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Spin Evolution of the Magnetar SGR J1935+2154

Research in Astronomy and Astrophysics 2024年第1期24卷 201-211页

作者： Ming-Yu Ge Yuan-Pei Yang Fang-Jun Lu shi-qi zhou Long Ji Shuang-Nan Zhang Bing Zhang Liang Zhang Pei Wang Kejia Lee Weiwei Zhu Jian Li Xian Hou qiao-Chu Li Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China South-Western Institute For Astronomy Research Yunnan UniversityKunming 650504China Purple Mountain Observatory Chinese Academy of SciencesNanjing 210023China Key Laboratory of Stellar and Interstellar Physics and School of Physics and Optoelectronics Xiangtan UniversityXiangtan 411105China School of Physics and Astronomy Sun Yat-Sen UniversityZhuhai 519082China University of Chinese Academy of Sciences Chinese Academy of SciencesBeijing 100049China Nevada Center for Astrophysics University of NevadaLas VegasNV 89154USA Department of Physics and Astronomy University of NevadaLas VegasNV 89154USA National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China Department of Astronomy Peking UniversityBeijing 100871China CAS Key Laboratory for Research in Galaxies and Cosmology Department of AstronomyUniversity of Science and Technology of ChinaHefei 230026China School of Astronomy and Space Science University of Science and Technology of ChinaHefei 230026China Yunnan Observatories Chinese Academy of SciencesKunming 650216China School of Astronomy and Space Science Nanjing UniversityNanjing 210023China Key laboratory of Modern Astronomy and Astrophysics Nanjing UniversityNanjing 210023China

Fast radio bursts(FRBs)are short pulses observed in radio frequencies usually originating from cosmological *** discovery of FRB 200428 and its X-ray counterpart from the Galactic magnetar SGR J1935+2154suggests that at least some FRBs can be generated by ***,the majority of X-ray bursts from magnetars are not associated with radio *** fact that only in rare cases can an FRB be generated raises the question regarding the special triggering mechanism of *** we report long time spin evolution of SGR J1935+2154 until the end of *** to v and v,the spin evolution of SGR J1935+2154 could be divided into two *** first stage evolves relatively steady evolution until 2020 April *** the burst activity in2020,the spin of SGR J1935+2154 shows strong variations,especially for *** the burst activity in 2022October,a new spin-down glitch with△v/v=(-7.2±0.6)×10^(-6)is detected around MJD 59876,which is the second event in SGR J1935+*** the end,spin frequency and pulse profile do not show variations around the time of FRB 200428 and radio bursts 221014 and 221021,which supply strong clues to constrain the trigger mechanism of FRBs or radio bursts.

关键词： (stars:)pulsars:general (stars:)pulsars:individual(SGR J1935+2154) X-rays:bursts

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30 glitches in 18 radio pulsars

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Research in Astronomy and Astrophysics 2021年第7期21卷 1-16页

作者： Hong-Yi Liu shi-qi zhou Yu-qi Zhang Zhong-Wen Feng Xia zhou School of Applied Technology XiHua UniversityNanchong 637000China Physics and Space Science College China West Normal UniversityNanchong 637009China

Pulsar timing is a classic technology of detecting irregularities in pulsar *** carried out this method for 18 young radio pulsars,with long-term timing observations obtained between 2007 and 2015 using the Parkes 64-m radio *** a result,30 glitches were identified,ranging from 0.75 × 10^(-9) to 8.6 × 10^(-6) in the relative glitch sizes Δv/v,where v=1/P is the pulse *** glitches are composed of 26 new glitches and four published glitches with new exponential *** pulsars exhibit normal glitches,and six pulsars were observed to undergo a glitch event for the first *** discuss the properties and implications for neutron-star physics of these glitches,and show that they are in agreement with previous work,except that the cumulative probability distributions of the mean waiting times for PSRs J0537-6910,J1341-6220 and J1740-3015 are not in consonance with the Poisson model.

关键词： methods:data analysis stars:neutron pulsars:general

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How to Extend the Bridge Density Functional Approximation to the Confined Non-hard Sphere Fluid

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Chinese Journal of Chemical Physics 2006年第4期19卷 319-324页

作者： shi-qi zhou Key Laboratory of Green Packaging and Biological Nanotechnolog of Hunan Province and Institute of Modern Statistical Mechanics Hunan University of Technology Zhuzhou 412008 China

A theoretical method was proposed to extend a bridge density functional approximation （BDFA） for the non-uniform hard sphere fluid to the non-uniform Lennard-Jones （LJ） fluid. The DFT approach for LJ fluid is simple, quantitatively accurate in a wide range of coexistence phase and external field parameters. Especially, the DFT approach only needs a second order direct correlation function （DCF） of the coexistence bulk fluid as input, and is therefore applicable to the subcritical temperature region. The present theoretical method can be regarded as a non-uniform counterpart of the thermodynamic perturbation theory, in which it is not at the level of the free energy but at the level of the second order *** National Natural Science Foundation of China （No. 20546004） and the Natural Science Foundation of Education Department of Hunan Province （No.04C711）.

关键词： Density functional theory Bridge density functional approximation Hard sphere fluid Correlation function

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Joule–Thomson expansion of higher dimensional nonlinearly AdS black hole with power Maxwell invariant source

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Communications in Theoretical Physics 2021年第6期73卷 110-118页

作者： Zhong-Wen Feng Xia zhou Guansheng He shi-qi zhou Shu-Zheng Yang Physics and Space Science College China West Normal UniversityNanchong637009China School of Mathematics and Physics University of South ChinaHengyang421001China

In this paper,the Joule–Thomson expansion of the higher dimensional nonlinearly anti-de Sitter(Ad S)black hole with power Maxwell invariant source is *** results show the Joule–Thomson coefficient has a zero point and a divergent point,which coincide with the inversion temperature Tiand the zero point of the Hawking temperature,*** inversion temperature increases monotonously with inversion *** the high-pressure region,the inversion temperature decreases with the dimensionality D and the nonlinearity parameter s,whereas it increases with the charge ***,Tifor the low-pressure region increase with D and s,while it decreases with *** ratioηBHbetween the minimum inversion temperature and the critical temperature does not depend on Q,it recovers the higher dimensional Reissner–N?rdstrom Ad S black hole case when s=***,for s>1,it becomes smaller and smaller as D increases and approaches a constant when D→∞.Finally,we found that an increase of mass M and s,or reducing the charge Q and D can enhance the isenthalpic curve,and the effect of s on the isenthalpic curve is much greater than other parameters.

关键词： Joule–Thomson expansion Maxwell invariant source higher dimensional nonlinearly AdS black hole

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Tiered clustering-based management architecture in mega-satellite networks

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Science China(Information Sciences) 2024年第5期67卷 215-227页

作者： qi HAO Di zhou Min SHENG Yan shi Jiandong LI State Key Laboratory of Integrated Service Networks Xidian University

Hybrid orbital networking and the proliferation of satellites raise explosive management complexity in mega-satellite networks(MSNs) and prompt the management architecture to the hierarchy. In this regard, we propose a tiered clustering-based management architecture(TCMA) to realize the high-efficient and low-cost management performance. Specifically, based on the constrained satellite coverage, we derive an expression of the mapping relationship between the required control overhead of the controller interaction,the average path length of the proposed TCMA, and the corresponding number of management tiers and cluster size. The expression can determine the optimal number of tiers of the TCMA by minimizing the required flow table size between controllers, while ensuring high transmission efficiency. We then exhibit the elasticity of the hierarchical TCMA by adding the peer connections at the second-highest management tier to reduce maximum redundant paths. Simulation results verify the effectiveness of the proposed TCMA and illustrate that a 3-tier TCMA is sufficient for thousands of satellites.

关键词： mega-satellite networks hierarchical architecture average hop tiered structure clustering

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The First Chinese Case of Creutzfeldt-Jakob Disease with Mutation of E200K in PRNP

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Biomedical and Environmental Sciences 2010年第2期23卷 158-160页

作者： CHEN GAO qi shi WEI zhou CHAN TIAN HHUI-YING JIANG BAO-YUN ZHANG JUN HAN XIAO-PING DONG State Key Laboratory for Infectious Disease Prevention and Control National Institute for Viral Disease Control and Prevention Chinese Center for Disease Control and Prevention Beijing 102206 China

Objective To investigate epidemiological, clinical and genetic features of the first Chinese case of Creutzfeldt-Jakob disease （CJD） with mutation of E2OOK in PRNP. Methods The general epidemiological and clinical data were collected; CSF 14-3-3 protein was analyzed by Western blot; The PRNP was amplified by PCR and analyzed. Results A missense mutation in codon 200 （E200K） of the PRNP was identified in this patient; CSF 14-3-3 protein was positive; sleep disturbance was the initial sign and the other symptoms gradually appeared, including memory loss, dizziness and ataxia. Conclusion The CJD patient who was first reported in China has a missense mutation in codon 200 （E200K） of the PRNP, and the codon 129 is a methionine homozygous genotype.

关键词： CJD PRNP Sleep disturbance 14-3-3

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Enhancement of mechanical properties of GTAW joints for ZC63 magnesium alloy by post-weld heat treatment

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Journal of Materials Science & Technology 2024年第2期169卷 251-263页

作者： Weiyang zhou qichi Le Ye shi qiyu Liao Tong Wang qi Zou Clodualdo Aranas Jr Key Lab of Electromagnetic Processing of Materials Ministry of EducationNortheastern UniversityShenyang 110819China Key Laboratory of Lightweight Structural Materials Liaoning ProvinceNortheastern UniversityShenyang 110819China School of Materials Science and Engineering Northeastern UniversityShenyang 110819China Department of Mechanical Engineering University of New BrunswickFrederictonE3B 5A3New BrunswickCanada

To further improve the microstructure and mechanical properties of gas tungsten arc welded(GTAW)welded joints for ZC63 magnesium alloy,post-weld heat treatment is carried *** is found that the majority of the MgZnCu phase in the fusion zone(FZ)is dissolved in theα-Mg matrix under suitable heat treatment *** remainder is diffusely distributed as rods or granules at the grain *** excessive heat treatment temperature(460℃)leads to abnormal grain growth(AGG)in the *** substructure gradient between the abnormally grown grains and the surrounding small grains pro-vides the driving force for ***,the dissolution of the MgZnCu phase weakens the hindering effect of the second phase on grain boundary migration,setting the stage for *** addition,the detri-mental impact of the continuous MgZnCu phase on the mechanical properties of the welded joint is also lessened by its *** ultimate tensile strength(UTS),yield strength(YS)and elongation(EL)of the welded joints are 255 MPa,119 MPa and 27.0%,respectively,under the post-weld heat treatment process of 440℃×12 *** welding coefficient of the welded joint reaches 97.0%,satisfying the service criteria set forth by the mechanical properties of the welded joints.

关键词： GTAW FZ Heat treatment AGG Mechanical properties

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城市轨道网络抗毁可靠性定义及评价指标模型研究

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铁道学报 2007年第3期29卷 29-33页

作者：高洁施其洲同济大学交通运输工程学院上海200331

从可靠性理论出发,结合城市轨道网络特点,提出了城市轨道网络系统抗毁可靠性的定义——整个轨道交通网络在受到外界破坏作用后正常运营的能力。将抗毁可靠度定义为抗毁可靠性的度量值。根据网络的拓扑结构及客流分布特点,从运输量分配入... 详细信息

从可靠性理论出发,结合城市轨道网络特点,提出了城市轨道网络系统抗毁可靠性的定义——整个轨道交通网络在受到外界破坏作用后正常运营的能力。将抗毁可靠度定义为抗毁可靠性的度量值。根据网络的拓扑结构及客流分布特点,从运输量分配入手,把从路网中单独隔离出子系统后所影响的客流量作为评价子系统抗毁可靠性的依据,建立子系统抗毁可靠性的评价,并应用矩阵逻辑或运算计算相应的评价指标。在评价子系统抗毁可靠性基础上,提出了5个网络系统抗毁可靠性特征值,从不同角度评价路网系统的抗毁可靠性。最后,用一算例验证了该模型及相应评价指标的可行性和有效性。

关键词：城市轨道网络可靠性拓扑结构客流分布抗毁测度

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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

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Ordered Bicontinuous Network Structures Regulated by Orientational Interactions in a Rod-Coil Block Copolymer

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Chinese Journal of Polymer Science 2024年第5期42卷 636-642,I0008页

作者： Xiao-Lin Lyu shi-Chu Yang An-qi Xiao Ping-Ping Hou Wei Zhang Hong-Bing Pan Zhi-Hao Shen Xing-He Fan qi-Feng zhou Beijing National Laboratory for Molecular Sciences Key Laboratory of Polymer Chemistry and Physics of Ministry of EducationCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing100871China Key Laboratory of Advanced Materials Technologies International(HongKong Macao and Taiwan)Joint Laboratory on Advanced Materials TechnologiesCollege of Materials Science and EngineeringFuzhou UniversityFuzhou350108China

The rich phase behavior of block copolymers(BCPs)has drawn great attention in recent ***,the double diamond(DD)phase is rarely obtained because of the competition between the minimization of interfacial energy and packing ***,a rod-coil BCP containing mesogen-jacketed liquid crystalline polymer is designed to acquire ordered bicontinuous network *** reduction of internal energy originating from the orientational interaction among the rod blocks can compensate for the free energy penalty of packing frustration to stabilize the DD *** resulting BCP can also experience lamellae-to-DD and double gyroid-to-lamellae transitions by changing the annealing *** results make the rod-coil BCP an excellent candidate for the self-assembly of ordered network structures,demonstrating great potential in nanopatterning and metamaterials.

关键词： Block copolymer Rod-coil Ordered bicontinuous phase Double diamond Double gyroid

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