133 research outputs found
Identity Authentication Security Management in Mobile Payment Systems
Mobile payment is a new payment method offering users mobility, reachability, compatibility, and convenience. But mobile payment involves great uncertainty and risk given its electronic and wireless nature. Therefore, biometric authentication has been adopted widely in mobile payment in recent years. However, although technology requirements for secure mobile payment have been met, standards and consistent requirements of user authentication in mobile payment are not available. The flow management of user authentication in mobile payment is still at its early stage. Accordingly, this paper proposes an anonymous authentication and management flow for mobile payment to support secure transaction to prevent the disclosure of users\u27 information and to reduce identity theft. The proposed management flow integrates transaction key generation, encryption and decryption, and matching to process users\u27 personal information and biometric characteristics based on mobile equipment authentication carrier
Highly Active and Stable Palladium Catalysts Supported on Surfacemodified Ceria Nanowires for Lean Methane Combustion
An efficient strategy was presented to synthesize highly active palladium catalyst supported on
ceria nanowires modified by organosilanes (abbreviated as Pd/CeO2NWs@SiO2) for lean
methane combustion. It is found that such a surface-modified strategy can significantly improve
the dispersion of surface palladium species and strengthen the concentration of active surfaceadsorbed
oxygen species via reconstructing the surface microenvironment, invoking an efficient
performance for methane oxidation. Under the space velocity of 60,000 mLg−1h−1, 0.5 wt%
Pd/CeO2NWs@SiO2 displayed extraordinary catalytic activity with 90 % conversion rate at a
temperature of around 327 °C, far lower than that of pristine Pd/CeO2NWs (378 °C) under the
same conditions. What's more, unexpected stability was observed under high temperature and
the presence of water vapor conditions owing to the intense metal support interaction of
Pd/CeO2NWs@SiO2 catalyst. The possible reaction mechanism of lean methane oxidation was
probed by in situ DRIFT spectra. It is observed that the pivotal intermediate products (carbonate
and carbon oxygenates) generated on Pd/CeO2NWs@SiO2 surface are more readily
decomposed into CO2. Importantly, the silicon hydroxyl groups (Si−OH) formed during the
reaction can efficiently restrict the generation of the stable Pd(OH)x phase and release more
active sites to facilitate the catalytic performance. This study provides a convenient method to
design the highly reactive and durable palladium-based catalyst for methane combustion
Response of turbulent enstrophy to sudden implementation of spanwise wall oscillation in channel flow
Applying resolved-scale linearly forced isotropic turbulence in rational subgrid-scale modeling
Slope stability analysis under seismic load by vector sum analysis method
AbstractThe vibration characteristics and dynamic responses of rock and soil under seismic load can be estimated with dynamic finite element method (DFEM). Combining with the DFEM, the vector sum analysis method (VSAM) is employed in seismic stability analysis of a slope in this paper. Different from other conventional methods, the VSAM is proposed based on the vector characteristic of force and current stress state of the slope. The dynamic stress state of the slope at any moment under seismic load can be obtained by the DFEM, thus the factor of safety of the slope at any moment during earthquake can be easily obtained with the VSAM in consideration of the DFEM. Then, the global stability of the slope can be estimated on the basis of time-history curve of factor of safety and reliability theory. The VSAM is applied to a homogeneous slope under seismic load. The factor of safety of the slope is 1.30 under gravity only and the dynamic factor of safety under seismic load is 1.21. The calculating results show that the dynamic characteristics and stability state of the slope with input ground motion can be actually analyzed. It is believed that the VSAM is a feasible and practical approach to estimate the dynamic stability of slopes under seismic load
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