Luminescence of ytterium(III) β-diketonate complexes containing different ligands

The spectral and luminescent characteristics of ytterbium(III) β-diketonate complexes containing different nitrogen- and phosphorus-containing ligands are determined. The most intensive luminescence in the IR region is observed for the neutral phosphorus-containing ligands.     

Luminescence and magnetic properties of mixed-ligand europium trifluoroacetates

The luminescence and magnetic properties of mixed-ligand europium trifluoroacetates with nitrogen- and phosphorus-containing neutral ligands [Eu(TFA)₃ · 3H₂O]₂ and Eu(TFA)₃ · 2D · nH₂O were studied (here TFA is the trifluoroacetic acid anion, and D is Phen (1,10-phenanthroline), n = 1; DMF (dimethylformamide), n = 1; or TPPO (triphenylphosphine oxide), n = 3). The molar magnetic susceptibility increased in the series of complex compounds Eu(TFA)₃ · 2Phen · H₂O < [Eu(TFA)₃ · 3H₂O]₂ < Eu(TFA)₃ · 2DMF · H₂O < Eu(TFA)₃ · 2TPPO · 3H₂O. Correlations were found between the luminescent and magnetic characteristics of the complex compounds.     

The effect of a longitudinal magnetic field on the plasma-dust structures in strata in a glow discharge

The plasma-dust structures in strata in a glow discharge exposed to a longitudinal magnetic field are studied in detail. In a weakly ordered structure, the angular velocity has a vertical gradient. A reversal of rotation of the structure in a magnetic field corresponding to the magnetization of electrons is found. With the help of the pair distribution function of particles, changes in the degree of order of the structure in the magnetic field are revealed. These changes correlate with changes in the angular velocity of rotation. To explain this effect, it is assumed that the dust structure is subjected to the action of ions in crossed electric and magnetic fields.     

Application of probing dusty particles to investigation of a stratified discharge with dusty plasma structures in a magnetic field

Experimental investigation of a stratified discharge in a magnetic field with the help of probe dusty particles falling through the discharge under the gravity force is described. The radial and azimuthal accelerations of probe particles in the stratum volume are measured. It is found that the particles move in the stratum without accelerations except in two regions. In the first region, the acceleration has two components directed toward the tube axis and upward, whereas, in the second region, they are directed toward the tube wall and downward.     

Photostability of rare-earth element hexafluoroacetylacetonates

Measurements have been made of the quantum yields in photodecomposition of adducts of lanthanide hexafluoroacetylacetonates in hexane, with various excitation energies. The photoreactivity of luminescing complexes of Eu³⁺ and Sm³⁺ is much lower than the reactivity of the nonluminescing complexes of La³⁺ and Gd³⁺. The photoreactivity of the complexes is lower when oxygen is present.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 1975–1978, September, 1989.     

Thermal expansion of water in fine pores

The relative expansion of water in pores about 50 Å in size has been investigated within the temperature range of 0 to 90°C. It has been established that at a temperature higher than 70°C, the runs of curves in pores and the bulk phase coincide. This demonstrates that the structural peculiarities of water disappear at these temperatures. Comparison between the plotted curves enables one to evaluate the density of water in pores, which at room temperature differs from the bulk density by about 2%.     

Extension dimension and quasi-finite CW-complexes

We extend the definition of quasi-finite complexes from countable complexes to arbitrary ones and provide a characterization of quasi-finite complexes in terms of L-invertible maps and dimensional properties of compactifications. Several results related to the class of quasi-finite complexes are established, such as completion of metrizable spaces, existence of universal spaces and a version of the factorization theorem. Furthermore, we define UV(L)-spaces in the realm of metrizable spaces and show that some properties of UV(n)-spaces and UV(n)-maps remain valid for UV(L)-spaces and UV(L)-maps, respectively.