We study two families of two-dimensional bright lattice solitons in photovoltaic-photorefractive crystals.It is shown that self-focusing and self-defocusing lattice solitons are possible only when their power level ex...We study two families of two-dimensional bright lattice solitons in photovoltaic-photorefractive crystals.It is shown that self-focusing and self-defocusing lattice solitons are possible only when their power level exceeds a critical threshold.It is found that self-focusing lattice solitons exist not only in the semi-infinite band gap,but also in the first band gap,whereas self-defocusing lattice solitons exist only in the first band gap.The structures of these lattice solitons are also analyzed.Our results indicate that a self-focusing lattice soliton in the semi-infinite band gap is more confined than in the first band gap so its tails in the first band gap occupy many lattice sites;when a self-defocusing lattice soliton is close to the second band,the self-defocusing lattice soliton is more confined so its tails occupy a few lattice sites.展开更多
The dynamic reconfiguration technique based on field-programmable gate array (FPGA) can improve the resource utilization. Discussed are the dynamic reconfiguration principles and methods. Proposed is a remote dynami...The dynamic reconfiguration technique based on field-programmable gate array (FPGA) can improve the resource utilization. Discussed are the dynamic reconfiguration principles and methods. Proposed is a remote dynamic reconfiguration scheme using Xilinx Virtex-Ⅱ FPGA and SMCS Ethernet Physical layer transceiver(PHY). The hardware of the system is designed with Xilinx Virtex-U XC2V30P FPGA that embedds MicroBlaze and MAC IP core, and its network communication software based on transmission control protoeol/Internet protocol (TCP/IP) protocol is programmed by loading LwIP to MicroBlaze. The experimental results indicate that the remote FPGA dynamic reconfiguration system(RFDRS) can switch freely in the eight lighting modes of light emitting diodes (LED), and that, using dynamic reconfiguration technology, FPGA resource utilization can be reduced remarkably, which is advantageous in the system upgrade and software update.展开更多
基金Supported by the National Natural Science Foundation of China(No 10674176).
文摘We study two families of two-dimensional bright lattice solitons in photovoltaic-photorefractive crystals.It is shown that self-focusing and self-defocusing lattice solitons are possible only when their power level exceeds a critical threshold.It is found that self-focusing lattice solitons exist not only in the semi-infinite band gap,but also in the first band gap,whereas self-defocusing lattice solitons exist only in the first band gap.The structures of these lattice solitons are also analyzed.Our results indicate that a self-focusing lattice soliton in the semi-infinite band gap is more confined than in the first band gap so its tails in the first band gap occupy many lattice sites;when a self-defocusing lattice soliton is close to the second band,the self-defocusing lattice soliton is more confined so its tails occupy a few lattice sites.
基金Science and Technology Innovation Fund of Tianjin(06FZZDGX01800)
文摘The dynamic reconfiguration technique based on field-programmable gate array (FPGA) can improve the resource utilization. Discussed are the dynamic reconfiguration principles and methods. Proposed is a remote dynamic reconfiguration scheme using Xilinx Virtex-Ⅱ FPGA and SMCS Ethernet Physical layer transceiver(PHY). The hardware of the system is designed with Xilinx Virtex-U XC2V30P FPGA that embedds MicroBlaze and MAC IP core, and its network communication software based on transmission control protoeol/Internet protocol (TCP/IP) protocol is programmed by loading LwIP to MicroBlaze. The experimental results indicate that the remote FPGA dynamic reconfiguration system(RFDRS) can switch freely in the eight lighting modes of light emitting diodes (LED), and that, using dynamic reconfiguration technology, FPGA resource utilization can be reduced remarkably, which is advantageous in the system upgrade and software update.