bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of Observation Performance of a Mobile Coherent Doppler Wind Lidar Using DBS Scanning Mode
Authors: Dong Debao , Yang Shizhi , Weng Ningquan , Zhang Guangyuan , Huang Jing 
Published: January 2021

Abstract
The Coherent Doppler Wind Lidar (CDWL) is one of the important remote sensing devices for atmospheric boundary layer wind field observation, it has broad application prospects in the fields of meteorological monitoring and warning, air pollution transportation and aviation safety. In order to test the observation performance of the CDWL using Doppler beam-swinging (DBS) scanning mode, description of the CDWL is introduced, and the main influencing factors of the CDWL observation accuracy is studied, the comparative observation experiments were carried out at the Anqing National Conventional Sounding Station (30°37″ N, 116°58″ E) during the course of Typhoon Rumbia (No. 18, 2018) from August 16 to August 26, 2018. The results show that: the wind observation accuracy is determined by the carrier-to-noise ratio (CNR) of the CDWL. In the precipitation conditions, the effective data acquisition rates of 1.5km and 2.0km detection height are only 46.2% and 38.8%, respectively and it was even difficult to continue operation. Under clear sky conditions, it could operate continuously and the effective data acquisition rates of 1.5km and 2.0km detection height were 85.4% and 64.4%. In addition, the correlation of wind direction and wind speed between the CDWL and the conventional sounding system (L-band secondary wind-finding radar) was 1.041 and 0.982, and the consistency is good. Based on the sounding, the wind direction and wind speed errors of the CDWL during the comparison experiment were 0.82m/s and 9.3°.
Preparation and Superior Absorbing of Electroless Deposited Ni-P-Fe3O4 Composite Powders
Authors: Li Yixian , Zhu Shaofeng , Zhou Xianzhi , Wang Yaqun 
Published: January 2021

Abstract
In this study, the Ni-P-Fe3O4 composite powders containing about 10% phosphorus were prepared by hydrothermal method. The phase, composition and morphology of the powders were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively. The wave absorption properties of the Ni-P-Fe3O4 composite powders were estimated by vector network analyzer (VNA). The results showed that the saturation magnetization and resistivity of the as-obtained Ni-P-Fe3O4 composite powders were significantly reduced, however their dispersion as well as conductivity were improved. The electromagnetic wave absorbed by Ni-P-Fe3O4 composite powders was mainly attributed to the dielectric loss, and the absorption of electromagnetic wave in the low frequency can reach to 90% (the reflection loss is less than -10 dB).
Exploration of Low-Energy Earth-Moon Transfer Orbit Based on Crossing Orbit of Double Three-Body System
Authors: Zhang Juan , Liu Wei , Cao Xiaofei 
Published: January 2021

AbstractThe design of low energy lunar transfer orbit and orbit optimization method based on crossing orbit is studied in this paper. The four-body problem of Sun-Earth-Moon-satellite is decoupled into two three-body problems of Sun-Earth-satellite and Earth-Moon-satellite. Low-energy lunar exploration orbit is designed by changing orbit at a certain intersection field through manifold of two Halo orbit of three-body system. A serial optimization design method for global initial value search and local gradient optimization are designed. When a motion state variable is partially modified, the differential correction method combined with adaptive regression algorithm is adopted. For the splicing points of manifolds of different systems, the velocity vector is modified to make the spacecraft get into the target berthing track, and to obtain the splicing points that can form crossing track of the two three-body systems. An example of orbit design is given to show that the Earth-Moon transfer orbit based on invariant manifold splicing has the characteristics of energy saving and long-time consumption, which can be used for the tasks with large loads and low time requirements. This research provides a method for the design of low energy lunar transfer orbit. It will benefit the energy consuming, material design of spacecraft, and so on.
Non-equilibrium critical behavior of multilayer magnetic nanostructures with a non-magnetic metal substrate
Authors: Boldyreva Marina , Prudnikov Pavel , Prudnikov Vladimir , Mamonova Marina 
Published: January 2021

Abstract
A Monte Carlo simulation of the non-equilibrium behavior of multilayer magnetic nanostructure Co/Cu(100)/Co is realized. Calculations of two-time dependent autocorrelation function for structures relaxing from both low-temperature and high-temperature initial states reveal occurrence of aging within a wide range of temperatures at T ≤ Tc
.
Calculating entropy by Ma’s method for a system of k-mers on a square lattice
Authors: Kokosinskii Denis V , Ulyanov Mikhail V 
Published: January 2021

Abstract
Random walk of rectangular particles on a square lattice leads to a pattern formation when the hard-core interaction between the particles is assumed. To estimate changes in the entropy during this random walk, we propose a modification of Ma’s method. The 2D sliding window technique was used to divide a system under consideration into subsystems. We used Ma’s “coincidence” method to estimate the total number of possible states for such subsystems. In this study, the accuracy of Ma’s method is studied in a simple combinatory model, both experimentally and theoretically. We determine which definition of “coincidence” for this scheme leads to greater accuracy. Ma’s estimate of the number of possible states for a system of k-mers correlates well with the estimate obtained using a “naive” method.
Mathematical model of biological tissue surface based on one dimensional stochastic process of fractional Brownian motion
Authors: Smirnov A , Kovalenko N , Ryabushkin O 
Published: January 2021

Abstract
In this work the model for the profiling of biological tissue surfaces is introduced. The surface was considered as the realization of the stochastic process of the fractional Brownian motion (fBm) with the scale parameter σ and Hurst index H. The contour of the epidermal surface of the normal cut banana peel was studied. The magnified digital photos of the investigated specimens were made using the microscope (spatial resolution 1 μm) with the built-in camera. The function that linearly interpolated the surface contour was derived. The dispersion law of the differences between the values of the interpolating function in the adjacent knots was in good agreement with that one of the fBm stochastic process. The values of σ=0.1 and H=0.806 were obtained.
Computer simulation of single burn transfers between low-Earth and halo orbits in the Sun-Earth system
Authors: Mezentsev Gleb , Aksenov Sergey 
Published: January 2021

Abstract
Halo orbits of Sun-Earth system are utilized in space missions as they allow to maintain the spacecraft in an area that is stationary relative to Sun and Earth. The advantage of halo orbits is their periodicity and their form allowing the spacecraft to avoid the zones of solar interference and the Earth shadow. The transfer between a low-Earth orbit and a halo orbit around a libration point can be realized by a single-burn maneuver, which transfers the spacecraft to an orbit of stable manifold resulting in a halo orbit. An amplitude of halo orbit depends on the altitude of the parking low-Earth orbit at which the transfer maneuver is performed. This work is aimed to explore and systemize the single burn transfer options utilizing single and multiple Earth passing trajectories in the framework of the circular restricted three-body problem. The algorithms providing transfer options for the desired halo orbit and the parking orbit altitude are developed. The transfer trajectories for the Sun-Earth L
1 and L
2 halo orbits in a wide range of out-of-plane amplitudes were constructed and studied. The constructed trajectories were clustered based on the transfer time and the halo orbit amplitude.
Calculation of libration point orbits in the circular restricted three-body problem
Authors: Korneev Alexander , Aksenov Sergey 
Published: January 2021

Abstract
This study investigates possibilities for extension and improvement of algorithms for generation of libration point orbits in the framework of the circular restricted three body problem. Two algorithms for orbit generation based on bisection approach using different ways for evaluation of unstable component of motion are considered. The spacecraft’s state vector is periodically adjusted in such a way that unstable component of motion is neutralized and the trajectory corresponding to the corrected state vector belongs to the central manifold associated with libration point. The first algorithm uses expression for unstable component derived from linearized equations of motion. The second one is based on the procedure of reduction to central manifold, utilizing canonical coordinate transformations to nullify high order monomials in the expansion of Hamiltonian of the system in terms of Legendre polynomials. This allows expressing unstable component as one of generalized coordinates of Hamiltonian system obtained as the result of aforementioned transformation. Evaluation of these techniques proved their applicability for orbit generation. However, the second approach allows generating orbits in greater vicinity of libration point.
Numerical simulation of superplastic bulge forming test
Authors: Zakhariev Ivan 
Published: January 2021

Abstract
Superplastic blow forming is a technology of shell parts production. The development of these processes requires computer simulation which cannot be realized without accurate parameters of the applied material. This characterization can be based on results of free bulging tests. Characterization techniques utilize the models of the dome growth during the bulging test. This study is devoted to the assessing of friction coefficient effect on the linear behavior of normalized thickness - normalized height relation.
Computer simulation of superplastic tensile test
Authors: Mikolaenko Vadim 
Published: January 2021

Abstract
Superplasticity is an ability of polycrystalline materials to archive extremely large deformations, which is utilized in advanced forming technologies demanded mainly in the aerospace industry. Design of such technologies needs an information of the material flow behaviour, which describes the relation of the effective stress on the strain and strain rate taking place during deformation. The most popular experimental method for investigation of the flow behaviour of superplastic materials is tensile testing. The procedure of superplastic tensile testing and interpretation of its results is described by several international standards. At the same time, it is known that the due to flow inhomogeneity in the specimen volume the accuracy of such tests may be violated. Moreover, different standards provide different ratio between the width and the height of the gauge area of a specimen. This work provides the numerical analysis aimed to study how the initial specimen geometry affects the results of tensile tests. A computer program implementing finite element method (FEM) was developed to predict the specimen deformation during the test. A flat specimen is discretized using prismatic elements with specific geometrical constraints reducing the degree of freedom to the order of a plane stressed task. The output stress and strain values were calculated as specified in the ASTM E2448 standard. The effect of the gauge length was studied focusing on the output stress strain curves. The results were compared with the experimental results available in the literature.
Applicability of regularized particles-on-demand method to solve Riemann problem
Authors: Zipunova E , Perepelkina A , Zakirov A 
Published: January 2021

Abstract
The lattice Boltzmann method (LBM) is a promising rapidly evolving simulation tool designed to capture the physics of the mesoscopic flow. But it is well known that the standard LBM is severely restricted to problems with low flow speed and small temperature range. The novel Particle-on-demand method (PonD) allows us to numerically solve the discrete Boltzmann equation for high Mach numbers. But the propagation step becomes more computationally intensive. A large part of the computational cost comes from matrix inversions during the rescaling of discrete distribution functions from one system of reference to another. We propose another method of discrete distribution function rescaling by applying regularization and moment conversion to avoid matrix inversions. This improvement shows drastic acceleration in calculations in comparison with standard PonD. Regularized PonD was applied to solve Riemann problems for a range of parameters. Results obtained by this improved method were compared to results received by the standard PonD and the standard LBM. The conservation of mass, momentum and energy of the new numerical method was studied. The necessary conditions for the stability of the solution were obtained.
Approximation of Multiparticle Distribution Function in Micromagnetic Modeling
Authors: Ivanov Anton , Khilkov Sergey , Elizaveta Zipunova 
Published: January 2021

Abstract
We propose the new system of equations for magnetodynamics. It is based on BBGKY hierarchy and uses a new approximations of mulit-particles distribution functions, which takes nearest-neighbour correlations into account. Thus we call the new system of equations correlational magnetodynamics system (CMD). It consists of well known Landau–Lifshitz–Bloch(LLB) equation complemented with an equation for two-particles correlations. Compared to traditional LLB equation, numerical simulations with CMD produces results that are closer to atomistic simulations.
Immersed boundary simulation of drop stability
Authors: Guskova Maria , Shchur Lev 
Published: January 2021

Abstract
The stability of the quasi-two-dimensional droplet flow is of great importance in microfluidic devices. We check the drop’s stability in the square box using the immersed boundary and lattice Boltzmann methods. We implement two-dimensional equations within the immersed boundary approach in the Palabos programming platform. We check the influence of the boundaries on the drop movement. We estimate fluctuations in the quantities while applying different initial conditions of the linear and angular velocities. We found that the level of fluctuations depends on the symmetrical displacement of drop at the initial state. The effect is connected with the hydrodynamic interaction of drop with the walls.
Exploring the accuracy of the Lattice Boltzmann method
Authors: Zagvozdina Ksenia , Burovski Evgeni 
Published: January 2021

AbstractLattice Boltzmann method is a mesoscopic method used for solving hydrodynamics problems of both incompressible and compressible fluids. Although the method is widely used, reliability of the results is unclear. Therefore, we use the method to solve a fundamental problem with a known analytical solution, the Couette flow. We estimate the accuracy of the simulation results obtained by setting different types of spatial grids, boundary conditions, and equilibrium distribution functions. However, the method imposes restrictions on a large number of simulation parameters such as Reynolds and Mach numbers. During simulation we discovered an unexpected behavior of the solution using classical lattice Boltzmann method. In these simulations we find that the conservation law is violated due to an unexpected inflow in the upper corners of the computational domain.
Fast simulation of the LHCb electromagnetic calorimeter response using VAEs and GANs
Authors: Sergeev Fedor , Jain Nikita , Knunyants Ivan , Kostenkov George , Trofimova Ekaterina 
Published: January 2021

Abstract
Modern experiments in high-energy physics require an increasing amount of simulated data. Monte-Carlo simulation of calorimeter responses is by far the most computationally expensive part of such simulations. Recent works have shown that the application of generative neural networks to this task can significantly speed up the simulations while maintaining an appropriate degree of accuracy. This paper explores different approaches to designing and training generative neural networks for simulation of the electromagnetic calorimeter response in the LHCb experiment.
Average cluster size inside sediment left after droplet desiccation
Authors: Zolotarev P A , Kolegov K S 
Published: January 2021

Abstract
In this work, we continue to study the formation of particle chains (clusters) inside the annular sediment during the drying of a colloidal droplet on a substrate. The average value of the cluster size was determined after processing experimental data from other authors. We performed a series of calculations and found the value of the model parameter allowed to get numerical results agreed with the experiment. Also, a modification of the previously proposed algorithm is analyzed here.
Ab initio computational study of the electronic and magnetic properties of the HoNiZ compounds accounting for electronic correlations
Authors: Lukoyanov A V , Gramateeva L N 
Published: January 2021

Abstract
In this paper, the electronic structure and magnetic properties of the ternary intermetallics of the HoNiZ series (Z = Ga, Si, Al) is studied using the LSDA+U first-principles method. An analysis of the densities of electronic states in the compounds HoNiGa, HoNiSi, and HoNiAl with accounting for electronic correlations is performed.
Modeling of charge effects in dielectric films of radiation MOS sensors
Authors: Andreev D V , Bondarenko G G , Andreev V V , Stolyarov A A 
Published: January 2021

Abstract
We have modeled the charge effects in radiation metal-oxide-semiconductor (MOS) sensors functioning in a wide range of electric fields including high-field injection of electrons into the dielectric film. In order to study the charge effects taking place in MOS sensors, we use the extended model suggested by us previously. The extended model, besides the accumulation of positive charge in the dielectric and the generation of the surface states at the interface, takes into consideration the accumulation of negative charge in the bulk of dielectric film caused by the electron capturing on traps. We demonstrate that the accumulation of the negative and positive charges in the bulk of the gate dielectric under high fields can significantly influence on the redistribution of electric fields inside the dielectric and, as a sequence, on change of the charge state of MOS structure which describes the sensor characteristics. We have ascertained that in order to properly utilize MOS sensors under high-field injection of electrons it has been necessary to take into consideration the possible capturing of electrons in the bulk of gate dielectric and adjust results of measurements with the model suggested.
Probability laws in multi-dimensional noisy HK-models
Authors: Bolychev Anton , Manita Anatoly 
Published: January 2021

Abstract
The classical Hegselmann-Krause opinion dynamics model is known for the simplicity of its interaction rules and for the striking complexity of its collective behavior observed in computer simulations. The nonlinearity of the dynamics makes an analytical study of the model a very hard task. Recently there is some interest in introducing a random noise in the HK dynamics. In our study we focus on exact analysis of probability laws for a noisy HK model and give a detailed description of distribution transformations related to such systems. Our results shed some light on a long-time behavior of the noisy HK model and open new possibilities for future analytical and numerical studies in this area.
Two-body metal-insulator transitions in the Anderson-Hubbard model
Authors: Stellin F , Orso G 
Published: January 2021

Abstract
We review our recent results on Anderson localization in systems of two interacting particles coupled by contact interactions. Based on an exact mapping to an effective single-particle problem, we numerically investigate the occurrence of metal-insulator phase transitions for the pair in two-(2D) and three-dimensional (3D) disordered lattices. In two dimensions, we find that interactions cause an exponential enhancement of the pair localization length with respect to its single-particle counterpart, but do not induce a delocalization transition. In particular we show that previous claims of 2D interaction-induced Anderson transitions are the results of strong finite-size effects. In three dimensions we find that the pair undergoes a metal-insulator transition belonging to the same (orthogonal) universality class of the noninteracting model. We then explore the phase diagram in the space of energy E, disorder W and interaction strength U, which reveals a rich and counterintuitive structure, endowed with multiple metallic and insulating phases. We point out that this phenomenon originates from the molecular and scattering-like nature of the pair states available at given energy and disorder strength.
A Simulation Model for Macro- and Micro-Fusion Algorithms in the CPU Core
Authors: Vishnekov A V , Ivanova E M , Stepanov N A , Shaimov N D 
Published: January 2021

Abstract
The article discusses the features of modern processor’s microarchitecture, the method of instruction’s and micro-operation’s accelerated execution. The research focuses on the organization of the decoding stage in the CPU core pipeline and Macro- and Micro-fusion algorithms. The Macro- and Micro-fusion mechanisms are defined. A computer simulator has been developed to explore these mechanisms. The developed software has a user-friendly interface, is easy to use, and combines training and research options. The computer simulator demonstrates the sequence of mechanism’ s implementation; the resulting macro-or microoperations set after Macro- and Micro-fusion, and also reflects each algorithm features for different processor’s families. The software allows you to use either a pre-prepared file with Assembler (x86) code fragments as source data, or enter/change the source code fragments at your request. The main combinations of machine instructions that can be fused into a single macro-operation are considered, as well as instructions that can be decoded into fused micro-operations. The simulator can be useful both for in Computer Science & Engineering students, especially for on-line education and for researchers and General-purpose CPU cores developers.
Selective pumping of a nonlinear quantum oscillator
Authors: Bastrakova M V , Klenov N V , Satanin A M 
Published: January 2021

Abstract
Selective pumping of a quantum system under the influence of unmodulated short-range pulses of large amplitude is studied using the example of a weakly nonlinear Josephson oscillator. An exact solution is obtained in the case of small parameter anharmonicity for changes in the system energy and population of levels after impact. It is shown that due to the interference of state amplitudes, it is possible to stabilize the system and prevent undesirable excitations (energy growth). When anharmonicity is taken into account, the system stability conditions are studied numerically. The obtained results are important when analyzing leakage to high-lying levels in a transmon-qubit under the influence of short unipolar control pulses.