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101.
Yasuhiko Arai Hiroyo Segawa Kazuaki Yoshida 《Journal of Sol-Gel Science and Technology》2004,32(1-3):79-83
In order to produce an excellent abrasive, a fabrication method for cocoon shaped silica particles has been studied. The particles are prepared from TMOS, water, ammonia and methanol by a sol–gel method. The method is to add the methanol solution of TMOS at a constant supply rate to a mixture of water, ammonia and methanol. Effects of various reaction conditions such as temperatures, supply rates of TMOS, and amounts of TMOS are studied on the diameter and shape of the particles. The diameter and shape are resulted in depending strongly on temperatures. High temperature makes particles with the high aspect ratio and the small diameter. And the mechanism of forming the cocoon shaped particle is also discussed. It is concluded that the primary particles are generated at the beginning stage of reaction and two of them become the cocoon shaped particle. For the polishing efficiency, particles have high polishing efficiency with the diameter between 40 nm and 210 nm. As a result, best diameter of particles for abrasive is 40–100 nm with respect to polishing efficiency and surface finish. 相似文献
102.
The lower half of the inverse of a lower Hessenberg matrix is shown to have a simple structure. The result is applied to find an algorithm for finding the inverse of a tridiagonal matrix. With minor modifications, the technique applies to block Hessenberg matrices. 相似文献
103.
Akihiro Ohta Masami Inoue Junichi Yamada Yasuhiko Yamada Teruo Kurihara Toshihiro Honda 《Journal of heterocyclic chemistry》1984,21(1):103-106
Some 2,3-diphenylpyrazine 1-oxides were heated with acetic anhydride to give the corresponding 2,3-di-acetoxy-2,3-dihydro-5,6-diphenylpyrazines. By X-ray diffraction analysis, the configuration of two acetoxyl groups was determined to be trans. 相似文献
104.
105.
Toshio Takayama Masatoshi Kitamura Yasushi Kobayashi Yasuhiko Arakawa Kazuaki Kudo 《Macromolecular rapid communications》2004,25(12):1171-1174
Summary: Polymethacrylate having a pendent 8‐hydroxyquinoline moiety was prepared using Kelex‐100 (7‐(4‐ethyl‐1‐methyloctyl)‐8‐hydroxyquinoline) as a starting material. A soluble polymer having tris(8‐hydroxyquinolinato)aluminum (Al Q 3)‐type side chains was obtained through the complexation of the polymer with Me3Al in the presence of a monomeric Kelex‐100. The polymer complex was applied to an organic light‐emitting diode (OLED) device through a spin‐cast process.
106.
We have demonstrated a flexible twin open ring WDM network for metro applications. A pair of optical switches in the network keeps the fiber rings open to prevent signal circulation. Traffics are broadcast to every node and selected at the receiving side. Superior transmission and protection switching are proved. 相似文献
107.
Yoji Imai Yasuhiko Takahashi Toshiya Kumagai 《Journal of magnetism and magnetic materials》2010,322(18):2665-43
Geometrical optimization of tetra-3d metal nitrides (Mn4N, Fe4N, Co4N, and Ni4N) has been performed and the relations of their energies (E) and their total magnetic moments (M) are obtained by plane-wave-basis density-functional calculations without any assumption of specific spin arrangement. The E vs. M relations obtained for Fe4N and Mn4N have a bimodal character. The ground state of Fe4N is a high-spin state, which would correspond to the ferromagnetic character, while that of Mn4N is a low-spin state, which would correspond to the observed ferrimagnetic character. Lattice constants and total magnetic moments of these tetra-3d metal nitrides are almost accurately predicted. From the spin-polarized densities of states curves, Co4N would have the largest spin polarization ratio of 0.88, which suggests Co4N can be a candidate material for ferromagnetic electrodes for spin-injection. 相似文献
108.
Kiyotaka Miura Kazuyuki Hirao Yasuhiko Shimotsuma Masaaki Sakakura Shingo Kanehira 《Applied Physics A: Materials Science & Processing》2008,93(1):183-188
Mixing metallic Al into the starting material for silicate glass is proposed as a means of forming Si structures in glass.
We confirmed that Si nanocrystals are space-selectively deposited in silicate glass via a thermite reaction triggered by femtosecond
laser pulses. Small Si particles were transformed into larger, but still micrometer sized, Si particles by laser irradiation.
These structures grew to micro-size particles due to the thermite reaction promoted by heat treatment. We discuss what effect
the irradiation of the focused laser pulse had on the Si deposition process in the laser-irradiated region. Localized high
temperatures and pressures and generation of shock waves appear to be very important in forming Si-rich structures that contribute
to the growth of Si particles. The diffusion of calcium ions by the generation of shock waves and the presence of Al-rich
structures is important for forming Si-rich structures such as Si clusters, which is achieved by continuously breaking Si–O
bonds using localized high temperatures. 相似文献
109.
Yasuhiko Arai Ryouichi Shimamura Shunsuke Yokozeki 《Optics and Lasers in Engineering》2009,47(5):563-569
The novel measurement method based on the virtual speckle patterns has been reported. This method has the feature of analyzing the deformation map of an object in high resolution without any information except for speckle pattern images under a deformation process. In this paper, the method is applied to the measurement of dynamic events including a complex deformation distribution. The optical system of the method is improved in order to deal with the complex deformation distribution, which includes the increase and the decrease distributions. In experiments, the phenomenon of collision of the metal sphere on the thin polymer film is analyzed. The method can analyze the large deformation measurement of dynamic events, which cannot be measured by ordinary methods. It is confirmed that the measurement accuracy of this method even in measurements of dynamic events is high. 相似文献
110.
Toru Takahashi Yasuhiko Hori Ichiro Sato 《Journal of polymer science. Part A, Polymer chemistry》1968,6(8):2091-2102
The ceric salt-initiated polymerization on acrylamide and graft copolymerization of acrylamide onto cellulose were studied. The mechanism of the ceric salt-initiated polymerization of acrylamide in the homopolymerization system can be explained by a radical mechanism based upon Ce4+-coordinated acrylamide, and the mechanism of the ceric salt-initiated graft copolymerization of acrylamide onto cellulose can be explained in two ways: a free-radical mechanism with the ceric—cerous redox system, and a radical mechanism based upon Ce4+-coordinated acrylamide. The velocities of initiation, propagation, and termination in the redox mechanism are quite different from those in the coordinated radical mechanism. From the infrared absorption and nuclear magnetic resonance spectra measurements it is concluded that the structure of the ceric-coordinated acrylamide is the π-complex. 相似文献