164 research outputs found

    Organopalladium catalyst on S-terminated GaAs(001)-(2×6) surface

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    Organopalladium molecules, such as Pd(CH3COO)2 ({Pd}), immobilized on the S-terminated GaAs(001), termed GaAs–S–{Pd} have high catalytic activity and cycle durability in the Mizoroki–Heck reaction. It is thought that the presence of Ga–S bonds in the single atomic layer S-termination is essential for these catalytic properties despite the much higher thickness (~100 nm) of the {Pd} films. In this study, the authors demonstrate the retention of Ga–S bonds in ultrathin GaAs–S–{Pd} by using reflection high-energy electron diffraction and scanning tunneling microscopy (STM). The ultrathin GaAs–S–{Pd} was prepared by using a vapor-deposition technique. Deposited {Pd} was observed as ~1 nm dotlike structures with STM. The adsorption rate of {Pd} was also investigated

    Quantum Annealing Based Difficulty Adjustable Maze Generation

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    In this paper, the maze generation using quantum annealing is proposed. We reformulate a standard algorithm to generate a maze into a specific form of a quadratic unconstrained binary optimization problem suitable for the input of the quantum annealer. To generate more difficult mazes, we introduce an additional cost function QupdateQ_{update} to increase the difficulty. The difficulty is evaluated by the time to solve the maze. To check the efficiency of our scheme to create the maze, we investigated the time-to-solution of a quantum processing unit, classical computer, and hybrid solver.Comment: 14pages, 12figure

    Pseudotachylytes from Langhovde and Skarvsnes in the Lützow-Holm Complex, East Antarctica, and their conditions of formation

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    The Tenth Symposium on Polar Science/Ordinary sessions: [OG] Polar Geosciences, Wed. 4 Dec. / Entrance Hall (1st floor), National Institute of Polar Researc

    Geological field survey in the regions of L*tzow-Holm Bay, Prince Olav Coast and Enderby Land, 2018-2019 (JARE-60)

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    The Tenth Symposium on Polar Science/Ordinary sessions: [OG] Polar Geosciences, Wed. 4 Dec. / 3F Seminar room, National Institute of Polar Researc

    Development of Precise Load Prediction System for Free Forging of Ni-based Superalloy having Softening

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    AbstractNi-based superalloys such as Alloy 706 that have high heat resistance are applied to gas turbine disks in electric power plant because. Free forging is one of the effective forging processes to form superalloy products, and forging simulation is quite useful method to optimize forging schedule. Softening behaviour at high temperature was not considered and implemented in conventional simulation, that induced the accuracy of load prediction. In this study, we investigated softening behaviour to improve the accuracy of forging simulation

    Variation in Courtship Ultrasounds of Three Ostrinia Moths with Different Sex Pheromones

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    Moths use ultrasounds as well as pheromones for sexual communication. In closely related moth species, variations in ultrasounds and pheromones are likely to profoundly affect mate recognition, reproductive isolation, and speciation. The European corn borer, Ostrinia nubilalis, and its Asian congeners, Ostrinia furnacalis and Ostrinia scapulalis, exhibit within-species and between-species variation in their pheromone communication. Recently, we reported ultrasound communication in O. furnacalis; however, variations in ultrasounds in the three congeners have not been addressed to date. Here we investigated features of ultrasound production and hearing in O. nubilalis and O. scapulalis, and compared them with those of O. furnacalis. As in O. furnacalis, males of O. nubilalis and O. scapulalis produced ultrasounds during courtship by rubbing specialized scales on the wings against scales on the thorax. The covering of these scales with nail polish muffled the sounds and significantly reduced mating success in O. nubilalis, showing the importance of ultrasound signaling in mating. The ultrasounds produced by O. nubilalis and O. scapulalis were similar, consisting of long trains of pairs of pulses with a main energy at 40 kHz, but distinctly different from the ultrasound produced by O. furnacalis, consisting of groups of pulses peaking at 50 kHz and with substantially more energy up to 80 kHz. Despite overall similarities, temporal features and patterns of amplitude modulation differed significantly among the geographic populations of O. nubilalis and O. scapulalis, which differed in pheromone type. In contrast, no significant difference in hearing was found among the three species with regard to the most sensitive frequencies and hearing threshold levels. The patterns of variations in the songs and pheromones well reflected those of the phylogenetic relationships, implying that ultrasound and pheromone communications have diverged concordantly. Our results suggest that concordant evolution in sexual signals such as courtship ultrasounds and sex pheromones occurs in moths
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