Complex Study of the Spearhead Superficial Crust from Burial Mound no. 1 near Novosvobodnaya Village

A complex study of a spearhead dated back to IV mill. BC from burial mound no. 1 near Novosvobodnaya village (collection of the State Historical Museum) and, in particular, the material of spearhead superficial crust has been performed. The elemental and phase composition of the metal of spearhead and the superficial crust on its surface have been determined by scanning electron microscopy, jointly with energydispersive X-ray microanalysis and X-ray phase analysis. A comparative analysis of the results of studying the spearhead superficial crust and similar crusts on other artifacts from the mounds near Novosvobodnaya village suggest natural origin of the crust on copper?arsenic artifacts.

     

Total Electron Content Measurements in the Ionosphere Disturbed by High-Power High-Frequency Waves by the Methods of Incoherent Scattering of Radio Waves and Radio Sounding by Glonass Satellite Signal

Radiophysics and Quantum Electronics - We present the results of comparing the total electron content measurements based on GLONASS satellite signals and the EISCAT UHF incoherent scatter radar...     

The stressed state of piecewise-homogeneous bodies subject to nonsteady thermal fields

The study of the distribution of thermal fields and the thermal stresses they generate, and the influence of these factors on the strength of piecewise-homogeneous bodies was begun and developed in the work of Ya. S. Pidstrigach, Yu. M. Kolyano, and their students [5, 12, 13]. In the present paper we use the theory of generalized functions to reduce the two-dimensional quasistatic problem of thermal stresses for piecewisehomogeneous bodies to solving systems of integral equations. The kernels of these equations are chosen as the corresponding Green's functions. We obtain a single system of integral equations for the entire region under consideration. To solve the system we apply the method of boundary elements [2]. On the basis of the results obtained we carry out a study of the thermostressed state of a half-plane with rectangular inclusions. Translated fromMatematichni Metodi i Fiziko-mekhnichni Polya, Vol. 40, No. 1, 1997, pp. 53–58.     

Formulation of perspective hepatoprotector polymeric forms based on silybin and ursodeoxycholic acid

Russian Chemical Bulletin - Silybin (Slb) and ursodeoxycholic acid (UDCA) are hepatoprotectors used in the pathogenetic therapy of liver and biliary tract. However, low bioavailability of these...     

Dynamics of the BiTeI lattice at high pressures

Raman measurements of the phonon spectrum of BiTeI at pressures of up to 20 GPa have been performed. A decrease in the linewidth of E² vibration by almost a factor of 2 with an increase in the pressure to 3 GPa has been detected. The frequencies of all four Raman active modes increase monotonically with the pressure. These lines are observed in spectra up to ～8 GPa. Sharp change in the spectrum occurs at pressures of 8–9 GPa, indicating a transition to the high-pressure phase, which holds up to 20 GPa. This transition is reversible and hardly has any hysteresis. A sample in the high-pressure phase is single crystal.     

The first representative of a new class of charge transfer complexes in o-quinone series for organic semiconductors

The first representative of a new class of charge transfer complexes for organic semiconductors was synthesized. The reaction of p-nitroaniline (PNA) with [1,10]-phenanthroline-5,6-dione (PD) results in the formation of a stable molecular charge transfer (CT) complex PNA₃-PD₂ in a ratio of 3:2. The structure of the molecular CT complex PNA₃-PD₂ was established by X-ray diffraction studies. Using the density functional theory method, it is shown that several types of intermolecular interactions are realized in the complex: between the PNA amino group and the nitro group of another PNA molecule, carbonyl groups, and PD nitrogen atoms. Complex PNA₃-PD₂ is stable only in solid form. The diffuse reflectance UV–vis spectrum of PNA₃-PD₂ crystal powder is characterized by the intense weakly structured long-wavelength absorption band up to 650 nm. Quantum chemical calculations of the electronic structure have shown that the complex PNA₃-PD₂ is a straight-band semiconductor with a band gap of 2.11 eV.     

Physical properties of carbon films obtained by methane pyrolysis in an electric field

A method of synthesizing carbon films on single-crystal silicon substrates by methane pyrolysis in an electrical field is suggested. The pressure and temperature arising in a working chamber when the substrate is exposed to C^–4 ions during pyrolysis are measured. Ion bombardment generates nuclei in the form of fibers about 2 μm in diameter providing the growth of a polycrystalline film. The resulting material is examined using electron microscopy and photo- and cathodoluminescence. Synthesized films are a composite material the matrix of which contains nanoclusters of a dissimilar crystalline nature. The effect of considerable two-stage decrease in the resistivity of the film material with increasing temperature from 300 to 1750 K is discovered. This points to the semiconducting properties of thick carbon films.     

Presowing Treatment of Spring Wheat Seeds by a Pulsed Electron Beam in the Atmosphere

High Energy Chemistry - The purpose of this work is to optimize the conditions of presowing treatment of spring wheat seeds with a low-energy pulsed electron beam. The absorbed dose in wheat has...