arXiv subjects

Toshiro Kaneko

Publications and source records attributed to Toshiro Kaneko.

3 recordsLinked to original sources

arXiv2014

Green tea induced gold nanostar synthesis mediated by Ag(I) ions

We report a synthesis of tea components conjugated gold nanostars (AuNSs) with strong near infrared absorption by reducing an aqueous solution of chloroauric acid trihydrate via green tea in association with Ag(I) ions. Green tea acts as a reducing agent by providing electrons for the gold (III) reduction as well as a stabilizing agent by conjugating some of its components on the surfaces of AuNSs. Moreover, the Ag(I) ions play an important role in mediating the branched growth of the resultant AuNSs by inducing anisotropic growth on the surfaces of initially formed spherical gold nanoparticles.

cond-mat.mtrl-sci↗

arXiv2004

Electrostatic ion-cyclotron instabilities modified by the parallel and perpendicular plasma flow velocity shears

The external and independent control of plasma flow velocity shears parallel and perpendicular to magnetic field lines is realized using segmented collisionless-plasma sources. Electrostatic ion-cyclotron instabilities are observed to be suppressed by the perpendicular flow velocity shears, the suppression physics of which is found to be distinguished into two aspects. On the other hand, the parallel flow velocity shears are demonstrated to destabilize the ion-cyclotron instabilities depending on the sign of the parallel shear in the absence of field-aligned electron drift flow.

physics.plasm-ph↗

arXiv2004

Polarization reversal of electron cyclotron wave due to radial boundary condition

Propagation and absorption of electromagnetic waves with electron cyclotron resonance (ECR) frequency are experimentally and theoretically investigated for the case of inhomogeneously magnetized plasma column with peripheral vacuum layer, when a left-hand polarized wave (LHPW) is selectively launched. The polarization reversal from the LHPW to the right-hand polarized wave is found to occur near the ECR point. As a result, it is clarified that the LHPW, which has been considered not to be absorbed at the ECR point, is absorbed near the ECR point. The phenomena can be explained by taking into account the effects of the radial boundary conditions. In addition, it is found that the polarization reversal point can be adjusted by the external parameters, for example, plasma radius.

physics.plasm-ph↗