期刊：
Journal of Physics B: Atomic, Molecular and Optical Physics,2009年42(12):125502- ISSN：0953-4075
通讯作者：
Li, Gao-xiang
作者机构：
[Tan, Hua-tang; Li, Gao-xiang] Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.;[Xia, Hong-xing] Xiaogan Univ, Dept Comp Sci, Xiaogan 432000, Peoples R China.
通讯机构：
[Li, Gao-xiang] H;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
摘要：
We investigate the effects of spontaneously generated interference on the spectrum of quantum fluctuations in phase quadratures of resonant fluorescence emitted from the transition of j = 1/2 to j = 1/2 of a monochromatically driven four-level atom with antiparallel dipole moments. It is found that the spectrum exhibits obvious characteristics of quantum interference in both cases of weak and strong laser fields. For the Zeeman-degenerate system, strong radiation squeezing in weak atomic excitation can occur at the central frequency of the spectrum, which is quite different from the case without consideration of the interference. Moreover, when we apply an external magnetic field to the atom, we find that the quantum interference can lead to a narrowing spectrum with much stronger squeezing by adjusting the magnetic field strength. These results suggest that the phase-dependent fluorescence spectrum can serve as a probe of the quantum interference effects in a realistic system such as a trapped 198Hg+ ion or charged quantum dots.
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
摘要：
A novel unconditionally stable pseudo-spectral time-domain (US-PSTD) method is implemented by virtue of a weighted Laguerre polynomial expansion. This novel algorithm preserves both unconditional stability and less mandatory spatial resolution, and hence is proved to be an efficient and accurate method. Numerical examples are included to validate the proposed algorithm.
作者机构：
[Shaowei L.; 刘毅; 黄璐] College of Physical Science and Technology, Central China Normal University, Wuhan 430079, China;Digital Engineering Research and Simulation Center, Hua zhong University of Science and Technology, Wuhan 430074, China;[刘蓉] College of Physical Science and Technology, Central China Normal University, Wuhan 430079, China, Digital Engineering Research and Simulation Center, Hua zhong University of Science and Technology, Wuhan 430074, China
通讯机构：
[Liu, R.] C;College of Physical Science and Technology, Central China Normal University, China
期刊：
Microwave and Optical Technology Letters,2009年51(8):1865-1868 ISSN：0895-2477
通讯作者：
Li, Minhua
作者机构：
[Yang, Helin; Li, Minhua] Huazhong Normal Univ, Coll Phys Sci & Technol, Wuhan 430079, Peoples R China.;[Wen, Ding-e] Natl Key Lab EMC, Wuhan 430079, Peoples R China.
通讯机构：
[Li, Minhua] H;Huazhong Normal Univ, Coll Phys Sci & Technol, Wuhan 430079, Peoples R China.
关键词：
metamaterials;left‐handed material;split ring resonator (SRR);plasma frequency;negative magnetic permeability
摘要：
Free-space microwave measurements are applied on composite metamaterials (CMMs) consisting of split ring resonators (SRRs) and wires, also known as left-handed material. Our experiments are based on a type of CMMs with unique configurations and the transmission and reflection measurements performed in free space exhibit a pass band at about 9 GHz. Simulation results are also given, which are in good agreements with experiments. The widely belief of the pass band is that the stop hands of the SRRs alone and the wires alone constitute a clear demonstration of left-handed (LH) behavior. The LH behavior only take place in the medium with simultaneously negative permittivity epsilon, and permeability mu, also called double negative materials. (C) 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1865-1868. 2009; Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/mop.24465
作者机构：
[Li, Xiao-Mei; Ma, Hai-Liang; Sa, Ben-Hao; Yan, Yu-Liang; Dong, Bao-Guo] China Inst Atom Energy, Beijing 102413, Peoples R China.;[Zhou, Dai-Mei; Sa, Ben-Hao] Huazhong Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.;[Dong, Bao-Guo] Natl Lab Heavy Ion Collis, Ctr Theoret Nucl Phys, Lanzhou 730000, Peoples R China.;[Sa, Ben-Hao] CCAST, World Lab, Beijing 100080, Peoples R China.;[Sa, Ben-Hao] China Inst Atom Energy, POB 275 18, Beijing 102413, Peoples R China.
通讯机构：
[Sa, Ben-Hao] C;China Inst Atom Energy, POB 275 18, Beijing 102413, Peoples R China.
摘要：
We have studied the centrality bin size dependence of charged particle forward-backward multiplicity correlation strength in 5%, 0–5%, and 0–10% most central Au+Au collisions at sNN=200 GeV with a parton and hadron cascade model, PACIAE based on PYTHIA. The real (total), statistical, and negative binomial distribution (NBD) correlation strengths are calculated by the real events, the mixed events, and fitting the charged particle multiplicity distribution to the NBD, respectively. It turned out that the correlation strength increases with increasing centrality bin size monotonously. If the discrepancy between real (total) and statistical correlation strengths is identified as dynamical one, the dynamical correlation may just be a few percent of the total (real) correlation.
作者：
Syed Ghazanfar Hussain;Deming Liu;Xintang Huang;Kamal Mahir Sulieman;Sahibzada T. Rasool
期刊：
International Journal of Nanoparticles,2009年2(1-6):443-450 ISSN：1753-2515
通讯作者：
Hussain, S. G.
作者机构：
1. Opto-Electronics Engineering Department, Huazhong University of Science and Technology, Wuhan 430074, P.R. China;Government College Gujranwala 52250 Punjab, Pakistan.;2. Opto-Electronics Engineering Department, Huazhong University of Science and Technology, Wuhan 430074, P.R. China.;3. Department of Physics, Central China Normal University, Wuhan 430079, P.R. China.;4. Physics Department, College of Education, Alzaim Alazhary University, Khartoum Bahry 1432, Sudan.
摘要：
We have reported the synthesis of porous particles of ZnO by thermal evaporation and transport method on silicon (111) substrates. The products were grown in a single-step catalyst-free process. In order to establish the optimum conditions for the preparation of ZnO porous particles, we performed synthetic studies on various growth temperatures. The morphological, structural and optical properties of the synthesised ZnO particles were characterised by field emission scanning electron microscope (FE-SEM), X-ray diffraction (XRD) and room temperature photoluminescence (RTPL) using a xenon lamp with an excitation wavelength of 325 nm. The photoluminescence spectrum of the sample-I showed stronger visible band emission as compared to others at room temperature. This stronger visible emission in the synthesised porous nanoparticles might be useful as a future UV-excited phosphor for producing bright and broad band visible-light. The change in growth temperature altered the morphological and optical characteristics of the nano- and microspheres.
摘要：
We report here the direct electron transfer of GOD and a novel glucose biosensor based on carbon-decorated ZnO(C-ZnO) nanowire array electrode. The C-ZnO nanowire array provides a novel platform for fast direct electrochemistry of GOD, and its based biosensor shows very high sensitivity and low detection limit. Based on the direct electrochemistry of horseradish peroxidase (HRP), the H2O2 biosensing application is further demonstrated using this new C-ZnO array architecture. The high conductivity of carbon and good electron transfer capability of ZnO nanowires, along with their low cost and biocompatibility make the C-ZnO nanowire array a promising platform for direct electrochemistry of enzymes and mediator-free enzymatic biosensors. (C) 2008 Published by Elsevier B.V.
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：
[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.
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.
期刊：
TECHNOLOGY AND APPLICATION OF ELECTRONIC INFORMATION,2009年:412-415
通讯作者：
Zhang Xinchen
作者机构：
[Zhang Xinchen; Liu Shouyin] Cent China Normal Univ, Coll Phys Sci & Technol, 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：
joint source-channel coding;wireless video transmission;wireless channel characteristics estimation;rate-distortion optimization model
摘要：
This paper proposed a new rate-distortion optimization model scheme of wireless video transform, which based on joint source-channel coding and the estimation of the wireless channel's transmission characteristics and performance. With comparing the experiment results, which based on H.264 JM90 Model added dynamic lose packets, the proposed scheme's output video would be more suited to transfer on wireless channel by better video quality. This scheme can apply for the wireless video with heavily lose packets.
通讯机构：
[Duan, Chuanxi] H;Huazhong Normal Univ, Coll Phys Sci & Technol, 152 Luoyu Rd, Wuhan 430079, Peoples R China.
关键词：
Rovibrational spectrum;He-N2O;van der Waals complex;POTENTIAL-ENERGY SURFACE;QUADRUPOLE HYPERFINE-STRUCTURE;ROTATIONAL SPECTRUM;ROVIBRATIONAL SPECTRA;AR-N2O;NE-N2O;DIMER
摘要：
The rovibrational spectrum of the He-N2O van der Waals complex has been recorded in the N2O-monomer nu(1) region (similar to 1285 cm(-1)) using an infrared tunable diode laser spectrometer in conjunction with a free supersonic jet expansion and an astigmatic multi-pass absorption cell. Twenty-two lines are assigned to the nu(2)-band of He-N2O. Rotational constants for the nu(2)-excited state are derived. The band-origin of the spectrum is determined to be nu(0) = 1285.0666(7) cm(-1) and shows a blue-shift of 0.1633(8) cm(-1) compared with the N2O nu(1)-band origin. (C) 2008 Elsevier Inc. All rights reserved.
期刊：
Journal of Physics B: Atomic, Molecular and Optical Physics,2009年42(5):055501- ISSN：0953-4075
通讯作者：
Li, Jingyan
作者机构：
[Hu, Xiangming; Li, Jingyan] Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
通讯机构：
[Li, Jingyan] H;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
摘要：
We analyse the effects of coherent or incoherent dressed population transfer on two-mode squeezing and continuous variable entanglement in four-wave mixing. Two cavity modes are generated from Rabi sidebands of dressed two-level atoms. A weak coherent or incoherent field couples one dressed state to an auxiliary excited state, from which the atoms decay to the other dressed state. This provides a two-step channel for dressed population transfer and reduces spontaneous emission into a squeeze-transformed mode that enters into an interaction with the dressed atoms. It is the reduction of spontaneous emission that leads to an enhancement of two-mode squeezing, whose degree is increased to 75% compared with 50% for the two-level case. This corresponds to a significant enhancement of the continuous variable entanglement.
