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麻花钻钻削过程的有限元动态仿真

机械科学与技术 2006年第10期25卷 1143-1146页

作者：白亚江杜云芝天津大学机械工程学院天津300072

孔钻削加工是一种常见且非常重要的金属加工工艺,麻花钻是钻孔加工中最普通的加工工具,文章用有限元方法模拟了麻花钻的钻孔加工过程进而分析预测了加工工艺中的部分结果和影响因素。应用的有限元仿真软件是DEFORM-3D。论文中动态模拟... 详细信息

孔钻削加工是一种常见且非常重要的金属加工工艺,麻花钻是钻孔加工中最普通的加工工具,文章用有限元方法模拟了麻花钻的钻孔加工过程进而分析预测了加工工艺中的部分结果和影响因素。应用的有限元仿真软件是DEFORM-3D。论文中动态模拟了麻花钻钻孔中切屑成形过程,工件采用了刚塑性材料模型,而刀具采用的是考虑温度变化的刚性材料模型,获得了麻花钻钻削加工过程中的连续切屑,分析预测了加工过程中工件的应力、温度分布以及刀具所受的扭矩。

关键词：有限元模拟麻花钻温度应力扭矩

Resonances of Spin-1/2 Fermions in Eddington-Inspired Born-Infeld Gravity

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Communications in Theoretical Physics 2016年第3期65卷 292-300页

作者：付启明赵力杜云芝古宝珉 Institute of Theoretical Physics Lanzhou University

We investigate the fermionic resonances for both chiralities in five-dimensional Eddington-inspired BornInfeld(EiBI)*** order to localize fermion on the brane,it needs to be considered the Yukawa coupling between the fermion and the background scalar *** our models,since the background scalar field has kink,double kink,or anti-kink solution,the system has rich resonant Kaluza-Klein(KK)modes *** massive KK fermionic modes feel a volcano potential,which result in a fermionic zero mode and a set of continuous massive KK *** inner structure of the branes and a free parameter in background scalar field influence the resonant behaviors of the massive KK fermions.

关键词： fermion resonance EiBI gravity

Topology of charged AdS black hole in restricted phase space

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Chinese Physics C 2024年第9期48卷 291-299页

作者： Han Wang Yun-Zhi Du College of Mathematics and Statistics Shanxi Datong UniversityDatong 037009China Department of Physics Shanxi Datong UniversityDatong 037009China Institute of Theoretical Physics Shanxi Datong UniversityDatong 037009China

The local topological properties of black hole systems can be expressed through winding numbers as *** date,AdS black hole thermodynamics are often depicted by the dual parameters of(T,S),(P,V),(Φ,Q) in the extended phase space,while there have been several studies on the black hole thermodynamics in the restricted phase *** this paper,we analyze the topological properties of charged AdS black holes in the restricted phase space under the higher-dimension and higher-order curvature gravity *** results show that the topological number of the charged black hole in the same canonical ensembles is a constant and is independent of the concrete dual thermodynamical ***,the topological number in the grand canonical ensemble is different from that in the canonical ensemble for the same black hole ***,these results are independent of dimension d and highe st order k of the Lanczos-Lovelock densities.

关键词： topology phase transition black hole

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德西特时空中RN黑洞的相变动力学

山西大同大学学报（自然科学版） 2023年第4期39卷 17-24页

作者：郭雄英杜云芝李怀繁山西大同大学物理与电子科学学院山西大同037009

理解黑洞的热力学相变可以深入了解黑洞引力的基本性质,从而建立量子引力。首先通过重构麦克斯韦等面积定律,发现德西特时空存在大/小体积相。然后从吉布斯自由能的角度研究了四维RN-dS时空的相变动力学,德西特时空稳定的大/小体积相对... 详细信息

理解黑洞的热力学相变可以深入了解黑洞引力的基本性质,从而建立量子引力。首先通过重构麦克斯韦等面积定律,发现德西特时空存在大/小体积相。然后从吉布斯自由能的角度研究了四维RN-dS时空的相变动力学,德西特时空稳定的大/小体积相对应于吉布斯自由能的两个具有相同深度的势阱,不稳定中间体体积相对应于吉布斯自由能的局部极大值。最后通过求解具有不同反射/吸收边界条件和初始条件的Fokker-Planck方程,探讨了在首次通过时间内共存的大/小体积相之间切换的动力学以及温度对相变动力学的影响。对相变动力学的研究有助于获得黑洞潜在微观相互作用的新见解。

关键词： RN黑洞德西特时空相变动力学吉布斯自由能

Continuous phase transition of the de Sitter spacetime with charged black holes and cloud of strings and quintessence

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Chinese Physics C 2023年第11期47卷 105-115页

作者：甄海龙杜云芝李怀繁李新平张丽春 Department of Physics Shanxi Datong UniversityDatong 037009China Institute of Theoretical Physics Shanxi Datong UniversityDatong 037009China

Recently,some meaningful results have been obtained by studying the phase transition,critical exponents,and other thermodynamical properties of different black *** for the Anti-de Sitter(AdS)black holes,their thermodynamical properties nearby the critical point have attracted considerable ***,there exists little work on the thermodynamic properties of the de Sitter(dS)spacetime with black *** this paper,based on the effective thermodynamical quantities and the method of the Maxwell's equal-area law,we explore the phase equilibrium for the de Sitter spacetime with the charged black holes and the cloud of string and quintessence(i.e.,C-dSSQ spacetime).The boundaries of the two-phase coexistence region in both P_(eff)−T_(eff)and T_(eff)−S diagrams are *** coexistent curve and the latent heat of phase transition for this system are also ***,we analyze the effect of parameters(the state parameterωand the ratio of two horizon radii x=r+/r_(c))on the two-phase coexistence region *** results indicate that the phase transition in C-dSSQ spacetime is analogous to that in a van der Waals fluid(vdw)system,which is determined by the electrical potential at the *** results are helpful for understanding the basic properties of black holes and are also of great value for the establishment of quantum gravity.

关键词： de Sitter spacetime effective thermodynamic quantities phase transition

Phase equilibrium and microstructure of topological AdS black holes in massive gravity

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Chinese Physics C 2022年第8期46卷 230-243页

作者： Fang Liu Yun-Zhi Du Ren Zhao Huai-Fan Li Department of Physics Shanxi Datong UniversityDatong 037009China Insitute of Theoretical Physics Shanxi Datong UniversityDatong 037009China

In order to clearly understand the gravitational theory through the thermal properties of the black hole,it is important to further investigate the first-order phase transition of black *** this paper,we adopt different conjugate variables(P~V,T~S,C_(1)~c_(1),and C_(2)~c_(2)) and apply Maxwell's equal-area law to study the phase equilibrium of a topological black hole in massive *** condition and latent heat of phase transition are displayed as well as the coexistent curve of *** result shows that the phase transition of this system is the high/low electric potentials one,not only the large/small black holes *** also analyze the effect of the model's parameters on phase *** we introduce a new order parameter to probe the microstructure of this *** work will provide the theoretical basis to study the phase structure of topological black holes in massive gravity and to further explore the gravitational theory.

关键词： black hole first-order phase transition Maxwell's equal-area law microstructure

Dynamic property of phase transition for non-linear charged anti-de Sitter black holes

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Chinese Physics C 2022年第5期46卷 189-197页

作者： Yun-Zhi Du Huai-Fan Li Fang Liu Li-Chun Zhang Department of Physics Shanxi Datong UniversityDatong 037009China Institute of Theoretical Physics Shanxi Datong UniversityDatong 037009China

Understanding the thermodynamic phase transition of black holes can provide deep insights into the fundamental properties of black hole gravity and help to establish quantum *** this work,we investigate the phase transition and its dynamics for the charged EPYM AdS black *** reconstructing Maxwell's equal-area law,we find there exists a high-/low-potential black hole(HPBH/LPBL)phase transition,not only the pure large/small black hole phase *** Gibbs free energy landscape(G_(L))is treated as a function of the black hole horizon,which is the order parameter of the phase transition due to thermal *** the viewpoint of G_(L),the stable HPBH/LPBL states correspond to two wells of G_(L),which have the same *** unstable intermediate-potential black hole state corresponds to the local maximum of G_(L).Then we focus on the probability evolution governed by the Fokker-Planck *** solving the Fokker-Planck equation with different reflection/absorption boundary conditions and initial conditions,the dynamics of switching between the coexistent HPBH and LPBL phases is probed within the first passage ***,the effect of temperature on the dynamic properties of the phase transition is also investigated.

关键词： dynamic phase transition EPYM AdS black hole Gibbs free energy probability evolution

Localization of five-dimensional Elko spinors on dS/AdS thick branes

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Chinese Physics C 2022年第2期46卷 1-12页

作者： Xiang-Nan Zhou Yun-Zhi Du Xin-Yuan Ma Zhen-Hua Zhao College of Physics and Information Engineering.Shanxi Normal University Linfen 04100China Institute of Theoretical Physics Datong UniversityDatong 037009China Department of Applied Physics Shandong University of Science and TechnologyQingdao 266590China

Owing to the special structure of a five-dimensional Elko spinor,its localization on a brane with codimension one becomes completely different from that of a Dirac *** introducing the coupling between the Elko spinor and the scalar field that can generate the brane,we have two types of localization mechanism for the five-dimensional Elko spinor zero mode on a *** is the Yukawa-type coupling,and the other is the non-minimal *** this study,we investigate the localization of the Elko zero mode on de Sitter and Anti-de Sitter thick branes with the two localization mechanisms,*** results show that both the mechanisms can achieve *** forms of the scalar coupling function in both localization mechanisms have similar properties,and they play a similar role in localization.

关键词： localization Elko spinor de Sitter and Anti-de Sitter thick brane Yukawa-type coupling non-minimal coupling

Phase transition of non-linear charged Anti-de Sitter black holes

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Chinese Physics C 2021年第11期45卷 1-10页

作者： Yun-Zhi Du Huai-Fan Li Fang Liu Ren Zhao Li-Chun Zhang Department of Physics Shan xi Da tong UniversityDatong 037009China Institute of Theoretical Physics Shan xi Da tong UniversityDa tong 037009China

Understanding the thermodynamic phase transition of black holes can provide a deep insight into the fundamental properties of black hole gravity to establish the theory of quantum *** investigate the condition and latent heat of phase transition for non-linear charged AdS black holes using Maxwell's equal-area *** addition,we analyze the boundary and curve of the two-phase coexistence area in the expanded phase *** suggest that the phase transition of the non-linear charged AdS black hole with the fixed temperature(T

关键词： phase transition AdS black hole Ruppeiner scalar curvature microstructure equal-area law