Farsighted Stability in an n-Person Prisoner’s Dilemma

Farsighted stability is examined in an n-person prisoner’s dilemma. It is shown that any individually rational and Pareto efficient outcome is a farsighted stable set and no other farsighted stable set exists; it is further shown that the largest consistent set consists of all individually rational outcomes.     

The Synthesis of Damascenone and β-Damascone and the possible mechanism of their formation from carotenoids

A brief synthesis of damascenone ( 5 ) from the acetylenic diol 2 and also that of β-damascone ( 8 ) from β-ionol, resembling the biogenetic synthesis, are described. A possible mechanism for the formation of damascenone from neoxanthin is proposed.     

Extreme fluorescence sensitivity of some aniline derivatives to aqueous and nonaqueous environments: mechanistic study and its implication as a fluorescent probe

Effects of solvent water on the photophysical properties of a series of meta- and para-substituted anilines have been investigated by means of time-resolved fluorescence, transient absorption, and photoacoustic measurements. Some aniline derivatives exhibit extremely short fluorescence lifetime (tau(f)) and small quantum yield (Phi(f)) in water (e.g., tau(f) = 45 ps and Phi(f) = 0.0019 for m-cyanoaniline (m-ANCN) in H(2)O), which is in marked contrast with their much larger values in nonaqueous solvents (tau(f) = 7.3 ns and Phi(f) = 0.14 for m-ANCN in acetonitrile). Photoacoustic and transient absorption measurements show that the remarkable fluorescence quenching of m-ANCN in water is attributed almost exclusively to fast internal conversion. The lifetime measurements of m-ANCN in H(2)O/acetonitrile binary solvent mixtures reveal that the quenching is related to variation of hydrogen-bonding interactions between the amino group and water molecules and the conformational change of the amino group upon electronic excitation. Similar fluorescence quenching due to solvent water is also found for N-alkylated m-ANCNs. The drastic differences in the fluorescence intensity and lifetime of m-ANCNs under hydrophobic and hydrophilic environments and also the large solvent polarity dependence of the fluorescence band position suggest the possibility that they can be utilized as fluorescent probes for investigating the microenvironment of biological systems. In suspensions of human serum albumin (HSA) in water, remarkable enhancement of the fluorescence intensity and lifetime is observed for m-ANCN and its N-alkylated derivatives, demonstrating that m-ANCNs can be a candidate for novel fluorescent probe with small molecular size.     

Trivial source modules in blocks with cyclic defect groups

We shall present a method to get trivial source modules easily just by looking at values of ordinary characters at non-identity p-elements in finite groups instead of doing huge calculation. The method is only for a case where defect groups are cyclic. Nevertheless, it works well at least when we want to prove Broué’s abelian defect group conjecture for blocks which have elementary abelian defect groups of order p ².     

Structural and Magnetic Properties of FexTiSe2 Intercalation Compounds

Abstract

Magnetic and neutron studies are done about iron-intercalated titanium diselenide, Fe^xTiSe² with 0<x≤0.5. A neutron diffraction measurement shows that Fe-atoms are located between neighboring selenium layers. Magnetic measurements show that FexTiSe² are spin glasses for 0. 15≤^x≤0.22 and antiferromagnets for 0.25≤^x≤0.5. T-x magnetic phase diagram is determined. This diagram is slightly different from that determined by Huntley et al. The difference may be caused by a formation of Fe-clusters in their samples. The x-dependence of the parameters of paramagnetic susceptibilities is determined.     

EXAFS and XANES Studies on 3d Transition Metal Intercalation Compounds M x TiS2

Abstract

EXAFS and XANES spectra of Ti K-edge have been measured for 3d transition metal intercalation compounds M _x TiS₂ (M = Mn, Fe, Co and Ni; x ≤ 0.33). We have found that the interatomic distance between Ti and the first nearest neighbor S atoms, R(Ti-S), increases with the guest concentration x. The variation in XANES spectra with x reveals the reduction of the valence state of Ti atoms upon intercalation of M. From these results as well as the M K-edge EXAFS data studied previously, we have proposed a simple model on the local structure of M _x TiS₂ to reproduce the observed values of R(Ti-S) by averaging local shift of S atoms caused by intercalation.     

Chemical etching op fission tracks in ethylene-tetrafluoroethylene copolymer

The chemical etching of fission tracks in ethylene-tetrafluoro-ethylene copolymer was studied. Etched holes 3000–4000 Å in diameter was recognized by electron microscopy for a film bombarded by fission fragments in oxygen and etched in a 12N sodium hydroxide solution at 125°C. The radial etching rate at 125°C was 6–8 Å/hr, which is less than 17 Å/hr for polyvinylidene fluoride in the same sodium hydroxide concentration at 85°C. The smaller rate is a reflection of the larger chemical resistivity of ethylene-tetrafluoro-ethylene copolymer than polyvinylidene fluoride.     

The Projective Cover of the Trivial Module Over a Group Algebra of a Finite Group

We determine all finite groups G such that the Loewy length (socle length) of the projective cover P(k _G ) of the trivial kG-module k _G is four, where k is a field of characteristic p > 0 and kG is the group algebra of G over k, by using previous results and also the classification of finite simple groups. As a by-product we prove also that if p = 2 then all finite groups G such that the Loewy lengths of the principal block algebras of kG are four, are determined.