160 research outputs found
Model Building of Metal Oxide Surfaces and Vibronic Coupling Density as a Reactivity Index: Regioselectivity of CO Adsorption on Ag-loaded GaO
The step-by-step hydrogen-terminated (SSHT) model is proposed as a model for
the surfaces of metal oxides. Using this model, it is found that the vibronic
coupling density (VCD) can be employed as a reactivity index for surface
reactions. As an example, the regioselectivity of CO adsorption on the
Ag-loaded GaO photocatalyst surface is investigated based on VCD
analysis. The cluster model constructed by the SSHT approach reasonably
reflects the electronic structures of the GaO surface. The geometry of
CO adsorbed on the Ag-loaded GaO cluster has a bent structure,
which is favorable for its photocatalytic reduction to CO.Comment: 18 pages, 11 figure
Investigation on Several Methods of Determination of Fluoride Ion : I. Gravimetric and Volumetric Determinations II. Colorimetric Determinations
ページ付に誤植あり([523]→[423]
Two-Fingered Haptic Device for Robot Hand Teleoperation
A haptic feedback system is required to assist telerehabilitation with robot hand. The system should provide the reaction force measured in the robot hand to an operator. In this paper, we have developed a force feedback device that presents a reaction force to the distal segment of the operator's thumb, middle finger, and basipodite of the middle finger when the robot hand grasps an object. The device uses a shape memory alloy as an actuator, which affords a very compact, lightweight, and accurate device
Oceanographic Data of the 42nd Japanese Antarctic Research Expedition from November 2000 to March 2001
The results of oceanographic observations on board the icebreaker "Shirase" and tidal observations at Syowa Station, Antarctica, are presented in this report. The oceanographic observations were carried out by the summer party of the 42nd Japanese Antarctic Research Expedition (JARE-42) during the austral summer of 2000/2001. The tidal observations were carried out by the winter party of JARE-41 from February 2000 to January 2001
Role of Catalyst Support and Regioselectivity of Molecular Adsorption on a Metal Oxide Surface: NO Reduction on Cu/{\gamma}-alumina
The role of catalyst support and regioselectivity of molecular adsorption on
a metal oxide surface is investigated for the NO reduction on a
Cu/{\gamma}-alumina heterogeneous catalyst. For the solid surface,
computational models of the {\gamma}-alumina surface are constructed based on
the Step-by-Step Hydrogen Termination (SSHT) approach. Dangling bonds, which
appear by cutting the crystal structure of a model, are terminated stepwise
with H atoms until the model has an appropriate energy gap. The obtained SSHT
models exhibit the realistic infrared (IR) and ultraviolet-visible (UV/Vis)
spectra. Vibronic coupling density (VCD), as a reactivity index, is employed to
elucidate the regioselectivity of the Cu adsorption on the {\gamma}-alumina and
that of the NO adsorption on the Cu/{\gamma}-alumina in place of the frontier
orbital theory that could not provide clear results. We discovered that the
highly dispersed Cu atoms are loaded on Lewis-basic O atoms, which is known as
anchoring effect, located in the tetrahedral sites of the {\gamma}-alumina
surface. The role of the {\gamma}-alumina support is to raise the frontier
orbital of the Cu catalyst, which in turn gives rise to the electron
back-donation from the Cu/{\gamma}-alumina to NO. In addition, the penetration
of the VCD distribution of the Cu/{\gamma}-alumina into the {\gamma}-alumina
support indicates that the excessive reaction energies dissipate into the
support after the NO adsorption and reduction. In other words, the support
plays the role of a heat bath. The NO reduction on the Cu/{\gamma}-alumina
proceeds even in an oxidative atmosphere because the Cu-NO bond is strongly
bounded compared to the Cu-O2 bond
Disruption of a Novel NADH-Glutamate Synthase2 Gene Caused Marked Reduction in Spikelet Number of Rice
Inorganic ammonium ions are assimilated by a coupled reaction of glutamine synthetase and glutamate synthase (GOGAT). In rice, three genes encoding either ferredoxin (Fd)-GOGAT, NADH-GOGAT1, or NADH-GOGAT2, have been identified. OsNADH-GOGAT2, a newly identified gene, was expressed mainly in fully expanded leaf blades and leaf sheaths. Although the distinct expression profile to OsNADH-GOGAT1, which is mainly detected in root tips, developing leaf blades, and grains, was shown in our previous studies, physiological role of NADH-GOGAT2 is not yet known. Here, we isolated retrotransposon mediated-knockout mutants lacking OsNADH-GOGAT2. In rice grown under paddy field conditions, disruption of the OsNADH-GOGAT2 gene caused a remarkable decrease in spikelet number per panicle associated with a reductions in yield and whole plant biomass, when compared with wild-type (WT) plants. The total nitrogen contents in the senescing leaf blade of the mutants were approximately a half of the WT plants. Expression of this gene was mainly detected in phloem companion cells and phloem parenchyma cells associated with large vascular bundles in fully expanded leaf blades, when the promoter region fused with a β-glucuronidase gene was introduced into the WT rice. These results suggest that the NADH-GOGAT2 is important in the process of glutamine generation in senescing leaves for the remobilization of leaf nitrogen through phloem to the panicle during natural senescence. These results also indicate that other GOGATs, i.e., NADH-GOGAT1 and ferredoxin-GOGAT are not able to compensate the function of NADH-GOGAT2
Formation of supramolecular hetero-triads by controlling the hydrogen bonding of conjugate bases with a diprotonated porphyrin based on electrostatic interaction
The thermodynamic stability of diprotonated saddle-distorted dodecaphenylporphyrin (H4DPP2+(X−)2) was controlled by the hydrogen-bonding strength of conjugate bases (X−) of strong acids (HX) or acids (R+-COOH) having positively charged moieties. The thermodynamic control of H4DPP2+(X−)2 made it possible to achieve selective formation of supramolecular hetero-triads, H4DPP2+(X−)(Cl−)
High-Speed Tactile Sensing for Array-Type Tactile Sensor and Object Manipulation Based on Tactile Information
We have developed a universal robot hand with tactile and other sensors. An array-type tactile sensor is crucial for dexterous manipulation of objects using a robotic hand, since this sensor can measure the pressure distribution on finger pads. The sensor has a very high resolution, and the shape of a grasped object can be classified by using this sensor. The more the number of measurement points provided, the higher the accuracy of the classification, but with a corresponding lengthening of the measurement cycle. In this paper, the problem of slow response time is resolved by using software for an array-type tactile sensor with high resolution that emulates the human sensor system. The validity of the proposed method is demonstrated through experiments
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