Measurements of cosmic-ray low-energy antiproton and proton spectra in a transient period of solar field reversal

The energy spectra of cosmic-ray low-energy antiprotons ( *p's) and protons ( p's) have been measured by BESS in 1999 and 2000, during a period covering reversal at the solar magnetic field. Based on these measurements, a sudden increase of the *p/p flux ratio following the solar magnetic field reversal was observed, and it generally agrees with a drift model of the solar modulation.     

Oligodeoxynucleotide-modified capillary for electrophoretic separation of single-stranded DNAs with a single-base difference.

We describe here a method of affinity capillary electrophoresis in which oligodeoxynucleotide (ODN) was immobilized onto the inner surface of the capillary. The immobilized ODN functioned successfully as an affinity ligand for sequence-based DNA separation. Six- or 12-mer ODN with a sequence complementary to one of the c-K-ras gene was used as an immobilized ligand. When the 12-mer ODN was used, the detection peak for the complementary ODN disappeared selectively, while the single-base mutant was detected as usual. In contrast, when the 6-mer ODN was used as the affinity ligand with a mixture of the complementary ODN and its single-base mutant, it was possible to detect both as completely separate peaks. That is, the separation mode was dependent on the base number of the immobilized ODN used as an affinity ligand.     

Highly oriented aragonite nanocrystal-biopolymer composites in an aragonite brick of the nacreous layer of Pinctada fucata

13C CP/MAS NMR and FE/TEM measurements of the aragonite brick of the nacreous layer of Pinctada fucata indicate that it assembles with highly oriented aragonite nanocrystals, which are regulated by biopolymers.     

Search for cosmic-ray antideuterons

We performed a search for cosmic-ray antideuterons using data collected during four BESS balloon flights from 1997 to 2000. No candidate was found. We derived, for the first time, an upper limit of 1.9 x 10(-4) (m2s sr GeV/nucleon)(-1) for the differential flux of cosmic-ray antideuterons, at the 95% confidence level, between 0.17 and 1.15 GeV/nucleon at the top of the atmosphere.     

CDW-induced negative thermal expansion in two-dimensional conductor η-Mo4O11

Two-dimensional oxide η-Mo₄O₁₁ exhibits almost isotropic thermal expansion in the normal phase, while anisotropic negative thermal expansion (NTE) in the charge density wave (CDW) phase below T_c1=105 K, where a remarkable anomalous expansion occurs along the a-axis. The incommensurate nesting vector along the b-axis is independent of temperature, q₁=(0.000(1) 0.2335(1) 0.0000(5)). We propose that the CDW-induced NTE occurs as a result of the structural relaxation of the MoO₆ octahedra layers along the stacking direction with the aid of the open spaces around the MoO₄ tetrahedra.     

Single Telephoto Lens for Focus Error Detection with Astigmatic Method

An astigmatic method for focus error detection has been integrated into a singlet. The first convex and the second concave surfaces compose a telephoto system with a telephoto ratio of about 0.4. The first surface of the lens is rotationally symmetrical asphere and the second surface is a toric shape whose aspherical profiles correct spherical aberration. We implemented our optical design using a molded glass process. Its performance was confirmed using the optical head of a magneto-optical disk system.     

Soft dipole resonance in the neutron-skin nucleus 6He

We consider a billiard model of a self-bound, interacting three-body system in two spatial dimensions. Numerical studies show that the classical dynamics is chaotic. The corresponding quantum system displays spectral fluctuations that exhibit small deviations from random matrix theory predictions. These can be understood in terms of a new type of scarring caused by a one-parameter family of orbits inside the collinear manifold.     

An improved apparatus for measuring the inhomogeneity of glasses

An improved apparatus capable of quantatively measuring the inhomogeneity of glasses within several minutes was developed as a prototype for practical use. Inhomogeneities were measured for several kinds of glass articles on the market, such as plate, bottle and optical glasses etc. and a “relative homogeneity” has been proposed for the purpose of deciding a ranking of glasses measured in comparison to the powdered single crystal of CaF₂ as a standard material of uniformity.     

Reaction of o-benzyne with tropothione involving biradical processes

A benzyne-tropothione reaction was studied experimentally and computationally. Three isomeric products were detected by a careful experiment using two benzyne sources. The three equimolar products were identified. The expected symmetry-allowed [4+2] or [8+2] cycloadduct was not detected. In order to explain the unexpected products, density functional calculations and complete active space self-consistent field (CASSCF) calculations were carried out. The benzyne is, first, added to the tropothione via one-center C-S bond formation. Then a singlet biradical intermediate is formed. In the biradical, an alpha hydrogen atom of the tropothione moiety is moved to the benzyne moiety. A closed-shell intermediate is generated. This allene-type intermediate is isomerized to the second intermediate. The intramolecular proton shift in the latter leads to the three products. The biradical character of the benzyne has a key role in the present reaction and was discussed in reference to other benzyne reactions.