The CO oxidation reaction on Ir(111) is observed by the near-edge x-ray absorption fine structure (NEXAFS) spectroscopy in the soft x-ray region. A continuous data acquisition at 33 ms real-time resolution is realized for a single event of the reaction without the repetition, by adopting the wavelength-dispersive NEXAFS technique. The time evolution of the coverages for atomic O and molecular CO is quantitatively estimated during the reaction. The obtained activation energy is significantly larger than that on Pt(111).

Transparent p-type CuBr 1%x I x semiconducting thin films with a variable band gap were prepared using spin coating, which is a non-vacuum process. The dependence of their structural and optical properties on the CuBr 1%x I x composition was investigated. In X-ray diffraction patterns, the dominant CuBr 1%x I x peak was found to shift to higher angles with decreasing mixing ratio x. The Z 1,2 and Z 3 exciton absorption bands were observed from 300 to 400 nm, and the absorption wavelength varied with x. The ionization potential was determined using photo yield spectroscopy, and was found to increase with increasing x. These results suggest that the valence band maximum for CuBr 1%x I x depends on the composition. The results obtained in the present study allowed the energy band structure for this material to be proposed.

Recent studies on swampland conjectures (e.g. non-SUSY AdS conjecture or AdS distance conjecture) predict that the (lightest) neutrino must be Dirac and the mass must be cosmologically small [Formula: see text]. The Dirac neutrino naturally accompanies a [Formula: see text] symmetry that can be embedded in the anomaly-free [Formula: see text] global symmetry of the standard model. We point out that the swampland conjectures applied to a circle compactification with the [Formula: see text] symmetry twisting lead to further constraints. In particular, the [Formula: see text] symmetry must be broken down to [Formula: see text], [Formula: see text] or [Formula: see text] in the case of normal hierarchy, and [Formula: see text] in the case of inverted hierarchy, providing evidence for the absence of continuous global symmetry in quantum gravity. We also predict a more constrained upper bound of the neutrino mass for each case.

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