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991.
Masao Kamiko Hiroyuki Mizuno Junhua Xu Ryoichi Yamamoto 《Solid State Communications》2005,134(12):803-808
This study was to investigate the surfactant effect of Bi on the heteroepitaxial growth of Fe/Cr(100) multilayers by reflection high-energy electron diffraction (RHEED) measurements. With predeposition of submonolayer Bi on Fe(100) prior to evaporation of Fe/Cr multilayer, more long-lasting RHEED intensity oscillations were observed. This implies that the layer-by-layer growth of Fe/Cr multilayer is enhanced. The observations of grazing incidence X-ray reflectivity confirmed that the interface structures of Fe/Cr multilayer with Bi were sharper than that of multilayer without Bi. The study was also to investigate the magnetotransport properties between Bi surfactant-mediated multilayers and normal ones. The magnetoresistance (MR) ratio of the multilayers was enhanced by predeposition of Bi. 相似文献
992.
Teruyuki Kondo Masatsugu Niimi Masato Nomura Kenji Wada Take-aki Mitsudo 《Tetrahedron letters》2007,48(16):2837-2839
A novel rhodium-catalyzed synthesis of substituted phenols by the ring-opening reaction of cyclobutenones with alkynes as well as electron-deficient alkenes has been developed. Both reactions involve C-C bond cleavage of cyclobutenones, and an (η4-vinylketene)rhodium complex rather than a rhodacyclopentenone is considered to be a key intermediate. 相似文献
993.
994.
Kotohiro Nomura 《Catalysis Surveys from Japan》1998,2(1):59-69
This review describes recent progresses in the selective reduction of aromatic nitro-groups to amines catalyzed by homogeneous ruthenium or rhodium catalysts under CO/H2O conditions. These catalytic reactions are useful from both synthetic and industrial viewpoints, because the after-treatment of by-products can be simplified in comparison to the conventional methods, since the reaction proceeds with extremely high selectivity. Efficient and convenient palladium–phosphine catalysts for hydrocarbonylation of chlorobenzenes affording benzoic acid derivatives in high yields are also described. 相似文献
995.
Hiroshi Nomura Masashi Takahashi Yasushige Ujiie Hitoshi Hara 《Proceedings of the Combustion Institute》2005,30(2):1991-1999
Flame spread on a fuel droplet array has been studied as a simple model of spray combustion. A three-fuel-droplet array with a pendulum suspender was employed to investigate interactions between flame spread and droplet motion in the axial direction. Initial droplet diameter was 0.8 mm, and fuel was n-heptane. A silicon carbide pendulum suspender of 15 μm in diameter and 30 mm in length was used for the third droplet. The first fixed droplet was ignited by electric spark. Behavior of the flame and the third droplet was observed using a high-speed video camera with an image intensifier. Particle tracking velocimetry (PTV) measurements were performed to explain the behavior of the third movable droplet. The dimensionless droplet span, which is the average of droplet-to-droplet distances divided by the average initial diameter of the three droplets, was varied from 2.5 to 8 for observing flame spread, and fixed at 5.5 for PTV measurements. It was observed that the third droplet moved away from the second droplet before the flame spread to the third droplet. The displacement of the third droplet is remarkable when the dimensionless droplet span is close to the limit of flame spread. This implies that the movement of the droplet decreases the dimensionless span of the flame spread limit and the flame spread speed near the flame spread limit. Results of PTV measurements suggest that the heat expansion wave, caused by ignition of the premixture which was accumulated around the second droplet, and the burned gas flow from the second droplet pushed away the third droplet; then natural convection, induced by the flames of the first and second droplets, drew the third droplet to the second droplet. The heat expansion wave and the burned gas flow of the second droplet reached nearly 12 in dimensionless span. 相似文献
996.
A blind deconvolution method using the concept of subband filter banks has been proposed. This method makes possible the speedy
convergence of solution, due to estimation of supports of the reconstructed images by a deconvolution in the lower layer.
We apply the method to blind deconvolution by a simulated annealing algorithm and confirm its usefulness.
Presented at 1996 International Topical Meeting on Optical Computing (OC’96), April 21–25, Sendai, Japan. 相似文献
997.
Takahisa Omata Masao Kita Motomi Katada 《Journal of Physics and Chemistry of Solids》2005,66(1):53-62
Two cation-ordered phases were prepared by the oxidation of a pyrochlore phase as a precursor in the Sn-Nb-O system. One was a cation-ordered fluorite related phase, whose unit cell volume was eight times larger than that of the fluorite structure, similar to the κ-CeZrO4 phase. The other was a cation-ordered α-PbO2 phase, in which the ordered arrangement of cations was distinctly different from the well-known cation-ordered α-PbO2 structures such as wolflamite and columbite. The chemical compositions of the phases, including valence states of cations, local structure and electronic structure near the energy band gap were studied. The compositions of the precursor and its oxidized phases were evaluated, respectively, to be SnII1.62(NbV1.86SnIV0.14)O6.55 and SnIV0.81(NbV0.93SnIV0.07)O4.085, i.e. SnIV1.62(NbV1.86SnIV0.14)O8.17, by TG-DTA and ICP analyses, 119Sn Mössbauer spectroscopy and X-ray photoemission spectroscopy. It was ascertained using IR and Raman spectroscopies that the structural framework of the cation-ordered fluorite related phase was close to that of the precursor pyrochlore phase, and the structural framework of the cation-ordered α-PbO2 phase was distinct from that of the precursor pyrochlore. The Mössbauer parameters obtained showed a strong deviation of oxygen atoms contained in the SnO8 polyhedron in the cation-ordered fluorite related phase from the cubic arrangement for the ideal fluorite related structure, and a lower site symmetry of SnIV in the cation-ordered α-PbO2 than in rutile SnO2. An increase in the energy band gap from ∼2.5 eV for the precursor pyrochlore to ∼3.5 eV for the oxidized phases was attributed to the vanishing of Sn 5s2 lone-pair states upon oxidation of SnII in the precursor to SnIV in the oxidized phases. 相似文献
998.
Yukio Isozaki Jianxin Yao Tetsuo Matsuda Harutaka Sakai Zhansheng Ji Noriei Shimizu Noritada Kobayashi Hodaka Kawahata Hiroshi Nishi Masao Takano Tomomi Kubo 《Proceedings of the Japan Academy. Series B, Physical and biological sciences》2004,80(1):10
Precise stratigraphic analysis of Middle-Upper Permian and Lower Triassic sequence at Chaotian in northern Sichuan, China, identified two remarkable mass extinction horizons, one at the Middle-Upper Permian (Guadalupian-Lopingian; G-L) boundary and the other at the Upper Permian-Lower Triassic (P-T) boundary. Across each of the boundaries, biodiversity declined sharply in fusulinid, rugose coral, brachiopod, ammonite, conodont, and radiolaria. Both boundaries are characterized by two biohorizons, i.e., one marked by major extinction of pre-existing fauna and the other by the first appearance of younger fauna. It is noteworthy that a peculiar rhyo-dacitic tuff bed occurs at each of the extinction horizons. Thus the Late Permian biosphere was strongly affected twice by highly explosive, severe volcanism. Regional correlation of the G-L and P-T boundary tuff beds throughout South China, and partly to Japan, positively suggests a cause-effect link between large-scale explosive volcanism and mass extinction. 相似文献
999.
Takaaki Nomura 《Journal of Functional Analysis》2003,198(1):229-267
In this paper, we present a geometric norm equality involving an admissible linear form ω for the Shilov boundary of a homogeneous Siegel domain D. We prove that the validity of this norm equality is equivalent to the symmetry of D and the reduction of ω essentially to the Koszul form. This, in particular, reveals a geometric reason that the Poisson kernel is annihilated by the Laplace-Beltrami operator if and only if D is symmetric, a theorem due to Hua, Look, Korányi and Xu. 相似文献
1000.
Hiroyasu Nomura Satoru Ando Tatsuro Matsuoka Shinobu Koda 《Journal of Molecular Liquids》2004,110(1-3):57-62
Stationary ultrasonically induced birefringence in various polymer solutions was measured in order to investigate its relation to the anisotropy in polarizability of a polymer chain. From the concentration dependence of stationary ultrasonically induced birefringence in polystyrene–toluene, polycarbonate–chloroform and polybutadiene–toluene solutions, the intrinsic values of the birefringence were obtained. A linear relationship between the intrinsic value of the birefringence per segment and the segmental anisotropy in polarizability was obtained. In aqueous solutions of polyelectrolytes, sodium polystyrenesulfonate and tetramethylammonium polystyrenesulfonate, the birefringence decreased with ionic strength by the addition of the salts. The stationary birefringence per ultrasonic intensity for all polymer solutions investigated here decreased with increasing frequency. 相似文献