Molecular-dynamics studies of binary mixtures of Lennard-Jones fluids with differing component sizes

Molecular-dynamics calculations have been carried out for six pure liquids and three binary mixtures of Lennard-Jones fluids with differing component sizes and attractive interactions. Internal energies, radial-distribution functions, velocity autocorrelation functions and self-diffusion coefficients have been calculated and are discussed together with our previous results. The three mixtures obey the Lorentz-Berthelot rules and show endothermic mixing. The excess internal energy ΔU^E of mixtures with equal-sized components is symmetrical with respect to the mole fraction, but those for mixtures of different-sized components become asymmetrical. A comparison is made between the present ΔU^E data and those for real mixtures.     

Mechanochemical reaction of polymers by ultrasonic irradiation. I. Mechanochemical reaction in mixtures of polystyrene,styrene, and cyclohexanone

Mechanical degradation and mechanochemical polymerization in polystyrene–styrene–cyclohexanone mixtures have been studied by ultrasonic irradiation at 60°C. The number of fresh polymer chains after the degradation is 2 × 10^?5 mole l^?1 hr^?1. The rate equations for mechanical scission and mechanochemical polymerization have been deduced. The rate equation for mechanical scission was found to be in agreement with the expression of a previous paper. In addition, the rate equation for mechanochemical polymerization is not essentially different from that for the general radical polymerization in the presence of solvents. The kinetic chain length for polymeric free radicals in the polymerization process has been calculated. The mechanochemical polymerization of styrene was initiated by only one of the two kinds of end radicals after mechanical scission of polystyrene. The molecular weight distributions of the samples after the degradation and the polymerization have been compared and discussed.     

Applications of the complex interpolation method to a von Neumann algebra: Non-commutative Lp-spaces

Non-commutative L^p-spaces, 1 < p < ∞, associated with a von Neumann algebra are considered. The paper consists of two parts. In part I, by making use of the complex interpolation method, non-commutative L^p-spaces are defined as interpolation spaces between the von Neumann algebra in question and its predual. Also, all expected properties (such as duality and uniform convexity) are proved in the frame of interpolaton theory and relative modular theory. In part II, these L^p-spaces are compared with Haagerup's L^p-spaces. Based on this comparison, a non-commutative analogue of the classical Stein-Weiss interpolation theorem is obtained.     

An example of a non quasi well-behaved derivation in C(I)

The aim of this paper is to study the closed derivations in C(I) induced by non-atomic signed measures with support I and to give an example of a non quasi well-behaved closed derivation in C(I).     

Infrared electronic absorption in a single-component molecular metal

The infrared spectra of the crystal of transition metal complex molecules with extended-TTF ligands, Ni(tmdt)2, which is the first single-component molecular metal that has a stable metallic state even at low temperatures, exhibited an extremely low-energy electronic absorption around 2200 cm-1 (tmdt = trimethylenetetrathiafulvalenedithiolate). The systematic shift of the absorption peaks for molecules similar to Ni(tmdt)2, which range from metallic to semiconducting crystals, shows that the single-component molecular conductors are composed of molecules with unprecedentedly small HOMO-LUMO gaps.     

Fluorometric determination of Ethofenprox in water by using solid-phase extraction

Ethofenprox (pesticide) exhibits a relatively strong fluorescence in the UV region. Its fluorescence properties were investigated in aqueous solution, organic solvents, and micellar media. The fluorescence intensity of Ethofenprox was enhanced by a factor of 1.2 to 2.7 in the presence of surfactants and by 1.4 in pure organic solvents without significant shift of the excitation and emission wavelengths. The conditions for solid-phase extraction of Ethofenprox from water samples were examined. Among the solid-phase extraction cartridges studied, a Sep Pak C8 with weak sorption ability was found to be the most useful due to the extremely high hydrophobicity of Ethofenprox. For the complete elution of Ethofenprox from the sorbent, an addition of 40%v/v methanol to the sample water was necessary and effective to eliminate the fluorescent impurities of the matrix. The calibration graph obtained was linear over the range of 0.03 to 2.4 mg L(-1) in 100 mL sample. The method was successfully applied to the determination of Ethofenprox in tap, well, and river waters with recoveries of 93.2-95.7%.     

Bunch compression at the SPring-8 linac and successive generation of THz pulse train in the isochronous ring

We have demonstrated the idea of circulating a short, intense linac bunch for some tens of turns in an isochronous ring. We compressed a bunch from the SPring-8 linac to a few picoseconds rms by means of an energy compression system and a beam transport line from the linac to NewSUBARU. The NewSUBARU storage ring was set to a quasi-isochronous condition and the bunch circulated for about 50 turns after injection while maintaining the short bunch length. At the same time, a pulse train of strong coherent synchrotron oscillation from the short bunch was observed.     

Orderings and Non-formal Deformation Quantization

We propose suitable ideas for non-formal deformation quantization of Fréchet Poisson algebras. To deal with the convergence problem of deformation quantization, we employ Fréchet algebras originally given by Gel’fand–Shilov. Ideas from deformation quantization are applied to expressions of elements of abstract algebras, which leads to a notion of “independence of ordering principle”. This principle is useful for the understanding of the star exponential functions and for the transcendental calculus in non-formal deformation quantization. Akira Yoshioka was partially supported by Grant-in-Aid for Scientific Research (#19540103.), Ministry of Education, Science and Culture, Japan.