摘要：
Novel sheetlike Cu2O two-dimensional (2D) nanoarchitectures were successfully synthesized via a copper nanoparticle-mediated process for the first time. Uniform and nearly monodisperse Cu nanocolloids were firstly synthesized by disproportionating reaction of Cu+ at the surfactant-free ambient conditions, and Cu2O nanosheets were subsequently synthesized by choosing ethanol solvent agent to limit the oxidized processes Of Cu nanocolloids. The synthesized products were systematically studied by X-ray powder diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and UV-vis absorption spectra. It was demonstrated that the solvent agent of ethanol played key roles in the formation of the as-synthesized nanosheets. By choosing the different solvent agents to limit the oxidized processes, Cu2O nanospheres and nanocubes can be selectively synthesized accordingly. (C) 2008 Elsevier Inc. All rights reserved.
作者机构：
[Long-gang Pang; Qun Wang] Interdisciplinary Center for Theoretical Study and Department of Modem Physics,University of Science and Technology of China,Anhui 230026,People's Republic of China;[Xin-nian Wang] Nuclear Science Division,Lawrence Berkeley National Laboratory,Cyclotron road,Berkeley,CA 94720,USA;[Rong Xu] Institute of Particle Physics,Huazhong Normal University,Wuhan 430079,People's Republic of China
会议名称：
The 10th International Conference on Nucleus-Nucleus Collisions(第十届国际核—核碰撞会议
会议时间：
2009-8-16
会议地点：
北京
会议主办单位：
中国物理学会;中国核学会
会议论文集名称：
The 10th International Conference on Nucleus-Nucleus Collisions(第十届国际核—核碰撞会议论文集
期刊：
2009 THIRD INTERNATIONAL SYMPOSIUM ON INTELLIGENT INFORMATION TECHNOLOGY APPLICATION, VOL 3, PROCEEDINGS,2009年3:15-18
通讯作者：
Zhang Xinchen
作者机构：
[Zhang Xinchen] Cent China Normal Univ, Coll Phys Sci & Technol, Wuhan, Peoples R China.;[Huang Mei] Hubei Inst Forestry Explorat & Design, Wuhan, Peoples R China.
通讯机构：
[Zhang Xinchen] C;Cent China Normal Univ, Coll Phys Sci & Technol, Wuhan, Peoples R China.
关键词：
error resilience;wireless video;video transcoding;rate-distortion model
摘要：
For video transmission over wireless or highly congested networks, video transcoding is typically used to reduce the rate and change the format of the originally encoded video source to match network conditions and terminal capabilities. Error resilient video transcoding can insert error resilient tools in the compressed video to enhance error resilience of the video over wireless channels by increasing bit rate. This paper proposed a novel error resilient video transcoding and streaming transmission scheme specially designed for Mpeg2 to H.264 transcoded video to portable devices in wireless channel. Based on the rate-distortion models developed in this paper, an optimal transcoding marcoblock mode selection and bit allocation scheme is proposed. In order to improve the video quality in the presence of transmission error, this paper also investigated how to allocate redundant pictures more efficiently according to the content characteristics of the primary pictures. The experiment results demonstrated that the proposed transcoding scheme can enhance speed and improve the decode image quality, get better error resilience.
作者机构：
[Dumitru, Adrian] CUNY, Baruch Coll, Dept Nat Sci, New York, NY 10010 USA.;[Dumitru, Adrian] Brookhaven Natl Lab, RIKEN, BNL, Res Ctr, Upton, NY 11973 USA.;[Dumitru, Adrian] CUNY, Grad Sch, New York, NY 10036 USA.;[Guo, Yun] Goethe Univ Frankfurt, Helmholtz Res Sch, D-60438 Frankfurt, Germany.;[Guo, Yun] Huazhong Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.
通讯机构：
[Dumitru, Adrian] C;CUNY, Baruch Coll, Dept Nat Sci, 17 Lexington Ave, New York, NY 10010 USA.
摘要：
We consider quarkonium in a hot quantum chromodynamics (QCD) plasma which, due to expansion and nonzero viscosity, exhibits a local anisotropy in momentum space. At short distances the heavy-quark potential is known at tree level from the hard-thermal loop resummed gluon propagator in anisotropic perturbative QCD. The potential at long distances is modeled as a QCD string which is screened at the same scale as the Coulomb field. At asymptotic separation the potential energy is nonzero and inversely proportional to the temperature. We obtain numerical solutions of the three-dimensional Schrödinger equation for this potential. We find that quarkonium binding is stronger at nonvanishing viscosity and expansion rate, and that the anisotropy leads to polarization of the P-wave states.
摘要：
An unconditionally stable finite-difference time-domain (US-FDTD) method based on wave equation is introduced by making use of Laguerre polynomials as basis functions for expanding field components in time. This new wave-equation-based FDTD scheme is not only unconditionally stable but also requires less memory usage. Comparisons among the traditional FDTD, the conventional Laguerre-polynomial US-FDTD, and this proposed scheme are presented in the numerical examples in terms of the memory usage and computational time. (C) 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51:529-532, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24101
作者机构：
[Wu, Shuang-Qing] Cent China Normal Univ, Coll Phys Sci & Technol, Wuhan 430079, Hubei, Peoples R China.
通讯机构：
[Wu, Shuang-Qing] C;Cent China Normal Univ, Coll Phys Sci & Technol, Wuhan 430079, Hubei, Peoples R China.
摘要：
The aim of this paper is to investigate the separability of a spin- 1/2 spinor field in a five-dimensional rotating, charged black hole constructed by Cvetič and Youm in string theory, in the case when three U(1) charges are set equal. This black hole solution represents a natural generalization of the famous four-dimensional Kerr-Newman solution to five dimensions with the inclusion of a Chern-Simons term to the Maxwell equation. It is shown that the usual Dirac equation cannot be separated by variables in this general spacetime with two independent angular momenta. However if one supplements an additional counterterm into the usual Dirac operator, then the modified Dirac equation for the spin- 1/2 spinor particles is separable in this rotating, charged Einstein-Maxwell-Chern-Simons black hole background geometry. A first-order symmetry operator that commutes with the modified Dirac operator has exactly the same form as that previously found in the uncharged Myers-Perry black hole case. It is expressed in terms of a rank-three totally antisymmetric tensor and its covariant derivative. This tensor obeys a generalized Killing-Yano equation and its square is a second-order symmetric Stäckel-Killing tensor admitted by the five-dimensional rotating, charged black hole spacetime.
作者机构：
[Jiang, Qing-Quan; Cai, Xu] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hebei, Peoples R China.;[Jiang, Qing-Quan] China W Normal Univ, Coll Phys & Elect Informat, Nanchong 637002, Sichuan, Peoples R China.
通讯机构：
[Jiang, Qing-Quan] C;Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hebei, Peoples R China.
关键词：
Kerr-Godel black hole;Covariant anomaly;Effective action
摘要：
The existence of the Godel rotation parameter in Godel universe creates many interesting special features for Godel-type black holes. In this Letter, motivated by the fact that these new features provide additional tests as to the robustness of the covariant anomaly cancellation method and the effective action technique, we attempt to adopt the analyses to study Hawking radiation from Kerr-Godel black hole. The result is interesting and showing that the covariant anomaly cancellation method and the effective action technique applied to Kerr-Godel black hole yield Hawking temperatures consistent with the previous results made via other methods. (C) 2009 Elsevier B.V. All rights reserved.
作者机构：
[Xu, Xin-Ping] Huazhong Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.;[Xu, Xin-Ping] Chinese Acad Sci, Inst High Energy Phys, Beijing 100049, Peoples R China.
通讯机构：
[Xu, XP ] ;Huazhong Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.
摘要：
We consider coherent exciton transport modeled by continuous-time quantum walks on long-range interacting cycles (LRICs), which are constructed by connecting all the two nodes of distance m in the cycle graph. LRIC has a symmetric structure and can be regarded as the extensions of the cycle graph (nearest-neighboring lattice). For small values of m, the classical and quantum return probabilities show power law behavior p(t)∼t−0.5 and π(t)∼t−1, respectively. However, for large values of m, the classical and quantum efficiency scales as p(t)∼t−1 and π(t)∼t−2. We give a theoretical explanation of this transition using the method of stationary phase approximation. In the long time limit, depending on the network size N and parameter m, the limiting probability distributions of quantum transport show various patterns. When the network size N is an even number, we find an asymmetric transition probability of quantum transport between the initial node and its opposite node. This asymmetry depends on the precise values of N and m. Finally, we study the transport processes in the presence of traps and find that the survival probability decays faster on networks of large m.
