摘要：
Left-handed metamaterials, of which the dielectric constant and the magnetic permeability are sim-ultaneously negative, are a kind of electromagnetism materials. This paper gives a introduction to the basic principles of left-handed materials, and expatiates on the preparation ways of this materials in microwave region,infrared region and visible light region.
期刊：
Journal of Physics: Conference Series,2012年396(PART 5) ISSN：1742-6588
通讯作者：
Zhu, Jianlin
作者机构：
[Zhou, Daicui; Zhang, Guoping; Zhu, Jianlin] Cent China Normal Univ, Coll Phys Sci & Technol, Wuhan 430079, Peoples R China.
通讯机构：
[Zhu, Jianlin] C;Cent China Normal Univ, Coll Phys Sci & Technol, Wuhan 430079, Peoples R China.
会议名称：
International Conference on Computing in High Energy and Nuclear Physics (CHEP)
会议时间：
MAY 21-25, 2012
会议地点：
New York Univ, New York, NY
会议主办单位：
New York Univ
会议论文集名称：
Journal of Physics Conference Series
摘要：
In this paper, we present the Program Analysis Framework (PAF) to analyze the software architecture and software modularity of large software packages using techniques in Aspect Mining. The basic idea about PAF is to record the call relationships information among the important elements firstly and then use the different analysis algorithms to find the crosscutting concerns which could destroy the modularity of the software from this recording information. We evaluate our framework through analyzing DATE, the ALICE Data-Acquisition (DAQ) software which handles the data flow from the detector electronics to the permanent storage archiving. The analysis results prove the effectiveness and efficiency of our framework. PAF has pinpointed a number of possible optimizations which could be applied and help maximizing the software quality. PAF could also be used for the analysis of other projects written in C language..
通讯机构：
[Zhu, Jianlin] C;Cent China Normal Univ, Coll Phys Sci & Technol, Wuhan 430079, Peoples R China.
会议名称：
International Conference on Computing in High Energy and Nuclear Physics (CHEP)
会议时间：
OCT 18-22, 2010
会议地点：
Taipei, TAIWAN
会议主办单位：
[Zhu, Jianlin;Zhou, Daicui;Zhang, Guoping] Cent China Normal Univ, Coll Phys Sci & Technol, Wuhan 430079, Peoples R China.^[Saiz, Pablo;Carminati, Federico;Betev, Latchezar;Lorenzo, Patricia Mendez;Grigoras, Alina Gabriela;Grigoras, Costin;Furano, Fabrizio;Schreiner, Steffen;Datskova, Olga Vladimirovna] CERN, CH-1211 Geneva 23, Switzerland.^[Schreiner, Steffen] CASED, Darmstadt, Germany.^[Banerjee, Subho Sankar] LNM Inst Informat Technol, Jaipur, Rajasthan, India.
会议论文集名称：
Journal of Physics Conference Series
摘要：
Web Services are an XML based technology that allow applications to communicate with each other across disparate systems. Web Services are becoming the de facto standard that enable inter operability between heterogeneous processes and systems. AliEn2 is a grid environment based on web services. The AliEn2 services can be divided in three categories: Central services, deployed once per organization; Site services, deployed on each of the participating centers; Job Agents running on the worker nodes automatically. A security model to protect these services is essential for the whole system. Current implementations of web server, such as Apache, are not suitable to be used within the grid environment. Apache with the mod_ssl and OpenSSL only supports the X.509 certificates. But in the grid environment, the common credential is the proxy certificate for the purpose of providing restricted proxy and delegation. An Authentication framework was taken for AliEn2 web services to add the ability to accept X.509 certificates and proxy certificates from client-side to Apache Web Server. The authentication framework could also allow the generation of access control policies to limit access to the AliEn2 web services.
作者机构：
[Zhang, Guoping; Xia, Hongxing; Xu, Hongbo] Huazhong Normal Univ, Coll Phys Sci & Technol, Wuhan, Peoples R China.
通讯机构：
[Xia, Hongxing] H;Huazhong Normal Univ, Coll Phys Sci & Technol, Wuhan, Peoples R China.
关键词：
noise uncertainty;three-threshold;cooperative sensing;cognitive radio
摘要：
In this paper, we propose a three-threshold decision based cooperative spectrum sensing algorithm (TTDCSS) with two rounds cooperation. Specifically, after the failure of the first cooperation, cognitive users begin to report the second local decision bit to the fusion center (FC) to perform a second cooperation, thus sensing failure is eliminated. Furthermore, by integrating uncertainty of noise variance, we propose a simple method to set local decision thresholds. Numerical results show that the TTDCSS algorithm is superior to the conventional double-threshold decision based sensing methods in the performance with a little increase of sensing bits.
摘要：
Light scattering by the microstructure defects of transparent ceramics causes losses of light and has an effect on the transmission properties. Effects of pores on transmission were studied using the Mie theory. The in-line transmissions of transparent magnesium aluminate spinel were calculated as a function of wavelength, pore size, width of distribution and porosity. The results show that the in-line transmission gradually increases with an increase in wavelength. Porosity has great impact as the transmission decreases with the increasing of porosity. The minimum of the transmissions were observed when the pore size close to the optical wavelength. Furthermore, it should be noted that the in-line transmission increases with decreasing of the width in pore size distribution in the visible part of the spectrum.
作者机构：
[张国平; 李小明; 潘栋] Department of Electronics and Information Engineering, College of Physical Science and Technology, Huazhong Normal University, Wuhan 430079, China
通讯机构：
[Xiao-ming Li] D;Department of Electronics and Information Engineering, College of Physical Science and Technology, Huazhong Normal University, Wuhan, China
摘要：
The propagation of two femtosecond pulses in the region with minimum group-velocity dispersion,influenced by the crossphase modulation（XPM） in photonic crystal fiber（PCF）,is investigated in this paper.The adaptive split-step Fourier method is used to simulate the generalized nonlinear Schrdinger equations（GNSE）.The numerical results show that the combination of the Raman scattering and XPM can make the spectrum and the pulse shape changed,inducing the pulse compression and supercontinuum generation.The Raman effect from molecular vibrations,which can make the pulse spectrum in anomalous-dispersion region to be more symmetrical,is also discussed.
摘要：
The optical transmission is getting more and more important in the access networks. The Gigabit-capable passive optical network (GPON) is the most important technology to support the next-generation fiber to the home (FTTH) systems. This paper analyzes new recommendation and network configuration of GPON, and the information about dynamic bandwidth allocation (DBA) in GPON recommendation. An improved DBA algorithm based on all transmission containers (T-CONT) and bandwidth priority is proposed, and the GPON model for this algorithm is established and tested The simulation results show that this algorithm can satisfy the full service quality of service (QoS) requirements of GPON.
摘要：
The method for measuring particles size and concentration based on the light extinction is widely used in the particles measurement technology. In the light extinction method, the extinction efficiency factor is an important parameter. Using the Mie theory, the extinction efficiency factor of spherical particles and equivalent-volume spheres instead of nonspherical particles can be calculated. For analyzing the characteristics of the non-spherical particles, the discrete dipole approximation (DDA) method is presented in this paper. The extinction efficiency factors of spherical, ellipsoid and cylinder particles were calculated by using the DDA method under different size parameters, and compared with the results of the equivalent-volume spheres based on Mie theory. The calculation results show that the extinction efficiency factors of spherical particles obtained by two methods differ slightly under the whole size parameters. The extinction efficiency factor of non-spherical particles and equivalent-volume spheres have discrepancy in evidence. The discrepancy between them changes with the different parameters of shape and size. Furthermore, it should be noted that when the size parameter is less than a critical size parameter, the extinction efficiency factor of non-spherical particles obtained by two methods differ slightly, and when the size parameter is greater than a critical size parameter, the extinction efficiency factor of non-spherical particles obtained by two methods differ greatly along with the increase of the size parameter, the non-spherical effect on the extinction efficiency factor can not be ignored. By contrast with the Mie theory, the DDA method has greater potential in application.
