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Lu Y.H.,University of Science and Technology Beijing | Wang J.P.,Beijing Institute of Civil Engineering and Architecture | Shen Y.G.,City University of Hong Kong
Applied Surface Science | Year: 2011

Two nanocomposite Ti-Cx-Ny thin films, TiC 0.95N0.60 and TiC2.35N0.68, as well as one pure TiN, were deposited at 500 °C on Si(1 0 0) substrate by reactive unbalanced dc-magnetron sputtering. Oxidation experiments of these films were carried out in air at fixed temperatures in a regime of 250-600 °C with an interval of 50 °C. As-deposited and oxidized films were characterized and analyzed using X-ray diffraction (XRD), microindentation, Newton's ring methods and atomic force microscopy (AFM). It was found that the starting oxidation temperature of nanocomposite Ti-Cx-Ny thin films was 300 °C irrespective of the carbon content; however their oxidation rate strongly depended on their carbon content. Higher carbon content caused more serious oxidation. After oxidation, the film hardness value remained up to the starting oxidation temperature, followed by fast decrease with increasing heating temperature. The residual compressive stress did not show a similar trend with the hardness. Its value was first increased with increase of heating temperature, and got its maximum at the starting oxidation temperature. A decrease in residual stress was followed when heating temperature was further increased. The film surface roughness value was slightly increased with heating temperature till the starting oxidation temperature, a great decrease in surface roughness was followed with further increase of heating temperature. © 2010 Elsevier B.V. All rights reserved.

Liu G.,Dalian University of Technology | Yang L.,Dalian University of Technology | Wang L.,Dalian University of Technology | Wang S.,Beijing Institute of Civil Engineering and Architecture | And 2 more authors.
Surface and Coatings Technology | Year: 2010

The corrosion behavior of electroless deposited Ni-Cu-P coating in flue gas condensate has been investigated using electron probe micro-analyzer (EPMA), metallographic microscope, differential scanning calorimetry (DSC), polarization curves and electrochemical impedance spectra (EIS). The results show that the enhanced corrosion resistance of Ni-Cu-P coating is mainly attributed to the formation of passivation layer, which results from the selective dissolution of Ni on coating surface in flue gas condensate. In addition, the Cu element in Ni-Cu-P coating tends to facilitate the enrichment of P and Cu elements by accelerating the dissolution of Ni on coating surface. © 2010.

Jiao Y.,Harbin Institute of Technology | Jiao Y.,Shanxi University of Finance and Economics | Zhao Q.,Harbin Institute of Technology | Jin W.,Harbin Institute of Technology | And 2 more authors.
Bioresource Technology | Year: 2011

In this study, specialized bacteria were domesticated and cultivated with polluted stream water. The bioaugmentation of specialized bacteria would significantly enhance the removal efficiency of TN and NH 4 +-N from 25.9% to 50.3%, and from 34.5% to 60.1%, respectively. Concomitant increases in the number of microbial communities and the proportion of nitrifying bacteria were also identified by the most probable number (MPN) method. PCR-DGGE profiles revealed that the bacterial community could be successfully enriched and the ammonia-oxidizing bacteria communities were shown predominant by the species of Nitrosomonas. The biological contact oxidation ditch (BCOD) system augmented with specialized bacteria can be a viable alternative for treating polluted stream water to achieve improved nitrogen removal. © 2010 Elsevier Ltd.

Li B.,Beijing Institute of Civil Engineering and Architecture
Wuhan Ligong Daxue Xuebao (Jiaotong Kexue Yu Gongcheng Ban)/Journal of Wuhan University of Technology (Transportation Science and Engineering) | Year: 2012

This paper review and discuss how to solve the permeability of unconfined aquifer and confined aquifer, with the basis of the Dupuit formula and pump tests. For the unconfined aquifer and confined aquifer, which do not meet the Dupuit basic assumptions, the paper do some discussion how to calculating the permeate coefficient of the aquifer by stability pump tests.

Liu G.,Dalian University of Technology | Huang Z.,Dalian University of Technology | Wang L.,Dalian University of Technology | Sun W.,Dalian University of Technology | And 2 more authors.
Surface and Coatings Technology | Year: 2013

In this paper, the effects of Ce4+ concentration on the structure and corrosion resistance of electroless deposited Ni-Cu-P coatings were investigated using microscopy, energy dispersive X-ray spectroscopy (EDX), inductively coupled plasma atomic emission spectrometry (ICP-AES), X-ray diffraction spectrometer (XRD), polarization curve (PC) and electrochemical impedance spectroscopy (EIS). The results show that the proper addition of Ce4+ can apparently refine the grain size and make the coating surface denser and more uniform, resulting in the enhancement of corrosion resistance of Ni-Cu-P coatings in the flue gas condensate. When the Ce4+ concentration is 8mg/L, the corrosion current density of Ni-Cu-P coating was reduced by nearly 60% as compared to that prepared without Ce4+ in the bath. However, the excessive addition of Ce4+ can degrade the homogeneity, resulting in the decrease of the corrosion resistance of Ni-Cu-P coatings. © 2013 Elsevier B.V.

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