Barrelledness of Generalized Sums of Normed Spaces

Let (E _i ) _iI be a family of normed spaces and a space of scalar generalized sequences. The -sum of the family (E _i ) _iI of spaces is

Room-temperature synthesis of Mn3O4 nanorods

Nanocrystalline Mn₃O₄ hausmannite has been easily prepared from manganese(II) acetate tetrahydrated, dissolved in a mixture of N,N’-dimethylformamide (DMF) and water (10%) at room temperature, without post-treatment of heating. Stability of the Mn₃O₄ colloidal dispersion was monitored by UV-visible electronic absorption spectroscopy. X-ray powder diffraction (XRD) pattern demonstrates its good phase purity. Analysis by transmission electron microscopy (TEM) image shows homogeneous nanorods with a narrow size distribution, being the average diameter and length of 6.58 nm and 17.44 nm, respectively. Moreover, the facility of the hausmannite nanorods to adhere to glass wall in this solvent mixture has allowed the formation of thin films which were analyzed by atomic force microscopy (AFM). PACS 81.07.Bc; 81.16.Be; 61.46.+w     

Hypervirial Theorems and SCF Wavefunctions for Coupled Oscillators

The SCF formalism is analysed in connection with hypervirial theorems. Coupled oscillator models are chosen in order to illustrate the formal results.     

Aqueous solutions of lithium hydroxide at various temperatures: Conductivity and activity coefficients

The conductivity of LiOH aqueous solutions has been determined at 15, 25, and 45°C. The data analysis showed that LiOH is a slightly associated electrolyte, its association increasing with temperature. The association constant and distance parameter obtained from the conductivity data were successfully employed to calculate the activity coefficients of the solutions. The same procedure applied to very precise conductivity data for NaOH aqueous solutions enabled us to assess the reliability of this method of calculation of activity coefficients up to 0.1m. The alkali metal hydroxides show a reverse trend in the way their properties change with cationic radius, as is the case for the fluorides with which they are compared.     

Atomic diamagnetic susceptibilities from the statistical Thomas-Fermi-Amaldi theory

We report the calculation of atomic diamagnetic susceptibilities from the statistical Thomas-Fermi-Amaldi theory. The importance of the Fermi-Amaldi correction for the Thomas-Fermi theory is examined. The calculated values are compared with those obtained from self-consistent-field wave functions as well as with respect to available experimental data. Several general trends are pointed out and the advantages of the statistical procedure are stressed.     

The van der Waals interactions as a tool for the interpretation of aromatic substitutions

The isoenergetic lines of van der Waals interaction between aromatic compounds and electrophilic or nucleophilic agents in parallel planes are drawn in order to detect the best approach channels for reagents in aromatic substitutions. The van der Waals interaction is comprised of the electrostatic, polarization and dispersion terms. It has been found that the channels depend on the molecules and on the positions of the centres attacked. The polarization term is shown to play a decisive role in electrophilic substitutions of phenanthrene and in nucleophilic substitutions of the pyridinium ion.