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41.
Takashi Hayakawa Hideo Orita Masao Shimizu Katsuomi Takehira Arnfinn G. Andersen Kiyoshi Nomura Yusuke Ujihira 《Catalysis Letters》1992,16(4):359-371
The catalytic activity of LaCoO3–-based mixed oxides for the oxidative coupling of methane has been tested by TPR and cyclic reaction. Characterization has been done by XRD, TGA and Mössbauer spectrometry. It is likely that the perovskite-crystal structure containing hypervalent metal ions has an important role and that unique structural oxygen species in the perovskite contribute to the partial oxidation of methane. 相似文献
42.
Porous glass-ceramics with a skeleton of the fast-lithium-conducting crystal Li1+ x Ti2− x Al x (PO4 )3 (where x = 0.3–0.5) were prepared by crystallization of glasses in the Li2 O─CaO─TiO2 ─Al2 O3 –P2 O5 system and subsequent acid leaching of the resulting dense glass-ceramics composed of the interlocking of Li1+ x Ti2− x Al x (PO4 )3 and β-Ca3 (PO4 )2 phases. The median pore diameter and surface area of the resulting porous Li1+ x Ti2− x Al x (PO4 )3 glass-ceramics were approximately 0.2 μm and 50 m2 /g, respectively. The electrical conductivity of the porous glass-ceramics after heating in LiNO3 aqueous solution was 8 × 10−5 S/cm at 300 K or 2 × 10−2 S/cm at 600 K. 相似文献
43.
Sudip Adhikari Sunil Adhikary Ashraf M.M. Omer Mohamad Rusop Hideo Uchida Tetsuo Soga Masayoshi Umeno 《Diamond and Related Materials》2005,14(11-12):1824
Nitrogenated diamond-like (DLC:N) carbon thin films have been deposited by microwave surface wave plasma chemical vapor deposition on silicon and quartz substrates, using argon gas, camphor dissolved in ethyl alcohol composition and nitrogen as plasma source. The deposited DLC:N films were characterized for their chemical, optical, structural and electrical properties through X-ray photoelectron spectroscopy, UV/VIS/NIR spectroscopy, Raman spectroscopy, atomic force microscope and current–voltage characteristics. Optical band gap decreased (2.7 to 2.4 eV) with increasing Ar gas flow rate. The photovoltaic measurements of DLC:N / p-Si structure show that the open-circuit voltage (Voc) of 168.8 mV and a short-circuit current density (Jsc) of 8.4 μA/cm2 under light illumination (AM 1.5 100 mW/cm2). The energy conversion efficiency and fill factor were found to be 3.4 × 10− 4% and 0.238 respectively. 相似文献
44.
Efficient gas recovery and separation in a hydrate-based system was investigated for a model gaseous mixture of R22 and nitrogen. The formed hydrate settled in the recovery vessel; excess water was recycled and the hydrate was subsequently decomposed by releasing pressure from the vessel. The gas uptake rate of R22 gas from the vapor phase and the gas recovery rate from the hydrate were determined from hydrate formation and decomposition, respectively. The gas recovery rate of R22 gas gradually increased with time. On the contrary, the nitrogen gas recovery rate was a maximum in the initial stage of hydrate decomposition. A high separation factor (S.F.) was achieved by first separating the N2-rich gas generated during initial hydrate decomposition. An efficient hydrate-based gas separation and recovery process is proposed. 相似文献
45.
Hydrothermal flames in supercritical water oxidation: investigation in a pilot scale continuous reactor 总被引:1,自引:0,他引:1
Roberto M. Serikawa Takashi UsuiTatuya Nishimura Hirokazu SatoShusaku Hamada Hideo Sekino 《Fuel》2002,81(9):1147-1159
Hydrothermal flames at 25 MPa supercritical water environment were investigated using a 4800 ml reaction tower, in which the sapphire windows were fitted for optical access. Down flowing hydrothermal flames were observed for oxidation of 2-propanol when the reactor was fed with inlet organic concentration higher than 2 vol% and air ratio higher than 1.8. Flame temperature, as high as 1100 °C, was measured by means of a thermocouple and the temperature was found to be strongly influenced by air ratio. Effective and stable oxidation of organics with TOC removal rate of 99.9% was achieved. Dioxins were also decomposed with a ratio higher than 99.9%, within 1 min reaction time in this reactor configuration. 相似文献
46.
Hideo Sawada Sachiko HataNobuhito Kawasaki Jun-ichi IidzukaKentaro Tokugi Jun KyokaneTomomi Maekawa Tokuzo Kawase 《Polymer》2002,43(3):1035-1038
New fluoroalkyl end-capped fullerene cooligomers were prepared by the reactions of fluoroalkanoyl peroxides with fullerene and comonomers such as acryloylmorpholine, N,N-dimethylacrylamide and acrylic acid. These fluorinated fullerene cooligomers were easily soluble in water and common organic solvents, and were able to reduce the surface tensions of both water and benzene, quite effectively. Additionally, these fullerene cooligomers were found to form a stable monomolecular film at the air-water interface, and the modified polystyrene surface treated with these cooligomers was shown to have a strong hydrophilicity with good oil repellency. 相似文献
47.
Kazuhiro Suzuki Hideo Fukuda Takatoshi Yamada Atsuhito Sawabe 《Diamond and Related Materials》2001,10(12):570-2156
We obtained an epitaxially grown free-standing diamond platelet utilizing epitaxial diamond film formed on a {100} iridium surface using a d.c. plasma CVD process. Iridium was selected as a suitable substrate material for the heteroepitaxy of diamond based on original criteria. Confocal Raman spectroscopy revealed that the diamond platelet contained little or no non-diamond carbon. The obtained diamond platelet is transparent to visible light and cleavable along the 110 direction on the surface. The angles between the top surface and the cross-sectional surfaces are approximately 55°, almost equal to the theoretical angle of 54.74° between {100} and {111} planes in cubic crystals. Therefore, the cross-sectional surfaces would be {111} planes of a typical facet for single-crystalline diamond. This means that the diamond platelet we have formed has relatively good crystallinity. 相似文献
48.
We have presented a numerical technique for analyzing one-dimensional transient temperature distributions in a circular hollow cylinder that was composed of functionally graded ceramic–metal-based materials, without considering the temperature-dependent material properties. The functionally graded material (FGM) cylinder was assumed to be initially in a steady state of gradient temperature; the ceramic inner surface was exposed to high temperature, and the metallic outer surface, which was associated with its in-service performance, was exposed to low temperature. Then, the FGM cylinder was cooled rapidly on the ceramic surface of the cylinder, using a cold medium. The transient temperature and related thermal stresses in the FGM cylinder were analyzed numerically for a model of the mullite–molybdenum FGM system. The technique for analyzing the temperature distribution is quite simple and widely applicable for various boundary conditions of FGMs, in comparison with methods that have been proposed recently by other researchers. 相似文献
49.
50.
Seiji Inaba Yasuhiko Benino Shinji Kohara Hideo Hosono Setsuro Ito 《Journal of the American Ceramic Society》2020,103(6):3631-3641
Orientation anisotropy, which is well known in organic polymers with appropriate network structures, is less common in oxide glasses. We present the intermediate-range order in anisotropic alkali metaphosphate glass which consists of oriented PO4 tetrahedral chains and intervening alkali cations along the elongation direction. The X-ray total structure factor S(Q) indicates that the inter-chain spacing depends on the size of alkali cations and varies from 5.03 to 6.28 Å. The mixed alkali effect is primarily related to an increase of the separation. The total correlation function T(r) provides the first definite evidence that the anisotropic structure is composed of phosphorus-bridging oxygen bonds (P–OB) lying along the elongation direction and phosphorus-non-bridging oxygen bonds (P–OT) oriented perpendicular to the elongation direction. The present result unveils fundamental aspects of the anisotropic structure of an oxide glass and provides essential information for the development of oxide glasses to control structural anisotropy. 相似文献