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191.
Takayuki Komatsu Kazuhide Shioya Kazumasa Matusita 《Journal of the American Ceramic Society》1993,76(11):2923-2926
To fabricate transparent oxide glasses containing ferroelectric KNbO3 crystals, a new method in which KNbO3 particles are directly incorporated into TeO2 ─K2 O─Nb2 O5 glasses has been developed. Transparent TeO2 -based glasses containing KNbO3 crystals with a diameter of ∼ 10 μm have been first successfully fabricated by adjusting temperature and time for incorporation. A small difference in the refractive indexes, n , between TeO2 -based matrix glasses ( n = 2.0) and incorporated KNbO3 crystals ( n = 2.21) is a significant reason for the transparency. This new method is applicable for the fabrication of new transparent glasses containing other functional materials with high refractive indexes. 相似文献
192.
Teruya Yamanishi Masashi Nosaka Haruhiko Nishimura Kazumasa Ohkuma 《Neural Processing Letters》2008,27(2):115-123
Stevens’ law, which is one of the well-known psychophysical laws, suggests that the perceived intensity R of a biological system is proportional to the power of the stimulus strength I, R ∝ I
n
. In order to realize a self-sustainable system that adapts to changes of the environment, it is important to understand the
neural mechanism behind this law. Here, we propose a new neural scheme based on the shunting short-term memory (STM) model
with the physiological properties of the nervous system, and examine the relation between the neural system and Stevens’ law
through computer simulations of the firing rate f with respect to the stimulus strength I. The simulations showed that the feedback-inputting connectivity plays an important role in reproducing the n > 1 and n < 1 cases of Stevens’ law. 相似文献
193.
Takeshige Takahashi Kazumasa Abe Takami Kai Hisamichi Kimura Takeshi Masumoto 《加拿大化工杂志》1992,70(1):197-200
The hydrogenation of benzene has been carried out over a catalyst prepared from an amorphous Pd-Zr alloy held in an alumina matrix. The catalytic activity was compared with that over the alloy cut into 1 mm fragments. It was found that the fixed alloy in the alumina had not only higher catalytic activity, but also a smaller catalyst fouling rate than the fragments of the alloy. The effect of palladium content in the amorphous alloy on the hydrogenation activity was examined. It was found that the initial activity increased with the fraction of palladium. However, the activity of the catalyst which had the highest palladium content decreased with repeated regeneration and reaction, whereas the activity of the other catalysts reached a stable value. 相似文献
194.
Takayuki Komatsu Michiko Ueta Tomohiro Ohki Ryuji Sato Kazumasa Matusita 《Journal of the American Ceramic Society》1992,75(7):1864-1869
The Ba-doped superconducting (Bi,Pb)2 Sr2- x Ba x Ca2 Cu3 O y and (Bi,Pb)2 Sr2 Ca2- x Ba x Cu3 O y (0 ≦ x ≦ 1.0) were prepared by using a melt-quenching method, and the effect of Ba additions on the glass-forming ability and the crystalline phase was examined. The glass-forming ability was not improved by substitution of Ba for Sr or Ca, and particularly BaPbO3 as well as CaO was observed in the melt-quenched sample of (Bi,Pb)2 SrBaCa2 Cu3 O y . BaPbO3 crystals were precipitated in all glass-ceramics with Ba substituted for Sr or Ca. The partial substitution of Ba substituted for Sr was effective for the formation of the high- T c phase, and (Bi,Pb)2 Sr1.4 Ba0.6 Ca2 Cu3 O y glass-ceramics obtained by annealing at 830°C for 100 h exhibited superconductivity with a T c of 103 K, although BaPbO3 and the low- T c phase were still largely present. 相似文献
195.
Removal of phenolic endocrine disruptors by Portulaca oleracea 总被引:1,自引:0,他引:1
Imai S Shiraishi A Gamo K Watanabe I Okuhata H Miyasaka H Ikeda K Bamba T Hirata K 《Journal of Bioscience and Bioengineering》2007,103(5):420-426
Portulaca oleracea, a garden plant prevalent from spring to autumn in Japan, showed the ability to efficiently remove from water bisphenol A (BPA), which is well known as an endocrine disrupting compound (EDC) having estrogenic properties. In water culture, 50 muM BPA was almost completely removed within 24 h when the ratio of whole plant weight to the water volume was set up at 1 g to 25 ml. The estrogenic activity of the water decreased in parallel with the elimination of BPA. This plant also rapidly removed other EDCs having a phenol group including octylphenol (OP), nonylphenol (NP), 2,4-dichlorophenol (2,4-DCP) and 17beta-estradiol and, thereby, removed the endocrine disrupting activities. In addition, the ability of P. oleracea to remove BPA was not affected by BPA concentration (up to 250 microM), by cultivation in the dark, by temperatures ranging from 15 degrees C to 30 degrees C, or by pH ranging from 4 to 7. Moreover, the ability of P. oleracea to individually remove BPA, NP, and OP was the same as when they were all present. These results suggest that P. oleracea is a promising material for practical phytoremediation of landfill leachates and industrial wastewater contaminated with the tested EDCs. 相似文献
196.
The central demagnetizing factor was calculated when the B–H curve of the specimen is given by a straight line using three-dimensional axial symmetrical finite element method (FEM). It is shown that the results obtained with FEM are almost similar to those reported by Bozorth. The central demagnetizing factor was calculated and the distribution of lines of magnetic flux was examined when (1) the coil length is modified for a constant specimen length and (2) when the specimen length is changed for a constant coil length. Moreover, we examined the influence of the relative permeability on the central demagnetizing field and calculated the central demagnetizing factor for the material whose B–H curve is non-linear. 相似文献
197.
Cermet/iron alloy cladding layers were coated on the surface of Al–Mg–Si alloy(A6061) plates by resistance seam welding method with tungsten carbide(WC) and high-carbon iron alloy(SHA) powders.The cladding layer consisted of WC reinforcement,SHA binder,A6061 and Fe Al3.The effect of WC ratio(30 wt%,50 wt% and 70 wt%) on the microstructure and wear behavior of the cladding layers was investigated in detail.Abrasive wear test was performed under two kinds of load condition by using a rubber wheel apparatus to evaluate wear resistance.The results showed that the wear resistance of the cladding layer was improved by 3.5–5 times than that of the substrate.At lower load,the wear resistances of the samples 30% and 70% WC were nearly the same,which suggested that Fe Al3 played an important role in improvement of the wear resistance instead of WC.While at higher load,the amount of WC determined the wear resistance of the cladding layer.Furthermore,wear behavior of these cladding layers was explained with reference to the observed microstructure of the worn surface. 相似文献
198.
Poly(L ‐lactide) (PLLA) films having different crystallinities (Xc's) and crystalline thicknesses (Lc's) were prepared by annealing at different temperatures (Ta's) from the melt and their high‐temperature hydrolysis was investigated at 97°C in phosphate‐buffered solution. The changes in remaining weight, molecular weight distribution, and surface morphology of the PLLA films during hydrolysis revealed that their hydrolysis at the high temperature in phosphate‐buffered solution proceeds homogeneously along the film cross‐section mainly via the bulk erosion mechanism and that the hydrolysis takes place predominantly and randomly at the chains in the amorphous region. The remaining weight was higher for the PLLA films having high initial Xc when compared at the same hydrolysis time above 30 h. However, the difference in the hydrolysis rate between the initially amorphous and crystallized PLLA films at 97°C was smaller than that at 37°C, due to rapid crystallization of the initially amorphous PLLA film by exposure to crystallizable high temperature in phosphate‐buffered solution. The hydrolysis constant (k) values of the films at 97°C for the period of 0–8 h, 0.059–0.085 h–1 (1.4–2.0 d–1), were three orders of magnitude higher than those at 37°C for the period of 0–12 months, 2.2–3.4×10–3 d–1. The melting temperature (Tm) and Xc of the PLLA films decreased and increased, respectively, monotonously with hydrolysis time, excluding the initial increase in Tm for the PLLA films prepared at Ta = 100, 120, and 140°C in the first 8, 16, and 16 h, respectively. A specific peak that appeared at a low molecular weight around 1×104 in the GPC spectra was ascribed to the component of one fold in the crystalline region. The relationship between Tm and Lc was found to be Tm (K) = 467·[1–1.61/Lc (nm)] for the PLLA films hydrolyzed at 97°C for 40 h. 相似文献
199.
Tip-enhanced Raman spectroscopy (TERS) has emerged as a powerful tool for optical imaging at nanoscale spatial resolution, and for investigating the vibrational properties of molecules adsorbed on a substrate. Plasmonic enhancement of the electromagnetic fields near a metallic nanostructure plays a very important role in TERS, where resonant excitation of plasmons is crucial. When two metallic nanostructures are placed at a gap of nanometric distance, their plasmons can interact with one other and result in hybridized shifted plasmon modes. Here, we apply this idea to TERS and demonstrate a significant tunability of the plasmon resonance enabling large electric field enhancement at a desired excitation wavelength. This finding paves the way for efficient optimization of TERS in imaging and spectroscopy applications. 相似文献
200.
Tsukasa Yoshida Jingbo Zhang Daisuke Komatsu Seiichi Sawatani Hideki Minoura Thierry Pauporté Daniel Lincot Torsten Oekermann Derck Schlettwein Hirokazu Tada Dieter Wöhrle Kazumasa Funabiki Masaki Matsui Hidetoshi Miura Hisao Yanagi 《Advanced functional materials》2009,19(1):17-43
Electrodeposition of inorganic compound thin films in the presence of certain organic molecules results in self‐assembly of various hybrid thin films with new properties. Examples of new discoveries by the authors are reviewed, taking cathodic formation of a ZnO/dye hybrid as the leading example. Hybridization of eosinY leads to the formation of highly oriented porous crystalline ZnO as the consequence of dye loading. The hybrid formation is a highly complicated process involving complex chemistry of many molecular and ionic constituents. However, electrochemical analyses of the relevant phenomena indicate the possibility of reaching a comprehensive understanding of the mechanism, giving us the chance to further develop them into industrial technologies. The porous crystals are ideal for photoelectrodes in dye‐sensitized solar cells. As the process also permits the use of non‐heat‐resistant substrates, the technology can be applied for the development of colorful and light‐weight plastic solar cells. 相似文献