Search for bound states in
,
, and
systems is performed by employing coupled homogeneous integral Faddeev equations written in terms of
-matrix components. Instead of the traditional partial-wave ...expansion, a direct integration with respect to angular variables is used in these equations, and three-body coupling in the phase space of each of the
–
–
,
–
–
, and
–
–
systems is taken precisely into account within this approach. Two-body
matrices are the only ingredient of the proposed method. In the case of two-body
interaction, they are found by solving the coupled Lippmann–Schwinger integral equations for the
–
–
system in the (
,
) state, the
system in the (
,
) state, the
–
system in the (
,
) state, and the
–
–
system in the (
,
) state. An updated version of the ESC16 microscopic model is used to obtain two-body
,
YY
, and
YN
interactions generating
matrices. Two-body
NN
interaction is reconstructed on the basis of the charge-dependent Bonn model. Direct numerical calculations of the binding energy for the systems being considered clearly indicate that either of the
and
systems has one bound state with binding energies of 4.5 and 5.5 MeV, respectively, and that the
system has two bound states with binding energies of 2.7 and 4.4 MeV.
Russian systems of intermediate separation and superheating of steam, operated as part of steam turbines of all nuclear power plants, operate with an insufficient level of reliability and efficiency. ...Design temperatures of overheating steam are not reached in most cases. The paper analyzes the characteristics of the working processes occurring in the apparatus: the flow of superheated wet steam in the separator and the superheater stages, dehumidification and subsequent flow of the separation in the separators, the intensity of heat exchange between the condensing heating steam of high pressure and the heated steam of low pressure, as well as the condensate flow of heating steam. Proposals are formulated to create more reliable and efficient devices, taking into account half a century of domestic and international experience in their design and operation.
The dynamics of intrachamber processes in a type of solid propellant rocket engine under consideration is investigated in order to optimize its parameters. The conjugate statement of the problem at ...the level of setting up a computational experiment is formulated. The results of numerical calculations are presented, which revealed an anomalous feature of the rocket engine firing process.
This work is devoted to the study of the distribution of residual plastic strains on outer and inner surface over the length of a cylindrical shell in the process of dynamic deformation generated by ...a longitudinal impact on its end face. As a mathematical model, the Timoschenko's model was used to describe the dynamic deformation of elastic thin shells, modified for the case of plastic deformations using the Bingham's model. As the boundary conditions, we selected a longitudinal impact applied at the end face of the shell with longitudinal strains constant in time. As a method for solving the resulting system of differential equations in partial derivatives of a hyperbolic type, the third-order ray method was implemented. The paper represents options for the numerical calculation of the distribution of residual plastic strains for various thicknesses, as well as the corresponding shell shape after unloading.
A systematic treatment of the procedure used to construct and solve the Faddeev-Yakubovsky integral equations for three and four different particles with nonzero spin is introduced. The four-body ...T-matrices are written in terms of solutions of the three-body Faddeev integral equations in total angular momenta representation. General spin-angular structure of the four-body Faddeev-Yakubovsky equations is written down and reduced to a spin-angular structure of the three-body system by elimination of one body. Partial-wave expansion performed for the system of four-body integral equations gives an infinite system of one-dimensional coupled equations with integral kernels containing four types of partial components of the three-body Faddeev integral equation solutions. The given method is tested on Λ−NN and Λ−NNN systems with two-body potential written down in only separable form. Both separable NN potential and ΛN potential rewritten in separable form for s-wave are used to determine the Λ-hyperon binding energies in Λ−NN and Λ−NNN systems. Calculation also includes the hyperon conversion in ΛN→ΣN process. Λ-hyperon separation energies were calculated from binding energies and turned out to be 0.147 MeV in Λ−NN system and 2.04 MeV in Λ−NNN system, respectively, that is in close coincidence with experimental ones.
Kaon Electroproduction on the Proton Egorov, M. V.; Postnikov, V. I.
Journal of experimental and theoretical physics,
07/2021, Letnik:
133, Številka:
1
Journal Article
Recenzirano
A model of kaon photoproduction in the
p
(
e
,
e
′
K
+
)Λ,
p
(
e
,
e
′
K
+
)Σ
0
, and
p
(
e
,
e
′
K
0
)Σ
+
processes with the square of the momentum transfer
Q
2
up to 2.5 GeV
2
is proposed. The ...photoproduction amplitude includes the
s
-,
t
-, and
u
-channel Born and
s
- and
u
-channel resonance contributions calculated in the tree approximation. The unitarity of the photoproduction amplitude is partially recovered by introducing the momentum dependence of the hadron decay widths of resonances and an additional effective width taking into account the effect of coupling between open channels without strangeness. The specificities of the calculations are allowance for the longitudinal electromagnetic coupling of photons to hadrons and the introduction of strongly
Q
2
-dependent suppression factors for the Born and resonance components of the photoproduction amplitude. This approach provides an accurate description of the existing data on the angular and
Q
2
distributions for the
p
(
e
,
e
′
K
+
)Λ and
p
(
e
,
e
′
K
+
)Σ
0
reactions. This model also correctly reproduces the dependence of the ratio σ(Σ
0
)/σ(Λ) separately for longitudinally and transversely polarized components of the kaon photoproduction cross section in the
p
(
e
,
e
′
K
+
)Λ and
p
(
e
,
e
′
K
+
)Σ
0
processes.
The response to stress involves the activation of pathways leading either to protection from the stress origin, eventually resulting in development of stress resistance, or activation of the rapid ...death of the organism. Here we hypothesize that mitochondrial reactive oxygen species (mtROS) play a key role in stress-induced programmed death of the organism, which we called "phenoptosis" in 1997. We demonstrate that the synthetic mitochondria-targeted antioxidant SkQ1 (which specifically abolishes mtROS) prevents rapid death of mice caused by four mechanistically very different shocks: (a) bacterial lipopolysaccharide (LPS) shock, (b) shock in response to intravenous mitochondrial injection, (c) cold shock, and (d) toxic shock caused by the penetrating cation C
TPP. Importantly, under all these stresses mortality was associated with a strong elevation of the levels of pro-inflammatory cytokines and administration of SkQ1 was able to switch off the cytokine storms. Since the main effect of SkQ1 is the neutralization of mtROS, this study provides evidence for the role of mtROS in the activation of innate immune responses mediating stress-induced death of the organism. We propose that SkQ1 may be used clinically to support patients in critical conditions, such as septic shock, extensive trauma, cooling, and severe infection by bacteria or viruses.
At present, powder materials are used in almost all known branches of science and technology such as the automotive industry and metalworking, medicine and nuclear research. This is a wide range of ...structural and tool materials, and special-purpose materials that have good heat resistance, wear resistance, and resistance within corrosive media. Ultrafine powders are used extensively in development of new functional materials and nanomaterials, since an increase in the discrete nature of structural elements leads to a significant change in material properties.
The coherent photoproduction of
and
on nuclei in the mass-number region of
is studied systematically over the range between the threshold and the laboratory photon energy of
GeV. The amplitude for ...photoproduction on nuclei is constructed on the basis of the impulse approximation with allowance for a number of processes responsible for meson–nucleus final-state interaction. The pion-rescattering processes
and
occurring on spectator nucleons,
and
production followed by
absorption by spectator nucleons, and three-body
–
NN
and
–
NN
interactions are described for the first time within a unified microscopic approach.
The dynamics of the intra-chamber processes of a solid-propellant rocket engine of the second stage of a cruise missile is investigated, taking into account the distributed space-three-dimensional ...and time-varying flight overloads by setting up a computational experiment. The results of numerical calculations are given without taking into account and taking into account the effect of flight overloads. It has been established that the impact of significant in-flight overloads affects the intra-chamber process in a solid-propellant rocket engine.
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