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Journal of Materials Science & technology 2024年第6期173卷 218-224页

作者： L.Y.Hao E.G.Fu state key laboratory of Nuclear physics and technology Department of Technical PhysicsSchool of PhysicsPeking UniversityBeijing 100871China

Superconducting materials with high critical temperature have the potential to revolutionize many fields,including military,electronic communications,and power ***,scientists around the world have been tirelessly working with the ultimate goal of achieving high-temperature *** 2023,a preprint by Lee et *** South Korea claimed the discovery of ultra-high-temperature superconductivity with a critical temperature of up to 423 K in Cu-doped lead-apatite(LK-99)(arXiv:2307.12008,arXiv:2307.12037),which caused a worldwide sensation and ***,the electronic structures,phonon dynamics,and electrical conductivities of LK-99 and its parent compound lead-apatite have been calculated using first-principles *** results show that the lead-apatite compound and the LK-99 compound are insulator and half-metal *** flat band characteristic is consistent with previous *** electrical conductivity of the LK-99 compound shows two extreme points,and the electrical conductivity along the C-axis increases significantly after 400 *** phonon dispersion spectra of the compounds were investigated,demonstrating their dynamic instability.

关键词： Superconductivity LK-99 Lead-apatite First-principles calculation

Efficient single-pixel imaging encrypted transmission based on 3D Arnold transformation

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Chinese physics B 2024年第3期33卷 378-386页

作者：梁振宇王朝瑾王阳阳高皓琪朱东涛许颢砾杨星 state key laboratory of Pulsed Power laser technology National University of Defense TechnologyHefei 230001China Advanced laser technology laboratory of Anhui Province Hefei 230001China

Single-pixel imaging(SPI)can transform 2D or 3D image data into 1D light signals,which offers promising prospects for image compression and ***,during data communication these light signals in public channels will easily draw the attention of ***,we introduce an efficient encryption method for SPI data transmission that uses the 3D Arnold transformation to directly disrupt 1D single-pixel light signals and utilizes the elliptic curve encryption algorithm for key *** encryption scheme immediately employs Hadamard patterns to illuminate the scene and then utilizes the 3D Arnold transformation to permutate the 1D light signal of single-pixel *** the transformation parameters serve as the secret key,while the security of key exchange is guaranteed by an elliptic curve-based key exchange *** with existing encryption schemes,both computer simulations and optical experiments have been conducted to demonstrate that the proposed technique not only enhances the security of encryption but also eliminates the need for complicated pattern scrambling ***,this approach solves the problem of secure key transmission,thus ensuring the security of information and the quality of the decrypted images.

关键词： single-pixel imaging 3D Arnold transformation elliptic curve encryption image encryption

Human radiological safety assessment for petawatt laser-driven ion acceleration experiments in CLAPA-T

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Matter and Radiation at Extremes 2024年第4期9卷 8-15页

作者： Xiaopeng Zhang Jiarui Zhao Shengxuan Xu Xun Chen Ying Gao Shiyou Chen Kun Zhu Xueqing Yan Wenjun Ma state key laboratory of Nuclear physics and technology and Key Laboratory of HEDP of the Ministry of EducationCAPTPeking UniversityBeijing 100871China key laboratory of Particle Astrophysics Institute of High Energy PhysicsCASBeijing 100049China Beijing laser Acceleration Innovation Center HuairouBeijing 101400China Institute of Guangdong laser Plasma technology BaiyunGuangzhou 510540China

The newly built Compact laser Plasma Accelerator-Therapy facility at Peking University will deliver 60 J/1 Hz laser pulses with 30 fs *** by this petawatt laser facility,proton beams with energy up to 200 MeV are expected to be generated for tumor *** high-repetition operation,both prompt radiation and residual radiation may cause safety ***,human radiological safety assessment before commissioning is *** this paper,we simulate both prompt and residual radiation using the Geant4 and FLUKA Monte Carlo codes with reasonable proton and as-produced electron beam *** find that the prompt radiation can be shielded well by the concrete wall of the experimental hall,but the risk from residual radiation is nonnegligible and necessitates adequate radiation *** the basis of the simulation results,we discuss the constraints imposed by radiation safety considerations on the annual working time,and we propose radiation cooling strategies for different shooting modes.

关键词： laser prompt acceleration

Principal components of nuclear mass models

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Science China(physics,Mechanics & Astronomy) 2024年第7期67卷 65-71页

作者： Xin-Hui Wu Pengwei Zhao department of physics Fuzhou UniversityFuzhou 350108China state key laboratory of Nuclear physics and technology School of PhysicsPeking UniversityBeijing 100871China

Principal component analysis(PCA)is employed to extract the principal components(PCs)present in nuclear mass models for the first *** effects from different nuclear mass models are reintegrated and reorganized in the extracted *** PCs are recombined to build new mass models,which achieve better accuracy than the original theoretical mass *** comparison indicates that using the PCA approach,the effects contained in different mass models can be collaborated to improve nuclear mass predictions.

关键词： nuclear mass principal component analysis nuclear models statistical methods

Tunable energy spectrum betatron x-ray sources in a plasma wakefield

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Chinese physics B 2024年第8期33卷 344-350页

作者：奚传易寿寅任韩立琦阿卜杜伍普尔·阿布力米提刘晓丹赵研英余金清 Hunan Provincial key laboratory of High-Energy Scale physics and Applications School of Physics and ElectronicsHunan UniversityChangsha 410082China Center for Relativistic laser Science Institute for Basic ScienceGwangjuKorea state key laboratory of Nuclear physics and technology and Key Laboratory of HEDP of the Ministry of EducationCAPTPeking UniversityBeijing 100871China

X-ray sources with tunable energy spectra have a wide range of applications in different scenarios due to their different penetration ***,existing x-ray sources face difficulties in terms of energy *** this paper,we present a scheme for tuning the energy spectrum of a betatron x-ray generated from a relativistic electron bunch oscillating in a plasma *** center energy of the x-ray source can be tuned from several keV to several hundred keV by changing the plasma density,thereby extending the control range by an order of *** different central energies,the brightness of the betatron radiation is in the range of 3.7×10^(22)to 5.5×10^(22)photons/(0.1%BW·s·mm^(2)·mrad^(2))and the photon divergence angle is about 2 *** high-brightness,energy-controlled betatron source could pave the way to a wide range of applications requiring photons of specific energy,such as phase-contrast imaging in medicine,non-destructive testing and material analysis in industry,and imaging in nuclear physics.

关键词： betatron plasma physics x-ray plasma wakefield acceleration(PWFA)

Micelle-directed self-assembly of single-crystal-like mesoporous stoichiometric oxides for high-performance lithium storage

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National Science Review 2024年第4期11卷 195-205页

作者： Yanhua Wan Changyao Wang Xingmiao Zhang Yang Yin Mengmeng Liu Bing Ma Linlin Duan Yuzhu Ma Wei Zhang Changlin Zheng Dongliang Chao Fei Wang Yongyao Xia Wei Li department of Chemistry Laboratory of Advanced Materials Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials State Key Laboratory of Molecular Engineering of Polymers College of Chemistry and Materials ScienceFudan University state key laboratory of Surface physics and department of physics Fudan University

Due to their uncontrollable assembly and crystallization process,the synthesis of mesoporous metal oxide single crystals remains a formidable ***,we report the synthesis of single-crystal-like mesoporous Li2TiSiO5by using soft micelles as *** key lies in the atomic-scale self-assembly and step-crystallization processes,which ensure the formation of single-crystal-like mesoporous Li2TiSiO5microparticles via an oriented attachment growth mechanism under the confinement of an in-situ formed carbon *** mesoporous Li2TiSiO5anode achieves a superior rate capability(148 mAh g-1at5.0 A g-1) and outstanding long-term cycling stability(138 mAh g-1after 3000 cycles at 2.0 A g-1) for lithium storage as a result of the ultrafast Li+diffusion caused by penetrating mesochannels and nanosized crystal frameworks（5-10 nm）.In comparison,bulk Li2TiSiO5exhibits poor rate capability and cycle performance due to micron-scale diffusion *** method is very simple and reproducible,heralding a new way of designing and synthesizing mesoporous single crystals with controllable frameworks and chemical functionalities.

关键词： mesoporous materials micelles single-crystal-like Li2TiSiO5 lithium-ion batteries

Generation and regulation of electromagnetic pulses generated by femtosecond lasers interacting with multitargets

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Nuclear Science and Techniques 2024年第1期35卷 96-107页

作者： Ya-Dong Xia De-Feng Kong Qiang-You He Zhen Guo Dong-Jun Zhang Tong Yang Hao Cheng Yu-Ze Li Yang Yan Xiao Liang Ping Zhu Xing-Long Xie Jian-Qiang Zhu Ting-Shuai Li Chen Lin Wen-Jun Ma Xue-Qing Yan state key laboratory of Nuclear physics and technology and Key Laboratory of HEDP of the Ministry of EducationCAPTPeking UniversityBeijing 100871China Beijing laser Acceleration Innovation Center Beijing 101407China Institute of Guangdong laser Plasma technology Guangzhou 510540China National laboratory on High Power laser and physics Shanghai Institute of Optics and FineChinese Academy of SciencesShanghai 201800China School of Materials and Energy University of Electronic Science and Technology of ChinaChengdu 611731China

Ultrashort and powerful laser interactions with a target generate intense wideband electromagnetic pulses(EMPs).In this study,we report EMPs generated by the interactions between petawatt(30 fs,1.4×10^(20) W/cm^(2))femtosecond(fs)lasers with metal flat,plastic flat,and plastic nanowire-array(NWA)*** analyses are conducted on the EMPs in terms of their spatial distribution,time and frequency domains,radiation energy,and *** results indicate that EMPs from metal targets exhibit larger amplitudes at varying angles than those generated by other types of targets and are enhanced significantly for NWA *** a plastic target holder and increasing the laser focal spot can significantly decrease the radiation energy of the ***,the composite shielding materials indicate an effective shielding effect against *** simulation results show that the NWA targets exert a collimating effect on thermal electrons,which directly affects the distribution of *** study provides guidance for regulating EMPs by controlling the laser focal spot,target parameters,and target rod material and is beneficial for electromagnetic-shielding design.

关键词： Electromagnetic pulses laser plasma interaction Electromagnetic shielding Electron distribution

Domain wall network:A dual solution for gravitational waves and Hubble tension?

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Science China(physics,Mechanics & Astronomy) 2024年第11期67卷 39-46页

作者： Ligong Bian Shuailiang Ge Changhong Li Jing Shu Junchao Zong department of physics and Chongqing key laboratory for Strongly Coupled physics Chongqing UniversityChongqing 401331China Center for High Energy physics Peking UniversityBeijing 100871China School of physics and state key laboratory of Nuclear physics and technology Peking UniversityBeijing 100871China department of Astronomy Key Laboratory of Astroparticle Physics of Yunnan ProvinceSchool of Physics and AstronomyYunnan UniversityKunming 650091China Beijing laser Acceleration Innovation Center Beijing 101400China department of physics Nanjing UniversityNanjing 210093China CAS key laboratory of Theoretical physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China

We explore the possibility that domain wall networks generate the stochastic gravitational wave background(SGWB) observed as a strong common power-law process in the Data Release-2 of Parkes Pulsar Timing Array. We find that a broad range of parameters, specifically wall tension around σ_(DW)^(29-414 TeV)^(3) and wall-decay temperature within T_(d) ~ 20-257 MeV, can explain this phenomenon at a 68% credible level. Meanwhile, the same parameters could ease the Hubble tension if particles from these domain wall networks decay into dark radiation. We establish a direct analytical relationship, ΩGW(f_(p), T_(0))h^(2)~ Ω_(rad)h^(2)(Ω_νΩN_(eff))^(2),to illustrate this coincidence, underlining its importance in the underlying physics and potential applicability to a wider range of models and data. Conversely, if the common power-law process is not attributed to domain wall networks, our findings impose tight limits on the wall tension and decay temperature.

关键词： domain wall gravitational waves Hubble tension

Ultrafast optical investigation of carrier and spin dynamics in low-dimensional perovskites

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Science China(Technological Sciences) 2024年第1期67卷 2-18页

作者： FU JinYue JIANG Ying FANG HongHua key laboratory for Micro-Nano physics and technology of Hunan Province School of Physics and ElectronicsHunan UniversityChangsha 410012China state key laboratory of Precision Measurement technology and Instruments Department of Precision InstrumentTsinghua UniversityBeijing 100084China

Low-dimensional perovskite(PVK)materials have attracted significant research interest,because of their quantum-confined effect,tunable band gap structures,and higher stability than that of three-dimensional(3D)*** semiconductor optoelectronic devices,high speed and small size are closely *** development of high-speed devices requires researchers to fully understand the properties of materials,especially the dynamic processes such as carrier recombination,separation,and transport,which often play a crucial role in the performance of *** an indispensable part of dynamic research,spin relaxation is also of great significance in studying the properties of materials and explore possible *** halide PVK materials have strong spin-orbit coupling(SOC),which provides a basis for information storage and processing by using spin degrees of ***,studying the carrier and spin dynamics of low-dimensional PVKs is an effective way to understand the internal properties of low-dimensional PVKs *** paper summarizes the latest research progress on the ultrafast carrier and spin dynamics in low-dimensional PVKs,to comprehensively understand their carrier and spin behaviors and present an outlook for relevant studies in this area.

关键词： low-dimensional perovskites carrier dynamics spin dynamics optoelectronic devices

A comprehensive diagnostic system of ultra-thin liquid sheet targets

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High Power laser Science and Engineering 2024年第3期12卷 41-50页

作者： Ziyang Peng Zhengxuan Cao Xuan Liu Yinren Shou Jiarui Zhao Shiyou Chen Ying Gao Pengjie Wang Zhusong Mei Zhuo Pan Defeng Kong Shirui Xu Zhipeng Liu Yulan Liang Tianqi Xu Tan Song Xun Chen Qingfan Wu Yujia Zhang Zihao Zhang Xueqin Yan Wenjun Ma state key laboratory of Nuclear physics and technology School of PhysicsPeking UniversityBeijingChina National key laboratory of Shock Wave and Detonation physics Institute of Fluid PhysicsChina Academy of Engineering PhysicsMianyangChina Center for Relativistic laser Science Institute for Basic ScienceGwangjuRepublic of Korea Institute of Radiation physics Helmholtz-Zentrum Dresden RossendorfDresdenGermany Beijing laser Acceleration Innovation Center BeijingChina Institute of Guangdong laser Plasma technology GuangzhouChina

To meet the demands of laser-ion acceleration at a high repetition rate,we have developed a comprehensive diagnostic system for real-time and in situ monitoring of liquid sheet targets(LSTs).The spatially resolved rapid characterizations of an LST’s thickness,flatness,tilt angle and position are fulfilled by different subsystems with high *** the help of the diagnostic system,we reveal the dependence of thickness distribution on collision parameters and report the 238-nm liquid sheet generated by the collision of two liquid *** methods for the flatness and tilt angle of LSTs have also been provided,which are essential for applications of laser-driven ion acceleration and others.

关键词： diagnostics laser-ion acceleration liquid sheet targets