Polymerization with organoboron compounds

In the presence of organoboron compounds, free-radical polymerization of vinyl monomers can proceed in spite of the presence of excess of typical radical inhibitors. The concept of free radical–organoboron complex formation is introduced to explain the unique role of organoboron compounds in such a polymerization system.     

Reducing elution method for copper(II) in cation-exchange chromatography by hydroxylamine hydrocloride solution

The cation-exchange Chromatographic behaviour of copper and several other metals in hydroxylamine hydrochloride solution has been investigated. At 50 degrees copper(II) is reduced to copper(I) which is eluted quickly in a narrow band and easily separated from other metals such as zinc, nickel, cobalt and iron.     

Generation of methoxide from methane and oxygen under mild conditions over an Sm2O3 catalyst investigated by in situ IR spectroscopy

The generation of methoxide over an Sm2O3 catalyst was clearly observed under a CH4-O2 atmosphere at 323 K by in situ Fourier transform IR spectroscopy.     

Proof of the Fukui conjecture via resolution of singularities and related methods. V

The present article is a direct continuation of part IV of this series. The Local Analyticity Proposition (LAP1), which admits a proof via resolution of singularities is a major key to proving the Fukui conjecture via resolution of singularities and related methods. By LAP1, the essential part of the mechanism of the “asymptotic linearity phenomena” is extracted and is elucidated by using tools from the theory of algebraic and analytic curves. Here in the present article, we complete the proof of the LAP1 by using fundamental tools developed in parts III and IV of this series, thus completing the proof of the Fukui conjecture via resolution of singularities and related methods. This series of articles I-V establishes, for the first time, a new linkage between (i) the mathematical field of resolution of singularities and (ii) the chemical field of additivity problems tackled and solved in a unifying manner via the repeat space theory (RST), which is the central theory in the First and Second Generation Fukui Project. A new development called the Matrix Art Program in the Second Generation Fukui Project has also been expounded with a graphical representation of energy band curves of a carbon nanotube.     

Photostimulated detection of radiation defects produced by VUV light in BaF2

Production of radiation defects in a widely used scintillation material BaF₂ has been studied by means of a combination spectroscopy of synchrotron radiation (SR) and laser, in which defects produced by SR irradiation are sensitively detected by observing the luminescence stimulated by laser light. The photostimulated luminescence arises from the recombination of self-trapped holes (V_K centers) with electrons released from trapped centers by laser light. The obtained result reveals that the production efficiency of radiation defects is drastically dependent on the excitation photon energy of valence or core excitons.     

Cyclotron resonance in (GaAs)n/(AlAs)n superlattices under ultra-high magnetic fields

We present a review on recent study of the type I to type II transition in short-period superlattices (SLs) of GaAs/AlAs by means of cyclotron resonance (CR) in pulsed high magnetic fields. The behavior of CR varies depending on the thickness of the GaAs and AlAs layers. In CR of (GaAs)_n/(AlAs)_n, the resonance peak at the X minima was observed in the type II regime for n smaller than 14, whereas the resonance at the Γ point was observed for n>15. We estimated electron masses on X and Γ point in the SLs by using the empirical sp³ tight-binding method including second-nearest-neighbor interaction. These calculations have shown good agreement with the experimental results. Moreover, it was found that the angular dependence of the CR peak position does not obey the simple cosine dependence due to the subband mixing in high magnetic fields. From the angular dependence in the SLs, the longitudinal and transverses electron masses of AlAs at the X point were deduced to be m_t=0.21m₀ and m_l=1.04m₀, respectively.