The CP1 model on the torus: Contribution of instantons

The contribution of instantons to the partition function is calculated for the two-dimensional CP₁ model defined on the torus.     

Electronic and ionic conductivities and point defects in ytterbium sesquioxide at high temperature

From the study of complex impedance diagrams applied to a symmetric cell Pt-Yb₂O₃-Pt, the authors have shown the mixed character of electrical conduction within the ytterbium sesquioxide. The measurements were performed at thermodynamic equilibrium in the temperature range from 1423 to 1623 K and the partial pressure of oxygen range from 10^?12 to 1 atm. The variations of ionic and electronic conductivity as a function of P_O2, were interpreted in terms of point defects e′, ?, V?_Yb and Yb_{$\text{I}\text{?}$}, in the general case of a Frenkel disorder. The relative contributions and the activation energies of conduction of these different defects were determined.     

General Hartree-Fock solutions for a one dimensional δ-function gas

The one dimensional fermion gas with δ-function interactions is studied within the General Hartree-Fock (GHF) framework. Solutions of the eight Fukutome types are constructed by pairing and the corresponding gap equations are solved. The character of the solutions is studied as a function of the particle density.     

Fuzzy Boolean algebras

The purpose of this paper is to generalize the following situation: from the concrete structure $\text{B}$, we define the notion of Boolean algebras; the Stone representation theorem allows us to replace the algebraic study of Boolean algebras by a topological one. Let E be a non-empty set, and J a non-empty ordered set. Note $\text{B}$ the set of all fuzzy subsets of (E,J). We shall introduce the concept of fuzzy Boolean algebra and find a representation theorem. But it will be difficult to speak of the dual fuzzy topological space of a fuzzy Boolean algebra as we shall see further, except in certain particular cases.     

Synthese regiospecifique d'un dinucleoside ponte : (O6- desoxyguanosinyl)-1 (N4-desoxycytidyl)-2 ethane

Appropriate protected deoxyguanosine and deoxyuridine derivatives, respectively activated at O⁶ and O⁴ positions by the 3-nitro 1,2,4-triazol 1-yl group, were reacted with ethylene glycol, ethylenediamine or ethanolamine to give monoalkylated nucleosides or cross-linked dimers or cross-linked dinucleosides.     

Isotope Effects on the Lipophilicity of Deuterated Caffeines

In the present study, it is confirmed that the deuteration of C? H groups is accompanied by a small but genuine decrease in lipophilicity. The lipophilicity of deuterated isotopomers of caffeine was measured by reversed-phase HPLC. Overall, lipophilicity was shown to decrease when going from unlabelled caffeine to the three isomeric trideuterated caffeines, then to the three isomeric hexadeuterated caffeines, and finally to nonadeuterated caffeine. In addition, position-specific effects were also proven. E.g. (7-methyl-²H₃)caffeine experienced a smaller isotope effect than its two positional isomers. Both a cavity factor (decreased volume of deuterated isotopomers) and intramolecular electronic effects are postulated to operate.     

Orthogonalization in momentum space

Since the overlap integral between two functions in position space is the same as the overlap integral between their counterparts in momentum space, there is an intimate connection between orthonormalization procedures in the two spaces. It is pointed out that in certain cases this situation can be used to simplify the orthogonalization.