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91.
Hayao Imamura Takayuki Nuruyu Tatsuya Kawasaki Toshihiro Teranishi Yoshihisa Sakata 《Catalysis Letters》2004,96(3-4):185-187
For the liquid-phase partial hydrogenation of benzene at 483 K, the selectivity toward cyclohexene was greatly improved upon treating rare earth nitride with ammonia. For YbN obtained by thermal decomposition of Yb(NH2)2 at 1173 K, the selectivity of the NH3-treated YbN was 75%, in contrast to nil for the untreated YbN. 相似文献
92.
Hayato Komatsu Tadanao Zanma Tatsuya Suzuki Shigeru Okuma 《Electrical Engineering in Japan》2003,142(2):68-75
In real control systems, certain constraints are placed on the input, state, and output values. If such constraints are violated, the system may become unstable, in a worst‐case scenario. One of the promising approaches to solving this problem is to switch the controller according to the state of the closed‐loop system. No useful design strategy for each controller, however, has yet been developed. In addition, the determination of the controller state at the instant of controller switching has not been investigated. First, this paper presents a new design methodology which merges the switching control and H∞ controller design into one design algorithm. Second, this paper presents a way of determining the controller state at the instant of controller switching. Finally, the proposed method is applied to force control of a one‐DOF manipulator in order to demonstrate the usefulness of the proposed method. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 142(2): 68–75, 2003; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10082 相似文献
93.
Natsuko Sakai Tatsuya Kawada Harumi Yokokawa Masayuki Dokiya Isao Kojima 《Journal of the American Ceramic Society》1993,76(3):609-616
Investigations have been made on the low-temperature sinterability of calcium-doped lanthanum chromites which are to be used as interconnectors in solid oxide fuel cells (SOFCs). Nominally chromium deficient lanthanum calcium chromites (La0.7 Ca0.3 Cr1 -y O3 , y = 0.02) were found to be sinterable to 94% theoretical density at 1573 K in air, whereas no densification was observed for samples with y = 0. The two-step shrinkage process suggests a liquid phase sintering mechanism with calcium oxychromates playing an important role as the liquid phase. After sintering at 1573 K, calcium-rich substances remained at grain boundaries. 相似文献
94.
In this study, the oxidation of ferrous iron by the acidophilic iron-oxidizing bacteria was investigated by field survey and laboratory-scale batch and continuous experiments. The activity of the acidophilic iron-oxidizing bacteria was affected by pH, water temperature and concentration of glucose. The rate of oxidation of pyrite was accelerated by the acidophilic iron-oxidizing bacteria. The number of bacteria attached to the surface of a rotating biological disk changed with the ferrous iron loading. 相似文献
95.
Masahiro Tabata Yoshikazu Nishida Tatsuya Kodama Keisuke Mimori Takashi Yoshida Yutaka Tamaura 《Journal of Materials Science》1993,28(4):971-974
An oxygen-deficient Mn(II) ferrite (Mn0.97Fe2.02O3.92) was synthesized and its reactivity to reduce CO2 gas into carbon was studied at 300°C. The oxygen-deficient Mn(II) ferrite was obtained by flowing H2 gas through Mn(II) ferrite with a nearly stoichiometric composition of Mn0.97Fe2.02O4.00 at 300° C. The lattice constant of the oxygen-deficient Mn(II) ferrite (0.8505nm) is larger than that of the Mn(II) ferrite with a nearly stoichiometric composition (0.8498nm). The chemical composition of the Mn(II) ferrite changed from Mn0.97Fe2.02O4.00 to Mn0.97Fe2.02O3.92 during the H2 reduction process, indicating that the oxygen is deficient in the spinel structure of the Mn(II) ferrite. This was confirmed by Mössbauer spectroscopy and X-ray diffractometry. The efficiency of CO2 decomposition into carbon at 300°C with the oxygen-deficient Mn(II) ferrite was much lower by about 105 than that of oxygen-deficient magnetite. This is considered to be due to the difference in electron conductivity between Mn(II) ferrite and magnetite, which determines the reductivity for CO2 into carbon by donation of an electron at the adsorption site. 相似文献
96.
Hidenori Yahiro Tatsuya ohuchi Koichi Eguchi Hiromichi Arai 《Journal of Materials Science》1988,23(3):1036-1041
The ionic conduction of oxygen in the ceria-alkaline earth oxide system was investigated as a function of temperature, partial pressure of oxygen and oxide composition, together with its crystal structure, density, and microstructure. Undoped ceria and its solid solution with alkaline earth oxides have a cubic fluorite structure. The ionic conductivity of ceria is greatly enhanced by additions of calcia and strontia, even when they are added in excess of the solubility limit. The conductivities of ceria-calcia and ceria-strontia were much higher than those of calcia-and yttria-stabilized zirconia. Up to the limit of calcia and strontia, the ionic transference number was nearly unity in the temperature range between 600 and 900°C. With an increase in calcia and strontia content, the ionic conductivity was little affected by the presence of a second phase of CaO and SrCeO3. 相似文献
97.
Tatsuya Motoki 《Journal of Computer and System Sciences》1984,29(3):312-329
A result/concept on star height is applied to two problems in the theory of control structures. First, Kosaraju's systems REn of control structures are generalized and it is shown by using Cohen's result on star height that the generalized systems constitute a pathwise hierarchy with respect to their expressive powers. Second, by using a concept on star height, a result of Peterson et al. (Comm. ACM16 (1973), 503–512) that RE∞ is pathwise complete is sharpened. 相似文献
98.
99.
Morita N Takamura N Ashizawa K Shimasaki T Yamashita S Okumura Y 《Radiation protection dosimetry》2005,113(3):326-329
To understand the current situation of internal radiation exposure in the population around the Chernobyl Nuclear Power Plant (CNPP), we examined the 137Cs body burden in six residents of Belarus, Ukraine and Russia in 2002 and 2004 using the whole-body counter (WBC) at Nagasaki University (Japan). The data were compared with those of our previous study performed in 1993-1994 using the same method. In 2002 and 2004, peaks of 137Cs were detected in two residents from Gomel, which was heavily contaminated by the CNPP accident, one from Minsk (Belarus) and one from Kiev (Ukraine), but another resident from Minsk showed no 137Cs peaks. The results of the present study suggests that residents around the CNPP are still exposed to chronic 137Cs internal irradiation, probably due to the daily consumption of contaminated domestic foods, but the risk of any disease by the irradiation is quite low. Long-term follow-up of WBC around the CNPP is useful and may contribute to radiation safety regulation together with a reduction of unnecessary radiophobia for the residents. 相似文献
100.
Akio Makishima Michiko Kobayashi Takajiro Shimohira Tatsuya Nagata 《Journal of the American Ceramic Society》1982,65(12):210-C
Formation of aluminosilicate glasses containing oxides of rare-earth elements, e.g. Sc, Ce, Pr, Nd, Eu, Gd, Tb, Dy, Ho, Er, and Yb, was studied by melting at 1550°C and air quenching. The upper limit of the amount of rare-earth oxide which can be incorporated into the aluminosilicate glasses decreases according to the lanthanide contraction. 相似文献