Stationary phase corrections in the process of bosonization of multi-quark interactions

The functional integration over the auxiliary bosonic variables of cubic order related with the effective action of the Nambu–Jona–Lasinio model with ’t Hooft term has recently been obtained in the form of a loop expansion. Even numbers of loops contribute to the action, while odd numbers of loops are assigned to the measure. We consider the two-loop corrections and analyse their effect on the low-lying pseudoscalar and scalar mass spectra, quark condensates and weak decay constants. The results are compared to the leading order calculations and other approaches. PACS 12.39.Fe, 11.30.Rd, 11.30.Qc     

Traresonator formation of submicron periodic structures

To whom correspondence should be addressd.     

Production of carbon nanotubes by self-propagating high-temperature synthesis

Carbon nanotubes are prepared by the method of self-propagating high-temperature synthesis for the first time. The initial components for this synthesis are carboniferous materials (soda, limestone, and Teflon) and reducers (magnesium, lithium, and sodium) with addition of a nickel or iron catalyst. The morphology of the nanotubes (straight multiwall nanotubes apparently free of a catalyst, bent nanotubes completely filled with a catalyst, and carbon nanofibers) is similar to that of nanotubes grown by chemical methods. The nanotubes account for 2–4 wt % of the product synthesized.     

The continuum gauge field-theory model for low-energy electronic states of icosahedral fullerenes

The low-energy electronic structure of icosahedral fullerenes is studied within the field-theory model. In the field model, the pentagonal rings in the fullerene are simulated by two kinds of gauge fields. The first one, non-abelian field, follows from so-called K spin rotation invariance for the spinor field while the second one describes the elastic flow due to pentagonal apical disclinations. For fullerene molecule, these fluxes are taken into account by introducing an effective field due to magnetic monopole placed at the center of a sphere. Additionally, the spherical geometry of the fullerene is incorporated via the spin connection term. The exact analytical solution of the problem (both for the eigenfunctions and the energy spectrum) is found.     

Self-organization in film nucleation in the high-T c superconductor Y-Ba-Cu-O system

The process of new-phase nucleation in the YBa₂Cu₃O_7−x system deposited by magnetron sputtering has been studied. The first experimental observation of the phenomenon of temporal self-organization in the course of new-phase formation, which was predicted theoretically,^1–3 is reported. Auto-oscillations in the number of nuclei of various chemical compounds 20–60 nm in size were observed to occur within the 15 to 300-s time interval, the total number of nuclei varying aperiodically from 10¹³ m⁻² to less than 10¹¹ m⁻². Fiz. Tverd. Tela (St. Petersburg) 39, 216–218 (February 1997)     

πa1 Transitions and low-energy limit in the linear sigma model

Joint Institute for Nuclear Research, Dubna. Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 86, No. 3, pp. 385–390, March, 1991.     

Carbon nanostructures in the industrial production of alkali metals by electrolysis

The carboniferous component of slimes in the electrolytic production of alkali metals (in our case, lithium) is studied for the first time with the aim to find nanostructures in it. The content of nanostructures in this component, which accounts for 10% of the slimes and can be separated by mild chemical treatment, is shown to be 2–4%. These structures are multiwall nanotubes or bundles of multiwall nanotubes, most of which are open. No twisted or single-wall nanotubes have been detected.