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排序方式: 共有1582条查询结果,搜索用时 31 毫秒
31.
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
32.
Pressure effects on the low temperature state of the α-(BEDT-TTF)2MHg(SCN)4 organic conductor family
X. Chen J. S. Brooks S. Valfells G. J. Athas S. J. Klepper M. Tokumoto N. Kinoshita H. Anzai Y. Tanaka 《Synthetic Metals》1995,70(1-3)
Systematic magnetotransport measurements as a function of hydrostatic pressure have been made on four members of the α-(BEDT-TTF)2MHg(SCN)4 organic conductor family (M = K, Tl, Rb, NH4). Applied pressure above about 6 Kbar removes the density wave state for M = K, Tl, and Rb. For M = NH4 the superconducting state is removed with pressure as dTc/dP = − 0.25 K/Kbar. In all cases the Shubnikov de Haas oscillation frequency increases with pressure, including the β orbit (which involves the entire Brillouin zone), and new orbits involving very small fractions of the Fermi surface are formed. 相似文献
33.
Isamu Yamauchi Takashi Okamoto Hajime Ohata Itsuo Ohnaka 《Journal of Alloys and Compounds》1997,260(1-2):162-171
The effects of Cu addition on the β phase formation rate and the thermoelectric power in various FeSi2 and Fe2Si5 based alloys was examined. The peritectoid reaction (a+→β) in FeSi2 alloys was initially enhanced by the addition of Cu but it became slower for longer annealing times. The retained metallic ε was harmful for the thermoelectric power. The inherent thermoelectric properties of (FeSi2)99−XMn1CuX (X=0–1.O at.%), (FeSi2)99−X Co1CuX (X=0–1.0 at.%) alloys were attained after the elimination of ε. In the case of eutectoid reaction (→β+Si). Differential thermal analysis, X-ray diffraction and microscopic observation clearly confirmed that the eutectoid reaction rate was drastically enhanced by the addition of a small amount of Cu and its rate decreased with decreasing Cu content. The rate also depends on the annealing temperature and reached a maximum at about 1073 K for most alloys. The addition of only 0.1 at.% Cu was still very effective even in Mn or Co doped alloys. The thermoelectric power of these alloys increased very quickly with annealing time. Their final values decreased with Cu content and saturated at 0.2 at.% Cu. The value of the 0.1 at.% Cu added alloy was higher than that of both the conventional p- and a-type FeSi2 based alloys. These results suggest that the Fe2Si5 alloys with a small amount of Cu may be attractive as new thermoelectric materials. 相似文献
34.
Mutsumu Fukada Kiyotaka Kinoshita Toshiyuki Kajioka 《Journal of the Society for Information Display》2016,24(5):307-311
Abstract — This paper proposes a new process to manufacture cover glass that overcomes a strength trade‐off between the face and the edge. In the process, alkali barrier films are deposited on glass faces before an ion exchange process in order to control face stress properties without inhibiting the edge strengthening. As a demonstration of the process, alkali‐alumino‐silicate glass sheets with sputter‐deposited SiO2 films were chemically strengthened, and then their stress properties and strengths were investigated. As a result, thicker SiO2 films cause lower face DOL (depth of strengthened layer), and it is observed that the faces have lower DOL than the edges. In strength tests corresponding to major fracture modes of smartphone cover glass, specimens with 80–100 nm films have more balanced face performance and better edge impact strengths than the no‐film specimen. 相似文献
35.
Naruhiko Kasai Yasuyuki Kudo Masato Ishii Hiroshi Kageyama Hajime Akimoto Norihiro Nakamura Takao Onoye 《Journal of the Society for Information Display》2009,17(10):779-784
Abstract— An external driving circuit that has realized long lifetime, power‐consumption control, and peak luminance for organic light‐emitting diode (OLED) displays have been developed. This circuit realizes an effective method for constant‐anode‐voltage (CV) driving refered to as clamped inverter (CI) driving. The feature of CV driving is to achieve low‐power consumption compared with constant‐anode‐current (CC) driving and to control the power consumption and peak luminance according to the image because display luminance can be easily changed by controlling the anode voltage. On the other hand, CV driving has the problem that luminance deterioration appears to be serious compared with that of CC driving because the current of the OLED element decreases according to usage time. To cope with this, a lifetime compensation circuit that has increased the anode voltage so that it compensates for the luminance deterioration has been developed. This circuit can compensate not only the decrease in current but also the decrease in luminance at a constant current that CC driving cannot. However, increasing the anode voltage causes an increase in stress on the OLED element. The influence of stress on OLED lifetime was verified. As a result, it was confirmed that this circuit can extend the lifetime by 32% even if the anode voltage is increased, causing stress on the OLED structure. 相似文献
36.
Toshihide Miyagi Norihiro Abe Yoshimasa Kinoshita Tatsushi Tokuyasu Hirokazu Taki Shoujie He 《Artificial Life and Robotics》2009,14(2):237-241
In this article, a system is proposed for a simulated operation which would help a trainee surgeon to perform a medical operation
to ensure that a cerebral aneurysm does not burst. The physician will have acquired empirical medical technologies from operations
in traditional clinical teaching. However, there is a problem with safety and the burden to the patient. Therefore, recently
a new training approach for a simulated medical operation using virtual reality has been explored. With the aim of developing
a simulated system for a medical operation for a cerebral aneurysm, we considered the necessary functions such as detecting
the brain aneurysm that is the target of the operation, and searching for a suitable blood vessel to make a plan for the operation. 相似文献
37.
M. Okuya T. Kimura R. Kobayashi J. Shimoyama K. Kitazawa K. Yamafuji K. Kishio K. Kinoshita T. Yamada 《Journal of Superconductivity》1994,7(2):313-318
Large single crystals of (La1–x
Ca
x
)2CaCu2O6 were synthesized by the travelling solvent floating zone (TSFZ) technique. The dimension of the grown boules was typically 4 mm×30 mm long with thec-axis perpendicular to the growth direction. After oxygen loading at 1080°C in 400 atm of O2, they became superconductive with a sharp transition at around 50 K. The resistivity was metallic both along thec-axis and within theab-plane, with an anisotropy ratio of
2(
c/
ab
) 50 which is almost independent of temperature. Details of the crystal growth, heat treatment procedures, and the results of electrical and magnetic property measurements are presented. 相似文献
38.
We describe a direct x-ray imaging system that uses an amplified metal-oxide-semiconductor imager to detect soft x rays directly for real-time imaging. From the absolute sensitivity of this system as measured through the use of a monochromatic synchrotron radiation beam and a GaAsP Schottky-type photodiode, the minimum sensitivity at a wavelength of 13 nm was estimated to be greater than 10(8)photons mm(-2). This is sufficient to detect soft x rays directly for real-time imaging. Onion cell observations at wavelengths of 4.3 and 4.6 nm indicate that x-ray absorption by the carbon in the cells was detected. This is a promising imaging system for the soft x-ray region in which conventional CCD's are difficult to use. 相似文献
39.
Theoretical analysis of the spatial phase-matching loci for second-harmonic generation and multiwave-mixing interactions 总被引:1,自引:0,他引:1
We report a theoretical analysis on spatial noncolinear phase matching of multiwave mixing and its application to a second-harmonic-generation (SHG) experiment. From the numeric calculations, the noncolinear phase-matching properties in general situations were determined. The theory gives the applicability for all noncolinear phase matching. Fine coincidences between theoretical calculations and observed spatial loci on noncollinear phase-matching SHG were confirmed. Relations that allow the calculation of the noncollinear phase-matching angle for any case of SHG are established. As an example, the noncolinear phase-matched SHG pattern on a screen is calculated numerically in the case of SHG of 1064 nm from a Nd:YAG laser under the phase-matched condition for two organic nonlinear crystals: 1-(2-thienyl)-3-(4-methyphenyl) propene-1 (TC-28), which is biaxial, and (2-furyl) methacrylic anhydride (FMA), which is uniaxial. Experimental results compared quite favorably with the theoretical analysis. Noncolinear phase matching may be of great practical interest in optical multiwave-mixing processes, such as optical parametric oscillation and optical parametric amplification. This technique also can be used for the measurement of crystal optical constants. 相似文献
40.
Kiyoshi Itatani Takayasu Kubozono F. Scott Howell Akira Kishioka Makio Kinoshita 《Journal of Materials Science》1995,30(5):1196-1202
The sinterability of mullite (3Al2O3·2SiO2) powder prepared by chemical vapour deposition was examined to improve the conditions for fabricating dense mullite ceramics. The starting powder contained not only mullite, but also a small amount of -Al2O3 (Al-Si spinel) and amorphous material. Although the compressed powder was fired at a temperature between 1550 and 1700 °C for 1, 3 and 5 h, the relative densities of the sintered compacts were limited to 90%: (i) due to the creation of pores/microcracks during the solid state reaction (1100–1350 °C), and (ii) due to restriction on the rearrangement of grains because the amount of liquid phase (1550–1700 °C) was insufficient. Calcination of the starting powder was effective for preparation of easily sinterable powder with homogeneous composition. When the compact formed by compressing the calcined powder at 1400 °C for 1 h was fired at 1650 °C for 3 h, the relative density was raised up to 97.2%; moreover, mullite was the only phase detected from the sintered compact. The sintered compact was composed of polyhedral grains with sizes of 1–2 m and elongated grains with long axes of 6 m. 相似文献