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Analysis on Microstructure and Misorientation of Ultrathin Hot Strip of Low Carbon Steel Produced by Compact Strip Production

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Journal of Materials science & technology 2002年第6期18卷 501-503页

作者： Hao YU, Yonglin KANG and Jie FUSchool of Materials science and Engineering, university of science and technology Beijing, Beijing 100083, China Sch. of Mat. Sci. and Eng. Univ. of Sci. and Technol. Beijing Beijing 100083 China

The microstructure and misorientation of ultrathin hot strip were analyzed by CSP technology using electron back scattered diffraction (EBSD) method and Autoforge finite element program. The experimental results showed that the finishing hot rolling microstructures were the mixture of recrystallized and deformed austenite. After phase transformation, ferrite grains embody substructures and dislocations, leading to the high strength and relatively low elongation rate of the ultrathin hot strip. The FEM simulation of strain mode and distribution in deformation area has been fulfilled. The simulation results are in good agreement with the theoretical analysis and experimental results.

关键词： CSP Electron back scattered diffraction, Texture, Finite element method

CABOSFV algorithm for high dimensional sparse data clustering

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Journal of university of science and technology Beijing 2004年第3期11卷 283-288页

作者： Sen Wu Xuedong Gao Management School, university of science and technology Beijing, Beijing 100083, China Mgmt. Sch. Univ. of Sci. and Technol. Beijing Beijing 100083 China

An algorithm, Clustering Algorithm Based On Sparse Feature Vector (CABOSFV),was proposed for the high dimensional clustering of binary sparse data. This algorithm compressesthe data effectively by using a tool 'Sparse Feature Vector', thus reduces the data scaleenormously, and can get the clustering result with only one data scan. Both theoretical analysis andempirical tests showed that CABOSFV is of low computational complexity. The algorithm findsclusters in high dimensional large datasets efficiently and handles noise effectively.

关键词： clustering data mining sparse high dimensionality

One-Dimensional Fractal Curves and Fractal Dimension Determination

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International Journal of Minerals,Metallurgy and Materials 1998年第3期12卷 165-168页

作者： Qikai Li Yue Zhang Wuyang Chu(Applied science School, university of science and technology Beijing, Beijing 100083, China) Applied science School University of Science and Technology Beijing Beijing 100083 China

Various methods for evaluating the fractal curves were reviewed and simulated on computer. It is shown box-counting and power spectrum methods generally give poor measuring results, while yard and variation methods could obtain good results. However,owing to multiple influencing factors, further study needs to be done before widespread application of variation method. In order to improve the measuring accuracy of yard method, a new method has been propoed to measure the fractal dimension by changing the instrumental resolutions.

关键词： fractal fractal dimension computer simulation

SOME FRACTAL STRUCTURES IN RAPIDLY SOLIDIFIED Al-Mn ALLOY

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Acta Metallurgica Sinica(English Letters) 1992年第3期5卷 203-205页

作者： FAN Chuanguang ZHANG Meng Jiangxi university Structure Research Laboratory,university of science and technology of China,Academia Sinica Hefei,ChinaWANG Yuansheng WU Ziqin university of science and technology of China,Hefei,China Jiangxi Univ China

The fractal structures formed in rapidly quenched Al_(86)Mn_(14)alloy have been observed on *** fractal dimensions are from 1.46 to *** principal phase examined by TEM and X-ray diffractometer is icosahedral quasicrystalline one with a small amount of Al phase. It is believed that these fractal structures are formed by many aggregated particles during the rapid-quenching process.

关键词： Al-Mn alloy rapid solidification fractal structure fractal dimension

Numerical Modeling of NO Formation during Packed-bed Combustion of Coke Granules

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International Journal of Minerals,Metallurgy and Materials 2000年第4期14卷 261-268页

作者： Chunbao Xu, Shengli Wu, Daqiang Cang (Metallurgy School, university of science and technology Beijing, Beijing 100083, China Institute for Chemical Reaction science, Tohoku university, Japan) Metallurgy School University of Science and Technology Beijing Beijing 100083 China Institute for Chemical Reaction science Tohoku University Japan

A comprehensive kinetic model of NO formation during coke combustion in packed-bed in presence of noncombustible particles was developed. The detailed homogeneous gas-phase chemistry (including 102 chemical reactions), heterogeneous gas-solid chemistry (including 11 reactions) of coke combustion and NO formation, and the heat and mass transfer were taken into account in the present model. The governing equations which are strongly coupled, non-linear and unsteady with 26 unknowns in total, were dispersed into differential equations with the finite differential method. Meanwhile, all the differential equations were numerically solved to give the time-histories and space-distributions oftemperatures of the bed and gas phase as well as the concentrations of all the gaseous species. By comparison, the experimental data were explained well by the calculated results. Based on the kinetic and mathematical model, the effects of O2 content of inlet gas, the initial chemical analysis of coke, bed-temperature and local reductive atmosphere (CO/O2) on NO formation during packed-bed coke combustion were numerically discussed. It was found that coke samples with a higher initial content of [N] and volatile matters, combusted under a suitable O2-containing atmosphere produced less NO emission. The reactions between CO and NO, catalyzed by high temperature surface of coke particles may be responsible for efficient reduction of NO.

关键词： kinetic model NO formation combustion packed-bed coke Metallurgy

Relation between Starlight and Nebular Emission Lines of Star-Forming Galaxies

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Research in Astronomy and Astrophysics 2005年第3期5卷 221-228页

作者： Hong-Lin Lu, Hong-Yan Zhou, Ting-Gui Wang, Zhen-Quan Zhuang, Xiao-Bo Dong, Jun-Xian Wang and Cheng Li Department for Electronics of science & technology, university of science and technology of China, Hefei 230026 Center for Astrophysics, university of science and technology of China, Hefei 230026 Department for Electronics of science & technology University of Science and Technology of China Hefei 230026 Center for Astrophysics University of Science and Technology of China Hefei 230026

We present an exercise that intends to establish a relationship between the strength of nebular emission lines and optical stellar features in the spectrum of a galaxy. After accurately subtracting the stellar continuum and the underlying stellar absorption, we made reliable measurements of the emission lines of all the galaxies in the Sloan Digital Sky Survey Data Release 2 (SDSS DR2). More than 4000 star-forming galaxies with high S/N ratio of both the stellar spectrum and the emission lines are selected. These galaxy spectra are fitted with the 10 PCs of Yip et al., after all the emission line regions have been filtered out. We find that the flux of hydrogen Balmer emission lines, Ha and Hβcan be well recovered from the PCs, while the metal lines are not well reproduced. The fluxes of Ha and Hβmeasured from the PC-reconstructed spectra and from the observed spectra agree well with an rms scatter of only - 0.1 dex. This result suggests that, with moderate spectral resolution and S/N ratio, the optica

关键词： galaxies: fundamental parameters - galaxies: starburst - radiation: lines continuum

Performance Modeling and Approximate Analysis of Multiserver Multiqueue Systems with Poisson and Self-similar Arrivals

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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, Beijing 100083, China) (Department of Computer science and technology, Tsinghua university, Beijing 100084, China) Information Engineering School University of Science and Technology Beijing 100083 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

PROFILE TOLERANCE EVALUATION OF PARAMETRIC CURVES AND SURFACES

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Chinese Journal of Mechanical Engineering 2002年第2期15卷 121-125页

作者： Huang Xiaoping Xiong YoulunSchool of Mechanical science and Engineering, Huazhong university of science and technology,Wuhan 430074, China School of Mechanical science and Engineering Huazhong University of Science and Technology Wuhan 430074

The profile error evaluation of complex curves and surfaces expressed inparametric form is considered. The linear error model is established on the base of two hypothesesfirstly. Then the profile error evaluation is converted into one of these optimal formulations:MINIMAX, MAXMIN and MINIDEX problems, which are easier to be solved than the initial form. To eachone of them, geometric condition and algebraic condition are presented to arbitrate whether theideal element reaches to the optimal position. Exchange algorithm is proven highly effective insearching for solutions to these optimization problems. At last some key problems in tolerance offreeform surfaces and curves in B spline method are discussed.

关键词： Parametric form Profile tolerance Linear error model Exchangealgorithm

Spiral waves in CIMA model and its LBGK simulation

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Communications in Nonlinear science and Numerical Simulation 2001年第2期6卷 68-73页

作者： Qing LI, Chuguang ZHENG and Nengchao WANG College of Computer science and technology, Huazhong university of science and technology, Wuhan 430074, China e-mail: qingli @ public. *** State Key Laboratory of Coal Combustion, Huazhong university College of Computer science and technology Huazhong University of Science and Technology Wuhan 430074 China State Key Laboratory of Coal Combustion Huazhong University of Science and Technology Wuhan 430074 China Parallel Computation Institute Huazhong University of Science and Technology Wuhan 430074 China

Two type of structures-Turing patterns and spiral waves-are obtained in chloride-iodide-malonic acid (CIMA) reaction-diffusion model by using lattice Bhatnagar-Gross-Krook (LBGK) method.

关键词： lattice Boltzmann method reaction-diffusion Turing patterns spiral waves