Half-Life and the Uncertainty Principle Petrova, E. N.; Pirogov, S. A.
Problems of information transmission,
12/2023, Letnik:
59, Številka:
4
Journal Article
Recenzirano
An attempt is made to give an accurate mathematical interpretation of the energy–time uncertainty relation.
We provide conditions for the existence of measurable solutions to the equation \xi (T\omega )=f(\omega ,\xi (\omega )), where T:\Omega \rightarrow \Omega is an automorphism of the probability space ...\Omega and f(\omega ,\cdot ) is a strictly nonexpansive mapping. We use results of this kind to establish a stochastic nonlinear analogue of the Perron-Frobenius theorem on eigenvalues and eigenvectors of a positive matrix. We consider a random mapping D(\omega ) of a random closed cone K(\omega ) in a finite-dimensional linear space into the cone K(T\omega ). Under the assumptions of monotonicity and homogeneity of D(\omega ), we prove the existence of scalar and vector measurable functions \alpha (\omega )>0 and x(\omega )\in K(\omega ) satisfying the equation \alpha (\omega )x(T\omega )=D(\omega )x(\omega ) almost surely.
We consider contact processes on locally compact separable metric spaces with birth and death rates that are heterogeneous in space. We formulate conditions on the rates that ensure the existence of ...invariant measures of contact processes. One of the crucial conditions is the so-called critical regime condition. To prove the existence of invariant measures, we use the approach proposed in our preceding paper. We discuss in detail the multi-species contact model with a compact space of marks (species) in which both birth and death rates depend on the marks.
There is a need to improve the methods of control of supersonic aircraft in order to increase the efficiency and reliability of their control elements. In this work, theoretical calculations of the ...flow around a body with a system of supersonic jets are carried out. Using numerical methods, the possibility of control the flow around a body using a system of jets has been investigated. The numerical study was based on a model of an inviscid perfect gas described by the Navier-Stokes equations.
The paper presents the results of the calculation of stresses and strains of the cultivator stand structure with a flexible tubular element under loading with internal pressure and external force. ...For research, we used the finite element method, implemented in the program "ANSYS". The tasks of building a grid model of a tubular element were solved, the displacements of the free end and stresses under the action of internal pressure were determined, and the maximum allowable pressure value was found. The horizontal component of the impact force of the soil on the cultivator, at which buckling occurs, is determined, and the influence of the section shape on the characteristics of the cultivator stand is investigated.
We study large fluctuations of emitted radiation in the system of N non-interacting two-level atoms. Two methods are used to calculate the probability of large fluctuations and the time dependence of ...excitation and emission. The first method is based on the large deviation principle for Markov processes. The second one uses an analogue of the quantum formalism for classical probability problems. Particularly we prove that in a large fluctuation limit approximately half of the atoms are excited. This fact is independent on the fraction of the excited atoms in equilibrium.
The development of supersonic aircrafts should rely on advanced methods of flow control in order to improve the efficiency and reliability of the aircrafts. This article presents numerical simulation ...of energy supply to the incoming flow and simulation of the flow over bodies with hemispherical and conical nose parts. The numerical study was based on the model of an inviscid perfect gas described by the Euler equations which were solved by using the explicit unsteady Godunov's numerical scheme with the second-order accuracy.
Aim : to evaluate, using the “GastroPanel®”, the frequency of detection of H. pylori infection and associated gastric diseases among doctors and medical staff of the National Medical Research ...Radiological Centre of the Ministry of Health of the Russian Federation, Moscow. Materials and methods . Employees of three branches of the National Medical Research Radiological Centre (n = 434, mean age — 48.5 ± 0.6 years) were examined using laboratory tests “GastroPanel®” (Biohit Oyj, Finland). The test results make it possible to identify infection of the stomach with H. pylori, hypo- and hyperacid conditions, as well as atrophic gastritis of the antrum and body of the stomach, as its precancerous conditions. Esophagogastroduodenoscopy (EGDS) for suspected atrophic gastritis was performed with an Olympus GIF-HQ190 video endoscope (Japan) in a narrow-spectrum mode with close focus (NBI Dual Focus). Results . The absence of pathological signs detected by “GastroPanel®” was established in 23.3 % of cases, hyperacid state — in 18.4 %, and hypoacid state — in 5.2 %. These disorders are classified as functional. Consequently, the conditional norm in total was identified in 46.9 % of observations. An increased level of antibodies to H. pylori was found in 43.3 % of those examined. Atrophic gastritis in the body of the stomach according to the results of the “GastroPanel®” was detected in 4.8 % of cases (median age — 59 years), in the antrum (or increased secretion of hydrochloric acid) — also in 4.8 % of cases (median age — 52 years). Within two months after laboratory diagnostics, EGDS was performed for 10 out of 15 patients examined at the P. Hertsen Moscow Oncology Research Institute in whom, based on the results of the “GastroPanel®”, the presence of atrophic gastritis in the antrum (or increased secretion of hydrochloric acid) was suspected. In 6 out of 10 cases, atrophic gastritis of the antrum was confirmed (in two of them, the atrophy extended to the body of the stomach and was assessed as severe). Of the 11 people with the “GastroPanel®” conclusion “Atrophic gastritis of the body of the stomach,” an endoscopic examination was carried out in 7 persons, and in all these cases the diagnosis was confirmed, and in two people the conclusion was made of severe atrophic pangastritis. Conclusion . “GastroPanel®” confirmed its high significance in identifying H. pylori infection and precancerous atrophic changes in the gastric mucosa. Regarding the occupational risks of infection among medical workers, we consider it advisable to conduct such screening without selecting an asymptomatic population.
The paper presents the results of the calculation of the forces acting on the cultivating shovel when moving in the ground. For research, the finite element method implemented in the ANSYS program ...was used. The tasks of constructing a grid model of the ground were solved, the horizontal component of the force of the impact of the ground when moving at different speeds was determined.
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