Cobalt(II) complexes with hydantoin

Complexes of Co(II) with hydantoin (L, C₃H₄N₂O₂) have been synthesized. The complexes had the following compositions: [CoL₂(OH₂)₂](NO₃)₂ · 2H₂O, [CoL₂(OH₂)₂]Cl₂ · 3H₂O, and [CoL₂(OH₂)₂]SO₄ · 2H₂O. The individual character of the synthesized compounds are proved by the study of the IR absorption spectra (400–4000 cm^?1) of all the compounds and the initial ligand, as well as the X-ray diffraction patterns, thermograms, and thermogravigrams of the synthesized compounds. The coordination modes of the ligand and acido groups are revealed. The properties of the synthesized compounds are characterized.     

Diamagnetic susceptibility of the electron gas in the cylindrical nanolayer

Diamagnetic properties of the electron gas in cylindrical nanolayer have been investigated. The dependence of mean energy, mean magnetization and mean magnetic susceptibility on the values of magnetic field is obtained. Comparison of these dependencies with the case, when the electron gas is localized in the cylindrical quantum dot, is carried out. In a nanolayer, the character of an effect of size quantization on the magnetic properties of the electron gas has been revealed.     

Supersaturated vapor recondensation: Analytical theories and numerical calculation

The time dependences of droplet size within the period from the end of nucleation until the onset of asymptotic regime of recondensation are determined by the numerical integration of equations describing droplet growth in a supersaturated vapor. The obtained dependences are compared with those derived in terms of the analytical theories of condensation. The character of variations in the final self-similar size distribution of droplets is studied as depending on variations in their initial distribution function and in the system parameters.     

Effect of parameters of the Fe3+/H2O2 catalytic system on the efficiency of oxidative destruction of azo dye acid chrome dark blue

Effect of physicochemical parameters on the rate and efficiency of oxidative destruction of the Acid chrome dark blue azo dye in aqueous solutions was studied. The reaction orders with respect to reagents and the optimal conditions of oxidative destruction of the azo dye in the Fe³⁺/H₂O₂ catalytic system were determined.     

Relativistic correction to the 1ssigma and 2psigma electronic states of the H2 + molecular ion and the moleculelike states of the antiprotonic helium He+ -p

Effective potentials of the relativistic Breit-Pauli corrections for the 1ssigma(g) and 2psigma(u) electron states of the H(2) (+) molecular ion and the 1ssigma, 2ssigma, and 3psigma states of the antiprotonic helium atom He(+)(-)p are calculated within the Born-Oppenheimer approximation. The variational expansion with randomly chosen exponents has been used for numerical studies. The results obtained for the Breit-Pauli effective potentials are accurate up to ten significant digits for the H(2) (+) molecular ion and eight digits for the He(+)(-)p atom.     

Experimental plant for investigation of the possibility of linac-based production of medicine-intended isotopes

We describe a technique of obtaining radioactive ^99mTc isotope by irradiation of molybdenum with high-intensity beam of bremsstrahlung photons from the electron beam of the linear electron accelerator (LUE50) of the Alikhanyan National Science Laboratory (ANSL, former Yerevan Physics Institute). We have elaborated and created an experimental plant for development of ^99mTc production technology. Upgrading of linac has been performed aimed at raising the beam intensity and density. A system of automated control of the parameters of the plant and accelerator was built up. We carried out preliminary studies of ^99mTc obtaining technique and give quantitative and qualitative results.     

An Investigation of the Positive Column of a Cd–Ne Glow Discharge. I: Steady State

An investigation of cadmium-neon plasma in cylindrical axially homogeneouspositive column of a dc glow discharge at low and intermediate pressure ispresented. Electron impact excitation cross sections, heavy-particlecollision rate coefficients, and radiative decay rates for Cd–Nemixture have been assembled from the literature and summarized. Aself-consistent collisional-radiative model based on numerical solution ofthe electron Boltzmann equation coupled with a system of particle balanceequations for the electrons, excited atoms and ions, as well as the electronenergy balance equation, is developed. By this model, the electron energydistribution function, mean energy, electron density, electron mobility, anddiffusion coefficient, populations of Cd and Ne excited states and theapplied dc electric field are calculated. The populations of the excitedCd(5p³P_0,1,2) atoms are measured using opticalabsorption spectroscopy. From these measurements the effective lifetime ofthe resonance state Cd(5p³P₁) and the diffusioncoefficients of both metastable states Cd(5p³P₀) andCd(5p³P₂) are determined. The electron density isderived by probes measurements. The influence of the Cd vapor pressure anddischarge current on the main plasma characteristics is studied. Modelpredictions compare favorably with measured electron density and populationsof excited states in a wide range of discharge conditions.     

Thermomechanical effect in a planar nematic induced by a quasistatic electric field

A thermomechanical flow of uniformly oriented nematic liquid crystal induced by a quasistatic electric field is observed. This flow occurs when the electric field strength exceeds the static Fréedericksz transition threshold. The effect is attributed to an electric-field-induced nonuniformity of the director orientation which is required for the onset of the thermomechanical effect. The experimental results show good agreement with the theoretical estimates. Zh. Tekh. Fiz. 69, 122–124 (April 1999)     

High-spin structure of the neutron-rich 107,109 45Rh isotopes: the role of triaxiality

The ^107,109Rh nuclei have been produced as fission fragments following the fusion reaction ²⁸Si +¹⁷⁶Yb at 145 MeV bombarding energy and studied with the Eurogam2 array. In both nuclei three new rotational bands with the odd proton occupying the πg_9/2, πp_1/2 and π(g_7/2/d_5/2) sub-shells have been observed. In ¹⁰⁷Rh, two other bands involving strong M1 transitions have been identified at excitation energy larger than 2 MeV. They can be interpreted in terms of three quasiparticle excitations. In addition new structures consisting of four transitions, built on states located at low excitation energy (680 keV in ¹⁰⁷Rh and 642 keV in ¹⁰⁹Rh), point out the importance of triaxial deformation in these two isotopes. Received: 1 September 1999