bluuebunny/crossref_metadata_2025_split huggingface dataset:
Entanglement generation and protection for two atoms in the presence of two parallel mirrors
Authors: Ye Yuhong , Yu Hongwei , Hu Jiawei 
Published: March 2021

Abstract
We study, in the framework of open quantum systems, the entanglement generation of two atoms in between two parallel mirrors in a thermal bath of quantum scalar fields. We find that the presence of mirrors plays an important role in entanglement generation and protection. The entanglement dynamics is crucially dependent on the geometric configurations of the two-atom system with respect to the mirrors, and the ranges of temperature and interatomic separation within which entanglement can be generated are significantly changed compared with those in a free space. In particular, when the atomic transition wavelength is larger than twice the distance between the two mirrors, the atoms behave as if they were isolated from the environment and the entanglement can persist in the steady state if the atoms are initially entangled and no entanglement can be created if they are initially separable, no matter how the atoms are placed with respect to the mirrors and to each other. This is in sharp contrast to the fact that in a free space, steady-state entanglement is possible only when the two atoms are placed extremely close to each other, while in the presence of one mirror, it is possible when the two atoms placed extremely close to the mirror.
Exploring effects of tensor force and its strength via neutron drops *
Authors: Wang Zhiheng , Naito Tomoya , Liang Haozhao , Long Wen Hui 
Published: March 2021

Abstract
The tensor-force effects on the evolution of spin-orbit splittings in neutron drops are investigated within the framework of the relativistic Hartree-Fock theory. For a fair comparison on the pure mean-field level, the results of the relativistic Brueckner-Hartree-Fock calculation with the Bonn A interaction are adopted as meta-data. Through a quantitative analysis, we certify that the

-pseudovector (

-PV) coupling affects the evolutionary trend through the embedded tensor force. The strength of the tensor force is explored by enlarging the strength

of the

-PV coupling. It is found that weakening the density dependence of

is slightly better than enlarging it with a factor. We thus provide a semiquantitative support for the renormalization persistency of the tensor force within the framework of density functional theory. This will serve as important guidance for further development of relativistic effective interactions with particular focus on the tensor force.
The moment generating function of pairwise velocity in the context of redshift space distortion
Authors: Zhao Jing-Wei , Chen Jun-De 
Published: March 2021

Abstract
We study the connections between the pairwise velocity moment generating function G(k
∥, r) and redshift space distortion (RSD) modeling. Here k
∥ is the Fourier wavevector parallel to the line of sight, and r is the pair separation vector. We demonstrate its usage by two examples. (1) Besides the known relations between G and the RSD power spectrum (and the correlation function), we propose a new RSD statistics Ps
(k
∥,r
⊥) whose connection to G is convenient to evaluate numerically. (2) We then develop a fast method to numerically evaluate G, and apply it to a high resolution N-body simulation. We find that G (ln G) shows complicated dependence on k
∥ beyond the linear and quadratic dependencies. This not only shows inaccuracy in some existing models and identifies sources of inaccuracy but also provides possible ways of improving the RSD modeling. Consequently, more comprehensive investigations on G are needed to fully explore the usage of G in RSD modeling.
Are pulsar giant pulses induced by re-emission of cyclotron resonance absorption?
Authors: Lu Ji-Guang , Wang Wei-Yang , Peng Bo , Xu Ren-Xin 
Published: March 2021

AbstractIt is conjectured that coherent re-emission of cyclotron resonance absorption could result in pulsar giant pulses. This conjecture seems reasonable as it can naturally explain the distribution of pulsars with giant pulses on theP-P˙diagram.
An HI intensity mapping survey with a Phased Array Feed
Authors: Li Lin-Cheng , Staveley-Smith Lister , Rhee Jonghwan 
Published: March 2021

Abstract
We report results from a neutral hydrogen (H i) intensity mapping survey conducted with a Phased Array Feed (PAF) on the Parkes telescope. The survey was designed to cover ∼ 380 deg2 over the redshift range 0.3 < z < 1 (a volume of ∼ 1.5 Gpc3) in four fields covered by the WiggleZ Dark Energy Survey. The results presented here target a narrow redshift range of 0.73 < z < 0.78 where the effect of radio frequency interference (RFI) was less problematic. The data reduction and simulation pipeline was described, with an emphasis on flagging of RFI and correction for signal loss in the data reduction process, particularly due to the foreground subtraction methodology. A cross-correlation signal was detected between the H i intensity maps and the WiggleZ redshift data, with a mean amplitude of ⟨ΔT
b
δ
opt⟩ = 1.32 ± 0.42 mK (statistical errors only). A future Parkes cryogenic PAF is expected to detect the cross-correlation signal with higher accuracy than previously possible and allow measurement of the cosmic H i density at redshifts up to unity.
He-shell flashes on the surface of oxygen-neon white dwarfs
Authors: Guo Yunlang , Liu Dongdong , Wu Chengyuan , Wang Bo 
Published: March 2021

Abstract
Accretion induced collapse (AIC) may be responsible for the formation of some interesting neutron star binaries (e.g., millisecond pulsars, intermediate-mass binary pulsars, etc). It has been suggested that oxygen-neon white dwarfs (ONe WDs) can increase their mass to the Chandrasekhar limit by multiple He-shell flashes, leading to AIC events. However, the properties of He-shell flashes on the surface of ONe WDs are still not well understood. In this article, we aim to study He-shell flashes on the surface of ONe WDs in a systematic approach. We investigated the long-term evolution of ONe WDs accreting He-rich materialwith various constantmass-accretion rates by time-dependent calculationswith the stellar evolution codeModules for Experiments in Stellar Astrophysics (MESA), in which the initial ONeWD masses range from 1.1 to 1.35 M
⊙. We found that the mass-retention efficiency increases with the ONe WD mass and the mass-accretion rate, whereas both the nova cycle duration and the ignition mass decrease with the ONe WD mass and the mass-accretion rate. We also present the nuclear products in different accretion scenarios. The results presented in this article can be used in the future binary population synthesis studies of AIC events.
Indium–gallium–zinc–oxide thin-film transistors: Materials, devices, and applications
Authors: Zhu Ying , He Yongli , Jiang Shanshan , Zhu Li , Chen Chunsheng , Wan Qing 
Published: March 2021

Abstract
Since the invention of amorphous indium–gallium–zinc–oxide (IGZO) based thin-film transistors (TFTs) by Hideo Hosono in 2004, investigations on the topic of IGZO TFTs have been rapidly expanded thanks to their high electrical performance, large-area uniformity, and low processing temperature. This article reviews the recent progress and major trends in the field of IGZO-based TFTs. After a brief introduction of the history of IGZO and the main advantages of IGZO-based TFTs, an overview of IGZO materials and IGZO-based TFTs is given. In this part, IGZO material electron travelling orbitals and deposition methods are introduced, and the specific device structures and electrical performance are also presented. Afterwards, the recent advances of IGZO-based TFT applications are summarized, including flat panel display drivers, novel sensors, and emerging neuromorphic systems. In particular, the realization of flexible electronic systems is discussed. The last part of this review consists of the conclusions and gives an outlook over the field with a prediction for the future.
Cluster mathematical model for conjugate thermal processes of the isothermal bodies system in the fluid flow
Authors: Madera A G 
Published: March 2021

Abstract
There has been developed a cluster mathematical modelling method for non-stationary thermal processes, occurring in complex technical system structures, which thermal models represent a system of clusters. Each cluster has a core, combining the heat-emitting elements that fall into the said cluster, a shell of the cluster, and a fluid, flowing through the cluster. The state of the thermal process in each cluster at any specific time is characterized by three state variables, namely, by the temperatures of the core, the temperatures of the shell and the ambient temperature. At that, the elements of each cluster (core, shell, fluid flow) exchange heat with each other and the elements of the adjacent clusters. As opposed to existing methods, the cluster method allows modelling thermal processes that occur in complex technical systems, taking into account non-uniform temperature distribution in the fluid flow, conjugate nature of heat transfer between the fluid flow, the cores and the shells of the clusters. The mathematical model, describing state variables of thermal processes in the cluster thermal model, represents a system of block matrix differential equations with matrix and vector blocks, corresponding to the respective clusters of the thermal model. The solution of equations of the mathematical model is the values of the state variables of the thermal processes in the clusters. The methodology of the application of the cluster method is shown on the example of a real technical system.
Heat exchange at the boiling of ozone-safe refrigerants and their oil-freon mixtures
Authors: Ovsyannik A V , Arshukov A I , Kovalchuk P A 
Published: March 2021

Abstract
The object of research is the processes of heat and mass transfer during phase transitions of ozone-safe refrigerants and their oil-freon mixtures on smooth finned and capillary-porous heat-transfer surfaces of industrial heat exchange apparatuses.
The purpose and objectives of the research was theoretical and experimental research of processes of heat transfer in developed bubble boiling of ozone friendly refrigerant and oil-refrigerant mixtures on smooth and developed surfaces of heat exchange by establishing relationships to determine the coeffi-cients of heat transfer and influence of the various factors that determine the intensity of heat transfer at phase transitions in devices of refrigeration, heat pump systems and air conditioning systems; the estab-lishment of the mechanism of heat transfer processes during evaporation of oil-refrigerant mixtures. De-velopment of practical recommendations for the calculation and design of high-efficiency heat exchange equipment, reducing the material consumption and weight and size indicators of heat exchangers. Development and implementation of improved performance vaporizers and condensers for refrigeration, heat pump installations and air conditioning systems.
For the first time, experimental studies of heat exchange processes during the boiling of refriger-ants and their oil-freon mixtures on various surfaces in a wide range of thermal loads (2,9…100,8 kW / m2). Graphic dependences of the heat transfer intensity on the operating parameters of the boiling process and other characteristics are obtained.
The results of the work are implemented in the technological process of VESA LLC and in the educational process of Sukhoi state technical University for lectures on the disciplines “heat and mass Transfer” and “Industrial heat and mass transfer processes and installations”.
The results obtained can be used in the development and creation of highly efficient evaporative heat ex-changers.
Experiments of superfluid helium flow in a channel with a monodisperse backfill
Authors: Puzina Yu Yu , Kryukov A P , Korolyov P V , Yachevskiy I A 
Published: March 2021

Abstract
The experimental data on the superfluid helium flow in a U-shaped channel filled with a monodisperse backfill at a certain length is considered in this paper. The entire channel is immersed in a volume of superfluid helium. A flat heater is located in one end of the channel. When the heat load is applied, a vapor plug is formed in the channel. The column of superfluid helium begins to fluctuate in size with a constant amplitude and frequency. On the basis of the video recording of experiments, the dependence of the coordinate of the interfacial surface on time was plotted, and a qualitative analysis of heat and mass transfer processes is performed.
Gradient heat flux measurement in study of condensation at inner surface of the tube
Authors: Sapozhnikov S Z , Mityakov V Y , Babich A Y , Zainullina E R 
Published: March 2021

Abstract
To study heat transfer during water steam condensation in the pipe, experiments were carried out with a steam supply from the top pipe edge with the gradient heatmetry. The results which allowed us to apply the new method for non-classical problem have shown compliance with literature data. When the pipe is inclined, the distribution of heat flux per unit area on the inner surface becomes asymmetric, that’s why it is necessary to measure local heat flux in some points there. The distribution of local heat transfer coefficients on the inner surface of the pipe at different angles of inclination is obtained. The heat flux decreases in the lower part of the pipe section, which corresponds to increasing of the condensate film thickness in this area.
Effect of the horseshoe-shaped vortex on heat transfer in vicinity of the leading edge of a cylinder immersed in the turbulent free convection boundary layer on a vertical plate
Authors: Chumakov Yu S , Smirnov E M , Levchenya A M , Panov D O 
Published: March 2021

Abstract
Measurement data obtained with a thermo-resistance (wolfram-wire) probe for fluctuating temperature field in the front of a finite-height adiabatic circular cylinder disturbing the turbulent free convection boundary layer on a heated vertical flat plate are presented. The measurements were focused on detection of the effects attributed to action of the horseshoe-shaped vortex structures developing in the flow separation zone upstream of the obstacle. It is shown that near-wall air temperature gradients at some measurement positions are dramatically higher, if compared with profiles measured far away from the obstacle. It points in particular to highly intensified heat transfer in the flow region under study. The experimental mean temperature profiles are compared with results of previous RANS- and LES-based numerical studies performed by the authors under conditions that were close to those adopted in the experiments. It is shown that the LES-predicted temperature distributions are in a good accordance with the experimental results. The steady-state solution obtained with the RANS approach partially overpredicts the deformation of the temperature field attributed to action of the horseshoe-shaped vortices, which are substantially unsteady in the reality.
Comparative analysis of energy efficiency of ballast tank anti-freezing systems
Authors: Bagaev D V , Syraleva M N , Kudinovich I V 
Published: March 2021

Abstract
Choosing the best way to deal with the internal icing of ballast tanks is the important task of the designing Arctic vessels. To prevent excessive ice formation in the ballast tank, various methods are used, the main of which are: heating the water and increasing of the water circulation intensity inside the tank (air and steam bubbling, forced water circulation). The report presents qualitative assessment of the heating method and air bubbling system and investigation of energy efficiency of anti-freezing systems.
Numerical investigation of hydrodynamic processes in combustion chamber with an intensified fluidized bed
Authors: Babakhodjaev R P , Mirzaev D A 
Published: March 2021

Abstract
A gas suspension fluidized bed is reviewed, as an intensified fluidized bed, where the principles of classical spouted and fluidized beds are used together. A physical model of the process is presented. The working chamber consists of horizontally arranged sections, with spouted bed of gas suspension in the lower section and fluidized bed here in the upper section. Moreover, the lower section has a geometric shape in the form of a truncated regular pyramid. The basic formulas of mathematical modeling and the results of a numerical investigation of the hydrodynamics of a combustion chamber with an intensified fluidized bed are presented. The resulting mathematical model solved by the fourth-order Runge-Kutta method in the Matlab software environment. The graphs of changes in the velocity of gases and solid particles, pressure loss of a gas suspension depending on the height of the working chamber and the angle between the vertical axis and the side faces of the lower part of the section are obtained. Also obtained graphs characterizing the rise time of solid particles in height and their residence time in sections of the working chamber.
Common features of swirling motion of two immiscible fluids in closed vortex reactors
Authors: Naumov I V , Shtern V N , Tsoy M A , Sharifullin B R 
Published: March 2021

Abstract
The paper analyses the typical topology of swirling flows of two immiscible fluids generated in the cylindrical container by its rotating end wall. Using the flow visualization and velocity measurements by PIV for different parameters of rotation of the upper end of the cylinder, this study reveals general features of the evolution of counter flow (bubble-like vortex breakdown, VB) which is common for vortex flows with various liquids at the interface or the solid rotated end. In both fluids, the rotation generates centrifugal meridional circulations and a local circulation cell (vortex breakdown bubble, VBB). The research shows that the scenario for the VBB appearance depends weakly on the properties of the medium that restricts the circulation of the working fluid. Patterns and formation of cellular structure appear common for flows with “liquid bottom” and “liquid rotating lid”. The VBB scenario is similar to that occurring in a single-fluid flow and in the upper or lower fluids of a two-fluid flow, but the range of the Reynolds numbers can be different depending on the volume of the upper fluid and kinematic viscosity of the lower liquid. This study can serve as the first step in the “rotating liquid lid” and “liquid lid” technology for chemical and biological processes where fine, gentle, and nonintrusive mixing is favourable.
Features of particle flows hydrodynamics in recirculating systems and pneumatic valves of CFB boilers
Authors: Ryabov G A , Folomeev O M 
Published: March 2021

Abstract
Circulating fluidized bed (CFB) technology is characterized by relatively high reactor velocity that exceed the transport velocity of medium-sized particles, and the presence of separators (mainly of the cyclone type) with a system for returning trapped particles to the reactor. These systems consist of downpipes equipped in the lower part with pneumatic valves for transporting material from the low (atmospheric) pressure zone in the cyclone to the high-pressure zone in the furnace. Pneumatic valves operate on the principle of fluidized valves, and the locking function of the valves is performed by a lifting section with an inclined return flow to the furnace (loop gate or J-valve) or a horizontal section connecting the drain to the furnace (L-valve). The report discusses the current state of development and methods for standpipe and pneumatic valve operation and calculating. A brief description of the test rigs and the results of our own studies of CFB returned system are given. The results of the work can be used for the design and commissioning of a circulating fluidized bed reactors, including systems with dual reactors for polygenerating systems and chemical looping.
Laboratory modeling of hydrodynamic instability and sound generation processes in the ship NPS
Authors: Sergeev D A , Kandaurov A A , Suvorov A S 
Published: March 2021

Abstract
This work is devoted to investigations of the self-oscillation regimes in the model of emergency stop valve chamber in the ductline of the systems of heat exchange in the ship nuclear power setup (NPS). Experiments were carried out on special aeroacoustical setup with simultaneous use of PIV methods for measuring velocity fields and measurements of sound generation characteristics. Dependency of parameters of self-oscillation regimes on the parameter of the length of the gap between the inlet and outlet ducts in the chamber was investigated. An explanation of the observed regimes was proposed.
Problem of heat transfer in compact heat exchangers using variable thermal resistance
Authors: Chichindaev A V , Dyachenko Yu V , Sidenko D E , Shakin A D 
Published: March 2021

Abstract
The paper presents the results of a complex of studies, analysis of the efficiency of the heat exchangers of aircraft ACS, as well as developed methods for protecting the heat transfer surface from freezing and thermal stresses. The basis of the work was the results of experimental studies of heat and mass transfer of a three-phase flow of “moist air - supercooled water aerosol” with a negative temperature in the CPFHE channels. As well as previously developed methods for modeling the processes of local heat transfer in compact heat exchangers with two-phase coolants (condenser) and in the presence of thermal stresses at high temperatures of hot air (preliminary heat exchanger). The proposed methods are based on the idea of obtaining a given surface temperature by changing the thermal resistances during the heat transfer process. The improvement of the models consists in taking into account the variable thermal resistances along the length of the hot and cold tract. In particular, the parameters of heat transfer processes defined by the geometry of the fins and flow regimes, as well as local heat and mass transfer processes during phase transitions.
Numerical simulation of the particle size distribution function evolution of an ultradispersed system in a vapor-gas medium
Authors: Ginevsky A F , Volgin Y S 
Published: March 2021

Abstract
To control the process of nanopowders generating in order to ensure the required characteristics, it is necessary to solve the general physical problem of vaporization and condensation of steam in a gas-phase synthesis plant. A model of the physical problem should describe besides the formation of condensed particles, the hydrodynamic features of the flow, as well as heat exchange processes with other objects inside the working chamber. The questions of interaction of particles within an ultradispersed system through coagulation were considered. A mathematical model that describes the process of coagulation of a monodisperse system inside the evaporation-condensation chamber was formulated. A variant of the optimization of a coagulation numerical model in an ultradispersed system by reducing the number of sections corresponding to particle fractions of the mass scale was proposed. The use of an reduced scale made it possible to optimize the information received, and also gave advantages in the speed of calculations, which made it possible to reduce the time spent in problems with coagulation of systems.