Megias, E.Timoteo, V. S.Gammal, A.Deppman, A....
12页查看更多>>摘要：We study the Bose-Einstein condensation in non-extensive statistics for a free gas of bosons, and extend the results to the non-relativistic case as well. We present results for the dependence of the critical temperature and the condensate fraction on the entropic index, q, and show that the condensate can exist only for a limited range of q in both relativistic and non-relativistic systems. We provide numerical results for other thermodynamics quantities like the internal energy, specific heat and number fluctuations. We discuss the implications for high energy physics and hadron physics. The results for the non-relativistic case can be of interest in cold-atom systems. (C) 2021 Elsevier B.V. All rights reserved.
原文链接:
NSTL
Elsevier
Wang, JingRen, XuepingLi, XiaolinZhou, Zhikun...
11页查看更多>>摘要：The dynamics of spin-1 Bose-Einstein condensate with a antiferromagnetic spin interaction through a moving obstacle potential are studied numerically. Various combinations of coreless vortex patterns are observed in two components. The average ratio of the distance between two vortex rows to the distance between two vortex pairs in a row is about 0.2, which is less than the stability criterion 0.28 for classical fluids. The angular velocity of the vortex street and the distance between two point vortices in a pair oscillate approximately periodically around an average value. The density of vortex-like structure also produces drag force, but it is very weak and the direction is opposite to the drag force generated by the quantum vortex. Finally, we provide an experimental protocol for the above realization and observation. (C) 2021 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Sudakov, IvanVakulenko, Sergey A.Bruun, John T.
12页查看更多>>摘要：Species extinction is a core process that affects the diversity of life on Earth. Competition between species in a population is considered by ecological niche-based theories as a key factor leading to different severity of species extinctions. There are population dynamic models that describe a simple and easily understandable mechanism for resource competition. However, these models cannot efficiently characterize and quantify new emergent extinctions in a large population appearing due to environmental forcing. To address this issue we develop a stochastic physics-inspired approach to analyze how environmental forcing influences the severity of species extinctions in such models. This approach is based on the large deviations theory of stochastic processes (the Freidlin-Wentzell theory). We show that there are three possible fundamentally different scenarios of extinctions, which we call catastrophic extinctions, asymmetric ones, and extinctions with exponentially small probabilities. The realization of those scenarios depends on environmental noise properties and the boundaries of niches, which define the domain, where species survive. Furthermore, we describe a hysteresis effect in species extinction showing that fluctuations can lead to dramatic consequences even if an averaged resource supply is sufficient to support population survival. Our stochastic physics-inspired approach generalizes niche theory by accounting for environmental forcing and will be useful to establish, with available data, which environmental perturbations may induce extinctions. (C) 2021 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Liu, QiujiaLu, LinjunZhang, YijingHu, Miaoqing...
20页查看更多>>摘要：The study of crowd evacuation dynamics is important for the management of public safety, and crowd evacuation dynamics models can be used to simulate the behaviors of pedestrians during an evacuation. In this paper, we propose a new force model for simulation of the evacuation of complex environments. In comparison to existing models, this model considers more environmental factors to make it applicable to complex emergency environments. By verification using real data, the model is demonstrated to be able to predict evacuation efficiency and better reproduce the microscopic behavior of pedestrians under extreme conditions. We discuss the impact of the presence of different kinds of hazards and different types of obstacles in the environment on pedestrian evacuation performance and put forward suggestions for crowd evacuation management. (C) 2021 Published by Elsevier B.V.
原文链接:- NSTL
- Elsevier
Silva, Joeliton B.de Albuquerque, Douglas F.
8页查看更多>>摘要：The spin-3/2 anisotropic Heisenberg model with Dzyaloshinskii-Moriya interaction is studied by using the framework of the two-spin cluster approximation. The formalism is developed for lattices with general coordination number. However, we address our attention to the simple cubic lattice (q = 6). The phase diagram of the system reveals the presence of tricritical points and the first and second-order phase transitions are obtained. The critical behavior is discussed and compared with the spin-1/2 and spin-1 Heisenberg systems. (C) 2021 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Jamaludin, AnuarNazar, RoslindaPop, Ioan
17页查看更多>>摘要：This work focuses on numerically investigating the mixed convection stagnation-point flow and heat transfer in an incompressible Cross fluid over a permeable shrinking sheet, with suction and thermal radiation effects. The governing equations defining the current problem have been first transformed into the ordinary differential equations through similarity transformations. The resulting equations obtained are then solved numerically using the bvp4c programmed in MATLAB, revealing dual (upper and lower branch) solutions for both assisting and opposing flow regions. Stability analysis has been employed afterwards to determine a stable solution between them. Following from there, the upper branch solution has been found to be stable, while the lower branch solution is unstable. In addition, the study has established that the Weissenberg number, the Prandtl number and the suction parameter are strongly influenced to uplift the range of existence for dual solutions. (C) 2021 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Han, WenchenGao, ShunHuang, ChangweiYang, Junzhong...
9页查看更多>>摘要：Most of opinion models focus on consensus induced by assimilation effects (attractive interaction). The roles of backfire effects (repulsive interaction dependent upon opinion difference) on non-consensus states are less paid attentions on. In this work, we introduce circular opinion which is defined on a circle with a circumference of 1. We study a circular opinion model on a ring with the backfire effect. The interplay between circular opinions and repulsive interaction leads to rich opinion dynamics. We identify six types of opinion states according to their profiles in opinion space and their spatial organizations: three opinion states without spatial structure including disordered state, fragment state with several opinion clusters, and polarized state with only two opinion clusters; three opinion states with spatial structure, travelling polarized state which is a tilted polarized state in space, clustered polarized states and clustered, and travelling clustered polarized state. The stability diagrams of different opinion states have been explored on the parameter plane and we find the coexistence among different opinion states is prevalent. (C) 2021 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
Guzman, OrlandoChapela, Gustavo A.Ignacio Machorro-Martinez, Brian
10页查看更多>>摘要：Phase diagrams for the deformed and extended kagome lattices are obtained using a computer model consisting of hard spheres decorated with attractive vibrating patches simulated using a molecular dynamics program designed for discontinuous potentials. The vibrating molecules gave the phase diagram of the deformed structure. In order to obtain the phase diagram of the extended kagome lattice, an "I" shaped model consisting of six hard spheres was used. The phase diagram of a new, extended open network formed with an "I" shaped molecule of five hard spheres, is also reported. These simple models serve as inspiration to study more complex self assembling systems like virus capsid formation. (C) 2021 Elsevier B.V. All rights reserved.
原文链接:- NSTL
- Elsevier
