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Journal of university of science and technology beijing 2001年第2期8卷 145-151页

作者： Zhiguang Shan, Chuang Lin, Yang Yang, Yan Wang (Information engineering School, university of science and technology beijing,{2.) (Department of Computer science and technology, Tsinghua university, beijing 100084, china) Univ Sci & Technol beijing Informat Engn Sch Beijing 100083 Peoples R China Tsinghua Univ Dept Comp Sci & Technol Beijing 100084 Peoples R China

The problem of state space explosion is still ran outstanding challenge in Markovian performance analysis for multiserver multiqueue (MSMQ) systems. The system behavior of a MSMQ system is described using stochastic high-level Petri net (SHLPN) models, and an approximate performance analysis technique is proposed based on decomposition and refinement methods as well as iteration technique. A real MSMQ system, Web-server cluster, is investigated. The performance of an integrated scheme of request dispatching and scheduling is analyzed with both Poisson and self-similar request arrivals. The study shows that the approximate analysis technique significantly reduces the complexity of the model solution and is also efficient for accuracy of numerical results.

关键词： multiserver multiqueue (MSMQ) system Web-server cluster performance analysis stochastic high-level Petri net (SHLPN) request dispatching request scheduling

Effect of Tempering Temperature on Microstructure and Properties of E690 Offshore Plate Steel

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Journal of Iron and Steel research International 2012年第3期19卷 67-72页

作者： ZHANG Jie, CAI Qing-wu, WU Hui-bin, ZHANG Kun, WU Bo (research institute of Metallurgy {2., university of science and technology beijing, beijing 100083. china) research institute of Metallurgy {2. University of Science and Technology Beijing Beijing 100083 China

A new kind of Mn Mo Nb Cu B bainite steel which satisfied mechanical demands of E690 offshore plate steel was designed. The effect of two processes thermomechanical control process （TMCP）＋ tempering （T） and thermomechanical control process （TMCP）＋ reheating and quenching （RQ）＋ tempering （T） on microstructure and mechanical properties were studied by means of scan electron microscope （SEM）, transmission electron micro- scope （TEM） and electron back scatter diffraction （EBSD）. The results showed that optimal mechanical properties were available when tempering at 550 ℃ for both processes. The microstructure of the TMCP＋T treated sample tempering in the range of 450 to 550 ℃ for 1 h did not change dramatically yet the lath in the TMCP＋RQ＋T trea- ted sample merged together and transformed into polygonal ferrite. At the same time, the sub-structure of grain bainite transformed from lath to cell shape to refine grains with tempering temperature mounting. Lots of sub-grain boundaries were located within bainite and adjacent bainite grain boundaries were high angle.

关键词： offshore plate low carbon bainitic steel tempering toughness EBSD

A chaos genetic algorithm for optimizing an artificial neural network of predicting silicon content in hot metal

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Journal of university of science and technology beijing 2003年第2期10卷 68-71页

作者： Deling Zheng, Ruixin Liang, Ying Zhou, and Ying WangInformation engineering School, university of science and technology beijing,{2. Information engineering School University of Science and Technology Beijing Beijing 100083 China

A genetic algorithm based on the nested intervals chaos search (NICGA) hasbeen given. Because the nested intervals chaos search is introduced into the NICGA to initialize thepopulation and to lead the evolution of the population, the NICGA has the advantages of decreasingthe population size, enhancing the local search ability, and improving the computational efficiencyand optimization precision. In a multi4ayer feed forward neural network model for predicting thesilicon content in hot metal, the NICGA was used to optimize the connection weights and thresholdvalues of the neural network to improve the prediction precision. The application results show thatthe precision of predicting the silicon content has been increased.

关键词： blast furnace optimization chaos genetic algorithm neural network silicon content prediction

Nanostructured Sulfide Composite Coating Prepared by Atmospheric Plasma Spraying

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材料工程 2006年第Z1期34卷 281-284页

作者： GUAN Yao-hui~1,XU Yang~1,ZHENG Zhong-yu~2.TONG Xiao-hui~2.1 engineering College of china Agricultural {2.,beijing 100083.china 2.beijing research institute of Mechanical & Electrical technology,beijing 100083.china) engineering College China Agricultural University Beijing 100083 China beijing research {2. of Mechanical and Electrical technology Beijing 100083 China

Nanostructured FeS-SiC coating was deposited by atmospheric plasma spraying（APS）.The microstructure and phase composition of the coating were characterized with SEM and XRD,*** addition,the size distribution of the reconstituted powders and the porosity of the coating have been *** was found that the reconstitiuted powers with sizes in the range of 2. to 80 μm had excellent flowability and were suitable for plasma spraying *** as-sprayed FeS-SiC composite coating exhibited a bimodal distribution with small grains（30～80nm） and large grains（100～2.0nm）.The coating was mainly composed of FeS and SiC,a small quantity of Fe1-xS and oxide were also *** porosity of the coating was approximately 19%.

关键词： plasma spraying nanostructured FeS-SiC composite coating

Generalized Self-Adaptive Genetic Algorithms

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International Journal of Minerals,Metallurgy and Materials 2000年第1期14卷 72-75页

作者： Bin Wu Xuyan Tu Jian Wu Information engineering School, university of science and technology beijing,{2. Department of Information and Control engineering, Southwest institute of technology, Mianyang 62.002. china Information engineering School University of Science and Technology Beijing Beijing 100083 China Department of Information and Control engineering Southwest Institute of Technology Mianyang 621002 China

In order to solve the problem between searching performance and convergence of genetic algorithms, a fast genetic algorithm generalized self-adaptive genetic algorithm (GSAGA) is presented. (1) Evenly distributed initial population is generated. (2. Superior individuals are not broken because of crossover and mutation operation for they are sent to subgeneration directly. (3) High quality im- migrants are introduced according to the condition of the population schema. (4) Crossover and mutation are operated on self-adaptation. Therefore, GSAGA solves the coordination problem between convergence and searching performance. In GSAGA, the searching per- formance and global convergence are greatly improved compared with many existing genetic algorithms. Through simulation, the val- idity of this modified genetic algorithm is proved.

关键词： generalized self-adaptive genetic algorithm initial population immigration fitness function

Comparison of Ferrite Refinement Mechanisms by Different Processing Schedules in 08 and 2.Mn Steels

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Journal of university of science and technology beijing 2001年第3期8卷 218-223页

作者： Ping Yang Feng’e Gui, Shicai Ma Material science and engineering School,{2., beijing 100083. china Univ Sci & Technol beijing Sch Mat Sci & Engn Beijing 100083 Peoples R China

The influence of deforming temperature on ferrite refinement was analyzed by comparing the microstructures obtained by deformation at above A(r3), in two-phase region of (alpha + gamma) and at below A(t) in clean 08 and 2.Mn steels. The results indicate that ferrite refinement through strain induced transformation by deformation at above A(r3) is more effective than that by deformation simply through ferrite dynamic recrystallization. The main problem of ferrite refinement by deformation at below A(r3) is the inhomogeneity of microstructure which is controlled by the orientations and sizes of ferrite grains and the distribution of second phases. Ferrite dynamic recrystallization after strain induced transformation can further effectively refine ferrite.

关键词： clean carbon steel strain induced transformation grain refinement ferrite dynamic recrystallization

Sticking-up Behaviors and Surface Friction of IF Electrogalvanized Sheet Steel in Forming

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International Journal of Minerals,Metallurgy and Materials 1999年第1期13卷 61-63,68页

作者： Jiming Hu Jixun Wu Yanping Lu Yanrong Zhu (Material science and engineering School,{2., beijing 100083. china) Univ of science and technology Beijing Beijing China

X-ray diffraction (XRD), ball-disc friction and wearing machine and draw-bead test were introduced to investigat the strcusture and workability of IF sheet steel electrogalvanized deposits prepared from sulphate solution system. It was shown that the picking-up of the zinc coating on die strengthened with the increasing of friction factor which was originally affected by the coating's structure. Duing forming, (00X) planes (X= 2. 4) preferential orientation of zinc deposits increased, which resulted in enhanc ing the coating's friction behaviors. Therefore, the forming mechanism of electrogalvedzed deposit was demonstrated that both friction and the stricking -up behaviors of the coating are intensified simultaneously and affect each other.

关键词： electrogalvanized deposit forming friction factor

A new method for simulating human emotions

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Journal of university of science and technology beijing 2003年第2期10卷 72-74页

作者： Weimin Xue, Zhiliang Wang, Wenhong Xia, and Wenbo MengInformation engineering School, university of science and technology beijing,{2. Information engineering School University of Science and Technology Beijing Beijing 100083 China

How to make machines express emotions would be instrumental in establishing acompletely new paradigm for man machine interaction. A new method for simulating and assessingartificial psychology has been developed for the research of the emotion robot. The human psychologyactivity is regarded as a Markov process. An emotion space and psychology model is constructedbased on Markov process. The conception of emotion entropy is presented to assess the artificialemotion complexity. The simulating results play up to human psychology activity. This model can alsobe applied to consumer-friendly human-computer interfaces, and interactive video etc.

关键词： emotion robot psychology entropy Markov model artificial psychology

Refinement of packet size in low carbon bainitic steel by special thermo-mechanical control process

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Journal of university of science and technology beijing 2004年第3期11卷 221-224页

作者： Chengjia Shang Xuemin Wang Shanwu Yang Xinlai He Materials science and engineering School,{2., beijing 100083. china Mat. Sci. and Eng. Sch. Univ. of Sci. and Technol. Beijing Beijing 100083 China

The packet size of bainitic steel can be refined by a specialrelaxation-precipitation-control phase transformation (RFC) technology. When processed by RPCprocess, the low carbon bainitic steel composes of two kinds of main intermediate transformationphases. One is ultra-fine lath-like bainitic ferrite and the lath is less than 1μm in width andabout 6 μm in length; the alignment of laths forms a refined packet, and the size of packets isabout 5-7 μm in length and about 3-4μm in width. The other is acicular structure. The morphologyand distribution of these acicular structures are influenced by relaxation process, the thin andshort acicular structures cut the prior austenite grain and refine the bainitic packet size. For theoptimum relaxation time, the packet size can be refined to the finest. The mechanical propertiesare influenced by relaxation time and the 800 MPa grade low carbon bainitic steel with excellenttoughness can be obtained by RPC process.

关键词： packet size refinement bainitic steel RPC process

Strain in solidifying shell of continuous casting slabs

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Journal of university of science and technology beijing 2003年第6期10卷 26-29页

作者： Guosen Zhu, Xinhua Wang, Huixiang Yu, and Wanjun WangMetallurgical engineering School, university of science and technology beijing,{2. Metall. Eng. Sch. Univ. of Sci. and Technol. Beijing Beijing 100083 China

Two-dimension unsteady heat transfer model was applied to obtain the surfacetemperature and the shell thickness of continuous casting slabs during the process ofsolidification. On the basis of which, the mathematical model of strain at the interface of solidand liquid steel was set up. Through which, the strain in the solidifying shell under normal andabnormal operation conditions was gained. The results indicate that the strain is small under thenormal operation conditions and the internal crack never happens. However, when the variation of theroll gap is above 2.mm, the strain caused by which is greater than that caused by ***, the total strain exceeds the critical one and the internal crack is the result. So itis of great importance to maintain the fine state of continuous casting machine to avoid theappearance of internal crack.

关键词： internal crack strain bulging unbending continuous casting slab