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121.
The dispersion of the transverse zero sound in superfluid3He-B in the colisionless limit is studied theoretically. The dispersion is most easily understood as due to strong coupling between two distinct modes; the original zero-sound mode which is present in normal liquid and the collective mode with energy gap
t
(T) proportional to (T), the temperature-dependent energy gap.Work supported by the National Science Foundation. 相似文献
122.
Cheng-Lin LiuAuthor Vitae Kazuki NakashimaAuthor VitaeHiroshi SakoAuthor Vitae Hiromichi FujisawaAuthor Vitae 《Pattern recognition》2003,36(10):2271-2285
This paper presents the results of handwritten digit recognition on well-known image databases using state-of-the-art feature extraction and classification techniques. The tested databases are CENPARMI, CEDAR, and MNIST. On the test data set of each database, 80 recognition accuracies are given by combining eight classifiers with ten feature vectors. The features include chaincode feature, gradient feature, profile structure feature, and peripheral direction contributivity. The gradient feature is extracted from either binary image or gray-scale image. The classifiers include the k-nearest neighbor classifier, three neural classifiers, a learning vector quantization classifier, a discriminative learning quadratic discriminant function (DLQDF) classifier, and two support vector classifiers (SVCs). All the classifiers and feature vectors give high recognition accuracies. Relatively, the chaincode feature and the gradient feature show advantage over other features, and the profile structure feature shows efficiency as a complementary feature. The SVC with RBF kernel (SVC-rbf) gives the highest accuracy in most cases but is extremely expensive in storage and computation. Among the non-SV classifiers, the polynomial classifier and DLQDF give the highest accuracies. The results of non-SV classifiers are competitive to the best ones previously reported on the same databases. 相似文献
123.
Cheng-Lin Liu Author Vitae Kazuki Nakashima Author VitaeAuthor Vitae Hiromichi Fujisawa Author Vitae 《Pattern recognition》2004,37(2):265-279
The performance evaluation of various techniques is important to select the correct options in developing character recognition systems. In our previous works, we have proposed aspect ratio adaptive normalization (ARAN) and have evaluated the performance of state-of-the-art feature extraction and classification techniques. For this time, we will propose some improved normalization functions and direction feature extraction strategies and will compare their performance with existing techniques. We compare ten normalization functions (seven based on dimensions and three based on moments) and eight feature vectors on three distinct data sources. The normalization functions and feature vectors are combined to produce eighty classification accuracies to each dataset. The comparison of normalization functions shows that moment-based functions outperform the dimension-based ones and the aspect ratio mapping is influential. The comparison of feature vectors shows that the improved feature extraction strategies outperform their baseline counterparts. The gradient feature from gray-scale image mostly yields the best performance and the improved NCFE (normalization-cooperated feature extraction) features also perform well. The combined effects of normalization, feature extraction, and classification have yielded very high accuracies on well-known datasets. 相似文献
124.
Takahiro Murakami Hiromichi Kobayashi Yoshihiro Okuno Shigeharu Kabashima 《Electrical Engineering in Japan》1999,126(4):48-54
The influence of azimuthal non‐uniformity of the seed fraction on plasma structure and performance in a non‐equilibrium disk MHD generator is investigated with a two dimensional r–θ numerical simulation. It is found that a locally high seed fraction causes mainly non‐uniformity of gas‐dynamical properties, whereas a locally low seed fraction develops a non‐uniform plasma. Both locally high and low seed fractions reduce generator performance considerably. These results suggest a spatially uniform seed fraction should be required for high power generation. ©1999 Scripta Technica, Electr Eng Jpn, 126(4): 48–54, 1999 相似文献
125.
Structural and chemical stabilities of substituted hexaaluminate catalyst films coated on some ceramic substrates were investigated for high-temperature combustion applications. The thermal stability of the hexaaluminate catalyst films on -SiC substrate was greatly enhanced by the insertion of both, a neat hexaaluminate and mullite intermediate layer. Pure alumina substrate was preferable in depositing the substituted hexaaluminate catalyst film to pure mullite, mullite-zirconia composite, or partially stabilized zirconia substrates. The thermal stability of the hexaaluminate catalyst films, coated on these oxide ceramic substrates, greatly depended on the extent of diffusion of components between the film and substrate at high temperatures. The substituted hexaaluminate microparticles in the film rearranged during the sintering process above 1400°C, and their (00l) plane oriented parallel to the surface of the substrate. Manganese introduced in the substituted hexaaluminate films or disks gradually decreased with an increase in the heat-treatment temperature because of its volatilization. 相似文献
126.
Enrico Traversa Stefano Villanti Gualtiero Gusmano Hiromichi Aono Yoshihiko Sadaoka 《Journal of the American Ceramic Society》1999,82(9):2442-2450
Ultrafine SmFeO3 powders were prepared by the thermal decomposition at 700°C of the corresponding hexacyanocomplex, Sm[Fe(CN)6 ]·4H2 O. These powders were used for the preparation of pastes which were deposited as thick films on alumina substrates with comb-type Au electrodes. The films were fired at different temperatures in the 800-1000°C range. The content of α-terpineol, a component of the organic vehicle, was varied in the range 0.0046-4 wt%. The microstructure, the chemical composition at the surface, the electrical conductivity, and the NO2 sensing properties of the films were investigated. The content of α-terpineol strongly influenced the electrical conductivity and its activation energy. A significant reduction in the NO2 response was observed for the films containing smaller amounts of α-terpineol, together with an increase in conductivity. On the other hand, the largest NO2 response was observed for the films fired at 1000°C when 4 wt% of α-terpineol was used. Such increase in conductivity is attributed to a different oxygen surface layer on the SmFeO3 surface, which is induced by the decomposition reaction of α-terpineol during sintering. The materials processing parameters are thus of primary concern for the NO2 sensing properties of the SmFeO3 thick films. The correlations found between activation energy, NO2 sensitivity, and materials characteristics (influenced by the preparation parameters) are reported. These correlations can be used to design the gas-sensing properties of SmFeO3 thick films for the optimization of their sensing characteristics. 相似文献
127.
Yifan Zhang Kecheng Cao Takeshi Saito Hiromichi Kataura Hans Kuzmany Thomas Pichler Ute Kaiser Guowei Yang Lei Shi 《Nano Research》2022,(3):1709-1714
Sub-nanometer armchair graphene nanoribbons(GNRs)with moderate band gap have great potential towards novel nanodevices.GNRs can be synthesized in the confined t... 相似文献
128.
Shin'ichi Wakui Kazumasa Ide Miyoshi Takahashi Gustavo Montoya Futoshi Hiyama Yasuomi Yagi 《Electrical Engineering in Japan》1998,123(3):73-83
This paper describes variations of turbine generator steady-state reactances for load conditions. When the turbine generator is of small size, magnetic saturation of the stator and rotor core is a problem. Therefore, it is important to understand the variations of the reactances for load conditions. The reactances of a 592-MVA turbine generator are calculated with d- and q-axis equations considering magnetic saturation and two-dimensional numerical magnetic field analysis. The results are as follows. (1) The equivalent synchronous reactances considering cross-magnetizing are smaller than the original synchronous reactances for load conditions. (2) Numerical values of the d- and q-axis mutual reactance and the field and q-axis mutual reactance are at their maximum when the d-axis linkage flux is nearly equal to the q-axis linkage flux under constant voltage. (3) The d-axis synchronous reactance drops with increasing reactive power under constant voltage and active power, but the q-axis synchronous reactance increases. (4) The variation of the equivalent d-axis synchronous reactance with increasing reactive power is similar to that of the d-axis synchronous reactance, but the variation of the equivalent q-axis synchronous reactance is different from that of the q-axis synchronous reactance. © 1998 Scripta Technica. Electr Eng Jpn, 123(3): 73–83, 1998 相似文献
129.
ABSTRACT The isotopic exchange rate of Cs+ between hydrous niobium(V) oxide in the Cs+ form and aqueous solutions was determined radiochemically. The rate was controlled by the diffusion of Cs+ in the exchanger particle at varying pH. The diffusion coefficients at 10°C increased with pH up to pH7; from 3.0x10?11 m2s?1 at pH6 to 4.0×10?11 m2s?1 at pH7, and became constant above pH8 (5.0x10?11 m2s?1). While the diffusion coefficients of Na+ monotonously decrease with increasing pH; from 7.9×l0?11 m2s?1 at pH6.5 to 2.8×l0?11 m2s?1 at pHll. The difference in the dependence of diffusion coefficients on pH between Cs+ and Na+ was interpreted in terms of strength of interaction between counterions and ion-exchange sites since hydrous niobium(V) oxide has selectivity higher for Cs+ than for Na+. 相似文献
130.
Hiromichi Aono Takaaki Nishida Masato Kurihara Masatomi Sakamoto Yoshihiko Sadaoka 《Ceramics International》2012,38(3):2333-2338
New heteronuclear (NH4)REIII[FeII(CN)6]·nH2O complexes (RE = La, Ce, Pr, Nd, Sm, Gd, Dy, Y, Er, Lu) were synthesized and their thermal decomposition products were investigated. The crystal structure of (NH4)RE[FeII(CN)6]·nH2O would be a hexagonal unit cell (space group: P63/m), which was the same as that of La[FeIII(CN)6]·5H2O. The hydration number n = 4 was estimated by TG results for all the RE complexes. The lattice constants depended on the ionic radius of the RE3+ ion for the heteronuclear complexes. The single phase of the perovskite type materials was directly obtained by decomposition of the heteronuclear complexes for RE = La, Pr, Nd, Sm, and Gd. A mixture of CeO2 and Fe2O3 was formed for RE = Ce because of its oxidation to Ce4+. In the case of RE = Dy, Y, Er, and Lu complexes, the perovskite type materials formed at higher temperature via. mixed oxides such as RE2O3 and RE4Fe5O13 due to the small RE3+ ionic radius. 相似文献