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1.
Shingo Kanehira Soshu Kirihara Yoshinari Miyamoto Kazuaki Sakoda Mitsuo Wada Takeda 《Journal of the American Ceramic Society》2003,86(10):1691-1694
Photonic crystals with a diamond structure of epoxy lattices in which TiO2 -based ceramic particles are dispersed were fabricated by stereolithography. The periodicity of the lattice was designed to reflect electromagnetic waves in the gigahertz range. The volume fraction (β) of the dielectric lattice medium was modified from 14% to 33% by changing the rod diameter of the lattice. The photonic band gap was observed along Γ-L 〈111〉, Γ-X 〈100〉, and Γ-K 〈110〉 directions and the complete photonic band gap was formed at over β= 20%. The width of the forbidden gap increased gradually when the β increased over 14%, and reached 2.4 GHz at β= 33%. These results agreed with the band calculation using the plane wave expansion method. 相似文献
2.
Poly(butylene succinate) and organically modified montmorillonite nanocomposites with there different compositions were prepared via melt blending in a twin‐screw extruder. The structure of the nanocomposites was studied with X‐ray diffraction and transmission electron microscopy, which revealed the formation of intercalated nanocomposites, regardless of the silicate loading. Dynamic mechanical analysis revealed a substantial increase in the storage modulus of the nanocomposites over the entire temperature range investigated. The tensile property measurements showed a relative increase in the stiffness with a simultaneous decrease in the yield strength in comparison with that of neat poly(butylene succinate). The oxygen gas barrier property of neat poly(butylene succinate) improved after nanocomposite preparation with organically modified montmorillonite. The effect of the layered‐silicate loading on the melt‐state linear viscoelastic behavior of the intercalated nanocomposites was also investigated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 777–785, 2006 相似文献
3.
Masahiro Kato Kazuaki Nakagawa Kenji Essaki Yukishige Maezawa Shin Takeda Ryosuke Kogo Yoshikazu Hagiwara 《International Journal of Applied Ceramic Technology》2005,2(6):467-475
We have discovered a series of lithium-containing oxides that immediately react with ambient carbon dioxide (CO2 ) up to 700°C. The products react and return reversibly to the oxides at a temperatures higher than about 700°C. The absorption capacity surpasses that of other CO2 absorbents by a factor of 10. Utilizing these absorbents, the possibility of a CO2 separation system that operates at around 500°C is proposed. It is generally believed that a CO2 separation process operable at temperatures higher than 500°C has the special benefit of a small energy penalty. Moreover, the absorption also proceeds at ambient temperature in the atmospheric environment. This property offers the possibility of many other applications, such as air cleaners or cartridges. Therefore, we think these materials have the potential to make a valuable contribution to the realization of CO2 emission control. 相似文献
4.
Hamid Noori Farhad Mehdipour Kazuaki Murakami Koji Inoue Morteza Saheb Zamani 《The Journal of supercomputing》2008,45(3):313-340
To improve the performance of embedded processors, an effective technique is collapsing critical computation subgraphs as
application-specific instruction set extensions and executing them on custom functional units. The problem with this approach
is the immense cost and the long times required to design a new processor for each application. As a solution to this issue,
we propose an adaptive extensible processor in which custom instructions (CIs) are generated and added after chip-fabrication.
To support this feature, custom functional units are replaced by a reconfigurable matrix of functional units (FUs). A systematic
quantitative approach is used for determining the appropriate structure of the reconfigurable functional unit (RFU). We also
introduce an integrated framework for generating mappable CIs on the RFU. Using this architecture, performance is improved
by up to 1.33, with an average improvement of 1.16, compared to a 4-issue in-order RISC processor. By partitioning the configuration
memory, detecting similar/subset CIs and merging small CIs, the size of the configuration memory is reduced by 40%. 相似文献
5.
Kazuaki Mita Shu Yamaguchi Masafumi Maeda 《Metallurgical and Materials Transactions B》2004,35(3):487-492
Most galvanized steel sheets are produced by a continuous galvanizing line. Some of the operations include a subsequent heat
treatment termed galvannealing to form intermetallic phases on the surface. These galvanizing reactions are essentially regarded
as “making intermetallic compounds” in the Fe-Zn-M system. This makes it important to know the thermodynamic properties of
the system for any detailed discussion on the formation of these intermetallics; however, experimental difficulties have limited
the number of studies. In the present study, two-phase regions of these intermetallics were examined, and the following two-phase
mixtures were prepared at 723 K: Fe(α)+Γ, Γ,+Γ1, Γ1+δ
1+ζ. The double cell-type Knudsen mass spectrometer system was developed and employed, in which two sets of Knudsen cells were
installed in the same cell holder. The reference material (pure zinc) was placed in one cell and a sample in the other. The
cell holder was rotated to the reference and sample positions to measure zinc vapor effused from two cells by a quadrupole
mass spectrometer. Material containing the two phases was placed in a Knudsen-type effusion cell and the mass spectrum studied
to evaluate the vapor pressure of zinc. The activity of zinc in the intermetallics was determined by comparing the intensity
from pure zinc and that from intermetallics. Results for Fe(α)+Γ were 0.46 to 0.48; for Γ+Γ1, 0.51 to 0.54; for Γ1+δ
1, 0.62 to 0.66; and for δ
1+ζ, 0.80 to 0.83, between the temperatures of 623 and 698 K. 相似文献
6.
为了阐明磨石研磨加工层对高碳铬轴承钢JIS SUJ2超长寿命疲劳行为的影响,分别使用经砂纸研磨和电解研磨的砂漏形试样,在室温空气环境下进行旋转弯曲疲劳试验.砂纸研磨试样被除去部分磨石研磨层,电解研磨试样被除去了全部的磨石研磨层.结果表明,两种试样的S-N曲线由位于短寿命区的表面破坏模式和位于长寿命区的内部破坏模式的两条组成,表面破坏模式的S-N曲线受表面粗糙度和表面压缩残余应力的影响.内部破坏模式的S-N曲线不受表面条件的影响,是材料固有的特性.砂纸研磨试样表面破坏模式的疲劳极限最高,是电解研磨试样1.11倍和磨石研磨的1.20倍.表面压缩残余应力对表面破坏模式疲劳极限的影响可以用修正Goodman图表示.还讨论裂纹的萌生和扩展条件,推定超长寿命的疲劳极限. 相似文献
7.
Kisu Lee 《Computational Mechanics》2014,53(4):789-806
For a stabilized Newmark time integration of dynamic contact problems of the rapidly sliding bodies, considering the equality and inequality contact constraints and a high-speed contact point motion sliding on the deforming contact surface, the velocity and acceleration contact constraints are derived. Also, to suppress the numerical oscillations accompanied by the node-to-segment contact of the finite element models, a pseudo-node-to-node contact technique is suggested with the linear shape function elements having the almost equal segment lengths on the contact surface. The numerical simulations are performed with a high-speed punch moving on the beam and the high-speed rotating disks to check the stability and accuracy of the solution. 相似文献
8.
Jiyoung Choi Toshio Takayama Hwan-Chul Yu Chan-Moon Chung Kazuaki Kudo 《Polymer》2012,53(6):1328-1338
Nanoporous films were prepared with alicyclic copolyimides (coPIs) having polypropylene glycol (PPG) side chains by way of spontaneous phase separation in the film forming process and the subsequent thermal degradation of PPG moieties. PIs having various content (6.5, 11.9, 26.3, 52.7 wt%) and different length (Mw = 1.2 × 103 and 2.4 × 103) of PPG side chains were examined in order to clarify the relationship between chemical structure and pore characteristics. Nanopores were formed by heating the coPI films at 200 °C for 9 h under slightly reduced pressure. The size and the number of the pores observed by SEM varied depending on the content and molecular weight of PPG moieties. In many cases, the pore size was larger than those of the reported values for related aromatic copolyimide films. The dielectric constant of the nanoporous films ranged from 2.52 to 3.38. 相似文献
9.
Satoshi Semboshi Shigeo Sato Mikio Ishikuro Kazuaki Wagatsuma Akihiro Iwase Takayuki Takasugi 《Metallurgical and Materials Transactions A》2014,45(8):3401-3411
We investigated the precipitation processes in Cu-4 mol pct Ti alloy specimens aged at 723 K (450 °C), by means of X-ray diffraction and chemical analyses of the precipitates extracted from the parent alloy specimens. Aging-induced precipitate particles of a spinodally decomposed disorder, α′; those of a metastable order, β′-Cu4Ti; and those of a stable order, β-Cu4Ti, were continuously formed in the aged specimens. The extraction of the precipitate particles from the aged specimens by submergence in a nitric solution allowed for not only the structural analyses of the constituent precipitate phases but also the quantitative evaluation of their chemical compositions and volume fractions. Early during the aging process, the supersaturated Cu solid solution decomposes spinodally in a continuous manner, and an unstable disorder, α′, appears. Then, fine needle-shaped β′-Cu4Ti particles, which have a Ti content of approximately 37.5 mol pct, form in the Cu matrix. During prolonged aging, coarse cellular components composed of the terminal Cu solid solution and stable β-Cu4Ti particles which have a Ti content of 20.5 mol pct nucleate and grow, primarily in the grain boundaries, at the expense of the metastable β′-Cu4Ti particles. The volume fraction of the β′-Cu4Ti particles in the alloy reaches a maximum of approximately 1.7 pct after aging for 24 hours, while that of the β-Cu4Ti particles increases steadily to more than 18 pct after 480 hours. The volume fraction of the fine β′-Cu4Ti particles in the alloy specimens remained constant throughout the age-hardening, indicating that the hardening is primarily owing to the fine dispersion of the β′-Cu4Ti particles and not because of the large volume fraction of coarse β-Cu4Ti particles. 相似文献
10.
Main‐chain smectic liquid crystalline polymer exhibiting unusually high thermal conductivity in an isotropic composite 下载免费PDF全文
Shusuke Yoshihara Masatoshi Tokita Toshiaki Ezaki Mitsuru Nakamura Masashi Sakaguchi Kazuaki Matsumoto Junji Watanabe 《应用聚合物科学杂志》2014,131(6)
The thermal conductivity (TC) of an isotropic composite comprising of a main‐chain smectic liquid crystalline PB‐10 polyester and 50‐μm‐sized roughly spherical magnesium oxide (MgO) particles is investigated. The increase in the composite TC with higher MgO fractions is steeper than that expected by Bruggeman's theory for the TC of a polydomain PB‐10 polyester (0.52 W m?1 K?1). When the filler content is larger than 30 vol %, the composite TC approaches a value that can be explained only if the polyester functions as a matrix with 1.0 W m?1 K?1, which is five times as high as those of isotropic common polymers (0.2 W m?1 K?1). Such an unusually high TC for a polymer matrix is attributed to some polymer lamellae that lie parallel to the particle surface and are stacked toward neighboring particles, thus creating effective heat paths between the particles and a continuous thermal network in a composite. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014 , 131, 39896. 相似文献