Threshold of ion cyclotron parametric instability in a multispecies plasma

Experimental and theoretical studies are presented of ion cyclotron parametric instability into two electrostatic ion cyclotron waves in a multispecies plasma. The instability threshold obtained experimentally is in reasonable agreement with that predicted theoretically.     

On Randers spaces of scalar curvature

Randers spaces of scalar curvature or of constant curvature have not yet been studied completely because of the complicated forms of the connection coefficients and the curvature tensors. A necessary and sufficient condition for a Randers space to be of scalar curvature, found under some assumptions by this time, is given in this paper. Also a condition for the space to be of constant curvature, found previously in a complicated form, is given in simple form with a geometrical meaning. It is shown that a Randers space is locally Minkowskian if and only if it is a space of vanishing constant curvature.     

Preparation of novel polymer ligands containing tetraaza macrocyclic schiff base as a highly selective extractant for copper(II)

Three types of the novel polymer ligands in which 6,8,15,17-tetramethyl-dibenzo-5,9,14,18-tetraaza-cyclotetradecene (L) is present as an integral part of the polymer backbone have been prepared. These polymer ligands are oligomers whose polymerization degree may be about five. Their complexing abilities and extractabilities for copper(II) and nickel(II) have been investigated. Among the polymer ligands, Poly-L3, which contains triethyleneglycol bis(p-phenylene) group as a linkage group, was found to be an excellent extractant for copper(II).     

Self-coupled optical pickup

When a double- or multi-heterostructure GaAlAs laser is irradiated by its own output laser beam, an oscillatory shift of about 25 MHz is observed in the electric conductivity of the laser. When the pumping current is clamped, the shift in the voltage across the laser electrodes amounts to the order of a millivolt at a return ratio of about 10%. This suggests an availability of the laser as an optical pickup in some types of optical memory playback systems.     

Highly stable passivation of a Si(1 1 1) surface using bilayer-GaSe

As a stable and ‘epitaxial’ passivation of a Si surface, we propose the bilayer-GaSe termination of a Si(1 1 1) surface. This surface is fabricated by depositing one monolayer of Ga on a clean Si(1 1 1) surface and subsequent annealing in a Se flux at around 520 °C, which results in unreconstructed 1×1 termination of the Si(1 1 1) surface by bilayer-GaSe. We found by scanning tunneling microscopy observation that slow cooling of the clean Si(1 1 1) surface from 850 to 520 °C with simultaneous deposition of a Ga flux results in better termination of the Si(1 1 1) surface. It was also found that this surface is stable against heating around 400 °C in O₂ atmosphere of 3×10⁻³ Pa. By utilizing these properties of the bilayer-GaSe terminated surface, we have succeeded in fabricating ZnO quantum dots on this substrate.