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CARBIDE FORMATION IN AUSTEMPERED DUCTILE IRON ALLOYED WITH NICKEL AND COPPER

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Acta Metallurgica Sinica(English Letters) 1995年第3期8卷 190-194页

作者： FA N Zhikang (xi’an university of technology, China)SMALLMANRE(university of Birmingham,UK) xi'an Univ of Technology Xi'an China

Carbide formation in austempered ductile iron (ADI) alloyed with Ni and Cu has been studied by use of TEM. The results show that η carbide precipitates in the bainitic ferrite when austempered at 350℃.for 6h, but no carbide was found at the austenite/.ferrite interfaces. When austempered at 300℃, two kinds of. s carbides appear in the bainitic ferrite when austempering time reached I h, and X carbide also precipitates at the austenite /ferrite interfaces when austempering time was extended up to 6h. The bainitic. ferrite and the retained austenite follow the Nishiyama- Wasserman relationship,

关键词： carbide austempered ductile iron

Fuzzy Evaluation of Thermal Comfort in Naturally Ventilated Residential Buildings in China

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湖南大学学报（自然科学版） 2009年第S1期36卷 71-74页

作者： WANG Yi1,NIU Tian-cai1,LIU Jia-ping2,xiAO Yong-qiang2,3(1.School of Environmental and Municipal Engineering,xi’an university of Architecture and technology,xi’an,Shaanxi 710055,China 2.School of Architecture,xi’an university of Architecture and technology,xi’an,Shaanxi 710055,China 3.School of Physical Education,xi’an university of Architecture and technology,xi’an,Shaanxi 710055,China) School of Environmental and Municipal Engineering Xi'an University of Architecture and Technology Xi'an 710055 China School of Architecture Xi'an University of Architecture and Technology Xi'an 710055 China School of Physical Education Xi'an University of Architecture and Technology Xi'an 710055 China

In order to assess the differences between the human body thermal sensation in naturally ventilated space and that in air-conditioned space,the fuzzy evaluation model was adopted in the research of thermal sensation in naturally ventilated *** on the questionnaires and field measurements,the membership functions were presented by the statistic of the covering frequency to the fuzzy ***-bulb temperature was taken as the only independent variable for membership *** maximum values of membership grades are all at 0.5 or so,which is a distinction character on thermal comfort of naturally ventilated *** the calculating results of membership grades value to different fuzzy evaluation subsets,the Predicted Mean Vote(PMV)was ***,energy coefficient(Ea)was introduced to calculate the energy consumption,and the prediction methods of residential building energy consumption were also ***,the importance of evaluation model of thermal sense is shown through the energy consumption prediction in a specific residential building.

关键词： natural ventilated space thermal sensation fuzzy evaluation membership functions

Induced phase transition of BECs in optical lattices by impurity

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Science China(Physics,Mechanics & Astronomy) 2010年第3期53卷 469-473页

作者： TIAN DongPing1,2 & LIU XuanZuo1 1Institute of Condensed Matter Physics, School of Science, xi’an Jiaotong university, xi’an 710049, China 2xi’an university of Architecture and technology, xi’an 710055, China 1. Institute of Condensed Matter Physics School of Science Xi’an Jiaotong University Xi’an 710049 China2. Xi’an University of Architecture and Technology Xi’an 710055 China

In this work, the influence of imparity on BECs in optical lattices is investigated, and the possibility of MI-SF transition induced by impurity is verified. After the numerical calculation, the schematic phase diagram is discussed with an emphasis on the role of impurity. When n10 = n20, the phase boundaries coincide with each other; when n10 0, the phase boundaries may or may not intersect, depending on the values of U12, n10 and n20.

关键词： BECs Green function MI-SF transition

Procedure Design to Fulfill Quality Management System

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厦门大学学报（自然科学版） 2002年第S1期41卷 277-278页

作者： LIU Shu-qing (xi’an university of technology, xi’an 710048, China)

With the application of the principle of PDCA, and dr awing on the experience of the process methods of the ISO9000 and the system met hods of management, the author analyses the basic requirement to fulfill quality management system in enterprises. Then the author inquires into the procedure t o establish the efficiency quality management system. Finally four stages (plan, do, check, action) and eight steps (decision, plan, analyze, design, do, check, improve, fulfill) are put forward to fulfill quality management system.

关键词： quality management system process methods fulfi ll procedure improve instantly

Interfacial forces between silica surfaces measured by atomic force microscopy

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Journal of Environmental Sciences 2009年第1期21卷 30-34页

作者： DUAN JinmingKey Laboratory of Northwest Water Resource,Environment and Ecology,MOE,xi’an university of Architecture and technology,xi’an 710055,China Key Laboratory of Northwest Water Resource Environment and Ecology MOE Xi'an University of Architecture and Technology Xi'an 710055 China

Colloidal particle stability and some other interfacial phenomena are governed by interfacial force interactions. The two well known forces are van der Waals force and electrostatic force, as documented by the classical Derjaguin, Landau, Verwey, and Overbeek （DLVO） theory. Moreover, advances in modern instrumentation and colloid science suggested that some short-ranged forces or structure forces are important for relevant colloidal systems. The interfacial and/or molecular forces can be measured as a resultant force as function of separation distance by atomic force microscopy （AFM） colloid probe. This article presents a discussion on AFM colloid probe measurement of silica particle and silica wafer surfaces in solutions with some technical notifications in measurement and data convolution mechanisms. The measured forces are then analyzed and discussed based on the ＇constant charge＇ and ＇constant potential＇ models of DLVO theory. The difference between the prediction of DLVO theory and the measured results indicates that there is a strong short-range structure force between the two hydrophilic surfaces, even at extremely low ionic concentration, such as Milli-Q water purity solution.

关键词： colloid probe DLVO theory solvation forces interfacial interactions

Electrical breakdown characteristic of a Ce-doped W-Cu contact material

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Rare Metals 2010年第3期29卷 261-264页

作者： HU Kewen,CHEN Mianzhi,and YE Heng School of Materials Science and Engineering,xi’an university of technology,xi’an 710048,China School of Materials Science and Engineering Xi’an University of Technology Xi’an China

W-Cu composite powder doped with Ce （1.5 wt.%） was prepared by mechanical alloying （MA）,and the W-Cu contact material was fabricated by hot pressing sintering in an electrical vacuum *** microstructure,electric conductivity,hardness,and breakdown voltage of the Ce-doped W-Cu alloy were measured and compared with a conventional W-Cu alloy prepared by powder *** results show that microstructural refinement and uniformity can improve the breakdown behavior and the electric arc stability of the Ce-doped W-Cu contact ***,the Ce-doped W-Cu contact material shows the characteristic of spreading electric arc,which is beneficial to electric arc erosion.

关键词： doping rare earth W-Cu alloy electrical breakdown

STRUCTURAL EVOLUTION OF UNDERCOOLED SINGLE-PHASE Ni-2wt%Pb MONOTECTIC ALLOY

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Acta Metallurgica Sinica(English Letters) 2001年第1期14卷 72-78页

作者： H.X. Zheng, H. xie and X.F. Guo (xi’an university of technology, xi’an 710048, China) xi’an university of technology

The structural evolution of undercooled single-phase Ni-2wt%Pb monotectic alloy was systematically investigated by the method of molten glass denucleating combined with superheating cycle. Within the achieved undercooling range of 22 to 280 K, the solidification structure undergoes three changes at 22 K, 88 K and 187 K, respectively. With the increase of undercooling, common dendrites, the first class granular grains, undercooled dendrites and the second class granular grains come out one after the other. Analytical results show that the granulation mechanism of the first class granular grains is owing to dendrite remelting and recrystallization, and the granulation mechanism of the second is owing to dendrite break-up and recrystallization.

关键词： Granulation Lead alloys Microstructure Structure (composition)

Thermal stability of nanocrystalline W-Ti diffusion barrier thin films

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Science China(Technological Sciences) 2010年第4期53卷 1049-1055页

作者： WANG Qingxiang,FAN ZhiKang & LIANG ShuHua School of Materials Science and Engineering,xi’an university of technology,xi’an 710048,China 1. School of Materials Science and Engineering Xi’an University of Technology Xi’an 710048 China

Nanocrystalline W-Ti diffusion barrier thin films with different phase structures and Cu/barrier/Si multilayer structures were deposited on p-type Si(100) substrates by DC magnetron *** films were annealed at different temperatures for 1 *** diffusion barrier properties and thermal stability were studied using four-probe tester(FPP),XRD,AFM,XPS,FESEM,and *** experimental results showed that the films were stable up to 700℃.When the annealing temperature was increased,the Cu and Ti atoms began to react and CuTi3 was *** addition,the high resistance Cu3Si was formed due to inter-diffusion between the Si and Cu atoms which made the surface rougher and caused the sheet resistance to increase *** the same time,failure mechanism of the nanocrystalline W-Ti diffusion barrier thin films during annealing process was also discussed.

关键词： nanocrystalline W-Ti thin films diffusion barrier anneal sheet resistance

TWO-GRID METHOD FOR CHARACTERISTICS FINITE-ELEMENT SOLUTION OF 2D NONLINEAR CONVECTION-DOMINATED DIFFUSION PROBLEM

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Applied Mathematics and Mechanics(English Edition) 2005年第11期26卷 1506-1514页

作者：秦新强School of Sciences xi’an Jiaotong university xi’an 710049 P.R.China School of Sciences xi’an university of technology xi’an 710048 P.R.China) 马逸尘章胤 School of Sciences Xi’an Jiaotong UniversityXi’an 710049 P.R.China School of Sciences Xi’an University of TechnologyXi’an 710048 P.R.China

For two-dimension nonlinear convection diffusion equation, a two-grid method of characteristics finite-element solution was constructed. In this method the nonlinear iterations is only to execute on the coarse grid and the fine-grid solution can be obtained in a single linear step. For the nonlinear convection-dominated diffusion equation, this method can not only stabilize the numerical oscillation but also accelerate the convergence and improve the computational efficiency. The error analysis demonstrates if the mesh sizes between coarse-grid and fine-grid satisfy the certain relationship, the two-grid solution and the characteristics finite-element solution have the same order of accuracy. The numerical is more efficient than that of characteristics example confirms that the two-grid method finite-element method.

关键词： convection-diffusion equation characteristics finite-element two-grid method convergence