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101.
Osamu Kimura Masafumi Matsumoto Mitsuo Sakakura 《Journal of the American Ceramic Society》1995,78(10):2857-2860
The high-frequency magnetic properties of strontium-partially-substituted Z-type magnetoplumbite with the composition 2CoO·3Ba1-x .Srx O.yFe2 O3 were studied using a hot-pressing technique. The best properties were obtained for a sample hot-pressed in oxygen, having x and y values of 0.5 and 10.8, respectively. The resonant frequency of that sample, corresponding to a μ" maximum reaching 2.5 GHz, was significantly larger than the value of 1.4 GHz previously reported for unsubstituted Z with the composition 2CoO·3BaO·12Fe2 O3 . This result implies that a new ferrite material, applicable in the gigahertz region, has been obtained. 相似文献
102.
Kazuo Tsutsui Ruifei Xiang Takashi Shiozawa Yasutoshi Okuno Masafumi Kubota Hiroshi Iwai 《Microelectronic Engineering》2008,85(2):315-319
The annealing conditions causing an irregular peak in sheet resistance of nickel silicides are investigated. It is found that the irregular rise in sheet resistance occurs at a critical temperature of 750-775 °C as a result of agglomeration related to phase transition from NiSi to NiSi2. Experiments on the effect of temperature, heating rate and annealing duration in rapid thermal annealing revealed that the high-resistance state produced by annealing at the critical temperature could not be changed by subsequent annealing at higher temperature, and that the high-resistance state required 30-40 s at the critical temperature to form. Pre-annealing at 600 °C was found to suppress the later formation of the high-resistance state. 相似文献
103.
Masafumi Kamiyama Masahiro Maeda Haruo Okutani Kikuhiko Koyama Hideomi Matsuda Yoshiki Sano 《应用聚合物科学杂志》1994,51(9):1667-1671
Triboelectrification of small polymer particles (< 10 microns) in which various functional groups are introduced by addition of substituted comonomers is studied. The particles are produced by suspension polymerization and mechanical crushing of larger particles. The effect of the different production methods on the particle is described. The particles produced by the polymerization method have a spherical shape with a smooth surface, and those produced by the crushing method have an irregular shape. Studies show that particles that have easily ionizable functional groups are charged more effectively. It is believed the iontransfer route is the dominant mechanism in the triboelectrification charging of the particle. The magnitude of charge becomes saturated after 0.5% addition of substituted comonomers in the particles. The particles produced by the polymerization method have a tendency to be charged effectively compared with those produced by the crushing method. © 1994 John Wiley & Sons, Inc. 相似文献
104.
Furfuryl alcohol was polymerized in the presence of a double-chain amphiphile using malonic acid or phosphoric acid as the catalyst, leading to an aggregate of spherical particles with a long period of 2.6 nm. On calcination at 1000 °C in nitrogen gas, the polymer particles were converted into lamella-patterned carbons with a long spacing of some micrometers that are composed of carbon layers 0.4 nm in spacing. The lamella-patterned carbon particles were further developed into a highly ordered structure in an appreciable portion on calcination at 2800 °C in argon gas. The present results demonstrate that the presence of a double-chain amphiphile in the polymerization process is effective for the synthesis of such a structurally modified carbon from non-graphitizable furan polymers. 相似文献
105.
Masafumi Takesue Kenji Shimoyama Sachiko Murakami Yukiya Hakuta Hiromichi Hayashi Richard L. Smith Jr. 《The Journal of Supercritical Fluids》2007,43(2):214
Phase formation of Mn-doped zinc silicate (Zn2SiO4:Mn2+, ZSM) in high-temperature and high-pressure water was studied by in situ observations with a hydrothermal diamond anvil cell (HDAC). Precursor was prepared with zinc oxalate dihydrate, manganese oxalate, and silica, where the Zn/Mn/Si molar ratio was 192/8/120 to 199/1/120. Conditions of particle formation were at temperatures up to 650 °C and at pressures up to 1250 MPa. Precursors dissolved at temperatures of 145–203 °C and needle-like particles formed through homogeneous nucleation at temperatures from 357 to 374 °C, close to the critical point of water. The needle-like particles grew at growth rates of 0.5–3.8 μm/s and were identified to be ZSM as evident from their green luminescence. ZSM synthesized in supercritical water (400 °C for 180 min) by batch reactions had comparable luminescence with that of ZSM produced by solid-state reaction (1200 °C for 240 min) using the same precursor. The key finding in this work is that the precursors can be made to dissolve in near-critical water and that this allows ZSM to form via a homogeneous nucleation process. 相似文献
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108.
A new type of heat pipe called roll heat pipe (RHP) is considered in this study. In RHP, the evaporator and the condenser are separated in the radial direction, and the energy is moved in radial direction. RHP is composed of two concentric annular pipes of unequal diameter, wick structure, and bridge wicks, which provide the return path of the working fluid to evaporator. A heat source is inserted in the inner pipe, which works as the evaporator region. RHP can be applied as heat roll in the laser printers or copy machines where isothermal heating as well as rapid response is desired. Three RHP samples are fabricated and tested in this work. They differ in the number of bridge wicks and inner tube diameter. The length of all samples is 300 mm. In this paper, the transient thermal characteristics of RHP samples are investigated experimentally and compared with numerical analysis results. Also, the effects of fill charge on the performance of RHP samples are studied. By using infrared thermography camera, we observed that the level of temperature uniformity on the outer surface of heat roll is very good in comparison with real heat roll. 相似文献
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