841 research outputs found
Electromagnetic Form Factors of Nucleons with QCD Constraints Sytematic Study of the Space and Time-like Regions
Elastic electromagnetic form factors of nucleons are investigated both for
the time-like and the space-like momentums under the condition that the QCD
constraints are satisfied asymptotically. The unsubtracted dispersion relation
with the superconvergence conditions are used as a realization of the QCD
conditions. The experimental data are analyzed by using the dispersion formula
and it is shown that the calculated form factors reproduce the experimental
data reasonably well.Comment: 14 page
Positioning device for outdoor mobile robots using optical sensors and lasers
We propose a novel method for positioning a mobile robot in an outdoor environment using lasers and optical sensors. Position estimation via a noncontact optical method is useful because the information from the wheel odometer and the global positioning system in a mobile robot is unreliable in some situations. Contact optical sensors such as computer mouse are designed to be in contact with a surface and do not function well in strong ambient light conditions. To mitigate the challenges of an outdoor environment, we developed an optical device with a bandpass filter and a pipe to restrict solar light and to detect translation. The use of two devices enables sensing of the mobile robot’s position, including posture. Furthermore, employing a collimated laser beam allows measurements against a surface to be invariable with the distance to the surface. In this paper, we describe motion estimation, device configurations, and several tests for performance evaluation. We also present the experimental positioning results from a vehicle equipped with our optical device on an outdoor path. Finally, we discuss an improvement in postural accuracy by combining an optical device with precise gyroscopes
Electronic state analysis of Li2RuO3 positive electrode for lithium ion secondary battery
An investigation was made on the electronic structure of 4d transition metal layered oxide material of Li2RuO3 using X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS). The intensity of O K pre-edge peak increased for Li ion extracted samples, suggesting increased ligand holes. The Ru 3d XPS spectrum suggested the variation of local structure around Ru ions by extraction of Li ions. We conclude that the delithiation from Li2RuO3 is charge-compensated by O anions, and that the creation of the ligand holes reorganizes electronic structures composed of highly hybridized Ru 4d and O 2p orbitals
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