射频识别技术(Radio Frequency Identification,RFID)是随着无线电技术和大规模集成电路的普及应用,在20世纪90年代所兴起的一种非接触式的自动识别技术。随着RFID系统应用范围的不断扩大,为了提高RFID标签的识别效率,标签防冲突算法成...射频识别技术(Radio Frequency Identification,RFID)是随着无线电技术和大规模集成电路的普及应用,在20世纪90年代所兴起的一种非接触式的自动识别技术。随着RFID系统应用范围的不断扩大,为了提高RFID标签的识别效率,标签防冲突算法成为了RFID领域的重点研究问题之一,本文提出了一种基于分组标签的动态时隙帧ALOHA算法,希望能够为提高RFID标签的识别效率和精度提供一定的参考。展开更多
Structural, electronic properties and mechanical anisotropy of Amm2-carbon are investigated utilizing tlrst-principles calculations by Oambridge Serial Total Energy Package （CASTEP） code. The work is performed with ...Structural, electronic properties and mechanical anisotropy of Amm2-carbon are investigated utilizing tlrst-principles calculations by Oambridge Serial Total Energy Package （CASTEP） code. The work is performed with the generalized gradient approximation in the form of Perdew Burke-Ernzerhof （PBE）, PBEsol, Wu and Cohen （WC） and local density approximation in the form of Ceperley and Alder data as parameterized by Perdew and Zunger （CA-PZ）. The mechanical anisotropy eMculations show that Amm2-carbon exhibit large anisotropy in elastic moduli, such as Poisson＇s ratio, shear modulus and Young＇s modulus, and other anisotropy factors, such as the shear anisotropic factor and the universal anisotropic index AU. It is interestingly that the anisotropy in shear modulus and Young＇s modulus, universal anisotropic index and the shear anisotropie factor all increases with increasing pressure, but the anisotropy in Poisson＇s ratio decreases. The band structure calculations reveal that Amm2-carbon is a direct-band-gap semiconductor at ambient pressure, but with the pressure increasing, it becomes an indirect-band-gap semiconductor.展开更多
文摘射频识别技术(Radio Frequency Identification,RFID)是随着无线电技术和大规模集成电路的普及应用,在20世纪90年代所兴起的一种非接触式的自动识别技术。随着RFID系统应用范围的不断扩大,为了提高RFID标签的识别效率,标签防冲突算法成为了RFID领域的重点研究问题之一,本文提出了一种基于分组标签的动态时隙帧ALOHA算法,希望能够为提高RFID标签的识别效率和精度提供一定的参考。
基金Supported by the National Natural Science Foundation of China under Grant No.61564005
文摘Structural, electronic properties and mechanical anisotropy of Amm2-carbon are investigated utilizing tlrst-principles calculations by Oambridge Serial Total Energy Package （CASTEP） code. The work is performed with the generalized gradient approximation in the form of Perdew Burke-Ernzerhof （PBE）, PBEsol, Wu and Cohen （WC） and local density approximation in the form of Ceperley and Alder data as parameterized by Perdew and Zunger （CA-PZ）. The mechanical anisotropy eMculations show that Amm2-carbon exhibit large anisotropy in elastic moduli, such as Poisson＇s ratio, shear modulus and Young＇s modulus, and other anisotropy factors, such as the shear anisotropic factor and the universal anisotropic index AU. It is interestingly that the anisotropy in shear modulus and Young＇s modulus, universal anisotropic index and the shear anisotropie factor all increases with increasing pressure, but the anisotropy in Poisson＇s ratio decreases. The band structure calculations reveal that Amm2-carbon is a direct-band-gap semiconductor at ambient pressure, but with the pressure increasing, it becomes an indirect-band-gap semiconductor.
