Koki Watanabe

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Introduction Photonic crystal is a periodic structure consisting of high contrast dielectrics, in which the electromagnetic wave cannot transmit in a specific wavelength range. It is therefore known that, if localized defects are introduced in the photonic crystal, the electromagnetic fields are strongly confined around the defects. For example, point(More)
In the Large Helical Device (LHD), a reversed magnetic shear (RS) configuration having non-monotonic rotational transform profile was formed by intense counter neutral beam (NB) current drive. In the RS configuration helical plasma, the reversed shear Alfvén eigenmode (RSAE) with n=1 toroidal mode number was identified together with energetic-ion-driven(More)
Centrioles surrounded by pericentriolar material (PCM) serve as the core structure of the centrosome. A newly formed daughter centriole grows into a functional mother centriole. However, the underlying mechanisms remain poorly understood. Here we show that Cep295, an evolutionarily conserved protein, is required for generation of a bona fide mother(More)
Here we present the first report of a carbon-γ-Fe₂O₃ nanoparticle composite of mesoporous carbon, bearing COOH- and phenolic OH- functional groups on its surface, a remarkable and magnetically separable adsorbent, for the radioactive material emitted by the Fukushima Daiichi nuclear power plant accident. Contaminated water and soil at a level of 1,739 Bq(More)
—This paper presents a novel formulation for the modeling of electromagnetic wave propagation in pillar-type photonic crystal waveguide devices. The structure under consideration is formed in an infinitely extended pillar-type photonic crystal and the wave propagation is controlled by removing some cylinders from the original periodic structure. The(More)
This paper presents a formulation of two-dimensional straight photonic crystal waveguide consisting of circular cylinder array in triangular lattice. The fields are expressed in the generalized Fourier series expansions but we also use the cylindrical-wave expansions. The present formulation is derived by the technique for multilayer with infinite thickness.