EPR spectroscopic study of the spin-labeled chelating reagent-solvent-neutral electron-donor compound system

Conclusions Dimerization of spin-labeled hydroxamic acid (I) in aprotic solvents was demonstrated, and the dimerization constants in heptane, toluene, and chloroform were calculated. There is an indirect exchange reaction between the radicals at the bonds in the molecule of the dimer. The effect of the nature of the solvent on the HFI constants of nitroxyl radicals, imidazoline and imidazolidine derivatives, was studied. The distance between the unpaired electrons in the molecule of the dimer in a glassy toluene solution of the reagent was determined. Addition of neutral electron-donor compounds inhibits the dimerization of (I). The constants for the formation of molecular complexes of the reagent with triethylamine, piperidine, triphenylphosphine oxide, tri-n-butyl phosphate, dimethylsulfoxide, ethanol, and acetone were estimated. An increase in the basicity of the additive compounds results in an increase in the constants for the formation of molecular complexes.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 64–70, January, 1985.     

A general treatment of solubility. 2. QSPR prediction of free energies of solvation of specified solutes in ranges of solvents

As part of our general QSPR treatment of solubility (started in the preceding paper), we now present quantitative relationships between solvent structures and the solvation free energies of individual solutes. Solvation free energies of 80 diverse organic solutes are each modeled in a range from 15 to 82 solvents using our CODESSA PRO software. Significant correlations (in terms of squared correlation coefficient) are found for all the 80 solutes: the best fit is obtained for n-propylamine (R(2) = 0.996); the lowest R(2) corresponds to toluene (0.604).     

Near-Vertical Local Density Spectra of the EAS Charged Particles in the Energy Range of 10 14 –10 17 eV

The results of the long-term measurements of extensive air showers with the calibration telescope system of the Cherenkov water detector are presented for an energy range of 1014–1017 eV. We have used two independent methods for reconstruction of the charged particle local density spectrum: by the multiplicity of the hit counters and by their amplitude responses. By means of Geant4 calculations, we have shown how the structure of the building and the water tank affect the results of the spectrum reconstruction. We obtained two different exponents of charged particles’ local density spectra for CTS top and bottom plane. The results are compared with CORSIKA calculations and data from other setups.     

NEVOD–DECOR Experiment on the Measurement of the Energy Deposit of Cosmic Ray Muon Bundles

Physics of Atomic Nuclei - In comparison with calculations, the excess of multimuon events found in many experiments at ultrahigh energies of extensive air showers (EASs) cannot be explained using...     

Preconcentration of Cesium, Cerium, Cobalt, Bismuth, and Lead Radionuclides by Solid-Phase Extraction

A procedure was proposed for the preconcentration of Sr, Cs, Pb, Co, Bi, and Ce beta radionuclides by solid-phase extraction as ion-pair complexes in the system dicyclohexyl-18-crown-6–sodium dodecyl sulfonate.     

Experimental observation of the effect of the Earth’s magnetic field on the EAS muon component

The dependence of the intensity of muon bundles recorded using the DECOR coordinate track detector on the angle between the directions of bundle arrival and the Earth’s magnetic field has been analyzed for several ranges of zenith angles. It is found that the intensity of muon bundles decreases with an increase in the transverse magnetic field component, in contrast to the results of the calculation performed on the assumption of flux azimuthal symmetry. The effect of coplanarity of particle tracks in the plane formed by the core of an extensive air shower and the Lorentz force vector is also observed.     

Measurements of the integrated muon intensity at large zenith angles

Precision measurements of the zenith-angle distributions of muons in the range 61°–89° are performed using the DECOR coordinate detector. The total number of selected events is more than 20 million. The dependence of the integrated muon intensity on the zenith angle is determined for several threshold energies in the range from 1.7 to 7.2. GeV. The experimental results in these ranges of zenith angles and threshold energies are obtained for the first time. It is demonstrated that the dependence of the integrated muon intensity on the zenith angle is adequately described by a simple analytical relationship.     

Field-emission diodes based on semiconductor—polycrystalline diamond heterojunctions

A complex of electrophysical and technological studies of solid-state field-emission diodes is carried out. Emission comes from an array of nanometer objects near the semiconductor—polycrystalline diamond interface. The process route of the diode heterostructures includes the fabrication of nanometer masks and nanometer cone (tip) arrays, as well as plasma-assisted growth of polycrystalline diamond films on the surface of structures with nanometer cone arrays. In field-emission diodes thus formed, a current density as high as 20 A/cm² is achieved at a threshold of field emission from the nanotip arrays into the diamond of about 0.5 V.     

Study of cascade showers generated by near-horizontal muons in the water Cherenkov detector with a dense array of optical modules

The method for reconstructing the cascade curve by the Cherenkov radiation in water of the NEVOD detector with a dense spatial array of optical modules is discussed. Cascades are generated by near-horizontal muons which are separated by the DECOR coordinate detector. The cascade curves and the cascade energy spectrum measured in an ～8000-hour measurement series are presented.