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learning topological defects formation with neural networks in a quantum phase transition

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Communications in Theoretical Physics 2024年第5期76卷 68-76页

作者： Han-Qing shi Hai-Qing Zhang Center for Gravitational Physics Department of Space ScienceBeihang UniversityBeijing 100191China Peng Huanwu Collaborative Center for Research and Education Beihang UniversityBeijing 100191China

Neural networks possess formidable representational power,rendering them invaluable in solving complex quantum many-body *** they excel at analyzing static solutions,nonequilibrium processes,including critical dynamics during a quantum phase transition,pose a greater challenge for neural *** address this,we utilize neural networks and machine learning algorithms to investigate time evolutions,universal statistics,and correlations of topological defects in a one-dimensional transverse-field quantum Ising ***,our analysis involves computing the energy of the system during a quantum phase transition following a linear quench of the transverse magnetic field *** excitation energies satisfy a power-law relation to the quench rate,indicating a proportional relationship between the excitation energy and the kink ***,we establish a universal power-law relationship between the first three cumulants of the kink numbers and the quench rate,indicating a binomial distribution of the ***,the normalized kink-kink correlations are also investigated and it is found that the numerical values are consistent with the analytic formula.

关键词： neural networks machine learning transverse-field quantum Ising model kibble-zurek mechanism

A modified smoothed particle hydrodynamics method considering residual stress for simulating failure and its application in layered rock mass

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Journal of Mountain Science 2024年第6期21卷 2091-2112页

作者： XIA Chengzhi shi Zhenming KOU Huanjia Department of Geotechnical Engineering College of Civil EngineeringTongji UniversityShanghai 200092China Key laboratory of Geotechnical and Underground Engineering of Ministry of Education Tongji UniversityShanghai 200092China

Residual strength is an indispensable factor in evaluating rock fracture,yet the current Smoothed Particle Hydrodynamics(SPH)framework rarely considers its influence when simulating *** improved cracking strategy considering residual stress in the base bond SPH method was proposed to simulate failures in layered rocks and slopes and verified by experimental results and other simulation methods(i.e.,the discrete element method).Modified Mohr–Coulomb failure criterion was applied to distinguish the mixed failure of tensile and *** fracture markψwas introduced to improve the kernel function after tensile damage,and the calculation of residual stress after the damage was derived after shear *** simulations were carried out to evaluate its performance under different stress and scale conditions and to verify its effectiveness in realistically reproducing crack initiation and propagation and coalescence,even fracture and *** results indicate that the improved cracking strategy precisely captures the fracture and failure pattern in layered rocks and rock *** residual stress of brittle tock is correctly captured by the improved SPH *** improved SPH method that considers residual strength shows an approximately 13%improvement in accuracy for the safety factor of anti-dip layered slopes compared to the method that does not consider residual strength,as validated against analytical *** infer that the improved SPH method is effective and shows promise for applications to continuous and discontinuous rock masses.

关键词： Smoothed particle hydrodynamics Cracking strategy Residual stress layered rock Crack propagation

Design and mechanical properties analysis of a cellular Waterbomb origami structure

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Theoretical & Applied Mechanics letters 2024年第3期14卷 193-202页

作者： Yongtao Bai Zhaoyu Wang Yu shi School of Civil Engineering Chongqing UniversityChongqing 400045China Research Center of Steel Structure Engineering Chongqing UniversityChongqing 400045China

Cellular structures are commonly used to design energy-absorbing structures,and origami structures are becominga prevalent method of cellular structure *** paper proposes a foldable cellular structure based on theWaterbomb origami *** geometrical configuration of this structure is ***-static compressiontests of the origami tube cell of this cellular structure are conducted,and load-displacement relationship curvesare *** simulations are carried out to analyze the effects of aspect ratio,folding angle,thicknessand number of layers of origami tubes on initial peak force and specific energy absorption(SEA).Calculationformulas for initial peak force and SEA are obtained by the multiple linear regression *** degree ofinfluence of each parameter on the mechanical properties of the single-layer tube cell is *** resultsshow that the cellular structure exhibits negative stiffness and periodic load-bearing capacity,as well as foldingangle has the most significant effect on the load-bearing and energy-absorbing *** adjusting the designparameters,the stiffness,load-bearing capacity and energy absorption capacity of this cellular structure can beadjusted,which shows the programmable mechanical properties of this cellular *** foldability andthe smooth periodic load-bearing capacity give the structure potential for application as an energy-absorbing structure.

关键词： Cellular structure Waterbomb origami Mechanical metamaterial Numerical simulation Energy absorption

Buckling optimization of curvilinear fiber-reinforced composite structures using a parametric level set method

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Frontiers of Mechanical Engineering 2024年第1期19卷 149-160页

作者： Ye TIAN Tielin shi Qi XIA State Key laboratory of Intelligent Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China

Owing to their excellent performance and large design space,curvilinear fiber-reinforced composite structures have gained considerable attention in engineering fields such as aerospace and *** addition to the stiffness and strength of such structures,their stability also needs to be taken into account in the *** study proposes a level-set-based optimization framework for maximizing the buckling load of curvilinear fiber-reinforced composite *** the proposed method,the contours of the level set function are used to represent fiber *** a composite laminate with a certain number of layers,one level set function is defined by radial basis functions and expansion coefficients for each ***,the fiber angle at an arbitrary point is the tangent orientation of the contour through this *** the finite element of buckling,the stiffness and geometry matrices of an element are related to the fiber angle at the element *** study considers the parallelism constraint for fiber *** the sensitivity calculation of the objective and constraint functions,the method of moving asymptotes is utilized to iteratively update all the expansion coefficients regarded as design *** numerical examples under different boundary conditions are given to validate the proposed *** show that the optimized curved fiber paths tend to be parallel and equidistant regardless of whether the composite laminates contain holes or ***,the buckling resistance of the final design is significantly improved.

关键词： buckling optimization curvilinear fiber composite structure level set method manufacturing constraint

Physiological and pathological functions of circular RNAs in the nervous system

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Neural Regeneration Research 2024年第2期19卷 342-349页

作者： Min Zhou shi li Chuan Huang School of life Sciences Chongqing UniversityChongqingChina

Circular RNAs(circRNAs)are a class of covalently closed single-stranded RNAs that are expressed during the development of specific cells and *** play crucial roles in physiological and pathological processes by sponging microRNAs,modulating gene transcription,controlling the activity of certain RNA-binding proteins,and producing functional peptides.A key focus of research at present is the functionality of circRNAs in the nervous system and several advances have emerged over the last 2 ***,the precise role of circRNAs in the nervous system has yet to be comprehensively *** this review,we first summarize the recently described roles of circRNAs in brain development,maturity,and ***,we focus on the involvement of circRNAs in various diseases of the central nervous system,such as brain cancer,chronic neurodegenerative diseases,acute injuries of the nervous system,and neuropathic pain.A better understanding of the functionality of circRNAs will help us to develop potential diagnostic,prognostic,and therapeutic strategies to treat diseases of the nervous system.

关键词： Alzheimer’s disease amyotrophic lateral sclerosis brain development circRNAs neuropathic pain Parkinson’s disease

Three-dimensional limit variation analysis on the ultimate pullout capacity of the anchor cables based on the Hoek-Brown failure criterion

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Journal of Mountain Science 2024年第3期21卷 1036-1047页

作者： ZUO shi ZHAO lianheng HU shihong College of Civil Engineering Changsha UniversityChangsha 410022China Hunan Provincial Key laboratory for Disaster Prevention and Mitigation of Rail Transit Engineering Structure Key Laboratory of Heavy-Haul Railway Engineering StructureMinistry of EducationCentral South UniversityChangsha 410075China College of Civil Engineering Central South UniversityChangsha 410075China

Only simplified two-dimensional model and a single failure mode are adopted to calculate the ultimate pullout capacity(UPC)of anchor cables in most previous *** study focuses on a more comprehensive combination failure mode that consists of bond failure of an anchorage body and failure of an anchored rock *** three-dimensional ultimate pullout capacity of the anchor cables is calculated based on the Hoek-Brown failure criterion and variation analysis *** numerical solution for the curvilinear function in fracture plane is obtained based on the finite difference theory,which more accurately reflects the failure state of the anchor cable,as opposed to that being assumed in *** results reveal that relying solely on a single failure mode for UPC calculations has limitations,as changes in parameter values not only directly impact the UPC value but also can alter the failure model and thus the calculation method.

关键词： Anchor cable Ultimate pullout capacity(UPC) Failure model Variation analysis Hoek-Brown failure criterion

THE RESEARCH ON NEW REFlECT ROAD MARK COATING

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Acta Metallurgica Sinica(English letters) 1999年第5期12卷 1064-1068页

作者： l.M. li, Z.J. lin, X.F. shi and G.l. Yu Fuzhou University, Fuzhou 350002, China

As the developing of the traffic and transport, road signs coating materials become important more and more. This paper introduces the development and current situation of the traffic marking coating and discusses its raw material and application operation. C 5 petroleum resin made in china is used as major material in a hot melt traffic marking coating. To get the best material composition, orthogonal test is used and wear resistant, water resistant, acidity proof, alkaline proof, adhesive strength, fluid characteristic of the coating is researched.

关键词： hot melt coating reflecting coating road sign coating

A Fuzzy Trust Management Mechanism with Dynamic Behavior Monitoring for Wireless Sensor Networks

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China Communications 2024年第5期21卷 177-189页

作者： Fu shiming Zhang Ping shi Xuehong School of Artificial Intelligence Chongqing University of EducationChongqing 400065China School of Communications and Information Engineering Chongqing University of Posts and TelecommunicationsChongqing 400065China

Traditional wireless sensor networks(WSNs)are typically deployed in remote and hostile environments for information *** wireless communication methods adopted by sensor nodes may make the network highly vulnerable to various *** encryption and authentication mechanisms cannot prevent attacks launched by internal malicious *** trust-based security mechanism is usually adopted to solve this problem in ***,the behavioral evidence used for trust estimation presents some uncertainties due to the open wireless medium and the inexpensive sensor ***,how to efficiently collect behavioral evidences are rarely *** address these issues,in this paper,we present a trust management mechanism based on fuzzy logic and a cloud ***,a type-II fuzzy logic system is used to preprocess the behavioral evidences and alleviate ***,the cloud model is introduced to estimate the trust values for sensor ***,a dynamic behavior monitoring protocol is proposed to provide a balance between energy conservation and safety *** results demonstrate that our trust management mechanism can effectively protect the network from internal malicious attacks while enhancing the energy efficiency of behavior monitoring.

关键词： behavior monitoring cloud fuzzy trust wireless sensor networks

Increased precipitation magnifies the effects of N addition on performance of invasive plants in subtropical native communities

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Journal of Plant Ecology 2022年第3期15卷 473-484页

作者： Xiang-Qin li Sai-Chun Tang Yu-Mei Pan Chun-Qiang Wei shi-Hong lü Guangxi Key laboratory of Plant Conservation and Restoration Ecology in Karst Terrain Guangxi Institute of BotanyGuangxi Zhuang Autonomous Region and Chinese Academy of SciencesGuilin 541006China Zhejiang Provincial Key laboratory of Plant Evolutionary Ecology and Conservation Taizhou UniversityTaizhou 318000China

Nitrogen(N)deposition,precipitation and their interaction affect plant invasions in temperate ecosystems with limiting N and water resources,but whether and how they affect plant invasions in subtropical native communities with abundant N and precipitation remains *** constructed in situ artificial communities with 12 common native plant species in a subtropical system and introduced four common invasive plant species and their native counterparts to these *** compared plant growth and establishment of introduced invasive species and native counterparts in communities exposed to ambient(CK),N addition(N+),increased precipitation(P+)and N addition plus increased precipitation(P+N+).We also investigated the density and aboveground biomass of communities under such conditions.P+alone did not enhance the performance of invasive species or native counterparts.N+enhanced only the aboveground biomass and relative density of invasive species.P+N+enhanced the growth and establishment performance of both invasive species and native *** growth and establishment parameters of invasive species were greater than those of native counterparts under N+,P+and P+N+*** density and aboveground biomass of native communities established by invasive species were significantly lower than those of native communities established by native counterparts under P+N+*** results suggest that P+may magnify the effects of N+on performance of invasive species in subtropical native communities where N and water are often abundant,which may help to understand the effect of global change on plant invasion in subtropical ecosystems.

关键词： community aboveground biomass community density growth and establishment increased precipitation invasive plants nitrogen addition subtropical native communities