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Wang Y.,Yanshan University | Li B.,North China Institute of Aerospace Engineering
Journal of Optical Communications and Networking | Year: 2010

An optical code-labeled router that performs packet forwarding through optical code label swapping (OCLS) based on code division multiplexing technology is proposed. It can enhance the processing speed of packets that can adapt to the growth of data and the aggregation of data service. The throughput of the router increases obviously since the optical code division multiplexing (OCDM) paths on the same wavelength can be processed in parallel. Moreover, it is attractive for its traffic control, bandwidth efficiency, protocol transparency, channel granularity, and so on. © 2010 Optical Society of America.

Xu A.-G.,CAS Beijing Institute of Applied Physics And Computational Mathematics | Zhang G.-C.,CAS Beijing Institute of Applied Physics And Computational Mathematics | Gan Y.-B.,North China Institute of Aerospace Engineering | Chen F.,Linyi Normal University | Yu X.-J.,CAS Beijing Institute of Applied Physics And Computational Mathematics
Frontiers of Physics | Year: 2012

In this mini-review we summarize the progress of Lattice Boltzmann (LB) modeling and simulating compressible flows in our group in recent years. Main contents include (i) Single-Relaxation-Time (SRT) LB model supplemented by additional viscosity, (ii) Multiple-Relaxation-Time (MRT) LB model, and (iii) LB study on hydrodynamic instabilities. The former two belong to improvements of physical modeling and the third belongs to simulation or application. The SRT-LB model supplemented by additional viscosity keeps the original framework of Lattice Bhatnagar-Gross-Krook (LBGK). So, it is easier and more convenient for previous SRT-LB users. The MRT-LB is a completely new framework for physical modeling. It significantly extends the range of LB applications. The cost is longer computational time. The developed SRT-LB and MRT-LB are complementary from the sides of convenience and applicability. © 2012 Higher Education Press and Springer-Verlag Berlin Heidelberg.

Guo M.-H.,University of Science and Technology Beijing | Liu J.-Y.,University of Science and Technology Beijing | Li Y.-X.,North China Institute of Aerospace Engineering
Transactions of Nonferrous Metals Society of China (English Edition) | Year: 2014

The electronic packaging shell of high silicon carbide (54%SiC, volume fraction) aluminum-based composites was produced by liquid-solid separation technique. The characteristics of distribution and morphology of SiC as well as the shell's fracture surface were examined by optical microscopy and scanning electron microscopy, and the thermo-physical and mechanical properties of the shell were also tested. The results show that Al matrix has a net-like structure while SiC is uniformly distributed in the Al matrix. The SiCp/Al composites have a low density of 2.93 g/cm3, and its relative density is 98.7%. Thermal conductivity of the composites is 175 W/(m·K), coefficient of thermal expansion (CTE) is 10.3×10-6 K -1 (25-400 °C), compressive strength is 496 MPa, bending strength is 404.5 MPa, and the main fracture mode is brittle fracture of SiC particles accompanied by ductile fracture of Al matrix. Its thermal conductivity is higher than that of Si/Al alloy, and its CTE matches with that of the chip material. © 2014 The Nonferrous Metals Society of China.

Zhou Y.,North China Institute of Aerospace Engineering
Advances in Mechanical Engineering | Year: 2015

Based on the surface piezoelectricity theory and first-order shear deformation theory, the surface effect on the axisymmetric wave propagating in piezoelectric cylindrical shells is analyzed. The Gurtin-Murdoch theory is utilized to get the nontraditional boundary conditions and constitutive equations of the surface, in company with classical governing equations of the bulk, from which the basic formulations are obtained. Numerical results show that the surface layer has a profound effect on wave characteristics in nanostructure at a higher mode. © 2015 SAGE Publications Ltd, unless otherwise noted. Manuscript content on this site is licensed under Creative Commons Licenses.

Liu L.,North China Institute of Aerospace Engineering
Mathematical Problems in Engineering | Year: 2014

Interval wavelet numerical method for nonlinear PDEs can improve the calculation precision compared with the common wavelet. A new interval Shannon wavelet is constructed with the general variational principle. Compared with the existing interval wavelet, both the gradient and the smoothness near the boundary of the approximated function are taken into account. Using the new interval Shannon wavelet, a multiscale interpolation wavelet operator was constructed in this paper, which can transform the nonlinear partial differential equations into matrix differential equations; this can be solved by the coupling technique of the wavelet precise integration method (WPIM) and the variational iteration method (VIM). At last, the famous Black-Scholes model is taken as an example to test this new method. The numerical results show that this method can decrease the boundary effect greatly and improve the numerical precision in the whole definition domain compared with Yan's method. © 2014 Liwei Liu.

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