Pseudospin symmetry and structure of nuclei with <Emphasis Type="Italic">Z</Emphasis> ≥ 100

In the framework of the relativistic mean-field approach, a pseudospin dependence of the residual forces in nuclei is considered. It is shown that this dependence is relatively weak. As a consequence, a pseudospin dependence of the particle-core coupling is weak as well. This leads to a small splitting of the pseudospin doublets produced by a vector coupling of an odd particle pseudospin and a pseudoorbital momentum of the core. Some possibilities for experimental investigation of the manifestations of the pseudospin symmetry in the spectra of odd nuclei with Z ≥ 100 are indicated. The text was submitted by the authors in English.     

Direct 13C-13C spin-spin coupling constants in the vinyl group of N-vinylazoles

The unshared electron pair of the dicoordinated nitrogen atom introduces a stereospecific contribution to the ¹³C-¹³C spin-spin coupling constant (SSCC) in the vinyl group of a series of N-vinylazoles, the value of which depends on the energetics of the unshared pair.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 197–200, February, 1989.     

Structure of the internal boundary layer of a gas-discharge plasma in the axisymmetric case

An asymptotic representation for the solution of the problem of the radial structure of the internal boundary (transition) layer and the radial distribution of the basic physical plasma characteristics of the column of a free-burning low-pressure electric are in He is constructed. Sarov. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 3, pp. 185–195, May–June, 1998.     

Phase Behavior of Methane-Pentane Mixture in Bulk and in Porous Media

The adiabatic calorimetry method is used to measure the isochoric heat capacity and the dew-bubble curves for the methane-normal pentane mixtures in bulk for three different mixture compositions of n-pentane. The near-critical behavior of the mixture heat capacity indicates that at low n-pentane concentrations, this system is close to the special point of the critical locus. The effect of porous medium has been investigated for one of the mixtures studied in bulk. It has been shown that in porous medium the essential shift of the dew-bubble curve takes place. In our opinion this shift is caused by the formation of wetting film on the surface of porous medium. The estimation of film thickness resulting from the data obtained yields the value 7–8 nm.     

Manifestation of the bound state \bar NN (1870) in the annihilation process \bar pd \to p_s 5\pi

It is shown that the existence of an N?N bound state with a mass of approximately 1870 MeV and width 10 MeV follows from analysis of the experimental data on the momentum distribution of recoil protons in the annihilation process p?d→p _s5π.     

Nanoparticles produced by laser ablation of solids in liquid environment

A review of results on nanoparticles formation is presented under laser ablation of Ag, Au, and Ti solids targets in liquid environments (H₂O, C₂H₅OH, C₂H₄Cl₂, etc.). X-ray diffractometry (XRD), UV-Vis optical transmission spectrometry, and high-resolution transmission electron microscopy (HRTEM) characterise the nanoparticles. The morphology of nanoparticles is studied as a function of both laser fluence and nature of the liquid. The evidence of an intermediate phase of Au-Ag alloy is presented under exposure of a mixture of individual nanoparticles to laser radiation. Self-influence of the beam of a femtosecond laser is discussed under the ablation of the Ag target in liquids under Ti:sapphire laser. The factors are discussed that determine the distribution function of particle size under laser ablation. The influence of laser parameters as well as the nature on the liquid on the properties of nanoparticles is elucidated. PACS 42.62.-b; 61.46.+w; 78.66.-w     

Anomalies in the variation of elastic properties of cesium during phase transformations under a pressure up to 5 GPa

The pulsed ultrasonic method is used for studying polycrystalline cesium under a pressure up to 5 GPa. Elastic parameters and compression ratio of cesium are determined and anomalies in the elastic properties of cesium during phase transitions CsI-CsII-CsIII-CsIV are revealed. It is found that the CsII-CsIII electron-structure transformation is preceded by anomalous compressibility of the fcc phase of cesium and by softening of longitudinal and transverse acoustic modes of the cesium phonon spectrum.     

Raman spectroscopic study of the phase transitions induced by hydrostatic pressure in a Rb2KScF6 crystal

The Raman spectra of Rb₂KScF₆ elpasolite crystals are studied in the pressure range up to 7 GPa. A phase transition is revealed at a pressure of approximately 1 GPa. Analysis of the changes in the spectral parameters shows that the phase transition is accompanied by a doubling of the volume of the primitive cell in the initial cubic phase. Judging from the character of the variations in the pressure dependences of the frequency of the observed vibrations, there can exist another transition to the phase with a lower symmetry at a pressure of approximately 2.1 GPa.     

Separable Skyrme interactions and quasiparticle RPA

A finite rank separable approximation for the quasiparticle random phase approximation with Skyrme interactions is applied to study the low-lying quadrupole and octupole states in some S isotopes and giant resonances in some spherical nuclei. It is shown that characteristics calculated within the suggested approach are in good agreement with available experimental data.