Pole contributions in semileptonic decays of D mesons

The contributions of the axial-vector and vector resonance states to D → P(V)l $\bar \nu$ _l decays are investigated on the basis of phenomenological chiral Lagrangians. It is shown that inclusion of such intermediate states improves agreement with experimental data.     

On new two-dimensional structures produced on the Si (111) and Si (100) surface upon molecular-beam epitaxy of cobalt and silicon

Highly perfect epitaxial heterostructure CoSi₂ films have been grown on the surface of Si (111) and Si (100) single crystals by the method of molecular-beam epitaxy. The optimal regimes of the film growth with different thicknesses have been determined. It has been shown that short-term annealing of epitaxial films at T = 900–950 K leads to the formation of new CoSi₂/Si(111)-2 × 2 and CoSi₂/Si(100)−2 × 4 superstructures.     

Decay τ − → φπ − ν τ and ω−φ mixing

The decay process τ ^? → φπ ^? ν _τ is investigated on the basis of the method of chiral phenomenological Lagrangians. It is shown that the calculated value of the decay probability is very sensitive to variations in the angle of ω?φ mixing. The resulting value of this probability is compared with available experimental data and with the results of other theoretical calculations.     

Determination of the c-terminal amino acid residues of the proteins of the hormones of the hypophysis

Chemistry of Natural Compounds -     

A study of the peptides of a tryptic hydrolyzate of lactosomatotropin

Chemistry of Natural Compounds -     

Effect of temperature on the intrinsic viscosity and conformation of different pectins

The effects of temperature on the intrinsic viscosity and on the conformation of pectin obtained from Citrus, Apple and Sunflower in a 0.17M NaCl solution were studied. Mark-Houwink plots for Orange, Apple and Sunflower pectin were obtained using HPSEC with online light scattering and viscosity detection. The intrinsic viscosity and flow activation energy E _a of pectin from the sources studied were measured over the temperature range 20–60°C. E _a values were 0.67, 0.69, 1.34, and 1.44 × 10⁷ J/(kmol) for commercial Citrus, Orange, Sunflower and Apple pectin, respectively. Intrinsic viscosity decreased linearly with increasing temperature, for all pectins except Apple one. These results clearly indicated that Apple pectin underwent structural changes that were more drastic than those that occurred for pectin from the other sources. E _a increased with decreasing weight average molar mass M _w indicating that pectin with low M _w were more asymmetric than pectin with higher values of M _w. Changes in the Huggins coefficients K _h with temperature for pectin from the various sources were attributed to the ability of pectin to aggregate, disaggregate and re-aggregate according to the temperature at which it was stored.