity. Because PS decreased the soil's thermal conductivity, the heat transfer process of the reinforced soil was changed, and when external temperature had a change, the PS reinforced soil had a slower response to temperature than the unreinforced soil. From the analysis above, it is known that PS reinforced soil can slow down the physical weathering caused by temperature difference. And this viewpoint provides very useful scientific basis for studying the mechanism of PS and the earthen ruins' soil in northwest China arid regions. © 2011 Elsevier B.V.


Wang T.-R.,Shanghai JiaoTong University | Zhang D.-X.,Shanghai JiaoTong University | Wang X.-D.,Conservation Institute of Dunhuang Academy | Guo Q.-L.,Conservation Institute of Dunhuang Academy
Yantu Lixue/Rock and Soil Mechanics | Year: 2011

As a new type of newly arisen nondestructive testing technology, the conduction of infrared imaging technique is based on changes of the objects' temperature field, which is widely used in the detection of objects' structure state, properties, internal defects, etc. at present. In order to explore nondestructive testing method for potassium silicate(PS) reinforced earthen ruins soil, adopting the disturbed soil collected from site of Jiaohe Ruins to make soil models, halves of which are reinforced by 10% PS; and the others are untreated. And to keep the PS reinforced soil models standing for 30 d under the condition of room temperature until being naturally air-dried. And then, a laboratory model test detecting the reinforcement effect of PS through infrared imaging is conducted. It is shown that the PS hinders the heat transfer process of soil; besides, there is difference in the infrared thermal images for the PS reinforced soil and the PS untreated soil, which provides a possible method to carry out the non-destructive inspection of the reinforcement effect for earthen ruins soil. Finally, field test that micro-penetrometer detected the PS reinforcement effect and the determination test of the thermal conductivity are conducted; and the test results show that the reason for the difference in the heat conduction performance of the reinforced soil and the untreated soil is that PS reinforcement decreases the thermal conductivity and enhances the mechanical strength of earthen ruins soil.


Ouyang X.,Shanghai JiaoTong University | Zhang D.,Shanghai Normal University | Wang X.,Conservation Institute of Dunhuang Academy | Guo Q.,Conservation Institute of Dunhuang Academy
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2016

In order to explore the evaluating method of infrared imaging detection technique(differences in thermal conductivity) for potassium silicate(PS) reinforced earthen ruins soil, adopting the disturbed soil collected from Jiaohe ruins to make soil models, which are reinforced by different concentration of PS, the mechanical strength and thermal conductivity of soil models were determined. It is shown that mechanical strength increase and thermal conductivity reduce for PS reinforced soil. Under the condition of the same dosage of PS, the larger the concentration of PS is, the higher the mechanical strength of soil is, but the smaller the thermal conductivity of soil is. Through analyzing the experiment data regression, thermal conductivity and strength has a good linear negative relationship. Finally, explore the alterative mechanism of thermal conductivity of soil in the effect of PS, describe the relationship between thermal conductivity and strength in the from microstructure of soil. The relationship above shows that thermal conductivity can be used to evaluate the reinforcing effects of earthen sites, which provides a possible method to carry out the non-destructive inspection of the effect for PS reinforced earthen ruins soil. © 2016, Science Press. All right reserved.


Zhang D.,Shanghai JiaoTong University | Wang T.,Shanghai JiaoTong University | Wang X.,Conservation Institute of Dunhuang Academy | Guo Q.,Conservation Institute of Dunhuang Academy
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2011

As a new type of inorganic reinforced material, potassium silicate(PS) can greatly improve the mechanical strength and the ability of anti-wind erosion of earthen ruins soil after being reinforced. Therefore, a test device for determining the thermal conductivity of ruins soil was developed. Then, soil specimens were made from the disturbed soil collected from site of Jiaohe Ruins; and then, in order to study the influence of PS on the heat transfer process of the soil, the determination test of the thermal conductivity and the laboratory model test were carried out. Test results show that the thermal conductivity of PS reinforced soil is reduced; furthermore, the larger the concentration of PS is, the smaller the thermal conductivity of soil is. In addition, it is found from the laboratory model test that when external temperature changed, the PS reinforced soil responded slower to the temperature change compared with that of the untreated soil; so, it is inferred that due to PS reduced the thermal conductivity of reinforced soil, and the heat transfer process of the soil is hindered. The finding above shows that PS reinforced soil can slow down the physical weathering caused by temperature difference; and this will have an important significance on studying the conservation of earthen ruins in Northwest China arid areas.


Li Y.,Heritage University | Xie H.,Nanjing Southeast University | Ogura D.,Kyoto University | Hu S.,Nanjing Southeast University | Guo Q.,Conservation Institute of Dunhuang Academy
Journal of Asian Architecture and Building Engineering | Year: 2016

It is a challenge for the conservation of soil ruin sites that molds grow on the surface of damp soil ruins in soil ruin exhibition halls in high-humidity regions. The ventilation and lighting modes of soil ruin exhibition halls directly affect mold reproduction, but studies on the quantitative relationship between environmental factors and mold propagation on surfaces in damp soil ruins are insufficient. The Wenzhou Qiaolou soil ruin was selected as an example in this study, and rammed earth from this ruin was used as the experiment sample. For the ventilation and lighting modes as experimental variables, four ventilation and lighting environmental conditions were simulated for 56 days in a laboratory to compare differences in mold growth on samples of damp rammed earth surfaces. In this study, the difference of mold growth in different ventilation and lighting conditions were discussed, and some suggestions for the environmental management of soil ruin exhibition halls in high-humidity regions were given. © 2016, Architectural Institute of Japan. All rights reserved.


Zhang W.,Desert Research Institute | Tan L.,Desert Research Institute | Zhang G.,Conservation Institute of Dunhuang Academy | Qiu F.,Conservation Institute of Dunhuang Academy | Zhan H.,Conservation Institute of Dunhuang Academy
Aeolian Research | Year: 2014

The aeolian processes of erosion, transport and deposition are threatening the Mogao Grottoes, a world culture heritage site. A field wind tunnel experiment was conducted atop the Mogao Grottoes using weighing sensors to quantify aeolian processes over protective gravel beds. Results reveal that aeolian erosion and deposition over gravel beds are basically influenced by gravel coverage and wind speed. Erosion is a main aeolian process over gravel beds and its strength level is mainly determined by gravel coverage: strong (<30%), medium (30-50%) and slight (>50%). Aeolian deposition only occurs when gravel coverage is equal to or greater than 30% and wind speeds are between 8 and 12ms-1, and this process continues until the occurrence of the equilibrium coverage. In addition, the change in conditions of external sand supply affects the transition between aeolian deposition and erosion over gravel beds, and the quantity of sand transport at the height of 0-24mm is an important indicator of aeolian deposition and erosion over gravel beds. Our results also demonstrate that making the best use of wind regime atop the Mogao Grottoes and constructing an artificial gobi surface in staggered arrays, with 30% coverage and 30-mm-high gravels and in 40mm spacing can trap westerly invading sand flow and enable the stronger easterly wind to return the deposited sand on the gravel surface back to the Mingsha Mountain so as to minimize the damage of the blown sand flux to the Mogao Grottoes. © 2014 Elsevier B.V.


Li G.S.,Chinese Academy of Sciences | Li G.S.,CAS Institute of Remote Sensing | Li G.S.,University of Chinese Academy of Sciences | Qu J.J.,Chinese Academy of Sciences | And 4 more authors.
Terrestrial, Atmospheric and Oceanic Sciences | Year: 2013

To study the micro-meteorological effects of different underlying surfaces of structures to protect the Mogao Grottoes, we analyzed basic meteorological measurements collected at weather stations located in front of the grottoes, on top of the grottoes and in the artificial Gobi. The results show that the shelterbelts in front of the grottoes have a heat-retaining effect. The profile of average daily solar radiation in front of the grottoes forms a sharp peak and the profile in the Gobi forms a parabola, but these patterns vary in different seasons. The artificial Gobi was more susceptible to extremes in temperature and had a faster response and wider response range to ground temperature. The average monthly air temperature, average monthly relative humidity, and the average wind speed in the artificial Gobi tend to first decrease and then increase with measurement height. Copyright © 2005 TAO All right reserved.


Li G.S.,CAS Institute of Remote Sensing | Li G.S.,Chinese Academy of Sciences | Li G.S.,University of Chinese Academy of Sciences | Qu J.J.,Chinese Academy of Sciences | And 3 more authors.
Ecological Engineering | Year: 2013

Protecting the Mogao Grottoes in fragile ecology sites has significant values in sand control by using desert shrub belts. The monthly height changes of aeolian sand deposits by using erosion pins indicates that Hedysarum scoparium and Tamarix ramosissima Ledeb. are best arranged in two adjacent parallel configurations perpendicular to the main wind path, and T. ramosissima Ledeb., H. scoparium, and Caragana korshinskii Kom. exhibit sand prevention effects during April, June, and May and November, respectively, and H. scoparium is the most suitable desert shrub atop the Mogao Grottoes. The yearly change of accumulated sand suggests that shrub belts have better sand prevention effects. However, sand accumulated by shrub belts could become another sand source that can damage the grottoes. © 2013.


Wang W.,Lanzhou University | Wang W.,Conservation Institute of Dunhuang Academy | Ma Y.,Lanzhou University | Ma X.,Lanzhou University | And 4 more authors.
Aerobiologia | Year: 2012

The aim of this study was to analyze the phylogenetic composition of the bacterial community in the air at the Mogao Grottoes (Dunhuang, China) using a culture-dependent molecular approach. The 16S rRNA genes were amplified directly from the isolates with universally conserved and bacteria-specific rRNA gene primers. The PCR products were screened by restriction fragment length polymorphism, and representative rRNA gene sequences were determined and sequenced. A total of 19 bacteria genera were identified among 49 bacterial sequence types. Phylogenetic sequence analyses revealed high diversity within the bacterial community. The most predominant bacteria were Janthinobacterium (14.91%), Pseudomonas (13.40%), Bacillus (11.25%), Sphingomonas (11.21%), Micrococcus (10.31%), Microbacterium (6.92%), Caulobacter (6.31%), and Roseomonas (5.85%). The composition of bacterial communities differed greatly between different sites and at different times. The distribution of various bacteria was mainly affected by climatic parameters and human activities. These findings suggested that the opening of this cultural heritage site to visitors should be controlled and that maintaining the cave's natural climatic conditions would aid the conservation and management of the grottoes' paintings. © Springer Science+Business Media B.V. 2011.


Li H.S.,Conservation Institute of Dunhuang Academy | Li H.S.,Dunhuang Academy | Wu F.S.,Conservation Institute of Dunhuang Academy | Wu F.S.,Dunhuang Academy | And 4 more authors.
Vadose Zone Journal | Year: 2016

Past research has shown that evaporation of deeply buried phreatic water occurs in extra-arid areas where the soil surface is very dry. A dry surface layer can suppress the evaporation of capillary water, but it is not clear whether it suppresses deeply buried phreatic evaporation (PE). We deduced that the PE could be suppressed by a dry surface soil. Therefore, as the soil-water content increases during a precipitation pulse, this can lead to an increase in PE. To investigate the effects of precipitation pulses on PE, a simulated 10-mm precipitation recycling experiment using a shed–air-conditioning condensation method was performed on Gobi Desert land at the top of the Mogao Grottoes in 2011 to 2015. The results show that after the 10 mm of precipitation was completely recycled, the PE increased by 28.9% compared with the control during the following 3 yr. In addition, the soil moisture increased in the 10- to 20-cm layer for a long time. We hypothesize that this is a soil-water hysteresis phenomenon, which is important for the observed differences in the evaporation rate, and it is apparent that the higher water content in the shallow layer is conducive to PE entering into the atmosphere. This preliminary study reveals the effect of precipitation pulses on deeply buried PE; this hysteresis phenomenon must be analyzed in further studies. © Soil Science Society of America 5585 Guilford Rd., Madison, WI 53711 USA. All rights reserved.

Loading Conservation Institute of Dunhuang Academy collaborators
Loading Conservation Institute of Dunhuang Academy collaborators