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XIDM: A Common Data Model Based on XML

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wuhan university Journal of Natural {2.s 2001年第Z1期6卷 432-437页

作者： Li Bing 1, Lu Zheng ding 1, Peng De chun 2.1.College of Computer science & technology,{2. university of science & technology,wuhan 430074, china 2.state key laboratory of Software Engineering, wuhan university,wuhan 430072. china College of Computer science & technology Huazhong University of Science & Technology Wuhan China state key {2. of Software Engineering Wuhan University Wuhan China

Integration between file systems and multidatabase systems is a necessary approach to support data sharing from distributed and heterogeneous data sources. We first analyses problems about data integration between file systems and multidatabase systems. Then, A common data model named XIDM(XML\|based Integrating Dada Model), which is XML oriented, is presented. XIDM bases on a series of XML standards, especially XML Schema, and can well describe semistructured data. So XIDM is powerfully practicable and multipurpose.

关键词： file systems multidatabase systems data integration XML

A heuristic algorithm for cube packing with time schedule

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science china(Information sciences) 2010年第1期53卷 18-29页

作者： LI Wei1, HUANG WenQi2. JIANG DongChen1 & LIU XiangLong1 1state key {2. of Software Development Environment, Beihang university, Beijing 100191, china 2.chool of Computer science and technology, huazhong university of science and technology, wuhan 430074, china 1. state key {2. of Software Development Environment Beihang University Beijing 100191 China2. School of Computer Science and Technology Huazhong University of Science and Technology Wuhan 430074 China

Packing problem has been proved to be an NP-hard problem. Many algorithms such as simulation annealing algorithm, genetic algorithm and other heuristic algorithms have been proposed to solve twodimensional and three-dimensional packing problem. To solve the cube packing problem with time schedule, this paper first introduces some concepts such as packing level, space distance and average neighbor birth order and then proposes a greedy algorithm. The algorithm tries every feasible corner greedily to calculate the space utilization, packing level, space distance, average neighbor birth order of this placement, and chooses the best placement according to these criteria. Theoretical analysis indicates that the time complexity of this algorithm is O(A2.2.2. 2.5). The experiments show that the average space utilization of non-guillotine cutting test cases is 98.81%, and the average space utilization of guillotine cutting test cases achieves 99.87%. Furthermore, optimal solutions of more than half cases are achieved by this algorithm. The experimental results show that this algorithm can solve the problem of cube packing with time schedule effectively and effciently.

关键词： cube packing problem time schedule packing level space distance average neighbor birth order

Fabrication and Microstructure Evolution of Niobium-Niobium Silicide Composites by Spark Plasma Sintering

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Journal of wuhan university of {2.(Materials science) 2007年第2期22卷 299-302页

作者：陈哲严有为 state key Lab of Die & Mould {2. Huazhong University of Science & Technology

By using Nb and Si elemental powders as raw materials, dense Nb/NbsSi3 composites were successfully fabricated by a spark plasma sintering （SPS） technology. The microstructure of the fabricated composites was analyzed by OM, SEM, XRD and EPMA; the microstructure evolution of the composites was also investigated by a quenching test. The experimental results show that the prepared composites consist of Nb and Nb5Si3 phases; Nb particle uniformly distributes in the in-situ synthesized Nb5Si3 matrix. During the SPS process, an interfacial reaction occurs between Nb and Si particles to synthesize Nb5Si3 until reactant silicon has been completely depleted.

关键词： spark plasma sintering Nb/Nb5Si3 composites fabrication microstructure evolution

Modelling of the relationship between trace elements and three species of sulfur in coal

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Journal of Environmental sciences 1998年第2期10卷 89-95页

作者： Lu Xiao hua, Zeng Han cai National key laboratory of {2. combustion, huazhong university of science and technology, wuhan 430074, china Wei Lu xian Center of Microanalysis, wuhan university of Automobile Industry, wuhan, china

Based on the determination of several trace elements in coal particulate of different specific gravity, three variables regression equations relate the contents of trace elements Be, Cd, Co, Pb, Cu, Ni, As and three species of sulfur in coal were well established. For elements Cd, Co, Pb, Cu and Ni, the regression equations were successfully used for prediction of these trace elements in individual part of coal with different specific gravity. Factor analysis was also used to analyze the data sets. The results showed that a three factor model can interpret the data sets reasonably. Trace elements Cd, Co, Pb, Cu, Ni, inorganic sulfide and total sulfur in coal are high correlated with the first factor. Trace elements Be, sulfate and organic sulfide are high correlated with the second factor and trace elements Cr and As are high correlated with the third factor. The factors can be interpreted by the chemical properties of these elements.

关键词： trace elements coal regression analysis factor analysis.

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机械驱动下Ta-N_2.化反应的研究

物理学报 2002年第3期51卷 603-608页

作者：柳林华中科技大学材料科学与工程学院模具技术国家重点实验室武汉430074

借助X射线衍射和透射电子显微镜研究了在机械驱动下难熔金属Ta与N2.的氮化反应 .实验发现 ,在室温下的高能球磨可实现Ta N2.反应 ,并形成三种不同结构的氮化物 :六方结构的Ta2.N ,四方结构的Ta3 N5和非晶相 .研究表明 ,N2.在清洁的金属... 详细信息

借助X射线衍射和透射电子显微镜研究了在机械驱动下难熔金属Ta与N2.的氮化反应 .实验发现 ,在室温下的高能球磨可实现Ta N2.反应 ,并形成三种不同结构的氮化物 :六方结构的Ta2.N ,四方结构的Ta3 N5和非晶相 .研究表明 ,N2.在清洁的金属表面上发生可离解式的化学吸附是Ta N2.反应的基本过程 ,高的Ta—N键合能是N2.分子在Ta表面上发生化学吸附的热力学驱动力 ,而球磨在金属粉末中引入的储能 (界面能和缺陷能 )为Ta—N向金属氮化物转变提供了激活能 .球磨后期非晶相的形成则源于Fe的侵入 ,所形成的非晶相含有Ta Fe N三种元素 .

关键词：机械驱动 Ta/N2.化反应热力学动力学钽氮气高能球磨固态-气态反应微观机制

In-situ TEM Study on Microstructural Evolution of Nanostructured TiO_2

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Journal of wuhan university of {2.(Materials science) 2007年第2期22卷 209-213页

作者：邵艳群唐电 state key {2. of Die&Mould technology Huazhong University of Science and Technology Institute for Materials Research Fuzhou University

The effect of electron beam on the microstructures and phase transformation of nanostructured TiO2.heat treated at various temperatures for different time was studied by in-situ TEM and SAED. Anatase ex-situ heated at 2.0℃ and 360℃ transformed to rutile while irradiated by the electron beam. With the increasing sizes and distribution of the powders on the amorphous carbon, the process of phase transformation by the electron beam was encumbered. These evolutions may be due to the changes of vacuum atmosphere and the properties of powders.

关键词： electron beam sol-gel technique TiO2 phase transformation microstructure

Occurrence and migration of hazardous trace elements in coals from Guizhou Province, china

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Acta Geochimica 2006年第S1期 176-177页

作者： Dangyu SONG, Junying ZHANG, Chuguang ZHENG state key {2. of coal combustion, huazhong university of science and technology, wuhan 430074, china

Effects of molybdenum on the microstructure and mechanical properties of Ti(C,N)-based cermets with low Ni

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Rare Metals 2006年第1期25卷 90-95页

作者： WANG Saiyu XIONG Weihao YAN Mingshuang FAN Chou The Stale key laboratory for Die ＆ Mould {2. Huazhong University of Science and Technology Wuhan 430074 China Huangshi Institute of technology Huangshi 435003 China

The effects of Mo on the microstructure and mechanical properties of Ti（C,N）-based cermets with low Ni have been studied systematically. Different contents of Mo （4-12.wt.%） were added into Tl（C,N）-based cermets. Specimens were fabricated by conventional powder metallurgy and vacuum sintered at temperatures of 1440, 1450, and 1460℃ individually. The microstructure and fracture morphology were investigated by scanning electron microscope, and the mechanical properties such as transverse strength and hardness were measured. The results show that the microstructure is uniform and the thickness of rim phase is moderate when the content of Mo is 8 wt.%; the mechanical properties of the specimens sintered at 1450℃ are better than those sintered at 1440 and 1460℃. The integrated properties of transverse strength and hardness are the best when the content of Mo is 8 wt.% and the sintering temperature is 1450℃.

关键词： Ti(C,N)-based cermets microstructttre mechanical properties Mo content

Spectral anomalies and spectral switches of partially coherent and polychromatic light diffracted at an aperture

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science china(Physics,Mechanics & Astronomy) 2004年第1期47卷 24-35页

作者： Lü Baida1, 3 & PAN Liuzhan1, 2.1. Institute of Laser Physics and Chemistry, Sichuan university, Chengdu 610064, china 2. Department of Physics, Luoyang Normal College, Luoyang 47102., china 3. state key laboratory of Laser technology, huazhong university of science and technology, wuhan 430074, china Correspondence should be addressed to L Baida (email: badalu@***) Received July 10, 2.03 1. Institute of Laser Physics and Chemistry Sichuan University 610064 Chengdu China 2. state key {2. of Laser technology Huazhong University of Science and Technology 430074 Wuhan China 3. Department of Physics Luoyang Normal College 471022 Luoyang China

Based on the propagation theory of partially coherent light in the space-frequency domain, the anomalous spectral behavior and spectral switches in the far field of partially coherent and polychromatic light diffracted at an aperture are studied. It is shown that, as compared with spatially fully coherent and polychromatic light whose spectral anomalies are induced only by aperture diffraction, the spectral anomalies and spectral switches of partially coherent and polychromatic light depend on the aperture diffraction, spatial correlationβ and bandwidth of the original spectrum. Detailed numerical calculations are made to illustrate the behavior of spectral switches of partially coherent and polychromatic light, and the results for spatially fully coherent and polychromatic light are treated as a special case ofβ=1 and included in our theory.

关键词： spectral anomaly spectral switch partially coherent and polychromatic light far field aperture diffraction