Density functional perturbation theory, combined with quasi-harmonic approximation theory and the Debye theory, has been used to calculate the thermal conductivity of the double-perovskite perovskite slab–rocksalt la...
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Density functional perturbation theory, combined with quasi-harmonic approximation theory and the Debye theory, has been used to calculate the thermal conductivity of the double-perovskite perovskite slab–rocksalt layer oxide compounds L2SrAl2O7 (L = La, Nd, Sm, Eu, Gd, and Dy), a promising class of high-temperature thermal insulators. The predicted properties are compared with experimental data and show excellent agreement from room temperature up to 1000 °C. This indicates that the methodology is an effective approach to calculating the thermal conductivity of complex, defect-free crystal structures.
Effect of stacking layers on the structure and properties of Ca(Mg 1/3Nb2/3)O3/CaTiO3 (CMN/CT) microwave dielectric heterogeneous thin films prepared was investigated. Precursor solutions for CMN and CT synthesis were...
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Nanocrystalline titanium dioxide powder was synthesized by in-flight oxidation of titanium dihydride （TiH2） powder in a thermal plasma jet. TiH2 powder was injected into the thermal plasma jet and allowed to react w...
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Nanocrystalline titanium dioxide powder was synthesized by in-flight oxidation of titanium dihydride （TiH2） powder in a thermal plasma jet. TiH2 powder was injected into the thermal plasma jet and allowed to react with oxygen injected downstream the jet. Characteriza- tion of the powder by various analytical tools indicated that the powder consisted of nano-sized titanium dioxide particles consisting predominantly of the anatase phase. It is suggested that the thermo-chemistry of the oxidation process contributes significantly to the formation of nano-sized titania. The large energy released during the oxidation process dissociates the TiO2 particles into TiO（g） and titanium vapour, which recombine downstream with oxygen and form nano particles of TiO2.
In the present work, silicon nitride nanowires (SNNWs) have been synthesized via nitriding cryomilled nanocrystalline silicon powder. The silicon powder exhibits a fine polycrystalline structure after the cryomilling ...
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Heavy steel castings, a symbol of the level of heavy industries, are high-tech products assembling materials, metallurgy, casting, etc. The feasible schemes for economizing manufacturing heavy steel castings were anal...
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Heavy steel castings, a symbol of the level of heavy industries, are high-tech products assembling materials, metallurgy, casting, etc. The feasible schemes for economizing manufacturing heavy steel castings were analyzed. The effects of riser design, sand mold, oxidation and deformation of casting during heat treatment, machining allowance, etc., on the economizing manufacture heavy steel castings were reviewed. Realization of efficient and economical manufacture of heavy steel castings will improve the output ratio of metal, shorten manufacturing period, save energy and resource, reduce pollution, and improve the competitiveness of enterprises.
Morphotropic phase boundary (MPB) of (0.8-x)PMT-xPbTiO3(PT)-0. 2PbZrO3(PZ) ternary system (x = 0.4) was studied by X-ray diffraction (XRD). It shows that by comparing with 0.4PMT-0.2PZ-0.4PT sample, after doping with ...
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Morphotropic phase boundary (MPB) of (0.8-x)PMT-xPbTiO3(PT)-0. 2PbZrO3(PZ) ternary system (x = 0.4) was studied by X-ray diffraction (XRD). It shows that by comparing with 0.4PMT-0.2PZ-0.4PT sample, after doping with Ni, c/a remains almost same (about1.009), while both c and a decrease indicating that lattice shrinks. Content of the tetragonal phase TP% of Ni-doped samples increase up to 81.1% when the doping limit of the nickel is reached (y = 0.05), and the dielectric constant Ε was found to increase up to 4570 when y = 0.05 and the Curie temperatures of doping samples were found to decrease from 175°C to 157°C.
The relation among electronic structure, chemical bond and thermoelectric property of Ca3Co2O6 and Cu-doped is studied by first-principle theory. The results indicate that the highest valence band(HVB) and the lowest ...
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The small punch creep (SP-C) test technique is a new method which is applied to evaluate the high temperature creep properties of materials by using miniature specimen. In the present paper, the Finite Element Method ...
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In real life, people always move according to a certain paths, for example, walking from one side of corridor to the other side of it, but not passing through the wall, and so on. Therefore, all kinds of possible path...
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