No abstract

The aims of the New SUBARU project are to promote industrial applications in the VUV and soft X-ray region and to develop research and development towards new light sources. The main facility of the New SUBARU project is the 1.5 GeV electron storage ring which is under construction at the SPring-8 site in Harima Science Garden City, Japan. The storage ring is quasi-isochronous and has variable momentum dispersion for the deep study of beam dynamics in very short bunches.

Surface relief associated with martensitic transformationtetragonal-to-monoclinic phase transformation-that occurred during isothermal aging at temperatures of 400 and 473 K was observed via atomic force microscopy, using prepolished and thermally etched surfaces of zirconia-3 mol% yttria that was sintered at a temperature of 1923 K for 5 h. The isothermal martensitic transformation occurred first at grain boundaries and advanced into grain interiors as the aging time increased and then spread successively into the surrounding grains. The transformation area, which had an approximately round shape, increased as the aging time increased. The fine structure of the surface relief was composed of many tent shapes that were several nanometers high with an angle of ∼165°.

No abstract

No abstract

The existence of a topological Dirac nodal loop is predicted for hydrogenated monolayer boron sheets with a nonsymmorphic symmetry. The three-center two-electron bonds in boron compounds restrict the electronic system to be insulating or semimetallic with a Dirac nodal loop. Two types of electronic structures are distinguished by the Z 2 topological index and confirmed by first-principles total-energy calculations. The topological taxonomy, developed in this research, can be applied to other two-dimensional materials and to seek novel Dirac fermions.

We systematically investigated electronic evolutions of nonsymmorphic borophene with chemical environments that were realized by the ion exchange method. Electronic structures can be characterized by the topological invariant. Spectroscopic experiments and DFT calculations unveiled that a sheet of hydrogenated borophene (borophane) is the Dirac nodal loop semimetal ( ), while a layered crystal of YCrB4 is an insulator ( ). The results demonstrate the electronic topological transition by replacement of the counter atoms on the nonsymmorphic borophene layer.

No abstract