Waseda University

About: Waseda University is a education organization based out in Tokyo, Japan. It is known for research contribution in the topics: Catalysis & Large Hadron Collider. The organization has 24220 authors who have published 46859 publications receiving 837855 citations. The organization is also known as: Waseda daigaku & Sōdai.

The fermi large area telescope on orbit: Event classification, instrument response functions, and calibration

Abstract: The Fermi Large Area Telescope (Fermi-LAT, hereafter LAT), the primary instrument on the Fermi Gamma-ray Space Telescope (Fermi) mission, is an imaging, wide field-of-view, high-energy \gamma-ray telescope, covering the energy range from 20 MeV to more than 300 GeV. During the first years of the mission the LAT team has gained considerable insight into the in-flight performance of the instrument. Accordingly, we have updated the analysis used to reduce LAT data for public release as well as the Instrument Response Functions (IRFs), the description of the instrument performance provided for data analysis. In this paper we describe the effects that motivated these updates. Furthermore, we discuss how we originally derived IRFs from Monte Carlo simulations and later corrected those IRFs for discrepancies observed between flight and simulated data. We also give details of the validations performed using flight data and quantify the residual uncertainties in the IRFs. Finally, we describe techniques the LAT team has developed to propagate those uncertainties into estimates of the systematic errors on common measurements such as fluxes and spectra of astrophysical sources.

Chelyabinsk airburst, damage assessment, meteorite recovery, and characterization

Abstract: The asteroid impact near the Russian city of Chelyabinsk on 15 February 2013 was the largest airburst on Earth since the 1908 Tunguska event, causing a natural disaster in an area with a population exceeding one million. Because it occurred in an era with modern consumer electronics, field sensors, and laboratory techniques, unprecedented measurements were made of the impact event and the meteoroid that caused it. Here, we document the account of what happened, as understood now, using comprehensive data obtained from astronomy, planetary science, geophysics, meteorology, meteoritics, and cosmochemistry and from social science surveys. A good understanding of the Chelyabinsk incident provides an opportunity to calibrate the event, with implications for the study of near-Earth objects and developing hazard mitigation strategies for planetary protection.

Ultra-thin epitaxial films of graphite and hexagonal boron nitride on solid surfaces

Abstract: In this article, we have reviewed the recent progress of the experimental studies on ultra-thin films of graphite and hexagonal boron nitride (h-BN) by using angle-resolved electron spectroscopy together with other techniques. The fundamental properties of these high-quality films are discussed on the basis of the data on dispersion relations of valence electrons, phonon dispersion etc. The interfacial orbital mixing of the -state of the monolayer graphite (MG) with the d states of the reactive substrates is the origin for the phonon softening, expansion of the nearest-neighbour C - C distance, modification of the -band, low work function, and two-dimensional plasmons with high electron density, etc. In the cases of weak mixing at the interface between the MG and relatively inert substrates, the observed properties of the MG are very close to the bulk ones. In contrast to the case for MG, the interfacial interaction between the h-BN monolayer and the substrate is weak.

Direct Synthesis of MOF‐Derived Nanoporous Carbon with Magnetic Co Nanoparticles toward Efficient Water Treatment

Abstract: Nanoporous carbon particles with magnetic Co nanoparticles (Co/NPC particles) are synthesized by one-step carbonization of zeolitic imidazolate framework-67 (ZIF-67) crystals. After the carbonization, the original ZIF-67 shapes are preserved well. Fine magnetic Co nanoparticles are well dispersed in the nanoporous carbon matrix, with the result that the Co/NPC particles show a strong magnetic response. The obtained nanoporous carbons show a high surface area and well-developed graphitized wall, thereby realizing fast molecular diffusion of methylene blue (MB) molecules with excellent adsorption performance. The Co/NPC possesses an impressive saturation capacity for MB dye compared with the commercial activated carbon. Also, the dispersed magnetic Co nanoparticles facilitate easy magnetic separation.