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21.
Sei-Ichi Aiba Masato Izume Norihiko Minoura Yukihiko Fujiwara 《Polymer International》1985,17(1):38-40
Chitin membrane was prepared by casting a N,N-dimethyl acetamide, N-methyl 2-pyrrolidone and lithium chloride (DMA-NMP-LiCl)solution of chitin and coagulating with several media. The effect of the coagulants on membrane formation was studied. 2-Propanol was found to be more favourable than methanol, ethanol, acetone and mixtures of 2-propanol and water. The membrane obtained in 2-propanol was subjected to annealing. Annealing made the membrane dense and strong. The tensile strength of the membrane annealed at 145°C for 2hr was about twice that of an unannealed membrane. The solute permeability of the annealed membranes was lower than that of the original one. These phenomena could be clearly interpreted in terms of crystallinity. 相似文献
22.
Ken Kato Yasuhiro Kasuga Masanori Fujiwara Kazuo Onda 《Electrical Engineering in Japan》1996,116(4):94-108
Laboratory-scale and parametric experiments of SO2 and NOx removal from the simulated combustion gas by pulsed corona discharge have been performed by changing the combustion gas composition and temperature, the electrode configuration of plasma reactor, and the polarity of high-voltage electrode. The following results are obtained: 1) the higher the concentration of H2O and O2, the higher the efficiency of desulfurization and denitrification at the same specific input; 2) the pulsed corona discharge with a voltage pulsewidth as short as 200 ns of negative polarity shows the possibility to attain almost 90 percent deSOx and deNOx efficiency at the specific discharge input of 20 J/g, which is almost the same as the specific input in the electron-beam process; 3) the deNOx characteristics show a little temperature dependence in the range of 70 to 130°C, but the deSOx efficiency increases rapidly in the temperature region below 100°C suggesting the thermochemical dependence of deSOx reaction; 4) when desulfurization and denitrification proceed, the white dendritic powder deposits on the plasma reactor whose composition is identified to be 49 mol% (NH4)2SO4 and 47 mol% of 2NH4NO3 · (NH4)2SO4, and the ratio of SO2, NO and NH3 of the deposit is almost equal to that of supplied gas. 相似文献
23.
Makoto Hino Minoru Hiramatsu Koichi Akiyama Hitoshi Kawasaki Masato Tsujikawa Makoto Kawamoto 《Materials and Manufacturing Processes》1997,12(1):37-46
A high powered YAG laser with kaleidoscope for surface modification was applied to the surface hardening of carbon steels containing 0. 18-0.54 wt% C without the absorbents, and the relationships between laser processing and surface hardening were investigated by hardness and microstructure. The structure of the hardened zone underwent complete martensitic transformation in all of the carbon steels tested, and its hardness increased with greater carbon content. Under identical irradiated conditions, the hardened zone expanded with increasing carbon content. A hardened zone extending from the surface to a depth of 1.0 mm was obtained at a laser power of 1.0 kW and a scanning speed of 1 mm/sec. It was found that in the surface hardening of carbon steels, a high powered YAG laser can be used to control the hardened zone by selecting the appropriate irradiation conditions, however, the hardened zone was affected by the assistant gas and the flow rate. 相似文献
24.
An improved T -Ω method that can analyze magnetic fields produced not only by eddy currents but also by magnetizing currents is proposed. The method is applied to the analysis of 3-D eddy-current models with holes. The usefulness of the method is investigated by comparing calculated results with measured results and with results obtained by the A -Φ method. The T -Ω method has the advantage that the CPU time can be considerably reduced when most of the analyzed region is current-free and the eddy current flows two-dimensionally. The method is especially effective when the shape of the winding is simple and the distribution of magnetizing current is known beforehand. It is not effective when most of the analyzed region is current-carrying 相似文献
25.
Komoda M. Kawashima T. Arakane M. Aihara M. Fujiwara Y. Shinagawa J. 《Power Delivery, IEEE Transactions on》1991,6(2):541-545
A cable fault location instrument based on the detection of traveling wave currents was developed. It is different from the conventional pulse radar method based on voltage detection. Measurement is automated, and the distance to the fault point is displayed by merely pushing a switch. In a branched or crossbonded line, the fault point can be located without interference from the branched or the crossbonded point. Tests performed in both real and simulated lines confirmed the practical utility of this instrument 相似文献
26.
Far-infrared reflection spectra of dielectric ceramics, BaSm2 Ti5 O14 , BaTi4 O9 , and some pcrovskites such as Ba(Zn1/3 Nb2/3 )O3 , have been measured at room temperature using a Fourier transform infrared spectrometer in order to investigate the effect of the crystal structure on the dielectric properties. As for perovskites, Sr(Zn1/3 Nb2/3 )O3 and Sr(Mg1/3 Nb2/3 )O3 , in which B site ions are ordered, were also measured. Reflectance data were analyzed by means of a factorized form of dielectric functions instead of the classical dispersion theory, and all of the spectra were well fitted. The values of dielectric constants and tan δ calculated from the reflectance data were in good agreement with resonant cavity measurements at 5 GHz. Furthermore, results of this study have shown that the main contribution to the microwave dielectric properties is caused by low-frequency optically active modes located at 50 to about 300 cm−1 , and for perovskite structures it is suggested that the ordering of B site ions is significant in obtaining low dielectric losses. 相似文献
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29.
Fujiwara T. Ito M. Kasami T. Kataoka M. Okui J. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》1991,37(2):379-384
The problem of distributing a Cartesian product file on multiple disks to maximize the parallelism for partial match queries is addressed. C. Faloutsos et al. (1989) have proposed an allocation method for Cartesian product files on multiple disks by using linear error-correcting codes. The performance of the allocation method is analyzed. Some conditions under which the allocation method is strictly optimal for queries with a given number of unspecified attributes are presented. A necessary and sufficient condition for a linear code to give a strictly optimal allocation method is discussed. Formulas for the average response time on queries with w unspecified attributes, denoted T w, in terms of the weight distribution of the code or its dual code, and formulas for the average response time T on all queries, are given. Several examples whose average response times T w or T are close to theoretical lower bounds are presented 相似文献
30.
Takanori Inoue Keiichiro Hoashi Koichi Eguchi Hiromichi Arai 《Journal of Materials Science》1993,28(6):1532-1536
The electrode characteristics of perovskite-type oxides, La0.6Sr0.4CoO3 and La0.6Sr0.4MnO3, on ceria-based oxide and stabilized zirconia were analysed by the a.c. impedance method. The ionic conductivities of the electrolyte and electrode conductivities from the a.c. impedance analysis agreed with those obtained from the current interruption and d.c. four-probe methods. Two semicircles from the charge transfer and diffusion processes appeared as the electrode resistance. The relative contribution of these two processes to the overall electrode resistance strongly depended on the microstructure of the electrode. The electrode microstructure could be controlled by the dispersion medium used for the electrode slurry. The La0.6Sr0.4MnO3 electrode coated with n-butyl acetate slurry exhibited the smallest electrode resistance. 相似文献