1,444 research outputs found
On the constrained KP hierarchy
An explanation for the so-called constrained hierarhies is presented by
linking them with the symmetries of the KP hierarchy. While the existence of
ordinary symmetries (belonging to the hierarchy) allows one to reduce the KP
hierarchy to the KdV hierarchies, the existence of additional symmetries allows
to reduce KP to the constrained KP.Comment: 7pp, LaTe
Negative high-frequency differential conductivity in semiconductor superlattices
We examine the high-frequency differential conductivity response properties
of semiconductor superlattices having various miniband dispersion laws. Our
analysis shows that the anharmonicity of Bloch oscillations (beyond
tight-binding approximation) leads to the occurrence of negative high-frequency
differential conductivity at frequency multiples of the Bloch frequency. This
effect can arise even in regions of positive static differential conductivity.
The influence of strong electron scattering by optic phonons is analyzed. We
propose an optimal superlattice miniband dispersion law to achieve
high-frequency field amplification
Generation of Relativistic Electron Bunches with Arbitrary Current Distribution via Transverse-to-Longitudinal Phase Space Exchange
We propose a general method for tailoring the current distribution of
relativistic electron bunches. The technique relies on a recently proposed
method to exchange the longitudinal phase space emittance with one of the
transverse emittances. The method consists of transversely shaping the bunch
and then converting its transverse profile into a current profile via a
transverse-to-longitudinal phase-space-exchange beamline. We show that it is
possible to tailor the current profile to follow, in principle, any desired
distributions. We demonstrate, via computer simulations, the application of the
method to generate trains of microbunches with tunable spacing and
linearly-ramped current profiles. We also briefly explore potential
applications of the technique.Comment: 13 pages, 17 figure
Multicscilling technologies in the system of continuous education
The article considers the application of multiskilling technologies in the system of continuous education. Examples of the use of multiskilling technologies in the training center of the Pervouralsky Novotrubny Plant are givenВ статье рассматривается применение технологий мультискиллинга в системе непрерывного образования. Приведены примеры использования технологий мультискиллинга в учебном центре Первоуральского новотрубного завод
Training of specialists in the educational centerof the enterprise as a way of designing a professional future
The article discusses the features of the system of training specialists relevant to the development of enterprises in the logic of the initiative FutureSkills Union WorldSkills Russia, taking into account the experience of the Educational training center group Chelyabinsk pipe rolling plantsРассматриваются особенности системы подготовки специалистов, актуальных для развития предприятий в логике инициативы FutureSkills союза WorldSkills Russia c учетом опыта образовательного учебного центра группы челябинских трубопрокатных заводо
Fermionic approach to the evaluation of integrals of rational symmetric functions
We use the fermionic construction of two-matrix model partition functions to
evaluate integrals over rational symmetric functions. This approach is
complementary to the one used in the paper ``Integrals of Rational Symmetric
Functions, Two-Matrix Models and Biorthogonal Polynomials'' \cite{paper2},
where these integrals were evaluated by a direct method.Comment: 34 page
Dispersionful analogues of Benney's equations and -wave systems
We recall Krichever's construction of additional flows to Benney's hierarchy,
attached to poles at finite distance of the Lax operator. Then we construct a
``dispersionful'' analogue of this hierarchy, in which the role of poles at
finite distance is played by Miura fields. We connect this hierarchy with
-wave systems, and prove several facts about the latter (Lax representation,
Chern-Simons-type Lagrangian, connection with Liouville equation,
-functions).Comment: 12 pages, latex, no figure
The using of modular training technology for training workers in the conditions of a corporate training center
The possibilities of modular training technology for solving the problem of forming the necessary professional competencies in corporate training organized on the basis of the dual system of education are shown. The experience of the corporate training center of the Chelyabinsk Tube Rolling Plant group is exemplified by the example of training workers in the profession ««Welder»Показаны возможности модульной технологии обучения для решения задачи формирования необходимых профессиональных компетенций в корпоративном обучении, организованном на основе дуальной системы образования. Приведен опыт корпоративного учебного центра группы Челябинских трубопрокатных заводов на примере подготовки рабочих по профессии «Сварщик
Quantum symmetries and exceptional collections
We study the interplay between discrete quantum symmetries at certain points
in the moduli space of Calabi-Yau compactifications, and the associated
identities that the geometric realization of D-brane monodromies must satisfy.
We show that in a wide class of examples, both local and compact, the monodromy
identities in question always follow from a single mathematical statement. One
of the simplest examples is the Z_5 symmetry at the Gepner point of the
quintic, and the associated D-brane monodromy identity
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