354 research outputs found
酸素発生反応用ペロブスカイト触媒に関する研究
京都大学新制・課程博士博士(工学)甲第25300号工博第5259号京都大学大学院工学研究科物質エネルギー化学専攻(主査)教授 安部 武志, 教授 作花 哲夫, 准教授 松井 敏明学位規則第4条第1項該当Doctor of Philosophy (Engineering)Kyoto UniversityDGA
First synthesis of 1-(indo1-2-yl)azulenes by the Vilsmeier-Haack type arylation with triflic anhydride as an activating reagent
Azulene derivatives reacted with 2-indolinones in the presence of triflic anhydride (Tf2O) to afford 1-(indo1-2-yl)azulenes in good yields. In the cases of the reaction of 6-tert-butyl-1-(methylthio)azulene (11) and 1-(1,4-dihydropyridin-4-yl)azulene 14, 1,1'-biazulene derivative 24 and 1-(indo1-2-yl)azulene (2) were obtained under the similar reaction conditions, respectively, instead of the presumed electrophilic substitution products.ArticleTETRAHEDRON LETTERS. 53(12):1493-1496 (2012)journal articl
Effects of Aspect Ratio and Distance between Two Square Cylinders in a Tandem Arrangement on In-Line Oscillation Characteristics
When multiple structures, such as the main towers for a bridge, heat exchangers and offshore structures, are placed adjacently in fluid, structures placed in the downstream side are exposed to complicated flow regions, because the separated shear layer reattaches to the downstream structures or interferes with the flow. For this reason, the distance between structures greatly influences changes in flow patterns around the downstream cylinder structures, so that the response characteristics of structures can be altered correspondingly. The purpose of this study is to identify the basic in-line oscillation characteristics of two square cylinders in a tandem arrangement. Based on the supposition of actual structures, spring-supported tests, with both square cylinders elastically suspended, were conducted. Not only the distance between the two cylinders but also the aspect ratio, was also chosen as the parameters. Because it was found by past researches that the in-line oscillation characteristics of single cylinder depends on the aspect ratio, it was thought to be important to confirm it by two cylinders. Furthermore, flow visualization tests were performed by forced-oscillating two cylinders for consideration from the results of the spring-supported test.9th International Symposium on Fluid-Structure Interactions, Flow-Sound Interactions, Flow-Induced Vibration & Noise (FIV2018: FSI2 & FIV+N.), July 8-11, 2018, Toronto, Ontario, Canad
A fast and accurate per-cell dynamic IR-drop estimation method for at-speed scan test pattern validation
ITC : 2012 IEEE International Test Conference , 5-8 Nov. 2012 , Anaheim, CA, USAIn return for increased operating frequency and reduced supply voltage in nano-scale designs, their vulnerability to IR-drop-induced yield loss grew increasingly apparent. Therefore, it is necessary to consider delay increase effect due to IR-drop during at-speed scan testing. However, it consumes significant amounts of time for precise IR-drop analysis. This paper addresses this issue with a novel per-cell dynamic IR-drop estimation method. Instead of performing time-consuming IR-drop analysis for each pattern one by one, the proposed method uses global cycle average power profile for each pattern and dynamic IR-drop profiles for a few representative patterns, thus total computation time is effectively reduced. Experimental results on benchmark circuits demonstrate that the proposed method achieves both high accuracy and high time-efficiency
Acceleration of Seed Ordering and Selection For High Quality VLSI Delay Test
Seed ordering and selection is a key technique to provide high-test quality with limited resources in Built-In Self Test (BIST) environment. We present a hard-to-detect delay fault selection method to optimize the computation time in seed ordering and selection processes. This selection method can be used to select faults for test generation when it is impractical to target all delay faults resulting large test pattern count and long Computation time. Three types of selection categories are considered, ranged in the number of seeds it produced, which is useful when we consider computing resources, such as memory and storage. We also evaluate the impact of the selection method in mixed-mode BIST when seed are expanded to more patterns, and evaluate the statistical delay quality level (SDQL) with the original work. Experimental results show that our proposed method can significantly reduce computation time while slightly sacrificing test quality
Modeling of Thermal Emission from ULX Pulsar Swift J0243.6+6124 with General Relativistic Radiation MHD simulations
We perform general relativistic radiation magnetohydrodynamics (MHD)
simulations of super-Eddington accretion flows around a neutron star with a
dipole magnetic field for modeling the galactic ultra-luminous X-ray source
(ULX) exhibiting X-ray pulsations, Swift J0243.6+6124. Our simulations show the
accretion columns near the magnetic poles, the accretion disk outside the
magnetosphere, and the outflows from the disk. It is revealed that the
effectively optically thick outflows, consistent with the observed thermal
emission at K, are generated if the mass accretion rate is much
higher than the Eddington rate and the magnetospheric
radius is smaller than the spherization radius. In order to explain the
blackbody radius ( km) without contradicting the reported spin
period () and spin-up rate (), the mass accretion rate of is
required. Since the thermal emission was detected in two observations with
of and but not in another with ,
the surface magnetic field strength of the neutron star in Swift J0243.6+6124
is estimated to be between and . From this restricted range of magnetic field strength, the accretion rate
would be when the thermal emission appears and
when it is not detected. Our results support the
hypothesis that the super-Eddington phase in the 2017-2018 giant outburst of
Swift J0243.6+6124 is powered by highly super-Eddington accretion flows onto a
magnetized neutron star.Comment: 24 pages, 9 figures, 2 tables, accepted for publication in Ap
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