This paper presents a new method for analysing complex NMR spectra. This method is based on creating entangled spin states of a selected group of nuclei. The approach is tested through analysing the NMR spectrum of ethyl alcohol.
Integral systems with four independent variables have special signifi-cance in mathematics and physics. The discovery of inverse scattering method played an important role in reconsidering the place of integrable systems of nonlinear partial differential equations in mathematical sciences. The search for a systematic approach to developing exact solutions of such systems has become one of the main problems in the theory of integrable systems.
This article presents the results of an experimental study into the effect of powder crystallite size on spin-lattice relaxation times in a rotating frame for 35Cl NQR in potassium chlorate, as well as the nutation interferograms. To obtain the distribution of relaxation times, a multi-exponential decay inversion of the longitudinal component of the nuclear magnetization in a rotating frame was used. The multimodal nature of distributions is explained by the influence of surface irregularities and impurities.
This article studies the effect of an extern heavy atom (KI salt) on the effi-ciency of nonradiative spin-forbidden singlet-triplet (S-T) transfer of elec-tronic energy between the rhodamine 6G (donor) and acriflavine (acceptor) dye molecules in polyvinyl alcohol films. The delayed fluorescence intensity enhancement and an increase in the lifetime of the acceptor triplet states in the presence of KI have been established. The constant rates of deactivation of the singlet and triplet states of dye molecules have been calculated.
This article presents a new simple analytical method that makes it possi-ble to design solutions in describing the dynamics of the universe near the ze-roes of the scalar field potential.
This article presents an experimental laboratory study of the movement of a finite volume of saline water (spots) surrounded by fresh and nonmoving water on the slope of the bottom in a non-rotating fluid. The findings include a quantitative assessment of the average rate of sliding of a saline water spot in fresh water along the slope of the bottom.
This article presents a method for approximate calculation of the compo-nents of an electromagnetic field produced by a cable system. This approach contributes to an efficient solution to the problem of electromagnetic compati-bility of radioelectronic equipment in a wide range of cable structure parame-ters.
This article presents the results of a MATLAB-assisted study into the maximum likelihood method resolution in the reception of two radioprobing signals based on Barker’s codes. The study is based on the expressions ob-tained by the authors within optimum reception theory that make it possible to carry out a joint evaluation of the same parameters of two signals and re-solve them based on these parameters.
This article presents the results of studies into the interaction between the walls of a test rig’s vacuum chamber and an SPD plasma jet. A method for calculating the spray elements of the vacuum chamber has been devised. The article presents the results of calculation of vacuum test chamber sputtering with an SPD-100 and SPD-100D plasma stream, as well as a way to protect the chamber’s walls from sputtering.
This article presents a solution to the problem of resolution of two radio impulses through the maximum likelihood method. The authors have obtained expressions for the optimum processing of a set of two radio impulses in the domains of their orthogonality and non-orthogonality, as well as expressions for the dispersion of radio impulse parameters (Rao-Cramér dispersion). The article presents the results of model calculations showing the possibilities of resolving two radio impulses using the maximum likelihood method. The au-thors assess the area of solution of the problem of resolving two radio impulses using the maximum likelihood method.
This article presents signal processing through linear frequency modula-tion (chirp signals) using the maximum likelihood method. The authors have obtained main expressions describing the optimal algorithm for processing these signals, as well as expressions for chirp signal dispersion (Rao-Cramér dispersion). The article presents key findings of model calculations during the reception of chirp signals.
This article presents the methods to improve the weight and size charac-teristics of a universal transmitting shortwave radio antenna. The proposed version of a shortened antenna with a performance management system can significantly increase the radiation power provided the inductive element is of high quality and losses are minimal.
It is proposed to use automatic bias voltage correction to increase the sta-bility of voltage controlled oscillator. Therefore, it is possible to improve the basic characteristics of the oscillator in the conditions of the unstable perform-ance of transistor.
This article formulates the problem of simulating extreme processes in the Earth's low-latitude ionosphere and describes the model equation imple-mentation methods based on an electrodynamically coherent mathematical mo-del of the equatorial F-layer of the ionosphere.
This article considers the problems of information support and automa-tion of loading and unloading processes in the sea zone of multimodal con-tainer terminals (berthage). The authors present the organization and algo-rithms of automated loading planning and complete and partial container loading and unloading at the transit terminal are presented.
This article considers the Grassmanian-like manifold of cen-tered m-planes in the projective space Pn. A torsion object of the Neifeld con-nection is introduced in the fibering over the manifold . It is shown that this object forms a tensor containing one elementary and four simple subtensors.
This paper focuses on the tangent bundle to the linear frame bundle of a smooth manifold. Brackets of the tangent vectors of this bundle are con-structed. A coordinate representation of the non-holonomic frame vectors is produced. Horizontal and vertical curvatures, torsions, and covariant derivatives are constructed in a homogeneous connection.
This article considers the problem of 3D visualization of two examples of top movement along a smooth surface. The authors analyze the cases where analytical solutions are possible. Graphical illustrations to these solutions are provided.
This article considers a parallel algorithm of the mathematical model of interaction between a charged small satellite and thermal space plasma. The main problem of the algorithm implementation is to maintain the total amount of current data for each calculator and to synchronize and minimize exchanges. The range of graphics accelerators chosen for calculation makes it possible to focus the maximum number of calculators on a single node. Syn-chronization problems are solved at the level of processor threads. The result-ing algorithm is difficult to implement; however, it shows the most efficient use of computing resources in solving the problem, can be easily scaled for hybrid computing, and has great potential when using the MPI + CUDA + CPU threads of a hybrid programming model.
This article tests the quantum resistance of McEliece CS based on an AG-code over any elliptic curve. Using the criteria suggested by Dinh, Moore, and Russell [3], the author proves the resistance of this CS to quantum Fourier sampling attack. Thus, Shor’s algorithm cannot identify the group structure of the code and break the CS.
This article considers the effect of the order of B-splines on the appearance of surface and smoothness degree. The surfaces based on B-splines of 2 x 2, 3 x 3, and 5 x 5 orders are presented.
The authors have developed a prototype of that information and analytical technology for modeling dragline waste rehandling in three-dimensional space through two-dimensional numerical algorithms. Using the methods of analytical geometry and mathematical statistics, a number of problems of transforming basic data to net models, creating average sections and local systems of coordinates, modeling routes of excavators in local systems of coor-dinates, and return transformation of modeling results to the initial system of coordinates have been solved.
The paper is devoted to two issues of ensuring population safety that are specific to the Kaliningrad region – the recording and mapping of located World War II ammunition and calculation of damage associated with devas-tating polder soil flooding. It is proposed to use SQL queries technology com-plemented by the spatial buffering functions and overlays to solve the first problem and the construction of digital spatial terrain models and calculation of volumes of overlay transactions with layers containing residential areas and economic entities to solve the second one.
The CSP (Sommon Scattering Point) method is used to identify diffrac-tors associated with cavernous fractured reservoirs of hydrocarbons. This method shows the highest efficiency in weakly inhomogeneous media. As to strongly inhomogeneous media, this method can be supplemented by the pre-liminary extension of wave field to a certain depth. To this end, the Reverse Time Datuming (RTD) procedure is used. The results of a numerical study of the joint application of RTD and CSP techniques (CSP-RTD method) are pre-sented in the case of the well-known Marmousi model.
This article gives an overview of the Low Angara oil-and-gas basin. The prospectively of the upper Riphean sediments of Angara folds is shown. The authors present the results of a forecast of fractured reservoir propagation in the top layer of Riphean sediments in the case of the Ilbokich license area. The article analyses scattered waves and identifies the objects interpreted as frac-tured reservoir propagation areas.
This article presents the results of developing a universal basic algorithm and choosing a methodology for creating a software system of the automated management of bank resources for crediting using the optimum strategy for risk management.