Low-Resolution Spectrum of the Diffuse Galactic Light and 3.3 um PAH emission with AKARI InfraRed Camera

We first obtained the spectrum of the diffuse Galactic light (DGL) at general interstellar space in 1.8-5.3 um wavelength region with the low-resolution prism spectroscopy mode of the AKARI Infra-Red Camera (IRC) NIR channel. The 3.3 um PAH band is detected in the DGL spectrum at Galactic latitude |b| < 15 deg, and its correlations with the Galactic dust and gas are confirmed. The correlation between the 3.3 um PAH band and the thermal emission from the Galactic dust is expressed not by a simple linear correlation but by a relation with extinction. Using this correlation, the spectral shape of DGL at optically thin region (5 deg < |b| < 15 deg) was derived as a template spectrum. Assuming that the spectral shape of this template spectrum is uniform at any position, DGL spectrum can be estimated by scaling this template spectrum using the correlation between the 3.3 um PAH band and the thermal emission from the Galactic dust.Comment: 7 pages, 5 figures, accepted by Publications of the Astronomical Society of Japan (PASJ

Mechanism of Catalytic Behavior and Structure of Active Centers in CuY Zeolite

The experimental and theoretical basis for the activated coppere xchanged Y zeolite system have been studied by the observation and analysis in the electronspin resonanace (ESR) , infrared (IR) and extended X-ray absorption fine structure (EXAFS) spectroscopies

FORMATION OF ACTIVE SITES ON IRON CATALYST

Fischer-Tropsch synthesis over preliminary carburized iron catalyst with CO was investigated in both isothermal and temperature programmed experiments under atmospheric pressure. In comparison with the freshly reduced catalyst, the pre-carburized catalyst showed similar activity for the formation of hydrocarbons at the steady state and shorter period of activation which decreased with the degree of carburization. The pre-carburization was observed to reduce the strength and to raise the amount of the CO adsorption. Since no significant differences were observed between the carburizations with CO/He and CO/H_2, it was confirmed that the role of the carburization during synthesis was not the formation of reaction intermediates but the development of the active surface available for catalysis

Preparation of Highly Dispersed Copper Particles in Zeolite

Temperature programmed reduction and desorption techniques have been used to investigate the reduction process of CuY. The reduction of Cu^2+ ions in zeolite with H_2 occurs via a two-step mechanism in which Cu^+ is first formed and then reduced to metal. In the first step of reduction NH_3 was used as the reducing agent instead of H_2. Cu particles in the reduced CuY with NH_3 pretreatment were uniformly dispersed compared with those of CuY without one. The average particle size of Cu metal was estimated to be 8.4 nm for the former and 18.5 nm for the latter. The detailed mechanism of reduction process of CuY has been discussed by the physico-chemical measurements, such as mass spectrometry, transmission electron microscope, infrared spectroscopy and electron spin resonance