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Research in Astronomy and Astrophysics 2024年第8期24卷 34-43页

作者： Yingze Shan Xiaoxuan Liu Xing Yang Haoyu Yuan Houjun Lü Guangxi Key Laboratory for Relativistic Astrophysics School of Physical Science and TechnologyGuangxi University Department of Astronomy School of PhysicsHuazhong University of Science and Technology

Theoretically,a supra-massive neutron star or magnetar may be formed after the merger of binary neutron ***210323A is a short-duration gamma-ray burst （GRB） with a duration of lasting～1 *** light curve of the prompt emission of GRB 210323A shows a signal-peaked structure and a cutoff power-law model can adequately fit the spectra with Ep=1826±*** interestingly,it has an extremely long-lasting plateau emission in the X-ray afterglow with a duration of～10～4s,and then follows a rapid decay with a decay slope～*** temporal feature is challenging by invoking the external shock *** this paper,we suggest that the observed long-lasting X-ray plateau emission is caused by the energy injection of dipole radiation from supra-massive magnetar,and the abrupt decay following the longlasting X-ray plateau emission is explained by supra-massive magnetar collapsing into a black *** is the short GRB（SGRB） with the longest X-ray internal plateau emission powered by a supra-massive neutron *** this is the case,one can estimate the physical parameters of a supra-massive magnetar,and compare with other *** also discuss the possible gravitational-wave emission,which is powered by a supra-massive magnetar and its detectability,and the possible kilonova emission,which is powered by r-process and magnetar spin-down to compare with the observed data.

关键词： (stars:) gamma-ray burst: general (stars:) gamma-ray burst: individual (GRB 210323A) stars: magnetars

An improved TDE technique for derivation of 2D turbulence structures based on GPI data in toroidal plasma

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Plasma Science and Technology 2024年第3期26卷 131-137页

作者：王威策程钧石中兵严龙文黄治辉弋开阳吴娜何钰邹千陈熙张文陈建聂林季小全钟武律 Southwestern Institute of Physics Chengdu 610299People's Republic of China Institute of Fusion Science School of Physical Science and TechnologySouthwest Jiaotong UniversityChengdu 610031People's Republic of China

This paper reports an improved time-delay estimation(TDE)technique for the derivation of turbulence structures based on gas-puff imaging *** improved TDE technique,integrating an inverse timing search and hierarchical strategy,offers superior accuracy in calculating turbulent velocity field maps and analyzing blob dynamics,which has the power to obtain the radial profiles of equilibrium poloidal velocity,blob size and its radial velocity,even the fluctuation analysis,such as geodesic acoustic modes and quasi-coherent mode,*** improved technique could provide important 2D information for the study of edge turbulence and blob dynamics,advancing the understanding of edge turbulence physics in fusion plasmas.

关键词： gas-puff imaging TDE method turbulence velocity field map

Laser-assisted synthesis of PtPd alloy for efficient ethanol oxidation

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Nano Research 2024年第7期17卷 6032-6037页

作者： Zihang Chen Tong Liu Huijuan Zhang Beibei Pang Yuanhua Sun Longfei Hu Qiquan Luo Xiaokang Liu Linlin Cao Tao Yao School of Nuclear Science and Technology National Synchrotron Radiation LaboratoryUniversity of Science and Technology of ChinaHefei 230029China Institutes of physical Science and Information Technology Anhui UniversityHefei 230601China

The inefficiency of ethanol oxidation reaction(EOR)presents a significant obstacle in harnessing renewable biofuels with high energy density into *** efforts,most Pt-based catalysts still suffer from drawbacks such as poor activity and susceptibility to CO poisoning,particularly in acidic ***,we employed a physical laser-assisted approach to synthetize a PtPd alloy with a 1:1 atomic *** alloy demonstrates remarkable performance in acidic EOR,boasting a high mass activity of 1.86 A·mgPt^(−1)and competitive resistance to *** in situ synchrotron radiation infrared spectroscopy with theoretical calculations,we reveal that the synergic interaction between Pt and Pd enhances both the adsorption of OH*intermediate and the dehydrogenation ability of *** work will prove the feasibility of synthesizing bimetallic alloys by a physical laser-assisted strategy and promote the development of advanced alloy electrocatalysts.

关键词： laser-assisted strategy Pt-based alloy in situ synchrotron radiation infrared spectroscopy ethanol oxidation reaction synergic interaction

Two-dimensional semiconductor heterostructures for photocatalytic COconversion

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Science China Chemistry 2024年

作者： Yang Wu Mingyu Wu Yongfu Sun Yi Xie University of Science and Technology of China Hefei National Research Center for physical Sciences at Microscale

The CO2reduction into carbon-contained fuel via solar energy offers the powerful tools to realize the zero-emission carbon cycle. Owing to the intriguing features of the two-dimensional(2D) heterostructures, it is susceptible to modulate the electronic structure as well as the surface geometry for optimizing the photocatalytic CO2reactivity. From this perspective, we surveyed the fundamental insights of 2D semiconductor heterostructures, involving the fabrication strategies and classification of the 2D semiconductor heterostructure. Also, we have detailly discussed the overview of 2D semiconductor heterostructure for optimizing CO2photocatalytic influenced factors, including the solar energy utilization, photogenerated carriers separation, and redox reaction kinetics. Afterwards, we showed the significant advantages of 2D heterostructures in elevating CO2photoreduction performance, focusing on activity, selectivity and photostability. By analyzing the limitations and developments, we ended by putting forward insights into the further researches about the CO2photocatalysts and reactor design, even industrial applications.

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Arbitrary acoustic orbital angular momentum detection using dual-layer metasurfaces

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Science China(Physics,Mechanics & Astronomy) 2024年第6期67卷 106-112页

作者： Zhanlei Hao Haojie Chen Yuhang Yin Shan Zhu Yadong Xu Cheng-Wei Qiu Huanyang Chen Department of Physics College of Physical Science and TechnologyXiamen UniversityXiamen 361005China Department of Electrical and Computer Engineering National University of SingaporeSingapore 117583Singapore Department of Mechanical and Electrical Engineering Xiamen UniversityXiamen 361005China Pen-Tung Sah Institute of Micro-Nano Science and Technology Xiamen UniversityXiamen 361005China School of physical Science and Technology and Jiangsu Key Laboratory of Thin Films Soochow UniversitySuzhou 215006China

Orbital angular momentum(OAM),with its unique physical properties and vast application prospects,has attracted widespread attention in various ***,the development of valid and practical acoustic OAM detection methods continues to be a challenging *** this paper,we propose a novel construction method of dual-layer metasurfaces to achieve a doubleconversion process for the waveform reshaping and differentiated focusing of two-dimensional vortex sources with different ***,by utilizing a concise formula,a one-to-one correspondence is established between the OAM of incident vortex waves and different imaging *** fundamental principle of this special conversion relationship is rigorously constrained by the directional compensation of phase and the material parameters of dual-layer metasurfaces with different quadratic phase *** importantly,the highly consistent results between numerical demonstrations and acoustic experiments further confirm the feasibility and effectiveness of the proposed OAM detection *** work provides a new perspective on the precise manipulation for the phase of vortex fields,holding potential applications in super-resolution imaging and the design of acoustic OAM-based devices.

关键词： arbitrary acoustic OAM detection vortex waves dual-layer metasurfaces waveform reshaping differentiated focusing acoustic experiments

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Experimental results of a magnetic field modification to the radio frequency driver of a negative ion source

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Plasma Science and Technology 2024年第4期26卷 162-167页

作者：谢俊炜谢亚红韦江龙梁立振彭旭峰杨宇雯顾玉明胡纯栋谢远来 Institute of Plasma Physics Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031People’s Republic of China University of Science and Technology of China Hefei 230026People’s Republic of China

A magnetic field produced by a current flowing through the plasma grid(PG) is one of the solutions to reduce the collisional loss of negative ions in a negative ion source, which reduces the electron temperature in front of the PG. However, the magnetic field diffused into the driver has some influence on the plasma outflowing. In order to investigate the effect of changing this magnetic field on the outflowing of plasma from the driver, a circular ring(absorber) of high permeability iron has been introduced at the driver exit, which can reduce the magnetic field around it and improve plasma outflowing. With the application of the absorber, the electron density is increased by about 35%, and the extraction current measured from the extraction grid is increased from 1.02 A to 1.29 A. The results of the extraction experiment with cesium injection show that both the extraction grid(EG) current and H-current are increased when the absorber is introduced.

关键词： neutral beam injection negative ion source magnetic filter radio frequency ion source

Calculation and prediction of divertor detachment via impurity seeding by using one-dimensional model

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Chinese Physics B 2024年第8期33卷 370-379页

作者：周文杰刘晓菊邬潇河李邦石奇奇樊皓尘杨艳杰李国强 Institute of Plasma Physics Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China University of Science and Technology of China Hefei 230026China

Achieving the detachment of divertor can help to alleviate excessive heat load and sputtering problems on the target plates,thereby extending the lifetime of divertor components for fusion *** order to provide a fast but relatively reliable prediction of plasma parameters along the flux tube for future device design,a one-dimensional(1D)modeling code for the operating point of impurity seeded detached divertor is developed based on Python language,which is a fluid model based on previous work(Plasma *** 58045013(2016)).The experimental observation of the onset of divertor detachment by neon(Ne)and argon(Ar)seeding in EAST is well reproduced by using the 1D modeling *** comparison between the 1D modeling and two-dimensional(2D)simulation by the SOLPS-ITER code for CFETR detachment operation with Ne and Ar seeding also shows that they are in good *** also predict the radiative power loss and corresponding impurity concentration requirement for achieving divertor detachment via different impurity seeding under high heating power conditions in EAST and CFETR phase II by using the 1D *** on the predictions,the optimized parameter space for divertor detachment operation on EAST and CFETR is also *** a simple but reliable 1D model can provide a reasonable parameter input for a detailed and accurate analysis by 2D or three-dimensional(3D)modeling tools through rapid parameter scanning.

关键词： divertor detachment impurity seeding one-dimensional modeling

Experimental Proposal on Non-Hermitian Skin Effect by Two-dimensional Quantum Walk with a Single Trapped Ion

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Chinese Physics Letters 2024年第4期41卷 19-24页

作者：侯琬儿唐皓许勤林毅恒 CAS Key Laboratory of Microscale Magnetic Resonance and School of physical Sciences University of Science and Technology of ChinaHefei 230026China Hefei National Laboratory University of Science and Technology of ChinaHefei 230088China

Non-Hermitian Hamiltonians are widely used in describing open systems with gain and loss,among which a key phenomenon is the non-Hermitian skin *** we report an experimental scheme to realize a twodimensional(2D)discrete-time quantum walk with non-Hermitian skin effect in a single trapped *** is shown that the coin and 2D walker states can be labeled in the spin of the ion and the coherent-state lattice of the ion motion,*** numerically observe a directional bulk flow,whose orientations are controlled by dissipative parameters,showing the emergence of the non-Hermitian skin *** then discuss an experimental implementation of our scheme in a laser-controlled trapped Ca^(+)*** experimental proposal may be applicable to research of dissipative quantum walk systems and may be able to generalize to other platforms,such as superconducting circuits and atoms in cavity.

关键词： effect dissipative quantum

Unveiling the pressure-driven metal–semiconductor–metal transition in the doped TiS_(2)

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Chinese Physics B 2024年第6期33卷 63-67页

作者：陈佳骏吕心邓李思敏但雅倩黄艳萍崔田 Institute of High Pressure Physics School of Physical Science and TechnologyNingbo UniversityNingbo 315211China State Key Laboratory of Superhard Materials College of PhysicsJilin UniversityChangchun 130012China

Conventional theories expect that materials under pressure exhibit expanded valence and conduction bands,leading to increased electrical ***,we report the electrical properties of the doped 1T-TiS_(2) under high pressure by electrical resistance investigations,synchrotron x-ray diffraction,Raman scattering and theoretical *** to 70 GPa,an unusual metal-semiconductor-metal transition *** first-principles calculations suggest that the observed anti-Wilson transition from metal to semiconductor at 17 GPa is due to the electron localization induced by the intercalated Ti *** electron localization is attributed to the strengthened coupling between the doped Ti atoms and S atoms,and the Anderson localization arising from the disordered *** pressures exceeding 30.5 GPa,the doped TiS_(2) undergoes a re-metallization transition initiated by a crystal structure phase *** assign the most probable space group as P2_(1)2_(1)2_(1).Our findings suggest that materials probably will eventually undergo the Wilson transition when subjected to sufficient pressure.

关键词： high pressure transition metal dichalcogenides doped TiS_(2) electronic phase transition

Practical Prescribed Time Tracking Control With Bounded Time-Varying Gain Under Non-Vanishing Uncertainties

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IEEE/CAA Journal of Automatica Sinica 2024年第1期11卷 219-230页

作者： Dahui Luo Yujuan Wang Yongduan Song the Key Laboratory of Dependable Service Computing in Cyber physical Society Ministry of EducationChongqing UniversityChongqing 400044 the School of Automation Chongqing UniversityChongqing 400044 the Star Institute for Intelligent Systems Chongqing 400044 IEEE

This paper investigates the prescribed-time control(PTC) problem for a class of strict-feedback systems subject to non-vanishing uncertainties. The coexistence of mismatched uncertainties and non-vanishing disturbances makes PTC synthesis nontrivial. In this work, a control method that does not involve infinite time-varying gain is proposed, leading to a practical and global prescribed time tracking control solution for the strict-feedback systems, in spite of both the mismatched and nonvanishing uncertainties. Different from methods based on control switching to avoid the issue of infinite control gain that involves control discontinuity at the switching point, in our method a softening unit is exclusively included to ensure the continuity of the control action. Furthermore, in contrast to most existing prescribed-time control works where the control scheme is only valid on a finite time interval, in this work, the proposed control scheme is valid on the entire time interval. In addition, the prior information on the upper or lower bound of gi is not in need,enlarging the applicability of the proposed method. Both the theoretical analysis and numerical simulation confirm the effectiveness of the proposed control algorithm.

关键词： Adaptive control prescribed time control(PTC) strict-feedback systems tracking control