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Feng J.,Xidian University | Zhang Y.,Intrusion | Wang H.,Huaibei Coal Normal College
IEICE Transactions on Information and Systems | Year: 2010

The security of P2P networks depends on building trust management among peers. However, current trust management models focus on preventing untrustworthy resources from spreading by malicious providers, but have few effects on reducing denial-of-service attacks of malicious consumers and free riding of selfish peers. Pointing to these problems, a bi-evaluation* * * trust management model, called BiTrust, is proposed. In this model, the trustworthiness of a peer is divided into service and request trustworthiness. Service trustworthiness shows the resources reliability of providers, and request trustworthiness is used to deal with requests from consumers, which can keep away malicious consumers and encourage selfish peers to share resources. A generic method for evaluating service and request trustworthiness is described. Furthermore, the implementation strategies of the model are also depicted in this paper. The following analysis and simulation show that BiTrust is more effective on enhancing high-quality resources sharing among peers and more advanced in successful exchanges rate. Copyright © 2010 The Institute of Electronics, Information and Communication Engineers. Source

Qiu G.,Xidian University | Wang H.,Huaibei Coal Normal College | Xiao H.,Xidian University | Xiao G.-Z.,Xidian University
Xi'an Dianzi Keji Daxue Xuebao/Journal of Xidian University | Year: 2010

Forward-secure blind signature schemes can provide important security guarantees: all secret keys and digital signatures before current key exposure will still be secure. We make a Security analysis of the recent two new forward-secure blind signature schemes respectively proposed by Hui-Feng Huang et al and Yali Liu et al. These schemes are totally broken by cryptanalysis on the key structure or hardness problem. It is proved that they are not forward-secure. Source

Shifu C.,Huaibei Coal Normal College | Wei L.,Huaibei Coal Normal College | Sujuan Z.,Huaibei Coal Normal College | Yinghao C.,Ocean University of China
Journal of Sol-Gel Science and Technology | Year: 2010

Co-TiO2 photocatalyst was prepared by a sol- gel method using Co(NO3)26H2O and tetrabutyl titanate [Ti(OC4H9)4] as raw materials, and Co-TiO 2/TiO2 photocatalyst was synthesized by mixing the Co-TiO2 sol with TiO2 sol. The Co-TiO2/TiO2 was characterized by X-ray powder diffraction, UV-Vis diffuse reflection spectrum, scanning electron microscopy, transmission electron microscopy, fluorescence spectra and X-ray photoelectron spectroscopy. The photocatalytic activity of the photocatalyst was evaluated by photocatalytic reduction of Cr2O 7 2- and photocatalytic oxidation of methyl orange under UV irradiation. The results showed that, for the photocatalytic reduction of Cr2O7 2-, the optimum percentage of Codoped for the Co-TiO2 was 0.5% (mole ratio of Co/Ti), and the optimum percentage of Co-TiO2 for the Co-TiO2/TiO2 was 2.0% (mole ratio of Co-TiO2/TiO2). The photocatalytic reduction activities of the Co-TiO2/TiO2 and Co-TiO 2 are much higher than that of TiO2. However, the photocatalytic oxidation activities of the Co-TiO2/TiO2 and Co- TiO2 are much lower than that of TiO2. Effects of heat treatment on the photocatalytic activities of the Co-TiO2/ TiO2 and Co-TiO2 were investigated. The mechanisms of influence on the photocatalytic activity were also discussed. ©Springer Science+Business Media, LLC 2010. Source

Hu W.,Huaibei Coal Normal College | Sun D.,Huaibei Coal Normal College | Ma W.,Huaibei Coal Normal College
Electroanalysis | Year: 2010

In this paper, a silver doped poly(L-valine) (Ag-PLV) modified glassy carbon electrode (GCE) was fabricated through electrochemical immobilization and was used to electrochemically detect uric acid (UA), dopamine (DA) and ascorbic acid (AA) by linear sweep voltammetry. In pH 4.0 PBS, at a scan rate of 100 mV/s, the modified electrode gave three separated oxidation peaks at 591 mV, 399 mV and 161 mV for UA, DA and AA, respectively. The peak potential differences were 238 mVand 192 mV. The electrochemical behaviors of them at the modified electrode were explored in detail with cyclic voltammetry. Under the optimum conditions, the linear ranges were 3.0×10-7 to 1.0×10-5 M for UA, 5.0×10-7 to 1.0×10-5 M for DA and 1.0×10-5 to 1.0×10-3 M for AA, respectively. The method was successfully applied for simultaneous determination of UA, DA and AA in human urine samples. © 2010 Wiley-VCH Verlag GmbH&Co. KGaA, Weinheim. Source

Chen S.,Huaibei Coal Normal College | Zhang H.,Huaibei Coal Normal College | Yu X.,Huaibei Coal Normal College | Liu W.,Huaibei Coal Normal College
Chinese Journal of Chemistry | Year: 2010

The feasibility of photocatalytic reduction of nitrobenzene using titanium dioxide powder as photocatalyst, underthe protection of nitrogen and presence of hole scavenger conditions, was studied. Effects of the illuminationtime, amount of catalyst and sorts of solvent on the photocatalytic reduction of nitrobenzene were investigated, respectively.The results showed that, for the photocatalytic reduction of nitrobenzene, aniline was the main product.When the illumination time was 6 h, 8.15×10-4 mol/L of nitrobenzene could be photocatalytically reduced completely,with the yield of aniline being 88.5%. The optimum amount of TiO2 used was 4.0 g/L, the optimum initialpH value of reaction solution was 4.0 and the best solvent was methanol. The kinetics and mechanisms of thephotocatalytic reduction of nitrobenzene were also discussed. © 2010 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

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