Color Center Laser–Microwave Double Resonance Spectroscopy of the ν1Vibrational State of HCCF

Rotational transitions of fluoroacetylene in the ν₁(CH stretch) vibrational state have been observed by the laser–microwave double resonance technique using a color center laser as a radiation source in the 3 μm region. The rotational constant and centrifugal distortion constant in the ν₁state were determined to be 9684.310(16) MHz and 2.68(62) kHz, respectively, where the uncertainties given in parentheses correspond to 2.5 standard deviations.     

AnN-person noncooperative discounted vector-valued dynamic game with a metric space

AnN-person noncooperative discounted vector-valued game with a metric space is investigated. We define aD-convex equilibrium point and prove that aD-convex equilibrium point exists in this game system. A modified version of the original game system is formulated so that an equilibrium point of the modified version is aD-convex equilibrium point of the original game system. Under appropriate conditions, the converse holds in the sense that aD-convex equilibrium point is also an equilibrium point of the modified game system.     

Synthesis and properties of π‐conjugated dithiafulvene oligomers by addition of a monofunctionalized compound

Dithiafulvene oligomers ( 3 ) were prepared by cycloaddition polymerization of aldothioketenes with their alkynethiol tautomers derived from 1,4‐diethynylbenzene ( 2 ) with the addition of 1‐ethynyl‐4‐methylbenzene ( 1 ) as a monofunctionalized compound. Different feed ratios of 2 / 1 were used to control the molecular weights of 3 . The structures of 3 were confirmed by IR and ¹H NMR spectroscopies in comparison with those of 2‐(4‐tolylidene)‐4‐tolyl‐1,3‐dithiol ( 4 ) as a model compound, which was obtained by the treatment of lithium 2‐tolylethynethiolate with water in Et₂O. The number‐average degree of polymerization (DP) and the number‐average molecular weight were measured by gel permeation chromatographic and ¹H NMR analysis. DP increased with an increasing feed ratio of 2 / 1 . The ultraviolet–visible spectra of 3 in diluted acetonitrile showed that the absorption maxima of 3 increased with an increasing DP of 3 . These redshifts are ascribed to an effective expansion of the π‐conjugation system in 3 . The oligomers exhibited a maximum conjugation length of seven repeating units. The redox properties of 3 were examined by cyclic voltammetry. The oxidation half‐peak potentials (E_p/2) of 3 were slightly cathodically shifted with increasing DP. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 708–715, 2003     

Dirichlet form approach to infinite-dimensional Wiener processes with singular interactions

We construct infinite-dimensional Wiener processes with interactions by constructing specific quasi-regular Dirichlet forms. Our assumptions are very mild; accordingly, our results can be applied to singular interactions such as hard core potentials, Lennard-Jones type potentials, and Dyson's model. We construct nonequilibrium dynamics.Dedicated to Professor Masatoshi Fukushima on his 60th birthday     

Thickening of crystals during rapid heating. II. Crosslinked polyethylene and methoxymethylated nylon 6

The effect of modification of polymer chains on crystal thickening during heating was investigated with an apparatus devised for rapid measurement of small-angle x-ray diffraction. Thickening of crystals still occurred even at a heating rate of 18°C/min in polyethylene irradiated with gamma ray doses of 30–300 Mrad, and the melting point was depressed. These results showed that the melting point depression due to irradiation is not due to a restriction on crystal thickening but rather to crystal lattice distortion. On the other hand, although methoxymethylation of nylon 6 completely inhibits crystal thickening, the melting point increases or decreases depending on the temperature of annealing preceding methoxymethylation. From these results we are led to conclude that irradiation and methoxymethylation are not effective means of obtaining the relation between melting point and crystal thickness.     

Solvent-induced morphological change of microporous hollow fiber membranes

Microporous polyethylene hollow fiber membranes (EHF-1 and EHF-2) were subjected to solvent treatment, and the effects of this treatment on membrane morphology and permeating properties were studied. Membranes treated with various organic solvents exhibited enhanced permeability, enlarged pore size, and increased shrinkage in the longitudinal direction. These phenomena were found to depend on the surface tension of the solvent: the higher the surface tension of the solvent, the larger the change in morphology and permeation of the membrane. A mechanism to account for the effects of solvent treatment on the morphology of the membrane is proposed taking into consideration the influence of the type of solvent used for treatment. The enhanced morphological and permeation changes are ascribed to the formation of liquid bridges between two microfibrils of the membrane during drying followed by the deformation and adhesion of the adjacent microfibrils based on the surface tension of the solvent.     

Carbon chemical shifts of 1,1-diphenylethylene and α-methylstyrene dimer dianions

The natural abundance C-13 NMR spectra of 1,1-diphenylethylene and α-methylstyrene dimer dianions have been obtained using the proton noise decoupling technique. The extra negative charge distributions in the carbanions have been discussed and compared with those obtained from the proton chemical shifts. The chemical shifts of the two ortho carbons in a phenyl ring are equivalent to each other for the former carbanion but not for the latter.     

Non-cooperative n-person game with a stopped set

A continuous time non-cooperative n-person Markov game with a stopped set is studied in this paper. We prove that, in the game process with or without discount factor, there exists an optimal stationary point of strategies, called the equilibrium point, and each player has his equilibrium stationary strategy, such that the total expected discounted or non-discounted gain are maximums.     

Soft x-ray spectroscopy of Ba24Ge100: electronic phase transition and Ba-atom rattling

The electronic states of Ba24Ge100 are studied by soft x-ray photoelectron spectroscopy (XPS) at a high-energy photon factory. A large reduction in the density of states (DOS) at the Fermi level is clearly shown before and after the electronic phase transition at 200 K. The changes in the spectrum widths and the fine structures of the core-level Ba 4d spectra give a very reasonable indication of the Ba-atom rattlings in the clathrate polyhedra. On-resonance experiments using the excitation from Ba 3d to 4f levels display that the wave functions of Ba 5d and 6s orbitals give only a small contribution to make a Fermi surface through the hybridization with the Ge20 cluster orbitals. Importantly, reliable values of the DOS at the Fermi level NEF are successfully deduced, using two data sets of DOS obtained from high-resolution XPS and the total magnetic susceptibilities by a superconducting quantum interference device, to be 0.149 and 0.0427 states eV(-1) (Ge atom)(-1) for a high-temperature and for a low-temperature phase.