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101.
Ichikawa T Bando M Kondo Y Nakahara M 《Philosophical transactions. Series A, Mathematical, physical, and engineering sciences》2012,370(1976):4671-4689
Unitary operations acting on a quantum system must be robust against systematic errors in control parameters for reliable quantum computing. Composite pulse technique in nuclear magnetic resonance realizes such a robust operation by employing a sequence of possibly poor-quality pulses. In this study, we demonstrate that two kinds of composite pulses-one compensates for a pulse length error in a one-qubit system and the other compensates for a J-coupling error in a two-qubit system-have a vanishing dynamical phase and thereby can be seen as geometric quantum gates, which implement unitary gates by the holonomy associated with dynamics of cyclic vectors defined in the text. 相似文献
102.
Hideki Yamagishi Mikio Fukuhara Hiroaki Matsumoto Akihiko Chiba 《Metallurgical and Materials Transactions A》2010,41(8):2151-2161
Nondestructive evaluation of cyclic-tension fatigue in a rolled magnesium alloy, Mg-3Al-1Zn, was performed using vertically
polarized shear wave (SV) reflection and shear horizontal wave (SH) transmission methods. Internal friction measured by SV
reflection increased rapidly in the early stages of the fatigue and finally saturated, showing dominating interactions of
movable dislocations and twinning boundaries with the waves as acoustic nonlinearities. The propagation time and logarithmic
damping ratio in the SH transmission method followed a repeated increase and subsequent sudden decrease pattern, and finally
converged toward fatigue failure due to acoustoelasticity, which represents the interaction with residual stresses. The wave
and phase data were determined using an optical microscope, a scanning electron microscope, a surface roughness tester, and
X-ray diffraction. The results demonstrated that during the fatigue process, residual stress accumulated on the compressive
side of the specimen, despite the applied cyclic-tension loading. Brittle cracks that originated in inclusions provided sudden
relief from the residual stress. 相似文献
103.
Koichiro Ezato Satoshi Suzuki Yohji Seki Hiroshi Nishi Kensuke Mohri Mikio Enoeda 《Fusion Engineering and Design》2012,87(7-8):1177-1180
Japan Domestic Agency (JADA) carried out R&Ds activities to improve joining CFC monoblocks onto a CuCrZr cooling tube in PFUs to boost the success rate of joint and to confirm load carrying capability of the monoblock attachments to Steel Support Structure (SSS) against tensile force simulating electromagnetic load to pull PFUs from SSS. In joining the CFC monoblocks to the cooling tube, JADA has adopted brazing by using noble-metal-free filler with the following improvements; (1) metalizing joint surface of CFC using Ti-coating with accurate thickness controlling, (2) Changing buffer layer material from soft pure copper to Cu–W alloy. By using the present improved joint, JADA has manufactured three mock-ups with 5 CFC monoblocks and tested against repetitive high heat loads more than 20 MW/m2. All of CFC monoblocks of each mockup can survive the high heat loads throughout 1000 cycles with no degradation of heat removal capability. Regarding the load carrying capability of monoblock attachments to SSS, tensile experiments were carried out using the same geometries of CFC and tungsten monoblocks in PFUs and the results show that both geometries and joints meet the ITER requirements, that is, 3 kN and 8 kN, respectively. 相似文献
104.
Alice Ying Jörg Reimann Lorenzo Boccaccini Mikio Enoeda Marc Kamlah Regina Knitter Yixiang Gan Jaap G. van der Laan Lida Magielsen P.A. Di Maio G. Dell’Orco Ratna Kumar Annabattula Jon T. Van Lew Hisashi Tanigawa Sander van Til 《Fusion Engineering and Design》2012,87(7-8):1130-1137
Among the international fusion solid breeder blanket community, there exists steady progress on the experimental, phenomenological, and numerical characterizations of the pebble bed effective thermo physical and mechanical properties, and of thermomechanic state of the bed under prototypical operating conditions. This paper summarizes recent achievements in pebble bed thermomechanics that were carried out by members of the IEA Fusion Nuclear Technology Subtask I Solid Breeding Blanket. A major goal is on developing predictive capability while identifying a pre-conditioned equilibrium stress state that would warrant pebble bed integrity during operations. The paper reviews and synthesizes existing computational modeling approaches for pebble bed thermomechanics prediction, and differentiating points of convergence/divergence among existing approaches. The progress toward modeling benchmark is also discussed. These advancements have led to a framework to help navigate future research. 相似文献
105.
Jingxian Zhang Masahiro Fujiwara Qiang Xu Yingchun Zhu Mikio Iwasa Dongliang Jiang 《Microporous and mesoporous materials》2008,111(1-3):411-416
Mesostructured calcium phosphate was synthesized by means of the combination of a soluble metal salt with an aqueous phenylphosphonic acid solution containing sodium dodecyl sulfate (SDS). Phenylphosphonic acid (PhP) was selected as the template to pattern the materials with pores generated by the formation of a lamellar calcium PhP phase. SDS was introduced to improve the thermal stability of the pore structure. The resulting materials were characterized by means of X-ray diffraction (XRD), small-angle X-ray diffraction (SAXS), electron microscopes and BJH gas absorption method. With the aid of SDS, calcium phosphate materials with the surface area and pore volume as 72 m2/g and 569 cm3/g, respectively, were successfully developed at the SDS:PhP molar ratio of 0.3:1. It was found that the addition of SDS could effectively improve the thermal stability of the pore structure. A possible mechanism was proposed to interpret the formation procedure and the improved thermal stability of the mesoporous structure. 相似文献
106.
Takashi Minemoto Mikio Murozono Yukio Yamaguchi Hideyuki Takakura Yoshihiro Hamakawa 《Solar Energy Materials & Solar Cells》2006,90(18-19):3009-3013
Structural and economical merits of a spherical silicon solar cell with semi-concentration reflector system have been discussed. The roles of the reflector system have been clarified; the reflector improves short-circuit current density and also open-circuit voltage by 4–6 times concentration to make a light irradiation area comparable to a p–n junction area. We have theoretically demonstrated that the spherical Si solar cell with semi-concentration reflector system can realize a performance comparable to that of conventional Si solar cells, with less amount of silicon material use. 相似文献
107.
Mikio Inoue Yuki Bisaiji Kohei Yoshida Nobuyuki Takagi Takao Fukuma 《Topics in Catalysis》2013,56(1-8):3-6
The detailed reaction mechanism of Di-Air, which showed the unprecedented high deNOx performance at high temperature conditions, was studied in this work. Since the Di-Air phenomenon occurs with continuous short pulse injections of hydrocarbons over NSR (NOx storage and reduction) catalyst, this study focused on the specific function of HC as an effective reductant for NOx reduction reaction. As a first step, the deNOx performance was compared with three different reductant gases including CO, H2 and C3H6 in a modified synthetic gas bench equipped with a gas injector which enables continuous small amount of injections. At inlet gas temperature of 450 °C C3H6 showed the best deNOx performance whereas H2 was the best at 150 °C. Moreover the result of temperature programmed desorption showed that intermediate species represented by –NCO (isocyanates) produced from C3H6 was thermally more stable than that produced from CO. These results confirmed that the injected HC reacts with adsorbed NOx on NSR catalyst generating thermally stable intermediates, which could contribute the high deNOx performance at high temperature conditions. 相似文献
108.
Kuniaki Gotoh Takashi Kawazu Mikio Yoshida Jun Oshitani 《Advanced Powder Technology》2010,21(1):34-40
A method for dispersing dry particles in a liquid is described. The method involves coating large carrier particles with fine particles. When two types of particles having different sizes are mixed in dry conditions, the particles adhere to one another, and the large particles become coated with small particles. When the large core particles are coated with a mono-layer of small particles, further agglomeration is inhibited. Because the single small particles generated by the disruption adhere to the core particles, we presumed that, if the small particles that are adhered to large particles could be separated from the large particles by a sonication in a liquid, the dry fine particles could be dispersed in a liquid.The dispersion experiments conducted using spherical silica particles having a count median diameter Dp50 of 74 nm as small particles and spherical glass beads as large particles. In this situation, the large particles carry the small particles from a dry condition into a liquid. We refer to the large particles as carrier particles. The experiments revealed that the proposed dispersion procedure results in a superior product, compared to sonication only. The effect of carrier size on dispersion performance is also investigated. The findings indicate and an optimum carrier size exists. Observations of the carrier particle surfaces after dry mixing indicate that the optimum condition is the condition at which a mono-layer of Silica particles is formed. 相似文献
109.
The synthesis of a thermoelectric NaxCo2O4/Ag composite was attempted by the polymerized complex (PC) process using AgNO3 as an Ag source and subsequent sintering at 1153 K for 72 ks. The effects of the PC process and Ag addition to NaxCo2O4 on microstructure and thermoelectric properties of the NaxCo2O4/Ag composite were investigated. Ag was hardly substituted for Na and Co sites, and the sintered sample was composed of the NaxCo2O4 and Ag phases. The electrical resistivity of the composite was smaller than that of the NaxCo2O4 single phase and the Seebeck coefficient was slightly enhanced by Ag addition, resulting in the significantly large power factor. However, most of precipitated Ag particles in the NaxCo2O4 matrix were coarse, 5–8 μm in size, and the thermal conductivity of the composite was high as compared to the NaxCo2O4 single phase. From these results, the dimensionless figure of merit of the composite was almost the same as that of the NaxCo2O4 single phase. 相似文献
110.