通讯机构：
[Cao, Can] C;Cent South Univ, Sch Phys & Elect, Changsha 410083, Peoples R China.
关键词：
density functional theory, doping, Fermi level, graphene, Green's function methods, nanoribbons, spin polarised transport
摘要：
By using non-equilibrium Green’s functions in combination with the density-functional theory, we investigate the spin transport properties of molecular junctions based on 3d transition terminated zigzag graphene nanoribbons. The results show that the electronic transport properties are strongly depending on the type of terminated atom at the edge of ribbon. The currents of spin-up and spin-down display different behaviors, and the spin-filter effects can be observed. These unconventional doping effects could be used to design novel nanospintronics devices.
作者：
Wu, X. Z.;Long, M. Q.*;Chen, L. N.;Cao, C.;Ma, S. S.;...
期刊：
Physica E-Low-Dimensional Systems & Nanostructures,2012年45:82-85 ISSN：1386-9477
通讯作者：
Long, M. Q.
作者机构：
[Cao, C.; Wu, X. Z.] Cent S Univ, Sch Mat Sci & Engn, Changsha 410083, Hunan, Peoples R China.;[Long, M. Q.; Xu, H.] Cent S Univ, Coll Sci & Technol, Sch Phys & Electon, Changsha 410083, Hunan, Peoples R China.;[Chen, L. N.] Univ S China, Sch Comp Sci & Technol, Hengyang 421001, Peoples R China.
通讯机构：
[Long, M. Q.] C;Cent S Univ, Coll Sci & Technol, Sch Phys & Electon, Changsha 410083, Hunan, Peoples R China.
摘要：
Applying nonequilibrium Green’s functions in combination with the density functional theory, we investigated the effect of amino and hydroxyl groups on the transport property of the carbon atomic chains. The results show the conductance oscillation with the length and the parity of the carbon atomic chains, and the electronic transport properties can be modulated by the sites of amino and hydroxyl groups. And also, the negative differential resistance behaviors can be observed clearly. These phenomena may originate from the interaction of side groups with the carbon atomic chains and the change in coupling degree between the molecular orbitals and electrode states.
作者：
Chen, L. N.;Wu, X. Z.;Huang, W. R.;Ma, S. S.;Xu, H.*
期刊：
Solid State Communications,2012年152(10):868-872 ISSN：0038-1098
通讯作者：
Xu, H.
作者机构：
[Ma, S. S.; Xu, H.; Wu, X. Z.; Huang, W. R.; Chen, L. N.] Cent S Univ, Sch Phys Sci & Technol, Changsha 410083, Peoples R China.;[Chen, L. N.] Univ S China, Sch Comp Sci & Technol, Hengyang 421001, Peoples R China.;[Huang, W. R.] Changsha Univ Sci & Technol, Sch Phys & Elect Sci, Changsha 410004, Hunan, Peoples R China.
通讯机构：
[Xu, H.] C;Cent S Univ, Sch Phys Sci & Technol, Changsha 410083, Peoples R China.
关键词：
A. Metallic carbon nanotube;D. Electronic property;D. Impurity and defect;E. First-principles
摘要：
Using first-principles calculations based on spin-polarized density functional theory, we investigate the electronic properties of metallic carbon nanotubes (MCNTs) with partial hydrogenation or vacancy defects. The calculated results show that the energy band structures of MCNTs strongly depend on the adsorption site or the vacancy-defect site. Interestingly, our results show the nonmagnetic semiconducting behavior of MCNTs in the case of balanced H adsorption or vacancy defects. However, the MCNTs exhibit magnetic metallic behavior in the case of imbalanced H adsorption or vacancy defects, and the energy band structure of MCNTs shows the appearance of a spin-polarized flat band near the Fermi level. This effect presents a possibility for spintronic device and semiconducting molecular wire applications.
作者机构：
[Jia Shu-ting; Xu Hui; Chen Ling-na] Cent S Univ, Sch Phys Sci & Technol, Changsha 410083, Hunan, Peoples R China.;[Chen Ling-na] Univ S China, Sch Comp Sci & Technol, Hengyang 421001, Peoples R China.
通讯机构：
[Xu Hui] C;Cent S Univ, Sch Phys Sci & Technol, Changsha 410083, Hunan, Peoples R China.
关键词：
electronic transport properties;negative differential resistance;first-principle;molecular device
摘要：
By using the first-principle calculations and nonequilibrium Green functions method, the electronic transport properties of molecular devices constructed by C82, C80BN and C80N2 were studied. The results show that the electronic transport properties of molecular devices are affected by doped atoms. Negative differential resistance (NDR) behavior can be observed in certain bias regions for C82 and C80BN molecular devices but cannot be observed for C80N2 molecular device. A mechanism for the negative differential resistance behavior was suggested.
期刊：
Discrete Dynamics in Nature and Society,2012年2012(Pt.4):578064-1-578064-22 ISSN：1026-0226
通讯作者：
Wu, Daqing
作者机构：
[Zheng, Jianguo; Wu, Daqing] DongHua Univ, Glorious Sun Sch Business & Management, Shanghai 200051, Peoples R China.;[Wu, Daqing] Univ S China, Comp Sci & Technol Inst, Hengyang 421001, Hunan, Peoples R China.;[Wu, Daqing] Sichuan Univ Sci & Engn, Artificial Intelligence Key Lab Sichuan Prov, Zigong 643000, Peoples R China.
通讯机构：
[Wu, Daqing] D;DongHua Univ, Glorious Sun Sch Business & Management, Shanghai 200051, Peoples R China.
摘要：
A novel dynamic multistage hybrid swarm intelligence optimization algorithm is introduced, which is abbreviated as DM-PSO-ABC. The DM-PSO-ABC combined the exploration capabilities of the dynamic multiswarm particle swarm optimizer (PSO) and the stochastic exploitation of the cooperative artificial bee colony algorithm (CABC) for solving the function optimization. In the proposed hybrid algorithm, the whole process is divided into three stages. In the first stage, a dynamic multiswarm PSO is constructed to maintain the population diversity. In the second stage, the parallel, positive feedback of CABC was implemented in each small swarm. In the third stage, we make use of the particle swarm optimization global model, which has a faster convergence speed to enhance the global convergence in solving the whole problem. To verify the effectiveness and efficiency of the proposed hybrid algorithm, various scale benchmark problems are tested to demonstrate the potential of the proposed multistage hybrid swarm intelligence optimization algorithm. The results show that DM-PSO-ABC is better in the search precision, and convergence property and has strong ability to escape from the local suboptima when compared with several other peer algorithms.
作者机构：
[Cao Can; Jia Shu-Ting; Xu Hui; Zhang Dan; Chen Ling-Na] Cent S Univ, Sch Phys Sci & Technol, Changsha 410083, Peoples R China.;[Chen Ling-Na] Univ S China, Sch Comp Sci & Technol, Hengyang 421001, Peoples R China.
通讯机构：
[Xu Hui] C;Cent S Univ, Sch Phys Sci & Technol, Changsha 410083, Peoples R China.
关键词：
density functional theory;first-principles;MgF_2 codoped with cobalt and phosphorus;electronic structure optical properties
摘要：
By using the first-principles calculation based on density functional theory, we investigate the electronic structures and optical properties of Cl-doped Ag crystal. The results show that the electronic structure of Cl-doped Ag crystal depends on the doped concentration and the site of impurity defect. Interestingly, the calculated adsorption spectra of Cl-doped Ag crystal show isotropy or anisotropy coincide with the symmetry of Ag crystal. These features are discussed to provide guidance to experimental efforts for Ag-based nanoeletronic devices.
摘要：
Using the first-principles study, we calculate the electronic band structure of metallic carbon nanotubes (MCNTs) with B/N co-doping. We show the formation energies which suggest that the B/N co-doping configuration is the energetically stable structure. We find that the electronic structure properties depend on the doping concentration of MCNTs, as well as the doping position. Energy gap opens rapidly when the symmetry breaking of MCNTs happens. These unconventional eloping effects could be used to design novel nanoelectronic devices. (c) 2010 Elsevier B.V. All rights reserved.
摘要：
Stable local feature detection is a fundamental component of many stereo vision problems such as 3-D reconstruction, object localization, and object tracking. A robust method for extracting scale-invariant feature points is presented. First, the Harris corners in three-level pyramid are extracted. Then, the points detected at the highest level of the pyramid are correctly propagated to the lower level by pyramid based scale invariant (PBSI) method. The corners detected repeatedly in different levels are chosen as final feature points. Finally, the characteristic scale is obtained based on maximum entropy method. The experimental results show that the algorithm has low computation cost, strong antinoise capability, and excellent performance in the presence of significant scale changes.
