382 research outputs found
A Global Potential Analysis of the O+Si Reaction Using a New Type of Coupling Potential
A new approach has been used to explain the experimental data for the
O+Si system over a wide energy range in the laboratory system
from 29.0 to 142.5 MeV. A number of serious problems has continued to plague
the study of this system for a couple of decades. The explanation of anomalous
large angle scattering data; the reproduction of the oscillatory structure near
the Coulomb barrier; the out-of-phase problem between theoretical predictions
and experimental data; the consistent description of angular distributions
together with excitation functions data are just some of these problems. These
are long standing problems that have persisted over the years and do represent
a challenge calling for a consistent framework to resolve these difficulties
within a unified approach. Traditional frameworks have failed to describe these
phenomena within a single model and have so far only offered different
approaches where these difficulties are investigated separately from one
another. The present work offers a plausible framework where all these
difficulties are investigated and answered. Not only it improves the
simultaneous fits to the data of these diverse observables, achieving this
within a unified approach over a wide energy range, but it departs for its
coupling potential from the standard formulation. This new feature is shown to
improve consistently the agreement with the experimental data and has made
major improvement on all the previous coupled-channels calculations for this
system.Comment: 21 pages with 12 figure
Collective Modes of Tri-Nuclear Molecules
A geometrical model for tri-nuclear molecules is presented. An analytical
solution is obtained provided the nuclei, which are taken to be prolately
deformed, are connected in line to each other. Furthermore, the tri-nuclear
molecule is composed of two heavy and one light cluster, the later sandwiched
between the two heavy clusters. A basis is constructed in which Hamiltonians of
more general configurations can be diagonalized. In the calculation of the
interaction between the clusters higher multipole deformations are taken into
account, including the hexadecupole one. A repulsive nuclear core is introduced
in the potential in order to insure a quasi-stable configuration of the system.
The model is applied to three nuclear molecules, namely Sr + Be +
Ba, Mo + Be + Te and Ru + Be +
Sn.Comment: 24 pages, 9 figure
Study of the process in the c.m. energy range from threshold to 2 GeV with the CMD-3 detector
Using a data sample of 6.8 pb collected with the CMD-3 detector at the
VEPP-2000 collider we select about 2700 events of the process and measure its cross section at 12 energy ponts with about
6\% systematic uncertainty. From the angular distribution of produced nucleons
we obtain the ratio
Measurement of the cross section with the CMD-3 detector at the VEPP-2000 collider
The process has been studied in the
center-of-mass energy range from 1500 to 2000\,MeV using a data sample of 23
pb collected with the CMD-3 detector at the VEPP-2000 collider.
Using about 24000 selected events, the cross
section has been measured with a systematic uncertainty decreasing from 11.7\%
at 1500-1600\,MeV to 6.1\% above 1800\,MeV. A preliminary study of
production dynamics has been performed
Measurement of the Pion Form Factor in the Energy Range 1.04-1.38 GeV with the CMD-2 Detector
The cross section for the process is measured in the
c.m. energy range 1.04-1.38 GeV from 995 000 selected collinear events
including 860000 events, 82000 events, and 33000
events. The systematic and statistical errors of measuring the
pion form factor are equal to 1.2-4.2 and 5-13%, respectively.Comment: 5 pages, 2 figure
Elements of mathematics in problems. Through olympiads and circles to profession
This is a collection of teaching materials used in several Russian
universities, schools, and mathematical circles. Most problems are chosen in
such a way that in the course of the solution and discussion a reader learns
important mathematical ideas and theories. The materials can be used by pupils
and students for self-study, and by teachers.
This is an abridged pre-copyedit version of the published book submitted with
the permission of the publisher. Each included individual material is
self-contained and ready-for-use. Solutions to problems are not included
intentionally. This collection consolidates updates of several arXiv
submissions, e.g., arXiv:1305.2598.Comment: Edited by A. Skopenkov, M. Skopenkov, A. Zaslavsky. In Russian.
Optimized for printing on A5 paper. Moscow Center for Continuous Mathematical
Education, 2018, 592pp (in Russian
Allelic state of prolamin-coding loci in the new oat cultivar ‘Tobolyak’
Background. In order to fully reveal the advantages of a cultivar and use it effectively in production, it is necessary to ensure high sowing and varietal qualities of seeds, which requires improvement in breeding and seed production. Biotechnological methods are increasingly used in initial seed production. High efficiency was shown by the method of electrophoresis of seed storage proteins – prolamins. The aim of this study was to assess the biotype composition and allelic state of the prolamin-coding loci in the new spring oat cultivar ‘Tobolyak’ for its further use in initial seed production.Materials and methods. In 2021, 1519 families of cv. ‘Tobolyak’ were studied using the method of native electrophoresis. Three grains from each family were selected for analyses by random sampling. Electrophoresis was carried out in vertical plates of 13.2% polyacrylamide gel at a constant voltage of 500 V for 4.5–5.0 hours.Results and conclusion. The study of cv. ‘Tobolyak’ families resulted in identifying 13 types of avenin patterns with a frequency of occurrence from 96.36 to 0.07%. A new block of avenin components controlled by the allele of the Avn B locus was described. Number 8 was assigned to this block. It was established that cv. ‘Tobolyak’ had been developed by crossing a minor biotype of cv. ‘Taezhnik’ (Avn 4.4.2) with the first biotype of cv. ‘Orion’ (Avn 2.8.2). The basis of cv. ‘Tobolyak’ was one genotype with the Avn 4.8.2 avenin formula. The remaining biotypes arose as a result of crossing the biotypes of cvs. ‘Taezhnik’ and ‘Orion’ as well as through mechanical contamination. To maintain the genetic stability of cv. ‘Tobolyak’, it is recommended to use only families of the first biotype in the process of original seed production
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