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41.
Yong Fan Junqi Guo Minhyeok Lee Norihiko Iki Yuji Suzuki 《Proceedings of the Combustion Institute》2021,38(2):2361-2370
A premixed H2/air flame with N2 dilution (Uin = 533 cm/s, ? = 1) was formed in a quartz micro flow reactor with/without a 100-nm thick Inconel coating for the investigation of wall chemical effect of the metal surface. Two-dimensional distributions of OH radical, O atom and H atom in the hydrogen flame were measured via the planar laser induced fluorescence (PLIF) and two-photon absorption laser induced fluorescence (TALIF), respectively. It is found that the distributions of all these three main species in the hydrogen flame are significantly affected by the wall chemical effect. OH, O and H shift downstream in the Inconel-coated channel, and also their concentration becomes lower than those in the less-reactive quartz channel. Based on the measured distributions of OH, O and H over the Inconel surface, the initial sticking coefficients (S0) of the radical quenching model are optimized. It is found that S0 for Inconel are 0.4–0.5, 0.1–0.2 and < 0.05 for OH, O and H, respectively, showing different sticking coefficients for different species for the first time. 相似文献
42.
A series of cluster-based ruthenium zinc antimonides with a large unit cell were obtained. Their structures were solved by the single crystal X-ray diffraction methods. They crystallize in the cubic space group of Fm3?c (No. 226) with cell dimensions of 25.098(3), 24.355(3), 24.307(3), and 24.376(3) ? for Ru(26)Sb(24)Zn(67) (CA), Ru(13)Sb(12)Zn(83.4) (CB), Ru(13)Sb(6.29)Zn(91.56) (CC), and Ru(13)Sb(17.1)Zn(74.8) (CD), respectively. By all indications, compounds CA and CB are two phases showing pronounced distinctions regarding compositions, lattice parameters, thermal and transport properties, but they are not members of an extended solid solution. Compounds CB, CC, and CD are three members of a same solid solution. Topologically, these four compounds contain face-centered cubic packing of double-Mackay type clusters and (Sb(1-δ)Zn(δ))(24) snub cubes filled with highly disordered zinc aggregates, with or without glue atoms between them. Both phases CA and CB are diamagnetic. There is a difference of ~170 K between their thermally stable temperatures. CA exhibits rather low thermal conductivity with the value of ~0.9 W m(-1) K(-1) at room temperature, which is about one-third that of CB. The electrical resistivity of CB is almost temperature independent. The Seebeck coefficient of CB is small and negative, while that of CA exhibits a complicated temperature dependence and undergoes a transition from p- to n-type conduction around room temperature. 相似文献
43.
44.
In order to evaluate the effect of annealing treatment on the proton conductivity of ??-alumina, the electrical conductivity of Mg-doped polycrystalline ??-alumina kept at 1,873?K under various conditions of the surrounding atmosphere and then cooled in the furnace was measured in the temperature range 1,173?C1,473?K. The H+/D+ isotope effect on the electrical conductivity was also examined under a hydrogen atmosphere at 1,273?K. The protonic conductivity measured at 1,273?K increased with the increase in the activity of oxygen and water vapor in the annealing atmosphere at 1,873?K. It is considered that the solubility limit of magnesium ions in ??-alumina in equilibrium with the small amount of the spinel phase increased with the increase in the activity of oxygen and water vapor at 1,873?K. This enhanced amount of magnesium ions is frozen in a non-equilibrium state to 1,273?K and works as the enriched acceptor dopant for the incorporation of protons. 相似文献
45.
Koji Yamada Noboru Miura Chihiro Hamaguchi Norihiko Kamata 《Solid-state electronics》1989,32(12):1113-1117
Hot carrier magnetophonon resonances of n-type Si, short channel InP and p-type InSb were investigated in pulsed high magnetic fields up to 40 T. Using a recently developed high resolution technique in pulsed high fields, many new features of the hot carrier-phonon interactions in high magnetic fields were found. 相似文献
46.
Inelastic electron tunneling spectroscopy (IETS) is a unique surface and interface analytical technique using electron tunneling through a metal/insulator/metal tunneling junction at cryogenic temperatures. It gives the vibrational spectrum of a very thin (nm) insulator film and the adsorbed species on it. The high sensitivity, good resolution, and wide spectral range inherent in IETS enable us to analyze the surface and interface of the insulator in detail. The tunneling junction is a good model system for oxide catalysts, electronic devises, and solid state sensors. Information about the surfaces of alumina and magnesia, the adsorption states and chemical reactions of adsorbed species occurring on these oxides can be obtained through an analysis of the tunneling spectra. The structures and properties of evaporated thin semiconductor films can also be studied. In this review, the surface characterization of alumina and magnesia, the adsorption and surface reactions of organic acids, esters, amides, and nitryls on these oxides, and the characterization of thin evaporated films of Si, Ge, and the oxides are summarized. 相似文献
47.
Kurume A Kamata Y Yamashita M Wang Q Matsuda H Yoshikawa M Kawasaki I Ohta S 《Chemical & pharmaceutical bulletin》2008,56(9):1264-1269
Eleven 3-substituted isocoumarins and a benzylidenephthalide were synthesized through thermal cyclization reaction of delta- and gamma-ketoamides, respectively. Subsequent deprotection of the hydroxyl groups of the resulting isocoumarin and benzylidenephthalide compounds afforded thunberginols A, B, and F, respectively, which originated from the processed leaves of Hydrangea macrophylla SERINGE var. thunbergii MAKINO. The synthesized isocoumarins and thunberginols were evaluated for their anti-allergic activity, in which thunberginol B exhibited the highest inhibitory potency on the degranulation of RBL-2H3 cells induced by antigen. Structure-activity relationship studies were carried out to determine the necessary substituents on the 3-phenylisocoumarin skeleton for inhibitory activity. 相似文献
48.
49.
The growth and saturation characteristics of a Cherenkov laser with a Bragg cavity composed of dielectric gratings are investigated in detail with the aid of numerical simulation based upon the fluid model of the electron beam, For the analysis of the problem, a two-dimensional (2-D) model of the Cherenkov laser is considered which consists of a planar relativistic electron beam and a parallel plate waveguide, one plate of which is loaded with a dielectric sheet. For confinement and extraction of the electromagnetic wave, a Bragg cavity is formed by dielectric gratings fabricated at both ends of a dielectric-loaded parallel plate waveguide. The result of numerical simulation shows that a compact Cherenkov laser, the longitudinal dimension of which is about one order of magnitude smaller than that of the corresponding single-pass Cherenkov laser, can be realized by using a Bragg cavity composed of dielectric gratings 相似文献
50.
Takashi Toda Norihiko Shimazaki Toshio Mukai Chizuko Kabuto 《Tetrahedron letters》1980,21(41):4001-4004
The structure of a minor dimer () of 1-arylcycloheptatrienylidenethylene was determined by X-ray crystallography. Dehydration of and gave novel non-benzenoid aromatics---6,12-diarylazuleno[1,2-b]azulenes ( and ), whose electronic and NMR spectral properties were reported. 相似文献