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排序方式: 共有895条查询结果,搜索用时 15 毫秒
91.
Design methodology for a braided cylinder 总被引:1,自引:0,他引:1
Asami Nakai Akihiro Fujita Atsushi Yokoyama Hiroyuki Hamada 《Composite Structures》1995,32(1-4):501-509
In this study, the design methodology for a braided cylinder was presented. The concept of an analytical model which involved both micro model and macro model was proposed. The analytical method was applied to estimate the rigidity and elastic limit of a braided cylinder subjected to bending and torsional load independently and as combined load. Using the analysis method, the design of a braided cylinder would be carried out in consideration of the factors that decide the mechanical properties of braided cylinder. This method has the possibility to be useful for structural design of braided composites and can be included as a unit in CAE systems for braided composites. 相似文献
92.
Shoya Uchida Akihiro Sato Mamiko Inamori Yukitoshi Sanada Mohammad Ghavami 《Wireless Personal Communications》2014,79(2):987-1002
Overlapped FFT has been proposed as a signal detection scheme in dynamic spectrum access to reduce the variance of the noise and improve the detection probability. However, the improvement of the detection probability in the conventional overlapped FFT is bounded with the upper limit of the overlap ratio. This paper proposes a new overlapped FFT scheme using additional frames. In the proposed scheme, in addition to the original FFT frames, new frames that consist of multiple subframes with non-continuous samples are constructed and included. It can realize the increase of the number of the FFT frames and the improvement of the detection probability compared with the conventional scheme. Numerical results through computer simulation show that the proposed scheme improves the detection probability by up to 0.07. On indoor channel models the proposed scheme also improves the detection probability. In addition, it is clarified that as the delay spread increases the detection probability reduces due to the correlation between the frames. 相似文献
93.
Genki Yagawa Akihiro Matsuda Hideki Kawate Shinobu Yoshimura 《International Journal of Pressure Vessels and Piping》1995,63(3):303-313
This paper describes an application of the hierarchical neural network to the generation phase stable crack growth analysis of two kinds of welded CT specimens using the GE/EPRI simplified method. One of the specimens was machined from a submerged-arc-welded plate of nuclear pressure vessel A533B Class 1 steel, the other from an electron-beam-welded plate of A533B Class 1 steel and high-strength HT80 steel. A ratio of mixture of material constants was introduced to apply the GE/EPRI method to the analysis of crack growth in the welded specimens. The best ratio of mixture was identified using the neural-network-based inverse analysis approach as follows. At first, a number of generation phase crack growth analyses based on the GE/EPRI method were tested by parametrically varying the ratio of mixture. The relationship between the ratio of mixture and the calculated crack growth behavior is called here ‘learning data sets’. The neural network was then ‘trained’ using the learning data sets. In the training process, the calculated crack growth behavior is applied to the input units of the network, while the ratio of mixture is applied to its output units in the form of teaching data. Finally, the best ratio of mixture was estimated by applying measured crack growth behavior to the input units of the ‘trained network’. The effects of material inhomogeneity on crack growth behavior in the welded specimens are discussed with respect to the best ratio of mixture obtained. 相似文献
94.
Ishimori Y Mitsunobu F Yamaoka K Tanaka H Kataoka T Sakoda A 《Radiation protection dosimetry》2011,146(1-3):31-33
A radon test facility for small animals was developed in order to increase the statistical validity of differences of the biological response in various radon environments. This paper illustrates the performances of that facility, the first large-scale facility of its kind in Japan. The facility has a capability to conduct approximately 150 mouse-scale tests at the same time. The apparatus for exposing small animals to radon has six animal chamber groups with five independent cages each. Different radon concentrations in each animal chamber group are available. Because the first target of this study is to examine the in vivo behaviour of radon and its effects, the major functions to control radon and to eliminate thoron were examined experimentally. Additionally, radon progeny concentrations and their particle size distributions in the cages were also examined experimentally to be considered in future projects. 相似文献
95.
Sugano M Shimizu T Komatsu A Kakuta Y Hirano K 《Environmental science & technology》2011,45(6):2493-2497
Additive effects of glass powder upon the product yields and chlorine distribution after liquefaction of hydrothermally pretreated mixed waste (HMW) are compared with liquefaction of HMW with any one of water, quartz sand, or glass powder plus water. As a result, addition of either water or quartz sand did not affect liquefaction and dechlorination of HMW. Further, water (5 g) addition did not enhance liquefaction and dechlorination of HMW with glass powder. On the other hand, after liquefaction of HMW with glass powder, the yields of chlorine in the gas and water insoluble constituents decreased and the chlorine yield in the water-soluble constituent increased significantly. Because sodium in glass powder dissolved in a small amount (0.5 g) of water resulted from dehydration of HMW during liquefaction. Further, hydrogen chloride derived from polyvinylchloride in HMW was neutralized by ion exchange between H(+) and Na(+) dissolved in a small amount of water forming NaCl in the Residue (water-soluble) constituent. Therefore, most of chlorine in HMW was removed easily by water extraction of the Residue constituent after liquefaction of HMW with glass powder. Further, upgrading of HMW into the oil constituent was enhanced due to inhibition of production of chlorine containing organic compounds. Accordingly, it was clarified that glass powder was the most effective additive for liquefaction and dechlorination of HMW. 相似文献
96.
Hae-Seok Lee Hiroshi Okada Akihiro Wakahara Akira Yoshida Takeshi Ohshima Hisayoshi Itoh Shirou Kawakita Mitsuru Imaizumi Sumio Matsuda 《Solar Energy Materials & Solar Cells》2003,75(1-2):57-63
High-energy proton irradiation (380 keV and 1 MeV) on the electrical properties of CuInSe2 (CIS) thin films has been investigated. The samples were epitaxially grown on GaAs (0 0 1) substrates by Radio Frequency sputtering. As the proton fluence exceeded 1×1013 cm−2, the carrier concentration and mobility of the CIS thin films were decreased. The carrier removal rate with proton fluence was estimated to be about 1000 cm−1. The electrical properties of CIS thin films before and after irradiation were studied between 80 and 300 K. From the temperature dependence of the carrier concentration in CIS thin films, we found ND=9.5×1016 cm−3, NA=3.7×1016 cm−3 and ED=21 meV from the fitting to the experimental data on the basis of the charge balance equation. After irradiation, a defect level was created, and NT=1×1017 cm−3 for a fluence of 3×1013 cm−2, NT=5.7×1017 cm−3 for a fluence of 1×1014 cm−2 and ET=95 meV were also obtained from the same fitting. The new defect, which acted as an electron trap, was due to proton irradiation, and the defect density was increased with proton fluence. 相似文献
97.
The narrow-gap compound semiconductor PbTe has high Hall mobility. The Fermi surface at the L-point in the Brillouin zone
has large anisotropy. In this work, we measured thermomagnetic effects in PbTe thin films to confirm anisotropy of the Nernst
coefficient A
Ne and show Nernst mobility from the ratio of A
Ne and the Seebeck coefficient S: μ
Ne = A
Ne/S. Angular dependences of the Nernst voltage show that A
Ne is independent of the angle between the temperature gradient and the magnetic field, because of the high L-point symmetry.
The calculated Nernst mobility was compared with the Hall mobility. Because the former is smaller, the Mott equation cannot
explain the Seebeck coefficient at room temperature. 相似文献
98.
A mass gain for copper nanoparticles with a mean diameter of 20 nm in a 20% oxygen-nitrogen atmosphere was measured at 150-300 °C using thermogravimetry (TG). The mass gain equilibrium of the copper particles differed at each temperature, and a threshold temperature was recorded. Oxide products, consisting mainly of Cu2O, formed on the copper nanoparticles below the threshold temperature. Above the threshold temperature, there was an initial, and drastic, formation of Cu2O, which then changed to CuO. The activation energy for the oxidation of the copper nanoparticles that could be calculated from the rate of the mass gain was an indication of the nano-effect of the copper nanoparticles. 相似文献
99.
Akihiro YamanoHiromitsu Kozuka 《Thin solid films》2011,519(6):1772-1779
Polymethylmethacrylate (PMMA)-perhydropolysilazane (PHPS) hybrid thin films doped with spiropyran were prepared by spin-coating, which were then converted into 0.26-1.7 μm thick, spiropyran-doped PMMA-silica hybrid films by exposure treatment over aqueous ammonia. The spiropyran/(spiropyran + PHPS + PMMA) mass ratio was fixed at a high value of 0.2 so that the films exhibit visual photochromic changes in color, while the PMMA/(PMMA + PHPS) mass ratio, r, was varied. The spiropyran molecules in the as-prepared films were in merocyanine (MC) and spiro (SP) forms, with and without an optical absorption at 500 nm, at low (r ≤ 0.2) and high (r ≥ 0.4) PMMA contents, respectively. When PMMA content r was increased from 0 to 0.2, the degree of the MC-to-SP conversion on vis light illumination was enhanced, while at higher r's the spiropyran molecules underwent photodegradation. When the silica film (r = 0) was soaked in xylene under vis light, the spiropyran molecules were almost totally leached out, while not on soaking in the dark. On the other hand, no leaching occurred for the film of r = 0.2 either in the presence or absence of vis light. These suggest that the introduction of PMMA is effective in improving the chemical durability of the films, while the silica film (r = 0) is an interesting material with a photoresponsive controlled-release ability. The pencil hardness of the films decreased with increasing PMMA content, but remained over 9H at r ≤ 0.4. 相似文献
100.
Jun‐Ichi Itoh Ikuya Sato Hideki Ohguchi Kazuhisa Sato Akihiro Odaka Naoya Eguchi 《Electrical Engineering in Japan》2005,152(3):65-73
This paper proposes a novel control method based on the virtual AC/DC/AC conversion for the matrix converter. The virtual AC/DC/AC conversion method is a very simple strategy to control the input current and the output voltage for the matrix converter. There are two new topics proposed in this paper. First, this paper proposes the minimum switching loss modulation on the virtual rectifier. In our proposed modulation, only two arms switching in the virtual rectifier using DC link current control by the virtual inverter can obtain clean sinusoidal input current. Second, a novel lean controlled carrier modulation on the virtual inverter is proposed. The leans of the triangle carrier are controlled by the duty ratio of the rectifier side pulse. The lean controlled carrier reduces harmonic distortion of the input current by avoiding interference between the rectifier control and the inverter control. These new proposals are confirmed by simulation and experimental results. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 152(3): 65–73, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20144 相似文献