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Qin R.,Institute of Fluid Physics | Zhu W.,Institute of Fluid Physics | Zhang Y.,Institute of Computer Application | Deng X.,Institute of Fluid Physics
Nanoscale Research Letters

We perform first-principles calculations of mechanical and electronic properties of silicene under uniaxial strains. Poisson's ratio and the rigidity of silicene show strong chirality dependence under large uniaxial strains. The ultimate strains of silicene with uniaxial strain are smaller than those with biaxial strain. We find that uniaxial strains induce Dirac point deviation from the high-symmetry points in the Brillouin zone and semimetal-metal transitions. Therefore, no bandgap opens under the uniaxial strain. Due to its peculiar structure and variable sp3/sp2 ratio of the chemical bond, the deviation directions of Dirac points from the high-symmetry points in the Brillouin zone and variation of Fermi velocities of silicene exhibit significant difference from those of graphene. Fermi velocities show strong anisotropy with respect to the wave vector directions and change slightly before the semimetal-metal transition. We also find that the work function of silicene increases monotonously with the increasing uniaxial strains. © 2014, Qin et al.; licensee Springer. Source

Qin R.,Institute of Fluid Physics | Wang C.-H.,Institute of Fluid Physics | Zhu W.,Institute of Fluid Physics | Zhang Y.,Institute of Computer Application
AIP Advances

We perform first-principles calculations of mechanical and electronic properties of silicene under strains. The in-plane stiffness of silicene is much smaller than that of graphene. The yielding strain of silicene under uniform expansion in the ideal conditions is about 20%. The homogeneous strain can introduce a semimetal-metal transition. The semimetal state of silicene, in which the Dirac cone locates at the Fermi level, can only persist up to tensile strain of 7% with nearly invariant Fermi velocity. For larger strains, silicene changes into a conventional metal. The work function is found to change significantly under biaxial strain. Our calculations show that strain tuning is important for applications of silicene in nanoelectronics. © Author(s) 2012. Source

Deng X.,Institute of Fluid Physics | Zhu W.,Institute of Fluid Physics | Zhu W.,University of Sichuan | Zhang Y.,Institute of Computer Application | And 4 more authors.
Computational Materials Science

Void coalescence is one of the most critical stages leading to dynamic ductile fracture. In this paper, the effect of configuration on coalescence in single-crystal copper has been investigated using a molecular dynamics simulation. The configuration represented by which defines the angle between the line connecting the centers of two voids and shock direction. The results show that the 60° configuration coalesced most easily. Microscopic analysis revealed that the anisotropic emission patterns of shear dislocation loops around the voids during the compressive stage weaken the local structure between two voids and have a significant influence on coalescence during the tensile stage. An analytical model based on anisotropic dislocation emission has been derived, and it explains the coalescence phenomena very well. © 2010 Elsevier B.V. All rights reserved. Source

Yin M.,Institute of Computer Application | Wu C.,Southwest University of Science and Technology | Tao Y.,Institute of Computer Application
Communications in Computer and Information Science

The reliability analysis is of great significance for assessing the performance of network storage systems. This paper aims to analyze reliability of network storage system, either with or without maintenance requirement, using quantitative calculation and simulation evaluation. When the devices were non-repairable, a FC-SAN network storage system was tested in three typical redundancy modes (i.e. simplicity, dual-FC switches, dual-server & dual-FC switches).Reliability calculation was performed with help of reliability block diagram and mathematical analytical method. For the repairable devices, Markov analysis and Monte Carlo stochastic simulation were introduced to assess the reliability of the network storage systems. In addition, simulations were carried out to measure a number of reliability indices of the network storage systems. These indices, including availability, mean time to first failure, and the mean up time, are used for analysis and comparison of simulation data. This analysis can provide useful guidance for designing future network storage systems. © Springer-Verlag Berlin Heidelberg 2014. Source

Pan Q.,Institute of Computer Application | Hu W.,Institute of Computer Application | Li Q.,Institute of Computer Application | Shen Y.,Institute of Computer Application | And 3 more authors.
Jisuanji Fuzhu Sheji Yu Tuxingxue Xuebao/Journal of Computer-Aided Design and Computer Graphics

In this paper, we propose an adaptive multiple-channel dynamic perception model for autonomous virtual humans in the 3D cartoon games. Our method is based on pleasure arousal dominance (PAD) dimension observation model, and chooses the Ortony, Clore, Colins model as emotion model. Our work studies the influence of emotion state on the motivation state of dynamic perception of virtual humans, and consider the influence of the physiological status (physical power). Our model drives the motivation of virtual human by execution evaluation action cycle, and implements the transformation of emotion in different demands of virtual human by finite-state machine. Finally, we implement a demo system based on the model on PC. The experimental results show that our model can maintain the high credibility, immersive and entertainment of game. ©, 2015, Institute of Computing Technology. All right reserved. Source

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