Si Chuan University of Science and Engineering
Si Chuan University of Science and Engineering
Yan Z.Y.,Xi'an Jiaotong University |
Yan Z.Y.,Si Chuan University of Science and Engineering |
Wu J.H.,Xi'an Jiaotong University
Journal of Physics D: Applied Physics | Year: 2017
Periodic structures are effective in attenuating waves in a low frequency range at local resonance (LR) conditions, but it is still a challenge to achieve this in a very low frequency range, because the system stability can be damaged due to the excessive quality or the deduction of stiffness. However, the structural stability theory shows that the structural stability is closely related to the support surface; the larger the support surface, the more stable the structure, and thereby the array structure has the feature of maintaining the stability of the system through expanding the support surface. Based on the theoretical principle, a new type of local resonator with stiffness arrays is presented to further lower the band gaps of flexural wave propagation in LR beams, in which the traditional stiffness is equally divided into an array form. Due to the stiffness array connections, the system stiffness is not only reduced to a very low value, but also the stability is still better maintained through expanding the support surface. Meanwhile, the band structures of the LR beams with stiffness array connections, obtained by the finite element method, demonstrate that the lower bound of the band-gap can be successfully decreased more times than that of conventional LR beams under the premise of maintaining the stability of the system, and an ultra-low-frequency broadband of 25-395 Hz is realized. Clearly, the strategy of dividing the traditional stiffness into the stiffness array can successfully realize the low frequency band gap and overcome the shortcomings of the system instability in the traditional method. Therefore, two puzzles of realizing the ultra-low-frequency broadband and simultaneously maintaining the system stability may be successfully resolved through introducing the stiffness arrays into the local resonance system, and the new structures with stiffness arrays could have potential applications for ultra-low-frequency vibration and noise attenuation. © 2017 IOP Publishing Ltd.
Zeng X.,Si Chuan University of Science and Engineering |
Zeng X.,Material Corrosion and Protection Key Laboratory of Sichuan Province |
Gong M.,Si Chuan University of Science and Engineering |
Chen J.,Si Chuan University of Science and Engineering |
Zheng X.,Si Chuan University of Science and Engineering
International Journal of Electrochemical Science | Year: 2014
Porous spherical Li2FeSiO4/C microscale secondary particles have been synthesized by a spray drying-assisted process using citric acid as chelating agent and carbon source. The spherical Li2FeSiO4/C microscale particles (1-5μm) with porous structures consist of carbon-coated primary nanoparticles (20-40 nm), which promises high electronic conductivity and short lithium ion diffusion paths. The as-prepared Li2FeSiO4 sample exhibits desirable electrochemical performance, At 0.2 C and 5 C rates, the capacities of 150 mAh g-1, 94 mAh g-1 are observed, respectively. Meantime, good cycling stability is achieved with a capacity retention of 98.4% at high current density of 1C after 300 cycles. © 2015 The Authors.
Gui M.-S.,Si Chuan University of Science and Engineering |
Wang P.-F.,Si Chuan University of Science and Engineering |
Yuan J.-G.,Si Chuan University of Science and Engineering |
Li Y.-Q.,Si Chuan University of Science and Engineering |
Zeng W.-G.,Si Chuan University of Science and Engineering
Advanced Materials Research | Year: 2014
Hollow Bi2WO6 microspheres were synthesized using a simple solvethermal method in presence of urea at a proper EG/EtOH volume ratio. The products were characterized by the X-ray powder diffraction (XRD) techniques, Scanning electron microscopy (SEM), Brunauer-Emmett- Teller (BET) and UV-visible diffuse reflectance spectra (UV-Vis DRS). Results revealed that the as-obtained Bi2WO6 hollow spheres were pure orthorhombic phase, the BET surface area is 40 m2/g. On the basis of experiment observations and the resulting products a possible formation mechanism is proposed. The hollow Bi2WO6 microspheres exhibited superior photocatalytic activity in the photodegradation of rhodamine B (RhB) under visible light irradiation (λ>400nm). © (2014) Trans Tech Publications, Switzerland.
Zhao X.,Si Chuan University of Science and Engineering
Computer, Intelligent Computing and Education Technology - Selected Peer Reviewed Papers From 2014 International Conference on Computer, Intelligent Computing and Education Technology, CICET 2014 | Year: 2014
College English teaching is a long-term task, which is very complex and complicated. The most difficult part is the teaching for students who major in art and PE in this huge teaching system. Most of these students learn English with no passion and interest because of their low ability of mastering a language, which makes a great impact on college English teaching at many universities. It's extremely urgent for college English teachers to change the way of teaching and take some effective measures to deal with this big problem. © 2014 Taylor & Francis Group.