z Scaling at RHIC

The concept of z scaling reflecting the general regularities of high-p _T particle production is reviewed. Properties of data z presentation are discussed. New data on high-p _T particle spectra obtained at the RHIC are analyzed in the framework of z presentation. It was shown that these experimental data confirm z scaling. Predictions of strange particle spectra are considered to be useful for understanding of strangeness origin in mesons and baryons and search for new physics phenomena at the RHIC. The text was submitted by the author in English.     

Generalized z-scaling for charged hadrons and jets

Generalization of z-scaling observed in the inclusive high-p _T-charged hadron and jet production is proposed. Scaling function ψ(z) describing both charged hadrons and jets produced in proton-(anti)proton colisions for various multiplicity densities and collision energies is constructed. Anomalous fractal dimensions and parameters characterizing an associated medium for both classes of events are established. The basic features of the scaling established in minimum bias events are shown to be preserved up to the highest multiplicity densities measured in the experiments UA1, E735, CDF, and STAR. The obtained results are of interest for use of z-scaling as a tool for searching for new physics phenomena of particle production at a high transverse momentum and in the high-multiplicity region at U70, Tevatron, RHIC, and LHC. The text was submitted by the authors in English.     

Chain structure and stiffness of Teflon AF glassy amorphous fluoropolymers

The structure of the amorphous perfluorinated polymer Teflon AF 2400 and other structurally close perfluoropolymers was studied by means of a quantum chemistry method. The electronic and structural characteristics of the repeating unit and polymer models with ten and nine monomer units were obtained. It was found that two nonplanar isomers can exist for different models of the perfluorinated dioxole ring with a difference of their energy minimums of 10.8 kJ/mol. The orthogonal-block structure of the polymer chain of the perfluorodioxole homopolymer and its copolymer with tetrafluoroethylene was proposed, the block size was found, and a possible diameter of the void formed by two neighboring polymer chains was evaluated. Potential energy curves for the rotation of certain chain fragments about different bonds of the polymer main chain were constructed, and the polymer stiffness was shown to substantially depend on the molar ratio between perfluorodioxole and tetrafluoroethylene units in the copolymer and on the geometry of the perfluorodioxole ring.     

The influence of UV irradiation on surface composition of collagen/PVP blended films

The surface chemical composition and surface properties of collagen/poly(vinyl pyrrolidone) (PVP) blended films before and after UV irradiation (λ = 254 nm) were investigated using X-ray Photoelectron Spectroscopy (XPS), FTIR-ATR spectroscopy and Atomic Force Microscopy (AFM).The XPS results showed that collagen is enriched on the surface of the collagen/PVP blend. The surface composition of the collagen film was changed more by UV irradiation than the surface composition of the collagen/PVP blend.FTIR-ATR spectra showed that the positions of the amide bands in collagen are more altered after UV irradiation than those for the collagen/PVP blends.AFM images showed that the collagen surface is ordered contrary to PVP. The blend surface was similar to the pure collagen surface and confirms that there is more collagen present at the surface (higher concentration of collagen at the surface compared to PVP). UV irradiation caused only the small changes in the surface morphology of the collagen/PVP films. All of the results confirm that the surface of the collagen/PVP blend is more photoresistant than collagen.     

Repulsion in an instanton gas,formation of a core in the nucleon,and the method of Bogolyubov hierarchies

Institute of Nuclear Research, USSR Academy of Sciences. Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 86, No. 1, pp. 31–42, January, 1991.     

Luminescence of enrichment centers in yttrium-aluminum garnet crystals

The spectrum of enrichment centers in yttrium-aluminum garnet crystals is studied. Analysis of the photoluminescence and excitation spectra together with measurements of luminescence kinetics allow establishment of the energy structure of the centers found.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 83–87, January, 1984.     

Low temperature heat capacity of the system “silica gel–calcium chloride–water”

Heat capacity was measured for two composite systems based on silica gel KSK and calcium chloride confined to its pores. One corresponds to an anhydrous state, while another contains water bound with the salt to give the composition of CaCl₂·2.04H₂O. The measurements were performed in the temperature range of 6–300 K with a vacuum adiabatic calorimeter. The smoothed experimental curves C _p (T) were used for calculating the calorimetric entropy and the enthalpy increment for both studied systems as well as the effective heat capacity associated only with water in the hydrated composite. The heat capacities C _p (298.15 K) of both composites were compared with those calculated as a linear addition of the heat capacities of silica gel and bulk calcium chloride (or its dihydrate) with appropriate weight coefficients.     

Helical modes in low- and high-swirl jets measured by tomographic PIV

We report on a parallel study on properties of large-scale vortical structures in low- and high-swirl turbulent jets by means of the time-resolved tomographic particle image velocimetry technique. The high-swirl jet flow is featured by a well-established bubble-type vortex breakdown with a central recirculation zone. In the low-swirl flow, the mean axial velocity, while intermittently acquiring negative values, remains positive in the mean but with a local velocity defect immediately downstream from the nozzle exit, followed by a spiralling vortex core system and its eventual breakdown. Measurements of the 3D velocity fields allowed direct analysis of the azimuthal/helical modes via Fourier transform over the azimuthal angle and proper orthogonal decomposition (POD) analysis in the Fourier space. A precessing vortex core is detected for both swirl cases, whereas the POD analysis showed that the one originating in the bubble-type vortex breakdown is much more energetic and easier to detect.     

Analysis of fractals with combined partition

The space—time properties in the general theory of relativity, as well as the discreteness and non-Archimedean property of space in the quantum theory of gravitation, are discussed. It is emphasized that the properties of bodies in non-Archimedean spaces coincide with the properties of the field of P-adic numbers and fractals. It is suggested that parton showers, used for describing interactions between particles and nuclei at high energies, have a fractal structure. A mechanism of fractal formation with combined partition is considered. The modified SePaC method is offered for the analysis of such fractals. The BC, PaC, and SePaC methods for determining a fractal dimension and other fractal characteristics (numbers of levels and values of a base of forming a fractal) are considered. It is found that the SePaC method has advantages for the analysis of fractals with combined partition.