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Hu T.,CAS Institute of Earth Environment | Cao J.,CAS Institute of Earth Environment | Ho K.,CAS Institute of Earth Environment | An Z.,CAS Institute of Earth Environment | And 4 more authors.
Journal of the Air and Waste Management Association | Year: 2011

Day- and nighttime total suspended particulate matter was collected inside and outside Emperor Qin's Terra-Cotta Museum in winter and summer 2008. The purpose was to characterize the winter and summer differences of indoor airborne particles in two display halls with different architectural and ventilation conditions, namely the Exhibition Hall and Pit No. 1. The morphology and elemental composition of two season samples were investigated using scanning electron microscopy and energy dispersive X-ray spectrometry. It is found that the particle size, particlemass concentration, and particle type were associated with the visitor numbers in the Exhibition Hall andwith the natural ventilation in Pit No. 1 in both winter and summer. Evident winter and summer changes in the composition and physicochemical properties of the indoor suspended particulate matters were related to the source emission and the meteorological conditions. Particle mass concentrations in both halls were higher in winter than in summer. In winter, the size of themost abundant particles at the three sites were all between 0.5 and 1.0 μm, whereas in summer the peaks were all located at less than 0.5 μm. The fraction of sulfurcontaining particles was 2-7 times higher in winter than in summer. In addition to the potential soiling hazard, the formation and deposition of sulfur-containing particles in winter may lead to the chemical and physical weathering of the surfaces of the terra-cotta statues. © 2011 Air & Waste Management Association. Source

Jin P.,Shaanxi Normal University | Zhang W.,Shaanxi Normal University | Wang Q.,Longxian County Museum | Yang X.,Chongqing Cultural Heritage Research Institute | And 3 more authors.
Corrosion Science | Year: 2014

Ancient pottery stored in northern Chinese museums is apt to powder during long-term storage. A detailed investigation of the efflorescent products of such pottery was performed to shed light on the role of water-soluble salts, a type of curing-salt-laden colloidal substance that shows smooth edges and shrinkage holes containing Cl-, NO2-, NO3-, SO42-, Na+, K+, Ca2+, etc., in pottery efflorescence. For comparison, recent specimens of pottery, buried soil and storeroom dust were characterised as well, demonstrating that, in this samples, water-soluble salts mainly originated from the surrounding atmosphere. © 2014 Elsevier Ltd. Source

Gu Z.,Xian Jiaotong University | Luo X.,Xian Jiaotong University | Meng X.,Xian Jiaotong University | Wang Z.,Xian Jiaotong University | And 6 more authors.
Environmental Science and Technology | Year: 2013

Immovable historical relics in some archeology museums of China suffer deterioration due to their improper preservation environment. The existing environmental control systems used in archeology museums are often designed for the amenities of visitors, and these manipulated environments are often inappropriate for the conservation of abiotic relics. This paper points out that the large open space of the existing archeology museum could be a cause of deterioration of the relics from the point of view of indoor air convective flow. The paper illustrates the need to introduce a local pit environmental control, which could reintegrate a pit primitive environment for the preservation of the historical relics by using an air curtain system, orientated to isolate the unearthed relics, semiexposed in pits to the large gallery open space of the exhibition hall. © 2013 American Chemical Society. Source

Cao J.-J.,CAS Institute of Earth Environment | Cao J.-J.,Xian Jiaotong University | Li H.,CAS Institute of Earth Environment | Chow J.C.,Desert Research Institute | And 5 more authors.
Aerosol and Air Quality Research | Year: 2011

Indoor particles and microclimate were measured in summer (August 2004) and winter (January 2005) periods inside and outside Emperor Qin's Terra-Cotta Museum in Xi'an, China. Indoor temperature ranged from 21.9°C to 32.4°C in summer and from 0°C to 5.3°C in winter. Relative humidity varied from 56% to 80% in summer and from 48% to 78% in winter. The number concentrations of particles were lower (0.3-1.0 μm) in summer, and were higher (1.0-7.0 μm) in winter. The average indoor PM2.5 and TSP concentrations were 108.4 ± 30.3 μg/m3 and 172.4 ± 46.5 μg/m3 in summer and were 242.3 ± 189.0 μg/m3 and 312.5 ± 112.8 μg/m3 in winter, respectively. Sulfate, organic matter, and geological material dominated indoor PM2.5, followed by ammonium, nitrate, and elemental carbon. Several milligram of sulfate particles can deposited in the museum per square meter each year based on the dry deposition estimate. High concentrations of acidic particles suspended inside the museum and their depositions have high risk for the erosion of the terra-cotta figures. © Taiwan Association for Aerosol Research. Source

Hu T.,Xian Jiaotong University | Hu T.,CAS Institute of Earth Environment | Hu T.,Hong Kong Polytechnic University | Cao J.,Xian Jiaotong University | And 6 more authors.
Aerosol and Air Quality Research | Year: 2010

Indoor dust deposition, including long-term (>10 years) deposition, short-term (∼0.5 year) deposition, and pigment flake samples from partially restored warriors were collected in Emperor Qin's Terra-cotta Warriors and Horses Museum in Xi'an, Shaanxi Province, China. Morphological and elemental analyses of individual particles were performed with scanning electron microscopy and energy dispersive X-ray spectrometry to investigate their composition and potential to damage the statues. Most of the indoor dust was composed of clay minerals, fly ash, and biogenic particles. Particles in 51.5% of the short-term deposition, and 49.5% of the long-term deposition contained elemental sulfur. Particles which contained sulfur were mostly associated with calcium sulfate in an internally mixed state with clay or quartz. Crystals of calcium sulfate were also found near interconnected pits and cracks on the outer surface of pigment flakes, revealing an acidic chemical reaction between sulfur dioxide and pigment material or deposited particles as the cause of pits and cracks on the statues' faces. Copyright © Taiwan Association for Aerosol Research. Source

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