Synthesis of Monoazacryptands and their Excellent Transport Ability Toward Alkali Metal Cations in Comparison with Monoazacrown Ethers

The effects of transport conditions and the structure of monoazacrownethers on their transport ability for alkali metal cations through a bulkliquid membrane are summarized and discussed based on transport dataobtained in our laboratories. To improve the transport ability,monoazacryptands have been prepared. A lipophilic derivative consisting oftwo 18-crown-6 rings and one 20-crown-6 ring can selectively transport K+from a mixture of Na+, K+, Mg2+, and Ca2+ under pH control.     

Gibbs states of a one dimensional quantum lattice

A one dimensional infinite quantum spin lattice with a finite range interaction is studied. The Gibbs state in the infinite volume limit is shown to exist as a primary state of a UHF algebra. The expectation value of any local observables in the state as well as the mean free energy depend analytically on the potential, showing no phase transition. The Gibbs state is an extremal KMS state.On leave from Research Institute for Mathematical Sciences, Kyoto University Kyoto, Japan.     

Kinetics of radiation-induced grafting reactions. III. Poly(isobutylene oxide)—styrene systems

Graft polymerization of styrene onto preirradiated poly(isobutylene oxide) was carried out at 25°C. The concentration of active sites for grafting was estimated by means of ESR and by the activation analysis of bromine atoms bound to the chain ends. Kinetic data such as differential amount of active sites (DACT), growth rate (GR), and average lifetime (τ) were obtained to calculate the molecular weight distribution of graft chains by the Monte Carlo simulation method. The number-average molecular weight of the graft chain was calculated from the equation, M _n = 2GRτ (mw), which agreed well with the observed value.     

On the equivalence of KMS and Gibbs conditions for states of quantum lattice systems

The equivalence of a Gibbsian equilibrium condition and the KMS condition is proven for one-dimensional quantum lattice systems with a finite range interaction at arbitrary temperature, and for quantum lattice systems of arbitrary dimension, with a finite body interaction, at high temperature.     

Magnetic order in the heavy fermion compound CeCu6 at mK temperatures

We have measured the ac magnetic susceptibility in various fields and thermal expansion of single crystals of the heavy fermion compound CeCu6 at temperatures down to 250 &mgr;K. The susceptibility of CeCu6 shows a peak at about 2 mK and has a large anisotropy. We also detected an anomaly of thermal expansion at the same temperature. The observed behaviors of the susceptibility and the thermal expansion in CeCu6 indicate the occurrence of an antiferromagnetic order.     

Molecular vibration imaging in the fingerprint region by use of coherent anti-Stokes Raman scattering microscopy with a collinear configuration

We have developed a new coherent anti-Stokes Raman scattering (CARS) microscopy system with a collinear configuration for use in the fingerprint region. The system consists of a picosecond laser system and a transmission-type laser scanning microscope without a pinhole in front of the detector. The observable Raman-shift region is 900-1750 cm(-1), the spectral resolution is 30cm(-1), and the spatial resolution is smaller than 1 mum in the lateral direction and 3.2 mum in the depth direction, with objectives with a numerical aperture of 0.65. CARS spectra and images of polystyrene beads are demonstrated, and CARS imaging of a viable yeast cell is attempted.     

Simulation method of colloidal suspensions with hydrodynamic interactions: fluid particle dynamics

We develop a new simulation method of colloidal suspensions, which we call a "fluid particle dynamics" (FPD) method. This FPD method, which treats a colloid as a fluid particle, removes the difficulties stemming from a solid-fluid boundary condition in the treatment of hydrodynamic interactions between the particles. The importance of interparticle hydrodynamic interactions in the aggregation process of colloidal particles is demonstrated as an example. This method can be applied to a wide range of problems in colloidal science.     

Design,fabrication, and properties of macroscale supramolecular fibers consisted of fully hydrogen-bonded pseudo-polymer chains

Macro-scale supramolecular fibers composed of hydrogen bonded pseudo-polymer chains of guanosine derivatives were fibricated, and physical properties of the fibers were investigated.     

The corrosion of zircon and zirconia refractories by molten glasses

The corrosion of ZrO₂-containing refractories by molten glasses has been investigated experimentally in relation to the compositions of the glasses. For a zircon refractory, zircon crystals contacting the glass decomposed into ZrO₂ crystals and glassy phase at higher temperatures. The decomposition temperature was changed with the glass compositions. Alkali components in the glasses were confirmed to be most corrosive for the zircon refractory. For a ZrO₂ refractory, compositions of the glass-refractory interfaces were nearly saturated with ZrO₂. The corrosion rate of the ZrO₂ refractory was considered to be controlled by the transport rate of zirconium away from the interface.

The concentration of CaO in glasses, as well as that of alkali components, was found to be very effective for increasing the corrosion rate of ZrO₂ refractories.