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41.
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
42.
T. Fujitani T. Matsuda Y. Kushida S. Ogihara T. Uchijima J. Nakamura 《Catalysis Letters》1997,49(3-4):175-179
The effect of ZnO/SiO2 in a physical mixture of Cu/SiO2 and ZnO/SiO2 on methanol synthesis from CO2 and H2 was studied to clarify the role of ZnO in Cu/ZnO-based catalysts. An active Cu/SiO2 was prepared by the following procedure: the Cu/SiO2 and ZnO/SiO2 catalysts with a different SiO2 particle size were mixed and reduced with H2 at 523-723 K, and the Cu/SiO2 was then separated from the mixture using a sieve. The methanol synthesis activity of the Cu/SiO2 catalyst increased with the reduction temperature and was in fairly good agreement with that previously obtained for the
physical mixture of Cu/SiO2 and ZnO/SiO2. These results indicated that the active site for methanol synthesis was created on the Cu/SiO2 upon reduction of the physical mixture with H2. It was also found that ZnO itself had no promotional effect on the methanol synthesis activity except for the role of ZnO
to create the active site. The active site created on the Cu/SiO2 catalyst was found not to promote the formation of formate from CO2 and H2 on the Cu surface based on in situ FT-IR measurements. A special formate species unstable at 523 K with an OCO asymmetric
peak at ~1585 cm-1 was considered to be adsorbed on the active site.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
43.
Glyoxal, which was the strong mutagen formed by ozonation of humic substances, was treated with granular activated carbon (GAC) and the behavior of glyoxal was investigated. Glyoxal itself was adsorbed well on GAC at pH 5–7. But, glyoxal increased by GAC treatment of ozonated humic substances when the ozone dose was insufficient to decolorize the humic substances. The precursors of glyoxal may be among other ozonated products which may be changed to glyoxal on GAC. 相似文献
44.
The stability of lamellar structure is crucial for the creep resistance of TiAl alloys, but degradation of the lamellar structure
is unavoidable at high temperatures. The degradation of the lamellar structure in PST crystals of Ti-48mol.%Al was studied
during high temperature exposure (annealing and creep testing) to examine how to make a stable lamellar structure with high
creep deformation resistance. Since the six orientation variants of γ lamellae are nucleated independently of the adjoining
lamellae, pseudo twin and 120° rotational fault boundaries are most frequently observed at the initial stage of lamellar formation.
The preferential removal of high energy (pseudo twin and 120° rotational fault) boundaries during the evolution of lamellar
structure results in the highly probable appearance of a true twin boundary at a later stage of lamellar evolution. The coarsening
of lamellar spacing and the spheroidization of the lamellae are the major degradation events occurring during creep deformation,
and the migration of the lamellar boundaries brings both of them about. The lamellar structures of TiAl alloy contain four
types of lamellar boundaries. The stability of the four types of boundaries decreases in the following order: γ/α2 > true twin > pseudo twin > or=120° rotational fault boundaries. The γ/α2 boundary has the highest stability (lowest mobility), and the high density of γ/α2 boundaries is proposed to make a stable lamellar structure with good creep resistance. A material having the high density
of γ/α2 boundaries was produced through the heat treatment of a PST crystal in the α+γ two-phase regime. The excellent creep properties
of the material were proven through creep tests of hard oriented PST crystals made of the material.
This article is based on a presentation made in the 2002 Korea-US symposium on the “Phase Transformations of Nano-Materials,”
organized as a special program of the 2002 Annual Meeting of the Korean Institute of Metals and Materials, held at Yonsei
University, Seoul, Korea on October 25–26, 2002. 相似文献
45.
Development of flexible displays using back‐channel‐etched In–Sn–Zn–O thin‐film transistors and air‐stable inverted organic light‐emitting diodes 下载免费PDF全文
Mitsuru Nakata Genichi Motomura Yoshiki Nakajima Tatsuya Takei Hiroshi Tsuji Hirohiko Fukagawa Takahisa Shimizu Toshimitsu Tsuzuki Yoshihide Fujisaki Toshihiro Yamamoto 《Journal of the Society for Information Display》2016,24(1):3-11
We developed flexible displays using back‐channel‐etched In–Sn–Zn–O (ITZO) thin‐film transistors (TFTs) and air‐stable inverted organic light‐emitting diodes (iOLEDs). The TFTs fabricated on a polyimide film exhibited high mobility (32.9 cm2/Vs) and stability by utilization of a solution‐processed organic passivation layer. ITZO was also used as an electron injection layer (EIL) in the iOLEDs instead of conventional air‐sensitive materials. The iOLED with ITZO as an EIL exhibited higher efficiency and a lower driving voltage than that of conventional iOLEDs. Our approach of the simultaneous formation of ITZO film as both of a channel layer in TFTs and of an EIL in iOLEDs offers simple fabrication process. 相似文献
46.
Tetsuro Kobayashi Jeffrey Boase Tsutomu Suzuki Takahisa Suzuki 《Journal of Computer-Mediated Communication》2015,20(3):330-345
The tele‐cocooning hypothesis posits that mobile communication increases interaction with communication rich ties, while simultaneously weakening interaction with communication weak ties. In this study, we demonstrate how smartphones can be used to mitigate tele‐cocooning behavior by stimulating interaction with communication weak ties. Using a smartphone application to collect non‐identifying mobile communication log data, we conducted a field experiment with 193 Japanese participants. The treatment consisted of onscreen reminders designed to stimulate interaction with communication weak ties. The results indicate that the treatment promoted the activation of communication weak ties and the acquisition of information through those ties, suggesting that smartphones can be utilized to promote access to social capital. 相似文献
47.
Takayuki Goto Takao Watanabe Kyoichi Kinoshita Azusa Matsuda Masafumi Sera Tetsuo Fukase 《Journal of Low Temperature Physics》1996,105(3-4):401-406
Cu-NMR spectra and the nuclear spin-lattice relaxation rate T
1
-1
have been studied intensively on the bilayer type high-Tc cuprate La1.89Ca1.11Cu2O6+ (La2126). The resonance line shift showed a monotonic decrease with lowering temperature in the normal state, indicating that this compound belongs to the lightly-doped region. The Curie-Weiss temperature dependence of (T1T)–1 in the normal state shows that the pseudo spin-gap does not always exist in the light-doped bilayer systems. 相似文献
48.
CH Park K Nishimura M Kitano K Matsuda Y Okamoto T Ban 《Canadian Metallurgical Quarterly》1996,111(5):1092-1102
This study investigated the mechanism of right ventricular failure during bypass of the left side of the heart by precisely assessing right ventricular function with use of a conductance catheter. Bypass of the left side of the heart was established with a centrifugal pump in 10 mongrel dogs weighing 11 to 19 kg. Right ventricular function during left heart bypass was evaluated by two parameters that were both derived from measurement of relative change in right ventricular volume by the conductance catheter technique. One parameter was the right ventricular end-systolic pressure-volume relationship as a load-independent index, and the other was the peak right ventricular pressure-right ventricular stroke volume relationship as a "force-velocity relationship." These parameters were measured in both normal and failing hearts while afterload was increased by bilateral intrapulmonary balloon inflation. Moreover, changes in these relationships were observed by varying assist ratios of left heart bypass from 0% to 100%. Failing heart models were induced by normothermic aortic clamping for 20 minutes. The right ventricular end-systolic pressure-volume relationship in normal hearts did not change, irrespective of the assist ratio of left heart bypass, whereas that in failing hearts decreased from 4.25 +/- 1.41 mm Hg/ml without bypass of the left side of the heart to 3.53 +/- 1.30 mm Hg/ml after 100% assist of left heart bypass (p < 0.05). In the peak right ventricular pressure-right ventricular stroke volume relationship, right ventricular stroke volume was almost constant in normal hearts when afterload was increased regardless of the assist ratio of left heart bypass. Moreover, right ventricular stroke volume was maintained at a higher level during bypass of the left side of the heart compared with that without left heart bypass. However, that slope of the relationship in failing hearts was inversely linear and became significantly steeper after 100% assist of bypass of the left side of the heart compared with that without left heart bypass (-0.131 +/- 0.042 versus -0.051 +/- 0.038, p < 0.005). Therefore ++these two slopes of the relationship intersected at a point that was considered the critical point of afterload during bypass of the left side of the heart. In other words, right ventricular stroke volume was decreased by 100% left heart bypass above the critical point of afterload. In conclusion, this study demonstrates not only that bypass of the left side of the heart results in an increase in right ventricular stroke volume in both normal and failing hearts at the physiologic range of afterload, but also that right ventricular function against higher afterload is impaired by 100% assist of bypass of the left side of the heart in failing hearts. 相似文献
49.
Hiroki Yamaguchi Tsuneo Hanawa Oto Yamamoto Yu Matsuda Yasuhiro Egami Tomohide Niimi 《Microfluidics and nanofluidics》2011,11(1):57-64
The tangential momentum accommodation coefficient (TMAC) was investigated experimentally from the mass flow rate through a
single microtube under the slip flow and the early part of the transition regime. The measurements were carried out by the
constant-volume method under the mean Knudsen number smaller than 0.3, which is based on the mean pressure of the inlet and
the outlet of the microtube, to apply the second-order slip boundary condition. To measure TMACs on various materials, quite
large microtube was employed, which require the reduction in leakage. TMAC was obtained from the slip coefficient determined
by the relation of the mass flow rate to the mean Knudsen number. The obtained mass flow rate was well explained by the theoretical
equation. TMACs of deactivated-fused silica with argon, nitrogen, and oxygen were measured, showing the tangential momentum
was not accommodated completely to the surface, and the values showed good agreement with previous studies. From the comparison
between microtubes with different inner diameter, it is showed that TMAC is determined mainly by gas species and surface material. 相似文献