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Chinese physics B 2024年第7期33卷 448-454页

作者：潘小龙王豪柳雷陈向荣耿华运 College of physics Sichuan UniversityChengdu 610065China National Key Laboratory of Shock Wave and Detonation physics Institute of Fluid PhysicsChina Academy of Engineering PhysicsMianyang 621900China HEDPS Center for Applied Physics and Technologyand College of EngineeringPeking UniversityBeijing 100871China

Mn_(3)TeO_(6)(MTO) has been experimentally found to adopt a P2_(1)/In structure under high pressure,which exhibits a significantly smaller band gap compared to the atmospheric R3 *** this study,we systematically investigate the magnetism,structural phase transition,and electronic properties of MTO under high pressure through first-principles *** R3 and P2_(1)/n phases of MTO are antiferromagnetic at zero *** R3 phase transforms to the P2_(1)/n phase at 7.5 8 GPa,accompanied by a considerable volume collapse of about 6.47%.Employing the accurate method that combines DFT+U/and GW,the calculated band gap of R3 phase at zero pressure is very close to the experimental values,while that of the P2_(1)/n phase is significantly *** main reason for this difference is that the experimental study incorrectly used the Kubelka-Munk plot for the indirect band gap to obtain the band gap of the P2_(1)/n phase instead of the Kubelka-Munk plot for the direct band ***,our study reveals that the transition from the R3 phase to the P2_(1)/n phase is accompanied by a slight reduction in the band gap.

关键词： magnetism phase transition band gap high pressure

Multiplicity dependence of the freezeout parameters in high energy hadron-hadron collisions

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Chinese physics C 2024年第5期48卷 124-133页

作者： Muhammad Ajaz Majid Shehzad Muhammad Waqas Haifa I.Alrebdi Mohammad Ayaz Ahmad Antalov Jagnandan Shawn Jagnandan Murad Badshah Jalal Hasan Baker Abdul Mosawir Quraishi department of physics Abdul Wali Khan University MardanMardan 23200Pakistan School of Mathematics Physics and Optoelectronic EngineeringHubei University of Automotive TechnologyShiyan 442002China department of physics College of SciencePrincess Nourah bint Abdulrahman UniversityP.O.Box 84428Riyadh 11671Saudi Arabia department of Mathematics Physics and StatisticsFaculty of Natural SciencesUniversity of Guyana101110 GeorgetownGuyananSouth America department of physics Faculty of ScienceUniversity of TabukTabukKingdom of Saudi Arabia department of Electrical engineering College of EngineeringQassim UniversityUnaizahSaudi Arabia

We examined the transverse momentum(pT)spectra of various identified particles,encompassing both light-flavored and strange hadrons(π++π−,K++K−,p+p¯,ϕ,K0s,Λ+Λ¯,Ξ−+Ξ¯+,andΩ−+Ω¯+),across different multiplicity classes in proton-proton collisions(p-p)at a center-of-mass energy of s√=7 *** the Tsallis and Hagedorn models,parameters relevant to the bulk properties of nuclear matter were *** models exhibit good agreement with experimental *** our analyses,we observed a consistent decrease in the effective temperature(T)for the Tsallis model and the kinetic or thermal freeze-out temperature(T0)for the Hagedorn model,as we transitioned from higher multiplicity(class-I)to lower multiplicity(class-X).This trend is attributed to the diminished energy transfer in higher multiplicity ***,we observed that the transverse flow velocity(βT)experiences a decline from class-I to *** normalization constant,which represents the multiplicity of produced particles,was observed to decrease as we moved toward higher multiplicity *** the effective and kinetic freeze-out temperatures,as well as the transverse flow velocity,show a mild dependency on multiplicity for lighter particles,this dependency becomes more pronounced for heavier *** multiplicity parameter for heavier particles was observed to be smaller than that of lighter particles,indicating a greater abundance of lighter hadrons compared to heavier *** particle species were observed to undergo decoupling from the fireball at distinct temperatures:lighter particles exhibit lower temperatures,while heavier ones show higher temperatures,thereby supporting the concept of multiple freeze-out ***,we identified a positive correlation between the kinetic freeze-out temperature and transverse flow velocity,a scenario where particles experience stronger collective motion at a higher freeze-out *** reason for this positive correlation is th

关键词： multiplicity dependence collective properties thermal energy

Pedestrian lane formation with following–overtaking model and measurement of system order

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Chinese physics B 2024年第2期33卷 247-263页

作者：李碧璐李政周睿申世飞 department of engineering physics Tsinghua UniversityBeijing 100084China School of Safety Science Tsinghua UniversityBeijing 100084China

Pedestrian self-organizing movement plays a significant role in evacuation studies and architectural *** formation,a typical self-organizing phenomenon,helps pedestrian system to become more orderly,the majority of following behavior model and overtaking behavior model are imprecise and unrealistic compared with pedestrian movement in the real *** this study,a pedestrian dynamic model considering detailed modelling of the following behavior and overtaking behavior is constructed,and a method of measuring the lane formation and pedestrian system order based on information entropy is *** and analysis demonstrate that the following and avoidance behaviors are important factors of lane formation.A high tendency of following results in good lane *** non-selective following behavior and aggressive overtaking behavior cause the system order to *** most orderly following strategy for a pedestrian is to overtake the former pedestrian whose speed is lower than approximately 70%of his *** influence of the obstacle layout on pedestrian lane and egress efficiency is also studied with this *** presence of a small obstacle does not obstruct the walking of pedestrians;in contrast,it may help to improve the egress efficiency by guiding the pedestrian flow and mitigating the reduction of pedestrian system orderliness.

关键词： pedestrian movement lane formation information entropy order degree

Direct visualization of laser-driven dynamic fragmentation in tin by in situ x-ray diffraction

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Matter and Radiation at Extremes 2024年第5期9卷 109-114页

作者： Jing Yang Xinxin Wang Liang Xu Qiannan Wang Yi Sun Jiangtao Li Lin Zhang Yinghua Li Yuying Yu Pei Wang Qiang Wu Jianbo Hu Laboratory for Shock Wave and Detonation physics Institute of Fluid PhysicsChina Academy of Engineering PhysicsMianyang 621900China Laboratory of Computational physics Institute of Applied Physics and Computational MathematicsBeijing 100094China

We present a novel method for investigating laser-driven dynamic fragmentation in tin using in situ X-ray *** experimental results demonstrate the feasibility of the method for simultaneously identifying the phase and temperature of fragments through analysis of the diffraction ***,we observe a deviation from the widely accepted isentropic release assumption,with the temperature of the fragments being found to be more than 100 K higher than expected,owing to the release of plastic work during dynamic *** findings are further verified through extensive large-scale molecular dynamics simulations,in which strain energies are found to be transferred into thermal energies during the nucleation and growth of voids,leading to an increase in *** findings thus provide crucial insights into the impact-driven dynamic fragmentation phenomenon and reveal the significant influence of plastic work on material response during shock release.

关键词： dynamic release diffraction

Three-Wave Mixing of Dipole Solitons in One-Dimensional Quasi-Phase-Matched Nonlinear Crystals

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Chinese physics Letters 2024年第1期41卷 25-33页

作者：郭宇欣徐晓喜陈招拼周延桂刘彬和河向黎永耀谢嘉宁 School of physics and Optoelectronic engineering Foshan UniversityFoshan 528000China physics department and Solid-State Institute TechnionHaifa 32000Israel Guangdong-Hong Kong-Macao Joint Laboratory for Intelligent Micro-Nano Optoelectronic Technology School of Physics and Optoelectronic EngineeringFoshan UniversityFoshan 528000China

A quasi-phase-matched technique is introduced for soliton transmission in a quadratic[χ^((2))]nonlinear crystal to realize the stable transmission of dipole solitons in a one-dimensional space under three-wave *** report four types of solitons as dipole solitons with distances between their bimodal peaks that can be laid out in different *** study three cases of these solitons:spaced three stripes apart,one stripe apart,and confined to the same *** the case of three stripes apart,all four types have stable results,but for the case of one stripe apart,stable solutions can only be found atω_(1)=ω_(2),and for the condition of dipole solitons confined to one stripe,stable solutions exist only for Type1 and Type3 atω_(1)=ω_(2).The stability of the soliton solution is solved and verified using the imaginary time propagation method and real-time transfer propagation,and soliton solutions are shown to exist in the multistability *** addition,the relations of the transportation characteristics of the dipole soliton and the modulation parameters are numerically ***,possible approaches for the experimental realization of the solitons are outlined.

关键词： soliton solitons dipole

Are hydrides under high-pressure-high-temperature superconductors?

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National Science Review 2024年第7期11卷 9-12页

作者： J.E.Hirsch department of physics University of California

Contrary to the current consensus, I argue that the existing evidence for high-temperature superconductivity in hydrides under high pressure is not compelling. I suggest that the focus of the field should urgently shift to establish unequivocally experimentally whether or not superconductivity in pressurized hydrides exists, instead of continuing to search for new materials that might show elusive signals of unproven superconductivity at ever higher temperatures. The implications of a negative finding for the theoretical understanding of superconductivity are discussed.

关键词： Hydrides

Injection of a Self-propelled Polymer into a Small Circular Cavity

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Chinese Journal of Polymer Science 2024年第6期42卷 886-894页

作者： Chao Wang Yan-Li Zhou Xiao Yang Fan Wu Meng-Bo Luo department of physics Taizhou UniversityTaizhou318000China department of physics Zhejiang UniversityHangzhou310027China

The injection of a polymer chain into a small circular cavity under tangential self-propelled force is studied by using Langevin dynamics *** indicate that the injection dynamics of the active polymer shows strong correlation with the polymer conformation inside the cavity depending on the polymer rigidity(k_(b)).The injection timeτvaries nonmonotonously with increasing k_(b),and reaches its minimum at k_(b)^(*).When k_(b) is small(k_(b)≪k_(b)^(*)),the polymer is nearly random coil in the cavity,and spends a long time at the final stage of the injection process due to the large repulsion between monomers inside the *** k_(b) is moderate(k_(b)∼k_(b)^(*)),the part of polymer inside the cavity forms spiral configuration under the tangential active force,and the whole polymer moves synchronously with a constant velocity during the injection process,leading to a small injection *** k_(b) is large(k_(b)≫k_(b)^(*)),the polymer is nearly straight at the initial stage of the injection process,and takes a long time to bend itself,leading to a large injection time.

关键词： Active Polymer Injection Dynamics Simulation

Magnetically controllable multimode interference in topological photonic crystals

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Light(Science & Applications) 2024年第5期13卷 998-1005页

作者： Weiyuan Tang Mudi Wang Shaojie Ma Che Ting Chan Shuang Zhang New Cornerstone Science Laboratory Department of PhysicsThe University of Hong KongHong KongChina. department of physics The Hong Kong University of Science and TechnologyHong KongChina. department of Optical Science and engineering Fudan UniversityShanghai 200433China

Topological photonic insulators show promise for applications in compact integrated photonic circuits due to their ability to transport light robustly through sharp *** number of topological edge states relies on the difference between the bulk Chern numbers across the boundary,as dictated by the bulk edge *** interference among multiple topological edge modes in topological photonics systems may allow for controllable functionalities that are particularly desirable for constructing reconfigurable photonic *** this work,we demonstrate magnetically controllable multimode interference based on gyromagnetic topological photonic insulators that support two unidirectional edge modes with different *** successfully achieve controllable power splitting in experiments by engineering multimode interference with the magnetic field intensity or the frequency of *** work demonstrates that manipulating the interference among multiple chiral edge modes can facilitate the advancement of highly efficient and adaptable microwave devices.

关键词： multimode controllable microwave

Test of the Brans-Dicke theory with GW200105 and GW200115

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Communications in Theoretical physics 2024年第7期76卷 83-93页

作者： Qin Fei Yingjie Yang department of Mathematics and physics School of Biomedical EngineeringSouthern Medical UniversityGuangzhou 510515China School of Mathematics and physics Hubei Polytechnic UniversityHuangshi 435003China

We study whether it is possible to constrain the Brans-Dicke(BD)theory from the measurement of gravitational waves(GW)released in neutron star-black hole *** the scalar field modifications through monopole and dipole radiations,we find additional contributions to the phase evolution in the emitted gravitational *** effectively calculating such effect in the post-Newtonian order,we are in a position to measure the scalar field and give bounds on the BD coupling parameterω_(BD).We derive the analytical expression for the phase modification due to the orbital eccentricity of eccentric binaries in both general relativity and BD *** the Bayesian analysis,we obtain the constraints on ω_(BD) from the GW events,GW200105 and GW200115.

关键词： cosmology Brans-Dicke theory gravitational wave

Significantly enhanced thermal stability of HMX by phase-transition lysozyme coating

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Defence Technology（防务技术） 2024年第5期35卷 60-68页

作者： Jiahui Liu Congmei Lin Jianhu Zhang Chengcheng Zeng Zhijian Yang Fude Nie Institute of Chemical Materials China Academy of Engineering Physics(CAEP)Mianyang 621900China Graduate School China Academy of Engineering Physics(CAEP)Mianyang 621900China

A new robust bio-inspired route by using lysozyme aqueous solution for surface modification on 1,3,5,7-tetranitro-1,3,5,7-tetrazocane(HMX)was described in this *** crystals were coated by in situ phase transition of lysozyme(PTL)*** HMX decorated by PTL was characterized by SEM,XRD,FTIR and XPS,demonstrating a dense core-shell coating *** coverage of lysozyme on HMX crystal was calculated by the ratio of sulfur *** surface coverage increased from 60.5% to 93.5% when the content of PTL was changed from 0.5 wt% to 2.0 wt%,indicating efficient *** thermal stability of HMX was investigated by in situ XRD and *** thermal phase transition temperature of HMX(β to δ phase)was delayed by 42℃ with 2.0 wt% PTL coating,which prevented HMX from thermal damage and sensitivity by the effect of PTL *** heating at 215℃,large cracks appeared in the naked HMX crystal,while the PTL coated HMX still maintained intact,with the impact energy of HMX dropped dramatically from 5 J to 2 ***,the impact energy of HMX with 1.0 wt% and 2.0 wt% coating content(HMX@PTL-1.0 and HMX@PTL-2.0)was unchanged(5 J).Present results potentially enable large-scale fabrication of polymorphic energetic materials with outstanding thermal stability by novel lysozyme coating.

关键词： HMX Lysozyme Phase transition Thermal stability Sensitivity