Relativistic Reduced-Mass and Recoil Corrections to Vacuum Polarization in Muonic Hydrogen, Muonic Deuterium and Muonic Helium Ions

The reduced-mass dependence of relativistic and radiative effects in simple muonic bound systems is investigated. The spin-dependent nuclear recoil correction of order (Zalpha)^4 mu^3/m_N^2 is evaluated for muonic hydrogen and deuterium, and muonic helium ions (mu is the reduced mass and m_N is the nuclear mass). Relativistic corrections to vacuum polarization of order alpha (Zalpha)^4 mu are calculated, with a full account of the reduced-mass dependence. The results shift theoretical predictions. The radiative-recoil correction to vacuum polarization of order alpha (Z\alpha)^5 ln^2(Zalpha) mu^2/m_N is obtained in leading logarithmic approximation. The results emphasize the need for a unified treatment of relativistic corrections to vacuum polarization in muonic hydrogen, muonic deuterium and muonic helium ions, where the mass ratio of the orbiting particle to the nuclear mass is larger than the fine-structure constant.Comment: 6 pages; RevTe

Social and Speech Portrait of a Descendant of Russian Immigrants to the Chinese Three Rivers Region in the XX Century

The article is devoted to the study of a language functioning in foreign countries, outside its metropolis. This is a special form of language existence. The study is made in linguistic personology aspect: the factors of preservation of the native language in the speech of several generations of emigrants are identified by the means of analyzing the language competencies and the specifics of the native language of representatives of the foreign diaspora. The purpose of this article is to create the speech portrait of the representative of the East emigration, the descendants of Russian emigrants in China, the Chinese Three Rivers region, to identify the characteristics of preservation of the Russian language in conditions of the Russian-Chinese bilingualism in this area. The object of the speech portraiting was the linguistic personality of a descendant of Russian immigrants to China in the beginning of the 20th century, currently a resident of the city of Labudalin, Argun city district of the Inner Mongolia Autonomous region in China. Scientific novelty of the research consists in undertaking for the first time the analysis of a fragment of the Russian linguistic reality in one of the places of the Russian diaspora in the 20th century, in the Chinese Three Rivers region, and in the introduction record of oral speech of the representative of the descendants of Russian in Three Rivers Region, carried out during the scientific expeditions to China in 2017 and 2018, that makes a unique material. The study of the Russian language in foreign countries, namely in the Eastern abroad, in the Three Rivers region, is a contribution to linguistic emigrantology, which determines the relevance of the study. The authors analyze the speech of a representative of the descendants of Russian settlers in the Chinese Three Rivers Region at all levels of the language system, reveal the facts of phonetical, grammatical and lexical interference in Russian speech under the influence of the Chinese language, as well as the dialectal features preserved in it, and come to the conclusion that Russian language is highly preserved even in the third generation of immigrants from Russia to China and the authors name the sociolinguistic factors of this preservation: family, educational, professional, psychological, etc

Group analysis and renormgroup symmetries

An original regular approach to constructing special type symmetries for boundary value problems, namely renormgroup symmetries, is presented. Different methods of calculating these symmetries, based on modern group analysis are described. Application of the approach to boundary value problems is demonstrated with the help of a simple mathematical model.Comment: 17 pages, RevTeX LATeX file, to appear in Journal of Mathematical Physic

Composition of powders produced by electrospark dispersion of metal granules in water

The results of experimental studies of metal powders composition produced by electrospark dispersion according to the scheme "metal electrodes - metal granule loading - distilled water" are given in the paper. With a help of X-ray diffraction analysis and other methods, it was found that chemical and phase composition of dispersion products is determined by affinity of metal to oxygen

Microscopic Calculation of Total Ordinary Muon Capture Rates for Medium - Weight and Heavy Nuclei

Total Ordinary Muon Capture (OMC) rates are calculated on the basis of the Quasiparticle Random Phase Approximation for several spherical nuclei from 90^Zr to 208^Pb. It is shown that total OMC rates calculated with the free value of the axial-vector coupling constant g_A agree well with the experimental data for medium-size nuclei and exceed considerably the experimental rates for heavy nuclei. The sensitivity of theoretical OMC rates to the nuclear residual interactions is discussed.Comment: 27 pages and 3 figure

Developing the personal readiness of vocational school heads for management in the digital education space through distance postgraduate education

This paper examines the personal readiness of vocational school heads for management in the context of the digitalisation of education. An empirical study revealed insufficient leadership qualities like entrepreneurship, self-efficacy, focus and communication among vocational school heads. A training program was developed to improve these competencies through distance postgraduate education. The program consisted of two modules delivered online over 30 hours. It utilised interactive methods like group discussions, role-playing, case studies and individual assignments. The program's effectiveness was evaluated through a pre/post-test design with experimental and control groups. Results showed statistically significant improvement in personal readiness components like entrepreneurship and focus on business in the experimental group compared to the control. The study demonstrates the potential of distance postgraduate programs to develop the leadership competencies needed to manage vocational schools effectively in the digital era

The Boltzmann equation for colourless plasmons in hot QCD plasma. Semiclassical approximation

Within the framework of the semiclassical approximation, we derive the Boltzmann equation describing the dynamics of colorless plasmons in a hot QCD plasma. The probability of the plasmon-plasmon scattering at the leading order in the coupling constant is obtained. This probability is gauge-independent at least in the class of the covariant and temporal gauges. It is noted that the structure of the scattering kernel possesses important qualitative difference from the corresponding one in the Abelian plasma, in spite of the fact that we focused our study on the colorless soft excitations. It is shown that four-plasmon decay is suppressed by the power of $g$ relative to the process of nonlinear scattering of plasmons by thermal particles at the soft momentum scale. It is stated that the former process becomes important in going to the ultrasoft region of the momentum scale.Comment: 41, LaTeX, minor changes, identical to published versio

Dislocation Kinks in Copper: Widths, Barriers, Effective Masses, and Quantum Tunneling

We calculate the widths, migration barriers, effective masses, and quantum tunneling rates of kinks and jogs in extended screw dislocations in copper, using an effective medium theory interatomic potential. The energy barriers and effective masses for moving a unit jog one lattice constant are close to typical atomic energies and masses: tunneling will be rare. The energy barriers and effective masses for the motion of kinks are unexpectedly small due to the spreading of the kinks over a large number of atoms. The effective masses of the kinks are so small that quantum fluctuations will be important. We discuss implications for quantum creep, kink--based tunneling centers, and Kondo resonances