Two- and three-dimensional analysis of bose-einstein correlations inπ +/K+p interactions at 250 GeV/c

The NA22 data onπ ^? π ^? correlations are analyzed in terms of a number of two- and three-dimensional parametrizations (Gaussian space-time, Goldhaber, Bowler string-like, Bertsch hydrodynamical, Kopylov-Podgoretskii, etc.). Contrary to the results obtained for e⁺e^? andµp collisions, the Goldhaber parametrization, as well as string-like models, fail in describing the hadron-hadron data. Better fits are obtained in the framework of surface-emitting fireball-like models, both when including and excluding hydrodynamical expansion of nuclear matter. Our results indicate that pion radiation occurs at earlier stages of matter evolution than in nuclear collisions.     

Structure and electronic spectra of 2-phenylbenzimidazoles. Quantum chemical analysis of the intramolecular hydrogen bond

Institute of High-Molecular-Weight Compounds, Russian Academy of Sciences. Leningrad State University Translated from Zhurnal Strukturnoi Khimii, Vol. 33, No. 5, pp. 20–27, September–October, 1992.     

Logarithmic corrections for dilute uniaxial ferromagnets at the critical dimension

The leading logarithmic corrections to the critical behavior of a dilute uniaxial (Ising) ferromagnet in the disordered phase are derived using renormalization group methods. The values of the exponents in the logarithmic terms differ from those given by previous authors.     

Polyfunctional additives to oils, based on sulfonated oligomers

Studies in the field of development of polymeric oligoalkenesulfonate additives derived from sulfonated oligomers and exhibiting multifunctional effect when added to petroleum oils are summarized.     

Orientation and relaxation of polymer–clay solutions studied by rheology and small-angle neutron scattering

The influence of shear on viscoelastic solutions of poly(ethylene oxide) (PEO) and clay [montmorillonite, i.e., Cloisite NA+ (CNA)] was investigated with rheology and small-angle neutron scattering (SANS). The steady-state viscosity and SANS were used to measure the shear-induced orientation and relaxation of the polymer and clay platelets. Anisotropic scattering patterns developed at much lower shear rates than in pure clay solutions. The scattering anisotropy saturated at low shear rates, and the CNA clay platelets aligned with the flow, with the surface normal parallel to the gradient direction. The cessation of shear led to partial and slow randomization of the CNA platelets, whereas extremely fast relaxation was observed for laponite (LRD) platelets. These PEO–CNA networklike solutions were compared with previously reported PEO–LRD networks, and the differences and similarities, with respect to the shear orientation, relaxation, and polymer–clay interactions, were examined. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3102–3112, 2004     

Synchronization of periodic self-oscillations by common noise

We consider the effect of external noise on the stability properties of self-oscillations. A stochastic equation for the phase is derived at the limit of weak noise (in the appropriate sense). The stationary probability-density distribution is used for an analytic calculation of the Lyapunov exponent. We show that the exponent is always negative for the small noise level, which corresponds to synchronization of self-oscillations.     

A new model for a mode-locked semiconductor laser

We consider a new model for passive mode locking in a semiconductor laser comprising a set of delay differential equations. Bifurcations leading to the appearance and break-up of the mode-locking regime are studied numerically.