ДОСЛІДЖЕННЯ ПАРАМЕТРІВ ІМПУЛЬСУ ДЕФОРМАЦІЙНОЇ ХВИЛІ ПРИ ПОВЕРХНЕВО ПЛАСТИЧНОМУ ЗМІЦНЕННІ

The article considers the issue of increasing the efficiency of shock energy and recording equipment for the study of the parameters of the deformation wave pulse. The review of the last researches and publications is carried out and perspective directions at designing of the special measuring equipment are established. A method is proposed and an experimental-measuring complex for the study of the momentum parameters in the deformation zone under different initial conditions is developed. The study of the parameters, of the shock pulse and micro hardness, of the strengthened material in the deformation zone using different versions, of the impact systems. It is established that when using a shock system with a step-shaped striker, the shock wave is characterized by a complex shape of the pulse. To assess the reliability of the obtained results, a test problem was solved in the environment of the Abaqus software package. When designing new technological processes of strengthening, the results of experimental studies such as the impact system and the parameters and modes of the processing process are of particular importance. It is established that the best result is shown by shock systems, which allow forming a prolonged shock pulse.The article considers the issue of increasing the efficiency of shock energy and recording equipment for the study of the parameters of the deformation wave pulse. The review of the last researches and publications is carried out and perspective directions at designing of the special measuring equipment are established. A method is proposed and an experimental-measuring complex for the study of the momentum parameters in the deformation zone under different initial conditions is developed. The study of the parameters, of the shock pulse and micro hardness, of the strengthened material in the deformation zone using different versions, of the impact systems. It is established that when using a shock system with a step-shaped striker, the shock wave is characterized by a complex shape of the pulse. To assess the reliability of the obtained results, a test problem was solved in the environment of the Abaqus software package. When designing new technological processes of strengthening, the results of experimental studies such as the impact system and the parameters and modes of the processing process are of particular importance. It is established that the best result is shown by shock systems, which allow forming a prolonged shock pulse

Giant Pulses -- the Main Component of the Radio Emission of the Crab Pulsar

The paper presents an analysis of dual-polarization observations of the Crab pulsar obtained on the 64-m Kalyazin radio telescope at 600 MHz with a time resolution of 250 ns. A lower limit for the intensities of giant pulses is estimated by assuming that the pulsar radio emission in the main pulse and interpulse consists entirely of giant radio pulses; this yields estimates of 100 Jy and 35 Jy for the peak flux densities of giant pulses arising in the main pulse and interpulse, respectively. This assumes that the normal radio emission of the pulse occurs in the precursor pulse. In this case, the longitudes of the giant radio pulses relative to the profile of the normal radio emission turn out to be the same for the Crab pulsar and the millisecond pulsar B1937+21, namely, the giant pulses arise at the trailing edge of the profile of the normal radio emission. Analysis of the distribution of the degree of circular polarization for the giant pulses suggests that they can consist of a random mixture of nanopulses with 100% circular polarization of either sign, with, on average, hundreds of such nanopulses within a single giant pulse.Comment: 13 pages, 6 figures (originally published in Russian in Astronomicheskii Zhurnal, 2006, vol. 83, No. 1, pp. 62-69) translated by Denise Gabuzd

Particle Number Fluctuations in the Microcanonical Ensemble

Particle number fluctuations are studied in the microcanonical ensemble. For the Boltzmann statistics we deduce exact analytical formulae for the microcanonical partition functions in the case of non-interacting massless neutral particles and charged particles with zero net charge. The particle number fluctuations are calculated and we find that in the microcanonical ensemble they are suppressed in comparison to the fluctuations in the canonical and grand canonical ensembles. This remains valid in the thermodynamic limit too, so that the well-known equivalence of all statistical ensembles refers to average quantities, but does not apply to fluctuations. In the thermodynamic limit we are able to calculate the particle number fluctuations in the system of massive bosons and fermions when the exact conservation laws of both the energy and charge are taken into account.Comment: REVTeX, 17 pages, 9 figures, v3: misprints a correcte

Instantaneous Radio Spectra of Giant Pulses from the Crab Pulsar from Decimeter to Decameter Wavelengths

The results of simultaneous multifrequency observations of giant radio pulses from the Crab pulsar, PSR B0531+21, at 23, 111, and 600 MHz are presented and analyzed. Giant pulses were detected at a frequency as low as 23 MHz for the first time. Of the 45 giant pulses detected at 23 MHz, 12 were identified with counterparts observed simultaneously at 600 MHz. Of the 128 giant pulses detected at 111 MHz, 21 were identified with counterparts observed simultaneously at 600 MHz. The spectral indices for the power-law frequency dependence of the giant-pulse energies are from -3.1 to -1.6. The mean spectral index is -2.7 +/- 0.1 and is the same for both frequency combinations (600-111 MHz and 600-23 MHz). The large scatter in the spectral indices of the individual pulses and the large number of unidentified giant pulses suggest that the spectra of the individual giant pulses do not actually follow a simple power law. The observed shapes of the giant pulses at all three frequencies are determined by scattering on interstellar plasma irregularities. The scatter broadening of the pulses and its frequency dependence were determined as tau_sc=20*(f/100)^(-3.5 +/- 0.1) ms, where the frequency f is in MHz.Comment: 13 pages, 1 figure, 1 table (originally published in Russian in Astronomicheskii Zhurnal, 2006, vol. 83, No. 7, pp. 630-637), translated by Georgii Rudnitski

Lewis acid complexes: synthesis and application in polymerization processes

The published works by the present authors on the synthesis of organoaluminium compounds and complexes there of are summarized. The study of the reactivity of these latter in stereospecific and alternating polymerization made it possible to produce effective catalysts for synthe-sizing superhigh molecular weight polyolefins, alternating copolymers. The detailed investigation of the properties of the organoaluminium complexes with ethers allowed working out new catalytic systems capable of initiating styrene living cationic polymerization. The revealed regularities of living polymerization of styrene allows to realize for the first time the controlled polymerization of industrial C9-fraction, with the obtained results being used for developing technology for production of aromatic hydrocarbon resins from C9-fraction. An industrial process was developed and employed to produce oligopiperylene and aromatic hydrocarbon resins, which are used as film-forming components in paint and varnish compositio

Detection of Giant Pulses from the Pulsar PSR B0031-07

Giant pulses have been detected from the pulsar PSR B0031-07. A pulse with an intensity higher than the intensity of the average pulse by a factor of 50 or more is encountered approximately once per 300 observed periods. The peak flux density of the strongest pulse is 530 Jy, which is a factor of 120 higher than the peak flux density of the average pulse. The giant pulses are a factor of 20 narrower than the integrated profile and are clustered about its center.Comment: 7 pages, 2 figures, to appear in: Pis'ma v Astronomicheskii Zhurnal, 2004, v.30, No.4, and will be translated as: Astronomy Letters, v.30, No.

The Biomarker and Therapeutic Potential of Circular Rnas in Schizophrenia

Circular RNAs (circRNAs) are endogenous, single-stranded, most frequently non-coding RNA (ncRNA) molecules that play a significant role in gene expression regulation. Circular RNAs can affect microRNA functionality, interact with RNA-binding proteins (RBPs), translate proteins by themselves, and directly or indirectly modulate gene expression during different cellular processes. The affected expression of circRNAs, as well as their targets, can trigger a cascade of events in the genetic regulatory network causing pathological conditions. Recent studies have shown that altered circular RNA expression patterns could be used as biomarkers in psychiatric diseases, including schizophrenia (SZ); moreover, circular RNAs together with other cell molecules could provide new insight into mechanisms of this disorder. In this review, we focus on the role of circular RNAs in the pathogenesis of SZ and analyze their biomarker and therapeutic potential in this disorder.publishedVersio

Detection of Giant Radio Pulses from the Pulsar PSR B0656+14

Giant pulses (GPs) have been detected from the pulsar PSR B0656+14. A pulse that is more intense than the average pulse by a factor of 120 is encountered approximately once in 3000 observed periods of the pulsar. The peak flux density of the strongest pulse, 120 Jy, is a factor of 630 higher than that of the average pulse. The GP energy exceeds the energy of the average pulse by up to a factor of 110, which is comparable to that for other known pulsars with GPs, including the Crab pulsar and the millisecond pulsar PSR B1937+21. The giant pulses are a factor of 6 narrower than the average pulse and are clustered at the head of the average pulse. PSR B0656+14 along with PSR B0031-07, PSR B1112+50, and PSR J1752+2359 belong to a group of pulsars that differ from previously known ones in which GPs have been detected without any extremely strong magnetic field on the light cylinder.Comment: 10 pages, 3 figures, 1 table; originally published in Russian in Pis'ma Astron. Zh., 2006, v.32, 650; translated by George Rudnitskii; the English version will be appear in Astronomy Letter