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Nanjing, China

Shen G.,Nanjing Normal University | Fang Y.,Nanjing Museum | Bischoff J.L.,U.S. Geological Survey | Feng Y.-x.,University of Queensland | Zhao J.-x.,University of Queensland
Quaternary International | Year: 2010

The fossils of Chaoxian hominin, widely accepted as representing archaic Homo sapiens in eastern China, were recovered from the middle or slightly higher levels of Layer 2 deposits of a collapsed cave at Yinshan, Anhui Province. Results of mass spectrometric U-series dating of intercalated speleothem calcites are presented. Based mainly on four broadly coeval calcite samples, the hominin fossils should be bracketed in the range of 310-360 ka or somewhat older. These ages are much older than the previous estimate at 160-200 ka based on the U-series dating of fossil teeth and bones, and may be cited as supporting evidence for an earlier H. erectus-archaic H. sapiens interface in China. © 2009 Elsevier Ltd and INQUA. Source

Yang J.,Engineering Research Center for Historical and Cultural Heritage Conservation | Yang J.,Shaanxi Normal University | Hu D.-D.,Engineering Research Center for Historical and Cultural Heritage Conservation | Hu D.-D.,Shaanxi Normal University | Zhang H.,Nanjing Museum
Reactive and Functional Polymers | Year: 2012

In the work described here, poly(vinyl alcohol)-g-N-isopropylacrylamide was prepared via graft polymerisation of N-isopropylacrylamide (NIPAM) onto poly(vinyl alcohol) (PVA). The structure and components of the polymer were characterised by differential thermogravimetry (DTG), differential scanning calorimetry (DSC), 1H nuclear magnetic resonance spectroscopy ( 1H NMR) and fourier transform infrared spectroscopy (FT-IR) testing, respectively. The T-type peel adhesion strengths and water contact angles of the prepared graft copolymer membranes were determined at different temperatures. The results indicated that the membrane has an obvious change in adhesion and water contact angle around the lower critical solution temperature (LCST) of the thermosensitive PNIPAM, regardless of the composition of the copolymers. Based on the scanning electron microscope (SEM) and energy dispersive spectrometric (EDS) analysis of freeze-dried graft copolymer membranes swollen in water at various temperatures, a mechanism for the thermally induced adhesion properties of the graft copolymer was proposed. © 2012 Elsevier Ltd. All rights reserved. Source

Zhang H.,Nanjing Museum | Chen B.-R.,Nanjing University of Technology | Zhu Q.-G.,Nanjing Museum
Chung-kuo Tsao Chih/China Pulp and Paper | Year: 2014

Average polymerization degree of cellulose reflects the average length of the cellulose chains, polymerization degree is higher, the cellulose molecule chain is longer, and the paper is more durable. In contrast, polymerization degree is lower, the cellulose molecule chain is shorter, and the paper is less durable. Therefore, the polymerization degree of paper can reflect the level of paper degradation. The papers were individually treated by four kinds of oxidation decontamination material, and were aged by dry heat means, then the papers were characterized by means of measuring the polymerization degree of the papers. The results showed that polymerization degrees of the papers was decreased, the paper treated by KMnO4-H2C2O4 in particular, its polymerization degree decreased the most, it indicated that oxidative decontaminations had the large destructive action on paper relics. Therefore, oxidative decontamination would be cautionly used in the cleaning the stains of paper relics. Source

Wang H.-Y.,Nanjing University of Technology | Lu G.,Nanjing University of Technology | Zhang J.-P.,Nanjing Museum | Zheng D.-Q.,Nanjing Museum
Chung-kuo Tsao Chih/China Pulp and Paper | Year: 2012

The preparation of nano-Mg(OH) 2 by different processes, and the effect of the process on particle size and its distribution of nano-Mg(OH) 2 were studied. The nano-Mg(OH) 2 was used in deacidification treatment of the paper based cultural relics. The results showed that with the aid of ultrasonic and high temperature (90°C), the particles of Mg(OH) 2 prepared had a narrow size distribution between 17.9 nm and 86.6 nm, the mean size was 44.2 nm. After deacidification treatment with the nano- Mg(OH) 2 the pH value of the papers increased from 4.5 to 8.5. The heat aging test indicated that the papers after deacidification showed a good stability of pH value (~7.5) and the tensile strength (~715 N/m) so that they could be conserved for long-time. Source

Wang H.-Y.,Nanjing University of Technology | Lu G.,Nanjing University of Technology | Zhang J.-P.,Nanjing Museum | Zheng D.-Q.,Nanjing Museum
Chung-kuo Tsao Chih/China Pulp and Paper | Year: 2012

N, N, N-tris(triethoxysilylpropyl) melamine was prepared by using polychlorostyrene as a skeleton and grafting with aminosiloxane KH-550 was used to paper culture heritage treatment. The heat aging test was used to evaluate the changes of pH value, tensile strength, alkaline residue and the fiber breaking percentage of the paper before and after treatment. Results showed that the pH value increased from 3.2 to 7.7~7.8, the tensile strength also increased from 915 N/m to 1300 N/m. Furthermore, the colour change in appearance (ΔE*=1.72) was slight. The heat aging tests indicated that the pH value of treated paper can stabilize in neutral or slight alkaline and also the tensile strength is kept in ~1200 N/m. Compared with the untreated paper, the paper treated with N, N, N-tris(triethoxysilylpropyl) melamine can effectively decrease its aging rate. Source

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