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Air-source heat pump coupled with economized vapor injection scroll compressor and ejector:Design and experimental research

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Science China(Technological Sciences) 2010年第3期53卷 782-788页

作者： XU ShuXue&MA GuoYuan beijing university of technology,beijing 100124,China beijing university of technology

Ejector can utilize high pressure energy from liquid mechanism,it can be used in heat pump system coupled with economized vapor injection(EVI)scroll *** running under low temperature conditions,the performance of the EVI system with ejector can be improved *** this paper,the design method of the heat pump system with ejector is presented,and the process for designing the heat pump with ejector(EVIe)was *** prototype heat pump was designed under the condition of the evaporation temperature of -20oC,and an experimental setup was established to test the *** measured results demonstrated that the heating EER(energy efficiency ratio)of the EVIe could reach about 4%higher than that of the system without the ejector when the heating capacity remained nearly *** design method is helpful to development of a heat pump system coupled with scroll compressor and ejector.

关键词： heat pump ejector design scroll compressor

Application of mesoscale modeling optimization to development of advanced materials

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Progress in Natural Science:Materials International 2004年第8期14卷 8-15页

作者： SONG Xiaoyan(School of Materials Science and Engineering, beijing university of technology, beijing 100022, China) School of Materials Science and Engineering Beijing University of Technology Beijing 100022 China

The rapid development of computer modeling in recent years offers opportunities for materials preparation in a more economic and efficient way. In the present paper, a practicable route for research and development of advanced materials by applying the visual and quantitative modeling technique on the mesoscale is introduced. A 3D simulation model is developed to describe the microstructure evolution during the whole process of deformation, recrystallization and grain growth in a material containing particles. In the light of simulation optimization, the long-term stabilized fine grain structures ideal for high-temperature applications are designed and produced. In addition, the feasibility, reliability and prospects of material development based on mesoscale modeling are discussed.

关键词： mesoscale computer simulation Monte Carlo technique deformation recrystallization grain growth.

Tribological Performance of TiB_2-Ni Composite Coating Deposited by APS

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稀有金属材料与工程 2012年第S1期41卷 481-486页

作者： Zhu Hongbin,Li Hui,Li Zhuoxin beijing university of technology,beijing 100124,China beijing Univ Technol Beijing 100124 Peoples R China

TiB2-Ni composite powders were prepared by pressurized hydrogen reduction cladding with different proportion of *** coatings were then prepared by *** microstructures and the phase composition of the powders as well as the deposited coatings were analyzed by scanning electron microscopy(SEM)and X-ray diffraction(XRD).The coatings were tested using a ring-on-disc tribometer from ambient temperature to 300°C.A sprayed Cr3C2-NiCr coating was tested as a *** morphologies of the worn surface of the coatings were observed and *** is found that the TiB2-Ni composite coatings present higher friction coefficient than that of the Cr3C2-NiCr coating at room temperature due to the adhesive wear mechanism,whereas the main wear mechanism of Cr3C2-NiCr coating is rupture and ***,at high temperature,the friction coefficient of the TiB2-Ni composite coating decreases as a result of B2O3 solid lubricant,which alleviates the adhesive wear on ***,the TiB2-Ni composite coating greatly reduces the mass loss of the boron cast iron.

关键词： TiB2-Ni composite coating APS wear behavior

A Probe into China's Near Term Finished Petroleum Products Market

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China Petroleum Processing & Petrochemical technology 2009年第3期11卷 1-4页

作者： Duan Yanting Yin Zhe (beijing university of technology,beijing 100124) beijing university of technology Beijing 100124 China

This article described the changes in consumption of finished petroleum products in China since 2008, referring to the international economic environment that has reversed the consumption of finished oil products, and China＇s domestic economic situation and oil pricing policy and major factors related with changes in industrial sectors. This article, by making projections on future market trends, has estimated that in the foreseeable future the domestic finished oil products market will be glutted with oil products that will exceed the demand.

关键词： market finished petroleum product consumption analysis

Effects of Surface-Active Elements Sulfur on Flow Patterns of Welding Pool

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Journal of Materials Science & technology 2005年第3期21卷 408-414页

作者： Yuzhen ZHAO, Yongping LEI and Yaowu SHI School of Materials Science and Engineering, beijing university of technology, beijing 100022, China School of Materials Science and Engineering Beijing University of Technology Beijing 100022 China

A 3D mathematical model is developed to calculate the temperature and velocity distributions in a moving gas tungsten arc (GTA) welding pool with different sulfur concentrations. It has been shown that, the weld penetration increases sharply with increasing sulfur content. When sulfur content increases beyond 80 × 10-6, the increase in sulfur content does not have an appreciable difference on the welding pool size and shape, and the depth/width remains constant. Sulfur changes the temperature dependence of surface tension coefficient from a negative value to a positive value and causes significant changes on flow patterns. The increase in soluble sulfur content and the decrease at free surface temperature can extend the region of positive surface tension coefficient. As sulfur content exceeds 125×10-6, the sign of surface tension coefficient is positive. Depending upon the sulfur concentrations, three, one or two vortexes that have different positions, strength and directions may be found in the welding pool. The contrary vortexes can efficiently transfer the thermal energy from the arc, creating a deep welding pool. An optimum range of sulfur content is 20-150×10-6.

关键词： Surface-active elements Sulfur Plow patterns Depth/width

A cross-monotonic cost sharing method for the facility location game with service installation costs

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Science China Mathematics 2009年第11期52卷 2530-2536页

作者： XU DaChuan Department of Applied Mathematics,beijing university of technology,beijing 100124,China Department of Applied Mathematics Beijing University of Technology Beijing China

In this paper,we consider the metric uncapacitated facility location game with service installation costs. Our main result is an 11-approximate cross-monotonic cost-sharing method under the assumption that the install... 详细信息

关键词： facility location game cross-monotonic cost-sharing method linear programming relaxation 90C27 91A12

Correlation between Electronic Structures and Formability of Icosahedrai Quasicrystals in Aluminium-transition metal Binary Alloys

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Rare Metals 1989年第2期9卷 24-30页

作者： Cheng Tianyi Zhang Shouhua Department of Materials,beijing university of Iron and Steel technology beijing Univ of Iron and Steel Technology China

The relation between electronic structures and formability of icosahedral quasicrystals in Al-transition metal binary alloys is investigated *** is found that the number of (s+d) electrons in the transition metals and the parameter |Δ1| which is a measure of the relative bonding between Al and the transition metals are closely related to the formability of icosahedral *** rules of thumb are derived from the experimental results for twelve Al-transition metal alloys.

关键词： Correlation systematically bonding crystalline twelve filled absolutely symmetry metallurgy radius

Corrosion Inhibition of a Green Scale Inhibitor Polyepoxysuccinic Acid

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Chinese Chemical Letters 2003年第9期14卷 955-957页

作者： Rong Chun XIONG, Qing ZHOU, Gang WEI beijing university of Chemistry and technology, beijing 100029 beijing university of Chemistry and technology Beijing 100029

The corrosion inhibition of a green scale inhibitor, polyepoxysuccinic acid (PESA) was studied based on dynamic tests. It is found that when PESA is used alone, it had good corrosion inhibition. So, PESA should be included in the category of corrosion inhibitors. It is not only a kind of green scale inhibitor, but also a green corrosion inhibitor. The synergistic effect between PESA and Zn2+ or sodium gluconate is poor. However, the synergistic effect among PESA, Zn2+ and sodium gluconate is excellent, and the corrosion inhibition efficiency for carbon steel is higher than 99%. Further study of corrosion inhibition mechanism reveals that corrosion inhibition of PESA is not affected by carboxyl group, but by the oxygen atom inserted. The existence of oxygen atom in PESA molecular structure makes it easy to form stable chelate with pentacyclic structure.

关键词： Green scale inhibitor polyepoxysuccinic acid corrosion inhibition synergistic effect.

Rheological Behaviour for Polymer Melts and Concentrated SolutionsPart Ⅱ: Material Function with Nagai Chain Constraints and Determination of Their Parameters from Flow Curves

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Journal of Materials Science & technology 1995年第2期11卷 141-152页

作者： Mingshi SONG Sizhu WU and Xiuyun DU(Research Institute of Polymeric Materials, beijing university of Chemical technology, beijing, 100029, China) beijing Univ of Chemical technology Beijing China

An integral constitutive equation and a set of material functions for describing the strain history of polymer melts were formulated in terms of the Cauchy-Green and Finger tensors. A simple memory function and the dependence of ηo and τt on M3.4 were derived from the theory of non-linear viscoelasticity with constraints of entanglements for polymer melts and substituted into the Oldroye-Walters-Fredickson constitutive equation. An integral constitutive equation for polymer melts was consequently obtained. Some material functions of the constitutive equation related to certain 'test flow' are examined as follows : (1) simple steady shear flow; (2) steady elongation flow; (3) small-amplitude oscillatory shear flow; (4) stress growth upon the inception of steady shear elongation flow; (5) stress relaxation (modulus and compllance). These theoretical relations for simple steady shear flow were compared with experimental data from our laboratory and references for various polymer melts and concentrated solutions. A good agreement between the theory and experiment was achieved.

关键词： LDPE Material Function with Nagai Chain Constraints and Determination of Their Parameters from Flow Curves Rheological Behaviour for Polymer Melts and Concentrated SolutionsPart Flow GR