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71.
72.
Yasushi Sekine Haruka Takamatsu Sho Aramaki Kazuki Ichishima Mitsuko Takada Masahiko Matsukata Eiichi Kikuchi 《Applied Catalysis A: General》2009,352(1-2):214-222
The water gas shift (WGS) reaction over Pt and Pd catalysts supported on various perovskite oxides has been investigated at 573 K without catalyst pretreatment. The Pt and Pd catalysts on LaCoO3 support showed high catalytic activity. Interaction between Pt or Pd and the support is considered to promote the WGS reaction: Pt/LaCoO3 had high initial activity but deactivated immediately; Pd/LaCoO3 was less active than Pt/LaCoO3, but had superior stability. Catalysts were characterized using XRD, STEM, XPS, and H2-temperature programmed reduction (TPR). Results of this study showed that reduction of the support decreased the CO conversion on Pt/LaCoO3. On the other hand, Pd/LaCoO3 showed stable activity for the WGS reaction. Therefore, Pd was added to Pt/LaCoO3 for stabilizing the catalyst activity, and 0.5 wt.% Pd/1 wt.% Pt/LaCoO3 catalyst showed higher activity and stability. 相似文献
73.
Takeda Y. Sanada M. Morimoto S. Hirasa T. Taniguchi K. 《Industry Applications, IEEE Transactions on》1994,30(1):141-145
The advantages of the conventional cylindrical linear pulse motor (C-LPM), which has a ring permanent magnet between the A- and B-phase stators, are its simple magnet shape and small motor diameter; the disadvantages are the thrust imbalance resulting from the magnetic flux path of the outer poles being longer than that of the inner poles. This thrust imbalance decreases the pull-in thrust and increases the positioning error. In this paper, a new C-LPM with an interior permanent magnet mover which reduces this thrust imbalance is proposed. Steady and dynamic thrust are also examined and a magnetic equivalent circuit is discussed. It is shown that a C-LPM with an interior permanent magnet mover effectively improves the thrust imbalance and the dynamic thrust 相似文献
74.
The deposition of perovskite-type oxides thin films [La0.8Sr0.2MnO3 and La1–xSrxCo1–yFeyO3 (0 x 0.4 and 0 y 1)] was investigated using the electrostatic spray deposition (ESD) technique. Lanthanum nitrate, strontium chloride and manganese nitrate, or cobalt nitrate and iron nitrate were dissolved into a mixture of 33 vol% ethanol and 67 vol% butyl carbitol, which was used as precursor solution. The effect of process parameters, such as deposition temperature, deposition time and concentration of precursor solution, on the surface morphology and microstructure of thin films were examined with scanning electron microscope (SEM). The deposited La0.8Sr0.2MnO3 and La1–xSrxCo1–yFeyO3 thin films were amorphous at the used deposition temperature (573K). Subsequently, the samples were heated at 1173 K for 2 h and were studied using X-ray diffraction (XRD). As the result, the crystal structure of the samples transformed to the desired perovskite phase. The chemical analysis of the thin films was investigated using energy dispersion X-ray (EDX) analysis. The observed chemical compositions of the samples were in a fair agreement with the ones of the starting solutions. 相似文献
75.
T. Isa T. Fukase M. Sasaki M. Koyano N. Taniguchi T. Kimura Y. Isobe H. Negishi 《Journal of Low Temperature Physics》2002,127(1-2):63-79
We have measured electrical resistivity, Hall coefficient, thermoelectric power, and magnetization for charge-density wave (CDW) material 1T-TaS2 single crystals grown by varying the excess sulfur content x
es. We have revealed that a small mid-gap state is formed inside the Mott gap and that anomalous low temperature transport is not governed by the Mott gap state itself but by the mid-gap state. The electric properties of the mid-gap state are modified by increasing x
es (or hole doping), and we have found the insulator-metal transition occurs by hole doping below 60K. 相似文献
76.
Taniguchi Shigeji Zhu Yao-Can Fujita Kazuhisa Iwamoto Nobuya 《Oxidation of Metals》2002,58(3-4):375-390
Coupon specimens of TiAl were implanted with Nb ions at an acceleration voltage of 50 kV with a dose of 1021 ions m.–2 They were then slightly oxidized during heating to 900 or 1200 K, or at 1200 K for 3.6 ksec (1 hr) in a flow of purified oxygen under atmospheric pressure. The implanted specimens and oxidized specimens were characterized and observed by AES, X-ray diffractometry, SEM, TEM, EDS, and EPMA. Implantation improves the oxidation resistance significantly by forming virtually -Al2O3 scales. The implanted layer is about 75 nm thick; the outer part of 30-nm thickness is -Ti phase and the rest of 45-nm thickness is amorphous. Heating to 900 K in O2 results in partial crystallization of the amorphous layer to Ti5Al3O2 (Z-phase) and to 1200 K results in oxide scales of 270 to 400 nm thickness consisting mainly of Al2O3. The fraction of Al2O3 in the scale increases toward the substrate. Oxidation at 1200 K for 3.6 ksec results in Al2O3-rich scales of about 400-nm thickness. The oxide grain size is very fine, about 80 nm in size, and becomes smaller toward the outer scale surface. This implies that implantation enhanced the nucleation of Al2O3 grains relative to the growth of TiO2 grains. This finding and the formation of -Ti phase are thought to be responsible for the excellent oxidation resistance obtained. 相似文献
77.
This paper presents calibration of the Vehicle Routing and scheduling Problems with Time Windows-Probabilistic (VRPTW-P) model
which takes into account the uncertainty of travel times. Probe vehicle data of travel times were obtained from usual operation
of pickup-delivery trucks in South Osaka area. The optimal solution of the VRPTW-P model resulted in reducing total cost,
running times and CO2, NOx and Particle Materials (PM) emissions compared with the usual operation. This is attributed to better routing of VRPTW-P
to choose more reliable roads. Therefore, VRPTW-P can contribute to establish efficient and environmentally friendly delivery
systems in urban area. 相似文献
78.
C. Koshio H. Taniguchi K. Amemiya N. Saegusa T. Komaki Y. Sato 《Journal of the Society for Information Display》2002,10(3):231-236
New 50‐ and 43‐in. ACPDPs, which have been developed and commercialized in 2001, show high luminance with improved cell structure and higher Xe‐content gas. The specific features of the cell structure are “T”‐shaped electrodes and waffle‐structured ribs, which are same as those of the previous model. Both the cell structure and gas conditions have been optimized. New green and blue phosphors have also been adopted. As a result, the luminous efficacy has been improved up to 1.8 lm/W by using a black stripe. The peak luminance of the 50‐ and 43‐in. PDPs have reached 900 and 1000 cd/m2, respectively, while the power consumption of the 50‐in. PDP has been decreased to 380 W, which is 20% lower than that of our previous 50‐in. PDP. 相似文献
79.
Spontaneous hydrolytic degradability of copolyesters having tetrahydropyran rings in their backbones
Homo- and copolyesters, containing 2,5-linked tetrahydropyran rings in their backbones, were prepared by cationic ring-opening polymerization of bicyclic lactones, 2,6-dioxabicyclo [2.2.2] octan-3-one ( 1 ), and its 4-methoxy-carbonyl and 4-methoxy-carbonyl and 4-benzyloxycarbonyl derivatives ( 3 and 4 ). Copolyesters, having pendant carboxyl groups, were derived from the copolymers containing 4 as one of the comonomers by the catalytic hydrogenolysis of the pendant benzyloxy–carbonyl groups. Copolyesters, containing both 2,5-linked and 2,6-linked tetrahydropyran rings in the main chains, were obtained by the copolymerization of 1 with 6,8-dioxabicyclo [3.2.1] octan-7-one ( 13 ), which is a structural isomer of 1 . Spontaneous hydrolytic degradability of these polyesters was investigated in a phosphate buffer solution (pH 7.5) at 27°C. The degradability of the polyesters markedly depended on the molecular structure: hydrophobic pendant groups retarded the hydrolytic degradation, whereas hydrophilic pendant groups accelerated it. In particular, a small amount of pendant carboxyl groups significantly enhanced the hydrolytic degradability of the copolyesters from 1 . Polyesters, containing 2,6-linked tetrahydropyran rings in their backbones, underwent hydrolytic degradation more readily than those entirely consisting of 2,5-linked tetrahydropyran rings. © 1994 John Wiley & Sons, Inc. 相似文献
80.
Abstract. This paper deals with the asymptotic efficiency of the sample autocovariances of a Gaussian stationary process. The asymptotic variance of the sample autocovariances and the Cramer–Rao bound are expressed as the integrals of the spectral density and its derivative. We say that the sample autocovariances are asymptotically efficient if the asymptotic variance and the Cramer–Rao bound are identical. In terms of the spectral density we give a necessary and sufficient condition that they are asymptotically efficient. This condition is easy to check for various spectra. 相似文献