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Journal of Hydrodynamics 2024年第2期36卷 219-231页

作者： Chen Geng Zhao-hui Qian Ke-xin Zheng Wei-xiang Ye Xian-wu Luo State Key Laboratory of Hydroscience cand Engineering Deparment of Energy and Power EngineeringTsinghua UniversityBeijing 100084China Institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing 100084China

In the present paper,the unsteady cavitating turbulent flow over the twisted NACA66 hydrofoil is investigated based on an modified shear stress transfer k-ωpartially averaged Navier-Stokes(MSST PANS)model,i.e.,new MSST PANS(NMSST PANS)model,where the production term of kinetic energy in the turbulence model is modified with *** with the experimental data,cavitation evolution and its characteristic frequency are satisfactorily predicted by the proposed NMSST PANS *** is revealed that the interaction among the main flow,the reentrant jets,and sheet cavitation causes the formation of the primary shedding cavity near the mid-span and the secondary shedding cavity at each side of the twisted hydrofoil,and further induces the remarkable pressure gradient around shedding *** with the development of the primary and the secondary shedding cavities,the great pressure gradient associated with large cavity volume variation promotes the vortical flow generation and the spatial deformation of vortex structure during cavitation evolution,and results in the primary and the secondary U-type ***,dynamic mode decomposition(DMD)analysis is utilized to confirm the interaction among the main flow,the main reentrant jet and two side reentrant jets,and *** results indicate that the proposed NMSST PANS model is suitable to simulate the complicated cavitating turbulent flow for various engineering applications.

关键词： Cavitating turbulent flow partially averaged Navier-Stokes(PANS)model hydrofoil numerical simulation

Novel self-embedding holographic watermarking image encryption protection scheme

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Chinese Physics B 2024年第5期33卷 281-290页

作者：王励年周楠润孙博曹颖鸿牟俊 School of Information Science and Engineering Dalian Polytechnic UniversityDalian 116034 China School of Electronic and Electrical Engineering Shanghai University of Engineering ScienceShanghai 201620China

For digital image transmission security and information copyright,a new holographic image self-embedding watermarking encryption scheme is ***,the plaintext is converted to the RGB three-color channel,the corresponding phase hologram is obtained by holographic technology and the watermark is self-embedded in the frequency ***,by applying the Hilbert transform principle and genetic center law,a complete set of image encryption algorithms is constructed to realize the encryption of image ***,simulation results and security analysis indicate that the scheme can effectively encrypt and decrypt image information and realize the copyright protection of *** introduced scheme can provide some support for relevant theoretical research,and has practical significance.

关键词： color image encryption Hilbert transform self-embedding watermark holographic technology

Characteristics of cell motility during cell collision

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Chinese Physics B 2024年第2期33卷 72-77页

作者：马一凯李娜陈唯 State Key Laboratory of Surface Physics and Department of Physics Fudan UniversityShanghai 200438China china national Center for Bioinformation Beijing 100101China national Genomics Data Center Beijing Institute of GenomicsChinese Academy of SciencesBeijing 100101China

Quantitative examination of cellular motion and intercellullar interactions possesses substantial relevance for both biology and ***,the effects of intercellular interactions during cellular locomotion remain under-explored in experimental *** such,this study seeks to bridge this research gap,adopting Dictyostelium discoideum(Dicty)cells as a paradigm to investigate variations in cellular motion during reciprocal *** aim to attain a comprehensive understanding of how cell interactions influence cell *** observing and processing the motion trajectories of colliding cells under diverse chemical environments,we calculated the diffusion coefficient(D)and the persistence time(τ),using mean square *** analysis of the relationship dynamics between D andτprior to the collisions reveals intricate and non-monotonic alterations in cell movements during *** quantitatively scrutinizing theτtrend,we were able to categorize the cellular responses to interactions under different ***,we ascertained that the effect of cell interactions during collisions in Dicty cells emulates a classical sigmoid *** discovery suggests that cellular responses might comply with a pattern akin to the Weber–Fechner law.

关键词： cell migration random walk cell-cell interaction

Identifying influential spreaders in complex networks based on density entropy and community structure

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Chinese Physics B 2024年第5期33卷 765-774页

作者：苏湛陈磊艾均郑雨语别娜 School of Optical-Electrical and Computer Engineering University of Shanghai for Science and Technology

In recent years,exploring the relationship between community structure and node centrality in complex networks has gained significant attention from researchers,given its fundamental theoretical significance and practical *** address the impact of network communities on target nodes and effectively identify highly influential nodes with strong propagation capabilities,this paper proposes a novel influential spreaders identification algorithm based on density entropy and community structure(DECS).The proposed method initially integrates a community detection algorithm to obtain the community partition results of the *** then comprehensively considers the internal and external density entropies and degree centrality of the target node to evaluate its *** validation is conducted on eight networks of varying sizes through susceptible–infected–recovered(SIR)propagation experiments and network static attack *** experimental results demonstrate that the proposed method outperforms five other node centrality methods under the same comparative conditions,particularly in terms of information spreading capability,thereby enhancing the accurate identification of critical nodes in networks.

关键词： corrigendum electron impact ionization cross sections carbon monoxide

Epidemic threshold influenced by non-pharmaceutical interventions in residential university environments

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Chinese Physics B 2024年第2期33卷 551-556页

作者：卢泽超赵生妹束华中巩龙延 Institute of Signal Processing and Transmission Nanjing University of Posts and TelecommunicationsNanjing 210003China College of Science Nanjing University of Posts and TelecommunicationsNanjing 210003China

The control of highly contagious disease spreading in campuses is a critical *** residential universities,students attend classes according to a curriculum schedule,and mainly pack into classrooms,dining halls and *** move from one place to *** simulate such environments,we propose an agent-based susceptible–infected–recovered model with time-varying heterogeneous contact *** close environments,maintaining physical distancing is the most widely recommended and encouraged non-pharmaceutical *** can be easily realized by using larger classrooms,adopting staggered dining hours,decreasing the number of students per dorm and so *** real-world influence remains *** numerical simulations,we obtain epidemic *** effect of such countermeasures on reducing the number of disease cases is also quantitatively evaluated.

关键词： epidemic threshold susceptible-infected-recovered model non-pharmaceutical interventions time-varying heterogeneous contact networks

Residual stress modeling of mitigated fused silica damage sites with CO_(2)laser annealing

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Chinese Physics B 2024年第3期33卷 509-514页

作者：张传超廖威张丽娟蒋晓龙方振华蒋晓东 Laser Fusion Research Center China Academy of Engineering PhysicsMianyang 621900China

A numerical model based on measured fictive temperature distributions is explored to evaluate the residual stress fields of CO_(2)laser-annealed mitigated fused silica damage *** proposed model extracts the residual strain from the differences in thermoelastic contraction of fused silica with different fictive temperatures from the initial frozen-in temperatures to ambient *** residual stress fields of mitigated damage sites for the CO_(2)laser-annealed case are obtained by a finite element analysis of equilibrium equations and constitutive *** simulated results indicate that the proposed model can accurately evaluate the residual stress fields of laser-annealed mitigated damage sites with a complex thermal *** calculated maximum hoop stress is in good agreement with the reported experimental *** estimated optical retardance profiles from the calculated radial and hoop stress fields are consistent with the photoelastic *** results provide sufficient evidence to demonstrate the suitability of the proposed model for describing the residual stresses of mitigated fused silica damage sites after CO_(2)laser annealing.

关键词： fused silica damage mitigation residual stress laser annealing

Fabrication and application prospects of Pr-Fe-B/Alnico nanocomposite alloys

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Journal of Rare Earths 2024年第9期42卷 1717-1723,I0003页

作者： Hui Liang Sajjad Ur Rehman Ruibiao Zhang Yongqiang Deng Haihua Liu Munan Yang national Rare Earth Functional Materials Innovation Center College of Rare EarthsJiangxi University of Science and TechnologyGanzhou341000China Zhejiang Tiantong Electronic Information Materials Research Institute Co. Ltd.Haining314400China

The potentials of rare earth-based nanocomposite alloys have never been realized due to strict microstructural *** to the easy demagnetization it is challenging to increase the soft magnetic phase *** avoid the easy demagnetization,Pr-Fe-B/Alnico magnets were fabricated and reported in this *** content of the Alnico phase is increased from 0 to 25 wt%,while the content of Pr element is reduced to below the sub-stoichiometry of the 2:14:1 main *** maximum magnetic energy product,which is the figure-of-merit for permanent magnets,is increased from 122 kJ/m^(3) for the standard alloy to 146 kJ/m^(3) for the alloy with 15 wt% Alnico which shows a significant improvement considering the fact that the Curie point of the magnet is also increased by~66 *** special microstructure contains distinctly and heterogeneously distributed 2:14:1 and Alnico *** dimensions of neither the 2:14:1 nor the Alnico phases meet the dimensional requirements of the nanocomposite magnets,but still the smooth demagnetization curves are noted for the *** behavior of effective anisotropy,the performance of the magnets in applied magnetic field and the magnetic interactions among the various constituent grains were quantitatively studied by reversible susceptibility,irreversible susceptibility and re coil loop *** study may provide some guiding principles for the development of nanocomposite magnetic alloys with excellent magnetic properties by using much less RE elements.

关键词： Composite alloys High performance magnets Magnetic properties Alnico alloys Rare earth magnets

Enhancing quantum temporal steering via frequency modulation

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Chinese Physics B 2024年第5期33卷 239-245页

作者：吴孟凯程维文 Institute of Signal Processing & Transmission Nanjing University of Posts and TelecommunicationNanjing 210003China

Various strategies have been proposed to harness and protect space-like quantum correlations in different models under ***,little attention has been given to temporal-like correlations,such as quantum temporal steering(TS),in this *** this work,we investigate TS in a frequency-modulated two-level system coupled to a zero-temperature reservoir in both the weak and strong coupling *** analyze the impact of various frequency-modulated parameters on the behavior of TS and *** results demonstrate that appropriate frequency-modulated parameters can enhance the TS of the two-level system,regardless of whether the system is experiencing Markovian or non-Markovian ***,a suitable ratio between modulation strength and frequency(i.e.,all zeroes of the 0th Bessel function J_(0)(δ/?))can significantly enhance TS in the strong coupling *** findings indicate that efficient and effective manipulation of quantum TS can be achieved through a frequency-modulated approach.

关键词： quantum temporal steering frequency modulation decoherence

Enhancing quantum metrology for multiple frequencies of oscillating magnetic fields by quantum control

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Chinese Physics B 2024年第6期33卷 177-187页

作者：雷昕范静怡庞盛世 School of Physics Sun Yat-sen UniversityGuangzhou 510275China

Quantum multi-parameter estimation has recently attracted increased attention due to its wide applications, with a primary goal of designing high-precision measurement schemes for unknown parameters. While existing research has predominantly concentrated on time-independent Hamiltonians, little has been known about quantum multi-parameter estimation for time-dependent Hamiltonians due to the complexity of quantum dynamics. This work bridges the gap by investigating the precision limit of multi-parameter quantum estimation for a qubit in an oscillating magnetic field model with multiple unknown frequencies. As the well-known quantum Cramer–Rao bound is generally unattainable due to the potential incompatibility between the optimal measurements for different parameters, we use the most informative bound instead which is always attainable and equivalent to the Holevo bound in the asymptotic limit. Moreover, we apply additional Hamiltonian to the system to engineer the dynamics of the qubit. By utilizing the quasi-Newton method, we explore the optimal schemes to attain the highest precision for the unknown frequencies of the magnetic field, including the simultaneous optimization of initial state preparation, the control Hamiltonian and the final measurement. The results indicate that the optimization can yield much higher precisions for the field frequencies than those without the optimizations. Finally,we study the robustness of the optimal control scheme with respect to the fluctuation of the interested frequencies, and the optimized scheme exhibits superior robustness to the scenario without any optimization.

关键词： quantum metrology multi-parameter estimation quantum control

Synchronization and firing mode transition of two neurons in a bilateral auditory system driven by a high–low frequency signal

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Chinese Physics B 2024年第5期33卷 722-735页

作者： Charles Omotomide Apata 唐浥瑞周祎凡蒋龙裴启明 School of Physics and Optoelectronic Engineering Yangtze UniversityJingzhou 434023China

The FitzHugh–Nagumo neuron circuit integrates a piezoelectric ceramic to form a piezoelectric sensing neuron,which can capture external sound signals and simulate the auditory neuron *** piezoelectric sensing neurons are coupled by a parallel circuit consisting of a Josephson junction and a linear resistor,and a binaural auditory system is *** the non-singleness of external sound sources,the high–low frequency signal is used as the input signal to study the firing mode transition and synchronization of this *** is found that the angular frequency of the high–low frequency signal is a key factor in determining whether the dynamic behaviors of two coupled neurons are *** they are in synchronization at a specific angular frequency,the changes in physical parameters of the input signal and the coupling strength between them will not destroy their *** addition,the firing mode of two coupled auditory neurons in synchronization is affected by the characteristic parameters of the high–low frequency signal rather than the coupling *** asynchronous dynamic behavior and variations in firing modes will harm the auditory *** findings could help determine the causes of hearing loss and devise functional assistive devices for patients.

关键词： piezoelectric ceramic Josephson junction auditory neuron synchronization