Thermodynamic properties and phase diagram of quark matter within non-extensive Polyakov chiral SU(3)quark mean field model

In the present study,we applied Tsallis non-extensive statistics to investigate the thermodynamic properties and phase diagram of quark matter in the Polyakov chiral SU(3)quark mean field model.Within this model,the properties of the quark matter were modified through the scalar fieldsσ,ζ,δ,χ,vector fieldsω,ρ,ϕ,and Polyakov fieldsΦandΦ¯at finite temperature and chemical potential.Non-extensive effects were introduced through a dimensionless parameter q,and the results were compared to those of the extensive case(q→1).In the non-extensive case,the exponential in the Fermi-Dirac(FD)function was modified to a q-exponential form.The influence of the q parameter on the thermodynamic properties,pressure,energy,and entropy density,as well as trace anomaly,was investigated.The speed of sound and specific heat with non-extensive effects were also studied.Furthermore,the effect of non-extensivity on the deconfinement phase transition as well as the chiral phase transition of u,d,and s quarks was explored.We found that the critical end point(CEP),which defines the point in the(T−μ)phase diagram where the order of the phase transition changes,shifts to a lower value of temperature,TCEP,and a higher value of chemical potential,μCEP,as the non-extensivity is increased,that is,q>1.

Study of the Magnetocaloric Effect in La0.5Sm0.2Sr0.3Mn1-xFexO3 (x = 0 and 0.05) Manganites with the Mean-Field Theory

In this paper, the magnetocaloric in La0.5Sm0.2Sr0.3Mn1-xFexO3 compounds with x = 0 (LSSMO) and x = 0.05 (LSSMFO) were simulated using mean field model theory. A strong consistency was observed between the theoretical and experimental curves of magnetizations and magnetic entropy changes, −ΔSM(T). Based on the mean-field generated −ΔSM(T), the substantial Temperature-averaged Entropy Change (TEC) values reinforce the appropriateness of these materials for use in magnetic refrigeration technology within TEC (10) values of 1 and 0.57 J∙kg−1∙K−1under 1 T applied magnetic field.

A Fractional Micro-Macro Model for Crowds of Pedestrians Based on Fractional Mean Field Games

Modeling a crowd of pedestrians has been considered in this paper from different aspects. Based on fractional microscopic model that may be much more close to reality, a fractional macroscopic model has been proposed using conservation law of mass. Then in order to characterize the competitive and cooperative interactions among pedestrians, fractional mean field games are utilized in the modeling problem when the number of pedestrians goes to infinity and fractional dynamic model composed of fractional backward and fractional forward equations are constructed in macro scale. Fractional micromacro model for crowds of pedestrians are obtained in the end. Simulation results are also included to illustrate the proposed fractional microscopic model and fractional macroscopic model, respectively. © 2014 Chinese Association of Automation.

Exact analytical solutions to the mean-field model depicting microcavity containing semiconductor quantum wells

By using a two-mode mean-field approximation, we study the dynamics of the microcavities containing semiconductor quantum wells. The exact analytical solutions are obtained in this study. Based on these solutions, we show that the emission from the microcavity manifests periodic oscillation behaviour and the oscillation can be suppressed under a certain condition.

Kinetic Ising model in a time-dependent oscillating external magnetic field:effective-field theory

Recently, Shiet al. [2008 Phys. Left. A 372 5922] have studied the dynamical response of the kinetic Ising model in the presence of a sinusoidal oscillating field and presented the dynamic phase diagrams by using an effective-field theory （EFT） and a mean-field theory （MFT）. The MFT results are in conflict with those of the earlier work of Tome and de Oliveira, [1990 Phys. Rev. A 41 4251]. We calculate the dynamic phase diagrams and find that our results are similar to those of the earlier work of Tome and de Oliveira; hence the dynamic phase diagrams calculated by Shiet al. are incomplete within both theories, except the low values of frequencies for the MFT calculation. We also investigate the influence of external field frequency （w） and static external field amplitude （h0） for both MFT and EFT calculations. We find that the behaviour of the system strongly depends on the values of w and h0.

考虑用户能动性和流动性的舆情传播模型

针对现有信息传播模型忽略了用户主观能动性和社交网络动态性的问题,提出异构网络中考虑用户能动性和流动性的SCBRD(Susceptible-Commented-Believed-Recovered-Defensed)舆情传播模型。首先,利用下一代矩阵方法计算基本再生数,并运用Lyapunov稳定性定理和庞特里亚金原理分析了系统的动力学和最优控制问题。然后,基于BA(Barabási-Albert)无标度网络进行仿真分析以确定影响舆情传播的显著因素,结果表明,用户的好奇心理、转发行为和进入率在信息扩散中起着主导作用,并且系统存在最优控制解。最后,依据实际数据验证模型的合理性。与SCIR(Susceptible-inCubation-Infective-Refractory)模型相比,SCBRD模型的拟合优度提高了27.40%,预测的均方根误差(RMSE)减小了39.02%。因此,该模型能够适应信息传播复杂的变化形势,为官方的舆情监管提供较好的指导。

基于第十三代国际地磁参考场模型在中国区域特征分析与研究

根据最新的第十三代国际地磁参考场模型(IGRF13),计算了2015—2020年中国区域地磁场模型七要素长期变化速率,并在此基础上分析我国区域地磁场长期变化特征。通过分析计算我国28个地磁台的IGRF13模型值与实际地磁场的长期变化速率、差值及均方误差,结果显示:IGRF13模型所显示的地磁场长期变化与我国区域地磁场实际观测变化基本一致,但在局部区域也存在差异,IGRF13模型能够体现中国区域地磁场的特征。应用IGRF13模型数据时需要考虑局部区域与台站实际观测数据的误差。

A new model of foraging behavior in ant system

Foraging behavior in ant colonies has come to be viewed as a prototypical example to describe how complex group behavior can arise from simple individuals. In order to research the feature of self-organization in swarm intelligence (SI), a mean field model is given and analyzed in foraging process with three sources in this paper. The distance of trails and the richness of each source are considered. Both of the theoretical numerical analysis and Monte Carlo simulation show the power law relationship between the completion time and the flux of foragers. The work presented here guides a better understanding on self-organization and swarm intelligence. It can be used to design more efficient, adaptive, and reliable intelligent systems.

IGRF13和WMM2020模型在亚洲中低纬度地区的精度评估及分析

研究了最新的世界地磁场模型WMM2020和国际地磁参考模型IGRF13与亚洲中低纬度区域地磁台站年均值的一致性,计算该区域地磁台站与其对应的地磁场模型各个地磁要素之间的均方根误差,分析WMM2020与IGRF13两者之间的差异,以此来评估最新的世界地磁场模型WMM2020和国际地磁参考模型IGRF13在亚洲中低纬度地区的适用性。分析结果表明,IGRF13模型与亚洲中低纬度地区大部分地磁台站各地磁要素的年均值符合较好,存在显著的相关性,因此,在亚洲中低纬度地区,将最新的世界地磁场模型WMM2020和国际地磁参考模型IGRF13作为构建地磁异常模型时的参考背景场,或是对主磁场进行相关的改正都具有一定适用性。

高阶重力场模型的高程异常差值改正方法研究

通过水准仪测量获取区域高程控制网点正常高的方式,精度高但耗时费力。首先利用EGM2008、EIGEN-6C4、XGM2019e_2159和SGG-UGM-2四种高阶全球重力场模型获取高程异常,再利用少量GNSS水准控制点获取真实高程异常,最后采用平均差值改正短波值方法快速获取高程异常。结合滇中引水工程307个GNSS水准控制点成果,以验证东西方向10 km、20 km、40 km和80 km距离范围内的高程异常改正效果。结果表明,在东西方向40 km内采用4个和2个GNSS水准控制点改正4种模型的高程异常中误差在±5 cm以内,平均中误差改正率接近50%,其中XGM2019e_2159模型整体上更符合似大地水准面。该方法可提高小区域范围内高程异常获取的精度和效率。

A cellular automata model with probability infection and spatial dispersion

In this article, we have proposed an epidemic model based on the probability cellular automata theory. The essential mathematical features are analysed with the help of stability theory. We have given an alternative modelling approach for the spatiotemporal system which is more realistic from the practical point of view. A discrete and spatiotemporal approach is shown by using cellular automata theory. It is interesting to note that both the size of the endemic equilibrium and the density of the individuals increase with the increase of the neighbourhood size and infection rate, but the infections decrease with the increase of the recovery rate. The stability of the system around the positive interior equilibrium has been shown by using a suitable Lyapunov function. Finally, experimental data simulation for SARS disease in China in 2003 and a brief discussion are given.

EMMD-Prony approach for dynamic validation of simulation models

Model validation and updating is critical to model credibility growth. In order to assess model credibility quantitatively and locate model error precisely, a new dynamic validation method based on extremum field mean mode decomposition（EMMD） and the Prony method is proposed in this paper. Firstly, complex dynamic responses from models and real systems are processed into stationary components by EMMD. These components always have definite physical meanings which can be the evidence about rough model error location. Secondly, the Prony method is applied to identify the features of each EMMD component. Amplitude similarity, frequency similarity, damping similarity and phase similarity are defined to describe the similarity of dynamic responses.Then quantitative validation metrics are obtained based on the improved entropy weight and energy proportion. Precise model error location is realized based on the physical meanings of these features. The application of this method in aircraft controller design provides evidence about its feasibility and usability.

Mott transition in ruby lattice Hubbard model

Mott transition in a ruby lattice with fermions described by the Hubbard model including on-site repulsive interaction is investigated by combining the cellular dynamical mean-field theory and the continuous-time quantum Monte Carlo algorithm. The effect of temperature and on-site repulsive interaction on the metallic–insulating phase transition in ruby lattice with fermions is discussed based on the density of states and double occupancy. In addition, the magnetic property of each phase is discussed by defining certain magnetic order parameters. Our results show that the antiferromagnetic metal is found at the low temperature and weak interaction region and the antiferromagnetic insulating phase is found at the low temperature and strong interaction region. The paramagnetic metal appears in whole on-site repulsive interaction region when the temperature is higher than a certain value and the paramagnetic insulator appears at the middle scale of temperature and on-site repulsive interaction.

Particle number conserving BCS approach in the relativistic mean field model and its application to ^32-74Ca

A fixed particle number BCS （FBCS） approach is formulated in the relativistic mean field （RMF） model. It is shown that the RMF＋FBCS model obtained can describe the weak pairing limit. We calculate the ground-state properties of the calcium isotopes ＆32-74Ca and compare the results with those obtained from the usual RMF＋BCS model. Although the results are quite similar to each other, we observe the interesting phenomenon that for ^54Ca, the FBCS approach can enhance the occupation probability of the 2p1/2 single particle level and slightly increases its radius, compared with the RMF＋BCS model. This leads to the unusual scenario that although ^54Ca is more bound with a spherical configuration, the corresponding size is not the most compact. We anticipate that such a phenomenon might happen for other neutron-rich nuclei and should be checked by further more systematic studies.

Constraining the relativistic mean-field models from PREX-2 data:effective forces revisited

Based on the current measurement of the neutron distribution radius(R_(n))of ^(208)Pb from the PREX-2 data,we revisited the recently developed G3 and IOPB-I force parameters by fine-tuning some specific couplings within the relativistic mean-field(RMF)model.Theω-ρ-mesons coupling and theρ-meson coupling are constrained to the experimental neutron radius of^(208)Pb without compromising the bulk properties of finite nuclei and infinite nuclear matter observables.The modified parameter sets are applied to calculate the gross properties of finite nuclei such as binding energies,charge distributions,nuclear radii,pairing gaps,and single-particle energies.The root-mean-square deviations in binding energy and charge radius are estimated with respect to the available experimental data for 195 even-even nuclei,and the results compare favourably with the well-calibrated effective interactions of Skyrme,Gogny and other relativistic mean-field parametrizations.The pairing gap estimations for modified G3 and IOPB-I for Sn isotopes are also compared with the Hartree-Fock-Bogoliubov calculation with the Gogny(D1S)interaction.The isotopic shift and single-particle energy spacing are also calculated and compared with the experimental data for both original and modified versions of the G3 and IOPB-I parameter sets.Subsequently,both the modified parameter sets are used to obtain the various infinite nuclear matter observables at saturation.In addition to these,the force parameters are adopted to calculate the properties of a high isospin asymmetry dense system such as neutron star matter and tested for validation using the constraint from GW170817 binary neutron star merger events.The tuned forces predict relatively good results for finite and infinite nuclear matter systems and the current limitation on the neutron radius from PREX-2.A systematic analysis using these two refitted parameter sets over the nuclear chart will be communicated shortly.

GABA_(B)受体的慢动力学特性对癫痫样放电的影响

利用单向流动的双室皮质丘脑平均场模型,以丘脑网状核向中继核的抑制性投射以及投射产生的时滞为病理因素,探究丘脑网状核GABA_(B)受体的慢动力学对癫痫发作的影响。一方面,改变丘脑网状核向中继核的抑制性耦合强度,当时滞足够大时,室I和室II均产生棘慢波及2-棘慢波放电状态,室I动力学状态种类更多,室II的癫痫样放电区域更少。另一方面,通过探究以上两个病理因素的状态分析,发现时滞与癫痫样放电关联性更强,且当时滞足够大时,无论在室I还是室II中,均更容易诱导棘慢波及多棘慢波放电状态。

基于超高阶地球重力场模型的GNSS高程转化方法

为了将全球卫星导航系统(GNSS)得到的大地高直接应用于工程建设中,需要将大地高转换为正常高,基于5种超高阶地球重力场模型结合改进的“移去-拟合-恢复”法开展了GNSS高程转换方法研究,对实验结果的对比分析表明:在实验测区内,利用SGG-UGM-2地球重力场模型直接计算得出的高程异常值与真实高程异常的符合程度更高,中误差为±0.009 3 m.当采用“移去-拟合-恢复法”后,利用XGM2019e_2159地球重力场模型的高程异常拟合效果更优,中误差、极差、偏度值与峰度值最小,分别为±4.786 6 mm、18.875 7 mm、-0.648 8、0.887 8.

非高斯风场作用下桥梁抖振响应研究

为研究非高斯风场作用下桥梁结构的抖振响应特性,以太洪长江大桥为例,基于Hermite多项式模型,模拟了非高斯脉动风场时程,计算了不同平均风速下不同非高斯特性脉动风场的抖振响应。结果表明:非高斯风场作用下结构响应的幅值和均方根值均比高斯风场更大,非高斯特性越强,均方根值越大;随着平均风速的增加,风场峰度对结构响应均方根的影响逐渐明显。因此,对于非高斯风场,高斯过程假定低估了实际的响应情况。此外,不同非高斯特性脉动风场作用下,结构响应的偏度和峰度均趋近高斯过程的结果。

The symmetry energy γ parameter of relativistic mean-field models

The relativistic mean-field models tested in previous works against nuclear matter experimental values,critical parameters and macroscopic stellar properties are revisited and used in the evaluation of the symmetry energyγ parameter obtained in three different ways. We have checked that, independent of the choice made to calculate theγ values, a trend of linear correlation is observed between γ and the symmetry energy（S0） and a more clear linear relationship is established between γ and the slope of the symmetry energy（L0）. These results directly contribute to the arising of other linear correlations between γ and the neutron star radii of R（1.0） and R（1.4）, in agreement with recent findings. Finally, we have found that short-range correlations induce two specific parametrizations, namely,IU-FSU and DD-MEδ, simultaneously compatible with the neutron star mass constraint of 1.93≤M（max）/M☉≤2.05 and with the overlap band for the L0 ×S0 region, to present γ in the range of γ=0.25±0.05.

An Improved Heterogeneous Mean-Field Theory for the Ising Model on Complex Networks

Heterogeneous mean-field theory is commonly used methodology to study dynamical processes on complex networks,such as epidemic spreading and phase transitions in spin models.In this paper,we propose an improved heterogeneous mean-field theory for studying the Ising model on complex networks.Our method shows a more accurate prediction in the critical temperature of the Ising model than the previous heterogeneous mean-field theory.The theoretical results are validated by extensive Monte Carlo simulations in various types of networks.