On the mass composition of primary cosmic rays in the energy region 10^15-10^16 eV

The method of a determination of the Primary Cosmic Ray mass composition is presented. Data processing is based on the theoretical model representing the integral muon multiplicity spectrum as the superposition of the spectra corresponding to different kinds of primary nuclei. The method consists of two stages. At the first stage, the permissible intervals of primary nuclei fractions f_i are determined on the base of the EAS spectrum vs the total number of muons (E_mu > 235 GeV). At the second stage, the permissible intervals of f_i are narrowed by fitting procedure. We use the experimental data on high multiplicity muon events (n_mu > 114) collected at the Baksan underground scintillation telescope. Within the framework of three components (protons, helium and heavy nuclei), the mass composition in the region 10^15-10^16 eV has been defined: f_p = 0.235 +- 0.02, f_He = 0.290 +- 0.02$, f_H = 0.475 +- 0.03.Comment: 14 pages, 6 figure

Palladium-catalyzed air-based oxidative coupling of arylboronic acids with H-phosphine oxides leading to aryl phosphine oxides

We present a novel and highly efficient methodology that allows for the construction of C-P bonds via the palladium-catalyzed air-based oxidative coupling of various commercially available arylboronic acids with easily oxidized H-phosphine oxides leading to valuable aryl phosphine oxides, particularly triarylphosphine oxides, with the use of air as the green oxidant, broad substrate applicability and good to excellent yields. The described catalytic system should be an efficient complement to the Chan-Lam type reaction and be useful in synthetic programs. This journal is ? the Partner Organisations 2014

Linear Multiparametric Programming by Multicriteria Simplex Method

A recently derived Multicriteria Simplex Method [Yu, P. L., M. Zeleny. 1975. The set of all nondominated solutions in linear cases and a multicriteria simplex method. J. Math. Anal. Appl. 49 (2, February) 430-468.] is used to study some basic properties in the decomposition of parametric space. A new type of parametric space, which arises naturally in its formulation, is used. Two computational methods are discussed. The first one is an indirect algebraic method which locates the corresponding set of all nondominated extreme points. The second one is a direct geometric decomposition method which is similar to that discussed by Gal and Nedoma [Gal, T., J. Nedoma. 1972 Multiparametric linear programming. Management Sci.. 18 406-421.]. The difficulties of such a geometric method are discussed through an example.