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TEM observation of sintered permanent magnetic strontium ferrite

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Rare Metals 2006年第Z1期25卷 578-583页

作者： YU Hongya LIU Zhengyi ZENG Dechang College of Mechanical Engineering South China University of Technology Guangzhou 510640 China College of Mechanical Engineering South China University of Technology Guangzhou 510640 China College of Mechanical Engineering South China University of Technology Guangzhou 510640 China

Sintered permanent magnetic strontium ferrites were studied using transmission electron microscopy to investigate the microstructure morphology and its correlation with the magnetic properties. The present study shows that the microstructure of sintered permanent magnetic strontium ferrites is an important parameter in determining their magnetic properties. The microstructure morphology in low-performance ferrite magnet is obviously different from high-performance one. The magnetic properties of sintered permanent strontium ferrite depend strongly on the orientation degree of strong magnetic crystals. The presence of ferric oxide phase in ferrite magnet can deteriorate the magnetic properties. Moreover, proper quantities of crystal defects are beneficial to high coercive force due to the fixing of magnetic domain.

关键词： permanent magnetic strontium ferrite TEM Moiré pattern crystal defect

Fabrication of Ceramic Composites by Directed Metal Oxidation

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Journal of Wuhan university of technology(Materials Science) 2004年第1期19卷 48-50页

作者：周曦亚 south china university of technology

To explain the growth mechanism of Al 2O 3/Al Lanxide composites,the dynamics of the directed oxidation of Al-Mg-Si alloys are *** experimental methods to produce Lanxide composites by directed oxidation of metal melts at high temperatures are *** effect of the processing factors on the microstructures and properties of Al 2O 3/Al composites and enforced Al 2O 3/Al composites is also *** with sintering ceramic composites,the advantages of Lanxide process and Lanxide materials are as following:it is a near net shaped process;the process is very simple;the microstructures and properties of Lanxide materials can be adjusted;and this process can be used to infiltrate ceramic fiber or particle preforms.

关键词： composites ceramic directed oxidation Al 2O 3/Al alloy

EFFICIENT POLYMER PHOTOVOLTAIC DEVICES BASED ON POLYMER D-A BLENDS

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Chinese Journal of Polymer Science 2001年第6期19卷 597-602页

作者： Xian-yu Deng Li-ping Zheng Yue-qi Mo Gang Yu Wei Yang Wen-hua Weng Yong Cao Institute of Polymer Optoelectronic Material and Devices, south china university of technology Wuhan 430074, china 华南理工大学广东广州

Recent work demonstrated that efficient solar-energy conversion could be achieved in polymer photovoltaic cells (PVCs) based on interpenetrating bi-continuous networks([1,2]). In this paper we present a comprehensive study on improving energy conversion efficiencies of PVCs based on composite films of MEBPPV and fullerene derivatives. Carrier collection efficiency of ca. 30% el/ph and energy conversion efficiency of 3.9% were achieved at 500 nm. At reverse bias of 15 V, the photosensitivity reached 0.8 A/W, corresponding to a quantum efficiency over 100% el/ph. These results suggest that high efficiency photoelectric conversion can be achieved in polymer devices with M-P-M structure. These devices are promising for practical applications such as plastic solar cells and plastic photodetectors.

关键词： photovoltaic cell hetero-junction conjugated polymer fullerene

Multi-agent Based Modeling of Manufacturing Network

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武汉理工大学学报 2006年第S1期28卷 381-387页

作者： GUO Yuming,SUN Yanming,ZHENG Shixiong (School of Mechanical Engineering,south china university of technology,Guangzhou 510641,china) School of Mechanical Engineering South China University of TechnologyGuangzhou 510641China

An intelligent manufacturing system is modeled currently from the viewpoint of manufacturing applications,and the network platform’s influence to manufacturing applications is not considered adequately. However any bottleneck in service oriented architecture (SOA) for the manufacturing network can affect the agility of the IT environment. In this paper,to achieve a trade-off between manufacturing resources and network resources,the manufacturing network is modeled with multi-agent,in which two kinds of basic elements,the manufacturing application unit and the network carrier of manufacturing information,are presented. And their main characters are described by colored petri net. The manufacturing application model drives the network platform that inversely provides this application model technology supports. The proposed multi-agent system is demonstrated through an example integration scenario involving production plan,resources management and execution subsystems. And the result suggests that analyzing and designing the system architecture of networked manufacturing should give due attention to the operation system as well as manufacturing applications.

关键词： manufacturing network model multi-agent colored petri net SOA

Rate-oriented perceptual image coding using contrast-based quantization

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Chinese Optics Letters 2010年第4期8卷 381-383页

作者：余卫宇田菁 School of Electronic and Information Engineering South China University of Technology School of Electrical and Electronic Engineering Nanyang Technological University

A new image coding approach is proposed by controlling the quantization step via minimizing the perceptual distortions（in terms of image＇s contrast measurement）.The proposed method is a rate-oriented contrast-based approach,which is in contrast to the conventional quality-oriented contrast-based image *** algorithm achieves a higher perceptual quality performance against several methods developed previously.

关键词： Visual communication

Assessing Technical Progress Via Data Envelopment Analysis

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Systems Science and Systems Engineering 1996年第3期6卷 257-265页

作者： LI Guanajin LIU Yongqing(Automation Dept., south china university of technology Guanedou, 510641, china)

This paper examines the nature of production function and derives its mathematical description similar to Cobb-Douglas form. Defining pareto optimality production state and reducing multiple outputs to a single output, we present Data Envelopment Analysis (DEA) models, which have, in effect, extended the definition for decision making unit (DMU) from cross-section to timeseries so as to determine production function satisfying maximal output and minimal inputs under the condition of pareto optimality. By means of production function determined in this paper we can further obtain such important information in the context of technical progress as index of the level of disembodied type technology and so on. In addition, a case study shows the contributive consequent of this work.

关键词： production function technical progress pareto optimality model

Estimating the mixing matrix by using less sparsity

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Progress in Natural Science:Materials International 2009年第8期19卷 1027-1031页

作者： Guoxu Zhou a, Zuyuan Yang a, Xiaoxin Liao b, Jinlong Zhanga a School of Electrics & Information Engineering, south china university of technology, Guangzhou 510641, china b Department of Control Science and Engineering, Huazhong university of Science and technology, Wuhan 430074, china School of Electrics & Information Engineering South China University of Technology Guangzhou 510641 China Department of Control Science and Engineering Huazhong University of Science and Technology Wuhan 430074 China

In this paper, the nonlinear projection and column masking (NPCM) algorithm is proposed to estimate the mixing matrix for blind source separation. It preserves the samples which are close to the interested direction while suppressing the rest. Compared with the existing approaches, NPCM works efficiently even if the sources are less sparse (i.e., they are not strictly sparse). Finally, we show that NPCM provides considerably accurate estimation of the mixing matrix by simulations.

关键词： Sparse component analysis Blind source separation Particle swarm optimization

THE INVESTIGATION OF THE METAL DAMAGE AT THE CREEP BY THE METHOD OF ELECTRICAL RESISTANCE MEASURING

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Acta Mechanica Sinica 1991年第2期7卷 157-161页

作者： Lokochtchenko A.M.(Institute of Mechanics,Moscow university,USSR) Visiting scholar(1988—1989)at south china university of technology Institute of Mechanics Moscow University USSR

In this paper the method of damage measurement of metal structure at the creep is *** contrast to other methods,it allows the measurement of this damage to be carried out in the process of creep test without unloading and cooling of *** damage curves during creep are obtained as a result of test data processing by the suggested *** analysis of these curves leads to a conclusion that the material damage at repture is monotonically decreasing function of the applied *** conclusion is an experimental verification of the theoretical result,obtained earlier.

关键词： creep creep rupture structure damage electrical resistance metals copper kinetic equation

Exceptional groups of Lie type and flag-transitive triplanes

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Science china Mathematics 2010年第10期53卷 447-456页

作者： ZHOU ShengLin & DONG HuiLi Department of Mathematics, south china university of technology, Guangzhou 510640, china Department of Mathematics South China University of Technology Guangzhou China

A triplane is a ( v, k, 3)-symmetric design. Let G be a subgroup of the full automorphism group of a triplane D. In this paper we prove that if G is flag-transitive and point-primitive, then the socle of G cannot be a... 详细信息

关键词： symmetric design triplane flag-transitive point-primitive exceptional groups of Lie type

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