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排序方式: 共有491条查询结果,搜索用时 31 毫秒
1.
Shogo Mamada Naoyuki Yaguchi Masanori Hansaka Masafumi Yamato Hirohisa Yoshida 《应用聚合物科学杂志》2015,132(15)
This study was addressed to the influence of an electric field strength applied at fabrication process and matrix properties, such as the dielectric constant and the Young's modulus, on “pseudo‐1‐3 piezoelectric ceramic/polymer composite” in order to further enhance the piezoelectricity of that. The pseudo‐1‐3 piezoelectric ceramic/polymer composite consists of linearly ordered piezoelectric ceramic particles in polymer material. Silicone gel, silicone rubber, urethane rubber, and poly‐methyl‐methacrylate, which exhibit different dielectric constants and Young's modulus, were used as matrices to evaluate the matrix influence. The piezoelectricity of the pseudo‐1‐3 piezoelectric ceramic/polymer composite was evaluated using the piezoelectric strain constant d33. The d33 is one of the indices of the piezoelectric properties for piezoelectric materials. As a result, it was confirmed that d33 of the pseudo‐1‐3 piezoelectric ceramic/polymer composite increased with the increase of the electric filed strength applied at fabrication process, though, it reached a constant value at a certain strength value. Further it was confirmed that dielectric constant of the matrix had a small influence on d33 of the pseudo‐1‐3 piezoelectric ceramic/polymer composite, however, in case of matrix of lower Young's modulus, d33 was increase. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41817. 相似文献
2.
T Takeshita T Arita H Asao N Tanaka M Higuchi H Kuroda K Kaneko H Munakata Y Endo T Fujita K Sugamura 《Canadian Metallurgical Quarterly》1996,225(3):1035-1039
We molecularly cloned a cDNA coding for a novel phosphotyrosine molecule with a 70 kDa molecular mass, named STAM (signal transducing adaptor molecule), which is tyrosine-phosphorylated rapidly after stimulation with various cytokines such as IL-2, IL-3, IL-4, IL-7, GM-CSF, EGF and PDGF. STAM contains an SH3 (Src-homology 3) domain and the ITAM (immunoreceptor tyrosine-based activation motif), suggesting that STAM acts as an adaptor molecule involved in signal transducing pathways from the cytokine receptors. 相似文献
3.
Morihiko Nakamura Naoyuki Itoh Kenki Hashimoto Tokuzo Tsujimoto Toshiyuki Suzuki 《Metallurgical and Materials Transactions A》1994,25(2):321-330
Isothermally forged TiAl-base alloys (Al-rich, Mn-containing, and Cr-containing TiAl) were heat-treated in various conditions,
and equiaxed grain structures consisting of γ and α2 or Β phases were obtained. The heat-treated alloys were tensile tested in vacuum and air at room temperature, and the environmental
effect on tensile elongation was studied. The ductility of the alloys consisting of equiaxed γ grains and a large amount of
α2 grains was not largely affected by laboratory air, and a decrease in the amount of α2 grains resulted in a large reduction of ductility in air. The Β phase in the Cr-containing alloy improved the ductility in
vacuum, but it resulted in a large reduction of ductility in air.
Formerly with Kougakuin University, Shinjyuku-ku, Tokyo,
Formerly with National Research Institute for Metals, Meguro-ku, Tokyo, 相似文献
4.
Tetsuhiko Kobayashi Nolven Guilhaume Jun Miki Naoyuki Kitamura Masatake Haruta 《Catalysis Today》1996,32(1-4):171-175
In an attempt to develop new catalysts for the formation of formaldehyde from methane, the promotion effect of Fe on SiO2 and that of Sn on WO3 have been studied. The formation of formaldehyde on silica can be appreciably enhanced by the impregnation of Fe, as far as iron loadings are kept below 0.1 atom.% (Fe/Si × 100). In the case of Sn---W---Ox catalysts, both the addition of Sn to WO3, and that of W on SnO2 were effective to the selective formaldehyde formation. Absorption spectra (UV-Vis) and ESR measurements revealed that tetrahedrally coordinated Fe3+ in the silica network plays an important role in the formation of formaldehyde. A thin surface layer consisting of W and Sn oxides can account for the selective formaldehyde formation on the Sn---W---Ox catalysts. 相似文献
5.
The fatigue crack propagation rate and the fatigue threshold were investigated for transverse-butt-welded joints of the austenitic stainless steel SUS304. Specimens were of the center-cracked type. In three sets of tests the fatigue crack passed through the weld metal, and in the other two sets, through the base metal. The fatigue crack propagation properties coincided with each other at different stress ratios for the weld metal, and at the higher stress ratios for the base metal. The propagation properties improved at the stress ratio of zero for the base metal. The absence of a stress ratio effect means that the coincided properties are basic ones in which fatigue crack closure does not occur. However, fractographic appearance and surface roughness were quite different between weld metal and base metal. The coincidence of fatigue crack propagation properties in spite of the difference in fractographic features reveals that the fractographic appearance and surface roughness only have a minor effect on basic fatigue crack propagation behaviour. 相似文献
6.
In order to study the dehydrogenation of ethylbenzene to styrene, epitaxial iron oxide model catalyst films with Fe3O4(111), -Fe2O3(0001) and KFe
x
O
y
(111) stoichiometry were prepared in single crystal quality on Pt(111). They were investigated using surface science techniques before and after atmospheric pressure reaction experiments in a newly designed single crystal flow reactor. As expected from low-pressure measurements, Fe3O4(111) is catalytically inactive. The catalytic activity of -Fe2O3(0001) starts after an activation period of about 45 min. After that, the surface is essentially clean but shows a high concentration of defects. On the potassium-promoted films, however, the activation period is much longer, the activity then is higher and the surface gets covered completely with carbon and oxygen during reaction. This indicates a different reaction pathway on the promoted films with a carbon–oxygen species as catalytically active species. 相似文献
7.
Satoru Sano Noriko Saito Shin-ichi Matsuda Naoki Ohashi Hajime Haneda You Arita Minoru Takemoto 《Journal of the American Ceramic Society》2006,89(2):568-574
Forsterite (Mg2 SiO4 ) ceramics were prepared using Mg(OH)2 and SiO2 as precursors, and the effect of powder characteristics of Mg(OH)2 on calcination and sintering was investigated. The use of highly dispersed Mg(OH)2 powder (HD powder) resulted in a lower calcination temperature. Forsterite powder of high homogeneity and small particle size prepared from the HD powder enabled synthesis of high-density forsterite ceramics by ordinary sintering without applying external pressure. Moreover, transparent forsterite ceramics were successfully synthesized through addition of excess Mg to the precursors to compensate for Mg evaporated during the sintering process. Subsequent dielectric measurements revealed that the transparent forsterite ceramics had a very low dielectric loss (tan δ<10−4 ). 相似文献
8.
Shigeji Taniguchi Toshio Shibata Naoyuki Asanuma Hanyi Lou Fuhui Wang Weitao Wu 《Oxidation of Metals》1993,39(5-6):457-473
The oxidation behavior of TiAl coupons coated with a fine-grain Co-30Cr-4Al (mass %) film of about 30-m thickness has been studied at 1100–1400 K in a flow of purified oxygen at atmospheric pressure for up to 500 ks. Three oxidation stages were recognized: initial transient, parabolic, and accelerated stages. However, at 1100 K a parabolic stage continues for more than 800 ks. The activation energy for parabolic oxidation agrees with reported values for the oxidation of alumina-former alloys, although the mass gains during the parabolic stages are relatively small at 1200 and 1300 K. Micropores developed mainly at the scale/coating and coating/substrate interfaces as oxidation proceeded. This is attributable to recrystallization of the coating during oxidation and a Kirkendall effect due to preferential diffusion of Co into the substrate. The accelerated oxidation can be explained in terms of the formation of rutile mounds on the scale. 相似文献
9.
The finite element polyerystal model (FEPM) was extended and applied to simulate the development of the cold rolling textures of matrix aluminum in deformation processed two-phase 10% and 20% Nb/Al(in volume fraction) metal-metal composites on the basis of slip deformation of individual grains. This simulation method can assure the continuity of stress and displacement at the boundary during heterogeneous deformation and take arbitrary boundary conditions into consideration. The starting hot-extruded textures, as initial input condition, were taken into account in the FEPM simulation. The simulation results show that the main texture components and their evolution after various cold rolling reductions in 10% and 20% Nb/Al metal-metal composites are well qualitatively in agreement with the experimental ones. The initially extruded textures are rather weak, so they have no much influence on the simulated final cold rolling textures of the matrix aluminum for Nb/Al composites. 相似文献
10.
Porous Ti compacts for biomedical applications are successfully fabricated in the porosity range from 5.0 to 37.1 vol% by controlling sintering conditions and Ti powder sizes. Young’s modulus and bending strength at the porosity of around 30 vol% are found to be similar to those of human cortical bone. 相似文献