745 research outputs found
Effect of epitaxial strain on the electronic structure and magnetic correlations in infinite-layer (Nd,Sr)NiO
We present a theoretical study of the effect of electron-electron
interactions and Sr doping on the electronic structure of infinite-layer
(Nd,Sr)NiO using the density functional+dynamical mean-field theory
approach. In particular, we explore the impact of epitaxial compressive strain
that experience (Nd,Sr)NiO films on the electronic properties, magnetic
correlations, and exchange couplings. Our results reveal the crucial importance
of orbital-dependent correlation effects in the Ni shell of Sr-doped
NdNiO. Upon doping with Sr, it undergoes a Lifshitz transition which is
accompanied by a reconstruction of magnetic correlations: For Sr
(Nd,Sr)NiO adopts the N\'eel antiferromagnetic (AFM) order, while
for the -type AFM sets in the unstrained (Nd,Sr)NiO,
with a highly frustrated region at , all within DFT+DMFT at
K. Our results for the N\'eel AFM at Sr suggest that AFM
NdNiO appears at the verge of a Mott-Hubbard transition, providing a
plausible explanation for the experimentally observed weakly insulating
behavior of NdNiO for Sr . We observe that the Lifshitz transition
makes a change of the band structure character from electron- to hole-like with
Sr , in agreement with recent experiments. Our results for magnetic
couplings demonstrate an unanticipated frustration of the Ni magnetic
moments, which suppresses magnetic order near Sr . We find that the
effect of frustration is maximal for Sr doping that nearly
corresponds to the experimentally observed doping value. We conclude that the
in-plane strain adjusts a bandwidth of the Ni band, i.e., controls
the effect of electron correlations in the Ni orbitals. The
electronic properties of (Nd,Sr)NiO reveal an anomalous sensitivity upon a
change of the crystal structure parameters.Comment: 11 pages, 9 figures; the crystal structure used is under question;
this may affect the resul
Hidden attractors in fundamental problems and engineering models
Recently a concept of self-excited and hidden attractors was suggested: an
attractor is called a self-excited attractor if its basin of attraction
overlaps with neighborhood of an equilibrium, otherwise it is called a hidden
attractor. For example, hidden attractors are attractors in systems with no
equilibria or with only one stable equilibrium (a special case of
multistability and coexistence of attractors). While coexisting self-excited
attractors can be found using the standard computational procedure, there is no
standard way of predicting the existence or coexistence of hidden attractors in
a system. In this plenary survey lecture the concept of self-excited and hidden
attractors is discussed, and various corresponding examples of self-excited and
hidden attractors are considered
EVALUATION OF SUBMERGED HEALING OF COLONIC ANASTOMOSES IN SURGICAL HOSPITAL
Thus, the main causes of «hand technique» anastomosis by invagination are technical defects of the intervention in telescopic anastomosis by invagination and the ischemic disorders in colorectal anastomosis by invagination. 48 patients were operated on the colon and rectum with «hand technique» anastomosis. Invalidated «manual technique» anastomosis after 70 days of the formation were fully functional, and processes of healing and morphological transformation of mucosa were completed
General Scheme of Risk – Oriented Audit Stages
The article examines the problem of applying risk-oriented approach in audit. A risk-oriented approach on the one hand allows to increase efficiency of auditors’ activity, the level of compliance with mandatory requirements, and on the other hand, to avoid the excessive inspections’ procedures in the formation of a scientifically grounded framework of reasonable sufficiency inherent to each specific audit. At the same time, risk-oriented approach needs to create its own methodological base, develop methodologies and relevant accompanying documents, and, most importantly, train personnel capable of implementing this innovative methodology. For this reason, topic of this paper is extremely relevant.
Keywords: audit, risk-oriented approach, planning, accounting (financial) statement
Algorithmic decidability of Engel's property for automaton groups
We consider decidability problems associated with Engel's identity
( for a long enough commutator sequence) in groups
generated by an automaton. We give a partial algorithm that decides, given
, whether an Engel identity is satisfied. It succeeds, importantly, in
proving that Grigorchuk's -group is not Engel. We consider next the problem
of recognizing Engel elements, namely elements such that the map
attracts to . Although this problem seems intractable in
general, we prove that it is decidable for Grigorchuk's group: Engel elements
are precisely those of order at most . Our computations were implemented
using the package FR within the computer algebra system GAP
Rules of Internal Control of the Broker as a Tool for Risk Management of ML/FT
The article analyzes and identifies the features of a brokerage company as an economic entity, identifies the main risks of a broker in the sphere of ML/FT, and examines the rules of internal control and the requirements imposed on them.
Keywords: internal control, broker, risks, economic securit
The Use of Analytical Tools in the Conduct of Internal Control Procedures
The work is devoted to the study of the problems of management, the activities of international companies in solving urgent problems of risk assessment, international cooperation of companies in the development and use of software and the applications of the Business Intelligence class, Data Quality and Business Analytics, the role of SAS in the domestic market. The first part is devoted to the activities of international companies in the field of risk assessment. The second part is devoted to the review of analytical products of SAS.
Keywords: audit, risk assessment, in-depth analytics, business intelligenc
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