Solar Models with Helioseismic Constraints and the Solar Neutrino Problem

Imposing a constraint of the sound-speed profile determined from helioseismology and updating the microphysics, we have revised our seismic solar model, constructed with the assumption of a homogeneous metal abundance distribution, and have shown that the theoretically expected neutrino fluxes are still significantly more than the observations. With the same sound-speed profile constraint, we also constructed solar models with low metal abundance in the core, and evaluated the neutrino fluxes of these models to see if nonstandard solar models with a low metal core can solve the solar neutrino problem. Some of these models are in agreement with the Homestake data, the Super-Kamiokande data, and the sound-speed profile simultaneously, but none of these satisfy both the neutrino flux data, including GALLEX and SAGE, and the helioseismically determined density profile.Comment: 12 pages, 17 figures, uses pasj00.cls. Accepted for publication in PAS

Tunneling rotation of methyl group and the spin-lattice relaxations of the proton NMR in acetamide and thioacetamide

Thesis--University of Tsukuba, D.Sc.(A), no. 347, 1986. 3. 2

ディープニューラルネットワークの挙動解析を目的としたパーシステントホモロジーを用いたネットワーク内部構造の研究

早大学位記番号:新9146早稲田大

Dirac fermion reflector by ballistic graphene sawtooth-shaped npn junctions

We have realized a Dirac fermion reflector in graphene by controlling the ballistic carrier trajectory in a sawtooth-shaped npn junction. When the carrier density in the inner p-region is much larger than that in the outer n-regions, the first straight np interface works as a collimator and the collimated ballistic carriers can be totally reflected at the second zigzag pn interface. We observed clear resistance enhancement around the np+n regime, which is in good agreement with the numerical simulation. The tunable reflectance of ballistic carriers could be an elementary and important step for realizing ultrahigh-mobility graphene field effect transistors utilizing Dirac fermion optics in the near future

Expression of Th1/Th2 cell–related chemokine receptors on CD4+ lymphocytes under physiological conditions

学位記番号：保博乙12

Elevation of Ammonia Contents in the Cerebral Hemisphere under the Blood-Brain Barrier Opening

Elevation of ammonia contents was observed 1 hr following infusion of 4% ammonium acetate only in the cerebral hemisphere where reversible opening of the blood-brain barrier was induced by intracarotid injection of 0.1% deoxycholic acid. This finding suggests that ammonia may contribute to hepatic encephalopathy, when the permeability of the blood-brain barrier is altered