C.S.Hu1
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2) and Y.X.Gu3) 1) Department of Mechanical Engineering
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Fushun Petroleum Institute
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Fushun 113001
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China 2) State Key Laboratory for Corrosion and Protection
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Institute of Corrosion and Protection of Metal
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The Chi nese Academy of Science
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Shenyang 110015
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China 3) Departmentof Materials Scienceand Engineering
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Shenyang Polytechnic University
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Shenyang 110023
,
China
金属学报(英文版)
Weldingthermalcyclicsimulated techniquesisemployed in thestudy. By meansof analysismetalloscope, fracture morphology and impact toughness test of the sample, the effect ofweldingthermalcycle peak temperature and dualthermal cycle on the micro structure and toughnessoflow alloy high strength steel HQ100 isinvestigated.Inner fine martensitic andbainitic microstrctureisobservedby TEM.Theresultsshow that withtheincreaseof peaktem perature, grain sizesbecomelarger,theimpacttoughness drop down .Ifthermalcycleisim posed twiceand dualthermalcyclicpeaktemperatureis1275 ℃+ 750 ℃,theimpacttoughnessisatthelowest value.Alsotheimpacttoughnessagrees withthefracture morphology.
关键词:
thermalcycle
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Carbon
Preparation of dense carbon materials without use of any binder was attempted, effect of grinding treatment on the characteristics of raw petroleum needle coke and on the properties of the sintered carbon compacts was investigated, and the sintering mechanizm of the coke after grinding was discussed. It was found that the coke particle size and crystalline size was decreased and the specific surface area of the coke was increased with grinding, and the influence was obvious up to 20 hours grinding treatment. The interlayer spacing of the coke after graphitization at 2773 K was gradually increased and the a-axis constant was marginally reduced with the grinding time. Results from the sintering experiment show that carbon materials can be sintered from the ground coke, and the density and flexural strength of the sintering compacts reached stable values of 1.8 g cm(-3) and about 70 MPa, respectively, after 20 hours grinding of the coke. The sintering ability of the coke after grinding was considered to result from the increase of surface energy, lattice distortion energy and fraction of volatile matters of the coke, which were induced by grinding treatment. (C) 1997 Elsevier Science Ltd
关键词:
needle coke;semicoke;baking;mechanical properties;particle size;graphite
Journal of the Electrochemical Society
In the present study, the performances of a single solid oxide fuel cell (SOFC) and a micro-SOFC stack fueled with flame of combusting liquefied petroleum gas (LPG) were studied. La(0.75)Sr(0.25)Cr(0.5)Mn(0.5)O(3-delta) and Ni coimpregnated yttria-stabilized zirconia were used as the anode material of the direct-flame SOFC. The operation temperature of the cell can be sustained at 500-700 degrees C for the combustion of LPG. With the anode facing the LPG flame and the La(0.8)Sr(0.2)MnO(3-delta) cathode freely exposing to ambient air, the single cell exhibited an open-circuit voltage (OCV) of more than 0.85 V and the maximum power density (P(max)) of 238 mW/cm(2). The micro-SOFC stack with three single cells connected in series demonstrated an OCV of 2.5 V and the maximum power output of 64 mW (corresponding to a P(max) of 139 mW/cm(2)). The cell performance was found to be strongly influenced by the cell temperature. And the temperature is determined by cell position and gas composition. Additionally, the cell stability and carbon deposition after operation on the diffusion flame of the LPG were also tested. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3500976] All rights reserved.
关键词:
oxide fuel-cells;performance;stack;design;system;butane;lpg
B.W. Wang
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H. Shen
金属学报(英文版)
Ni-Cr System solar selective thin solid films were prepared by d.c. magnetron reactivesputtering under the atmosphere of O2 and N2. Ni-Cr alloy was chosen as targetmaterial and copper sheets as substrate. Using SEM, Spectrophotometer and Talystepto analyze the relations between the selective characteristic and the structure, theformation and the thickness of the thin films. The aim is to obtain good solar selectivethin films with high absorptance and low emittance, which is applied to flat plate solarheat collectors.
关键词:
solar selective thin film
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