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The hcp-bcc transition of Be via anisotropy of modulus and sound velocity

Chinese physics B 2024年第11期33卷 361-366页

作者： Zhen Yang Jia-Wei Xian Xing-Yu Gao Fu-Yang Tian Hai-Feng Song Institute of Applied Physics University of Science and Technology BeijingBeijing 100083China National Laboratory of Computational Physics Institute of Applied Physics and Computational MathematicsBeijing 100088China

Based on ab initio calculations,we utilize the mean-field potential approach with the quantum modification in conjunction with stress–strain relation to investigate the elastic anisotropies and sound velocities of hcp and bcc Be under high-temperature(0–6000 K)and high-pressure(0–500 GPa)*** propose a general definition of anisotropy for elastic moduli and sound *** suggest that the elastic anisotropy of Be is more significantly influenced by pressure than by *** pressure-induced increase of c/a ratio makes the anisotropy of hcp Be significantly ***,the hcp Be still exhibits smaller anisotropy than bcc Be in terms of elastic moduli and sound *** suggest that measuring the anisotropy in shear sound velocity may be an approach to distinguishing the hcp–bcc phase transition under extreme conditions.

关键词： anisotropy phase transition elastic and sound properties mean-field potential

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Designing(Hf,Ta)Fe_(2)-based zero thermal expansion composites consisting of multiple Laves phases

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Rare Metals 2024年第12期43卷 6596-6605页

作者： He Wang Yi-Han Wang Yuan-Yuan Gong Gui-Zhou Xu Er Liu Xue-Fei Miao Yu-Jing Zhang Yan-Yan Shao Jun Liu Najam UI Hassan Ishfaq Ahmad Shah Feng Xu MIIT Key Laboratory of Advanced Metallic and Intermetallic Materials Technology School of Materials Science and EngineeringNanjing University of Science and TechnologyNanjing210094China Division of Science and Technology Department of PhysicsUniversity of EducationLahore54770Pakistan Department of Physics Ghazi National Institute of Engineering and SciencesDG Khan10550Pakistan

MgZn_(2)-type(Hf,Ta)Fe_(2),known for its negative thermal expansion during magnetic transition,is a key component in the production of zero thermal expansion *** paper presents a basic approach for designing such composites by introducing an additional Laves phase through atomic ***,Co,Ni,A1 and V were chosen to substitute Fe in(Hf,Ta)Fe_(2).The addition of Co or Ni results in the creation of an extra MgCu_(2)(C15)phase in the MgZn_(2)(C14)*** C15phase exhibits positive thermal expansion,which effectively compensates for the negative thermal expansion of the C14 *** adjusting the amount of Co or Ni,zero thermal expansion can be achieved in a given temperature ***,the replacement of Fe by Al or V yields another C14 phase with a higher doping element content relative to the C14 *** two C14 phases possess different magnetic transition temperatures and negative thermal expansion temperature *** combination of the two C14 phases results in zero thermal expansion due to the effective thermal expansion compensation between *** results serve to identify potential approaches for designing(Hf,Ta)Fe_(2)-based zero thermal expansion composites.

关键词： Zero thermal expansion Negative thermal expansion (Hf,Ta)Fe_(2)compounds Laves phase

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The development of high bandwidth arbitrary waveform generator based on ADA14S800

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Radiation Detection technology and Methods 2024年第4期8卷 1682-1692页

作者： Jia-ming Li Hong-fei Zhang Jian Wang Jie Gao Kun Ge State Key Laboratory of Particle Detection and Electronics/Deep Space Exploration Laboratory Department of Modern PhysicsUniversity of Science and Technology of ChinaHefei230026China School of Microelectronics University of Science and Technology of ChinaHefei230026China Institute of Advanced Technology University of Science and Technology of ChinaHefei230088China

Purpose To enhance signal generation capabilities,improve the performance of experimental and testing equipment,and promote innovation in related technological fields,this study aims to develop a high-bandwidth Arbitrary Waveform Generator(AWG)using the high-speed Digital-to-Analog Converter(DAC)ADA14S8000 made in *** The AWG uses the Direct Digital Waveform Synthesis(DDWS)principle with FPGA assistance to generate the waveform and achieved a storage depth of 2 Gpts with four Double Data Rate 4 Synchronous Dynamic Random-Access Memory(DDR4 SDRAM).The AWG comprises the waveform generation module,waveform conditioning module,and an operational software called *** initiate waveform generation,the AWGOperator is used to configure the waveform parameters,after which the waveform data are transferred to the waveform generation module via USB ***,the waveform generation module processes the data and generates the corresponding analogue ***-time adjustments of amplitude,bias,and delay parameters of the output waveform are also *** and conclusion The AWG provides a maximum sampling rate of 4 GSPS,a resolution of 14 bits,and a bandwidth specification of 1.6 GHz,and typical non-harmonic distortion of−55 dBc and a phase noise of less than−110 dBc/Hz at 10 kHz offset.

关键词： Arbitrary waveform generator Field programmable gate array Digital-to-analog converter

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Observation 20-s periodic signals on Mars from InSight,Sols 800-1,000

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Earth and Planetary physics 2023年第2期7卷 193-215页

作者： HuiXing Bi DaoYuan Sun MingWei Dai Deep Space Exploration Laboratory/School of Earth and Space Sciences University of Science and Technology of ChinaHefei 230026China Laboratory of Seismology and Physics of Earth’s Interior School of Earth and Space SciencesUniversity of Science and Technology of ChinaHefei 230026China CAS Center for Excellence in Comparative Planetology ChinaHefei 230026China

Seismometers of the InSight probe(Interior Exploration using Seismic Investigation,Geodesy and Heat Transport)currently operating on Mars have recorded not only seismic events but also high-frequency non-seismic periodic signals that appear to have been induced by variations in the Martian environment and the ***,we report an observation of a long-period signal with a dominant period of~20 s from Martian solar days(Sol)800 to Sol 1,*** 20-s signal is detected mostly at quiet nighttime—from22:00 to 04:00 LMST(Local Mean Solar Time)—at the InSight landing *** measurement of the particle motion suggests that this linearly polarized signal focuses on the horizontal plane with an angle of~30°from the *** examining the temporal variation of the signal’s amplitude and polarization angle and its times of occurrence in relation to the planet’s atmospheric data,we suggest that this20-s signal may be relevant to wind and temperature variations on ***,we study the possible influence of this 20-s signal on the noise autocorrelation and find that the stacked autocorrelograms can be quite different when the 20-s signal is present.

关键词： Mars periodic signal particle motion autocorrelation

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Research progress and development tendency on storage mechanism of multi-principal element alloys for hydrogen/tritium storage

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Rare Metals 2024年第11期43卷 5549-5572页

作者： Yi-Jie Chen Jian-Wei Zhang Can-Hui Xu Mu-Hong Li Shuang-Lin Hu Yue-Xia Wang Xiao-Tao Zu Hai-Yan Xiao Xiao-Song Zhou Shu-Ming Peng Hua-Hai Shen Institute of Nuclear Physics and Chemistry China Academy of Engineering PhysicsMianyang 621900China Key Laboratory of Nuclear Physics and Ion-Beam Application(MOE) Institute of Modern PhysicsDepartment of Nuclear Science and TechnologyFudan UniversityShanghai 200433China School of Physics University of Electronic Science and Technology of ChinaChengdu 610054China

Sustainable clean energy is gradually replacing traditional fossil energy sources in important industrial applications and is placing higher demands on the technologies of energy storage and *** development of multi-principal element alloys(MPEAs)offers a new idea for safe solid-state hydrogen storage *** to the unique characteristics of complex components and severe lattice distortion,MPEAs are predicted to have better hydrogen storage performance and more probability for modulation and enhancement,allowing them to meet the requirements of different hydrogen storage *** unique structure characteristic potentially devotes the improvement of thermodynamic and kinetic performance,such as the hydrogen storage capacity and hydrogen adsorption/desorption ***,several important modulation factors originating from components and structures facilitate the understanding of the correlation between hydrogen storage properties and ***,we highlight the correlations of hydrogen storage mechanism,with the degree of lattice distortion,the element variation or segregation and valence electron ***,the development tendency on the hydrogen storage mechanism based on the advanced microscopy and computational approach is ***,the chemically short-range ordered structure in MPEAs is predicted as a potential modification factor of the hydrogen/tritium storage properties.

关键词： Multi-principal element alloys(MPEAs) Hydrogen/Tritium storage Hydrogenation mechanism Development tendency Advanced microscopy

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A statistical study on the correlation between sporadic Ca+layer and Es in Beijing(40.5°N,116°E)

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Earth and Planetary physics 2024年第5期8卷 753-761页

作者： YuChang Xun ZhiShan Chen LiFang Du HaoRan Zheng Jing Jiao ZeLong Wang ShaoHua Gong GuoTao Yang College of Physics College of Electronic Information and Optical EngineeringTaiyuan University of TechnologyTaiyuan 030024China State Key Laboratory of Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China School of Science Jiangsu University of Science and TechnologyZhenjiang Jiangsu 212100China School of Physics and Electronics Engineering Hainan Normal UniversityHaikou 571158China

From April 2020 to June 2022,a Ca+lidar with dual-wavelength and narrow-band emitting lasers utilizing all-solid-state technology was employed to conduct observations in Beijing(40.41°N,116.01°E)for a total duration of 1797.79 hours over 280 nights.A total of 286 sporadic Ca+layers were observed,with heights ranging from 88 to 120 km and densities varying from 5.33 to 2200 cm^(-3).We simultaneously observed the ionosonde,located 28 km from the lidar,and found a correlation of 61.89%between the sporadic Ca+layer and the sporadic E *** the sporadic Ca+layer has a downward phase trend,there is a correlation of 76.84%.By excluding the influence of ionosonde sensitivity,we focus only on calcium ions that have a density exceeding 140 cm^(-3),which exhibit a correlation of82.25%.Above 100 km,the correlation significantly increases,reaching approximately 90%.Furthermore,the correlation between the sporadic Ca+layer and the sporadic E layer is particularly noticeable during the summer season,reaching around 90%.This phenomenon can be attributed to the variations in metal ions that occur during different seasons.

关键词： layer lidar exceeding

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AdaPIP: Adaptive picture-in-picture guidance for 360° film watching

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Computational Visual Media 2024年第3期10卷 487-503页

作者： Yi-Xiao Li Guan Luo Yi-Ke Xu Yu He Fang-Lue Zhang Song-Hai Zhang Department of Computer Science and Technology Tsinghua UniversityBeijingChinaand Beijing National Research Center for Information Science and Technology(BNRist)Tsinghua UniversityBeijingChina Key Laboratory of Space Utilization Technology and Engineering Center for Space UtilizationChinese Academy of SciencesBeijingChina Victoria University of Wellington WellingtonNew Zealand

360°videos enable viewers to watch freely from different directions but inevitably prevent them from perceiving all the helpful *** mitigate this problem,picture-in-picture(PIP)guidance was proposed using preview windows to show regions of interest(ROIs)outside the current view *** identify several drawbacks of this representation and propose a new method for 360° film watching called *** enhances traditional PIP by adaptively arranging preview windows with changeable view ranges and *** addition,AdaPIP incorporates the advantage of arrow-based guidance by presenting circular windows with arrows attached to them to help users locate the corresponding ROIs more *** also adapted AdaPIP and Outside-In to HMD-based immersive virtual reality environments to demonstrate the usability of PIP-guided approaches beyond 2D *** user experiments on 2D screens,as well as in VR environments,indicate that AdaPIP is superior to alternative methods in terms of visual experiences while maintaining a comparable degree of immersion.

关键词： 360°videos picture-in-picture(PIP) virtual reality(VR) visual guidance

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Modulating low-frequency tribocatalytic performance through defects in uni-doped and bi-doped SrTiO_(3)

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Journal of Advanced Ceramics 2024年第8期13卷 1153-1163页

作者： Yjing Xu Yingzhi Meng Xu Xiang Qing Tang Hongfang Zhang Lajun Liu Ju Gao Bo Xu Renhong Liang Longlong Shu Yanmin Jia Wanping Chen School of Physical Science and Technology Suzhou University of Science and TechnologySuzhou 215009China College of Materials Science and Engineering Guilin University of TechnologyGuilin 541004China Key Laboratory of Advanced Electrode Materials for Novel Solar Cells for Petroleum and Chemical Industry of China Suzhou University of Science and TechnologySuzhou 215009China School of Science and Key Laboratory of Biomedical Functional Materials China Pharmaceutical UniversityNanjing 211198China School of Physics and Materials Science Guangzhou UniversityGuangzhou 510006China School of Physics and Materials Science Nanchang UniversityNanchang 330031China School of Physics and Information Technology Shaanxi Normal UniversityXi'an 710062China School of Physics and Technology Wuhan UniversityWuhan 430072China

Triboelectrification,a process that transforms mechanical energy into electrical energy through friction,holds promise for eco-friendly wastewater *** study delves into the enhancement of tribocatalytic dye degradation using SrTiO_(3),a material notable for its non-piezoelectric and centrosymmetric *** synthesis of uni-and bi-doped SrTiOs particles,achieved through a solid-state reaction at 100℃,results in a high-purity cubic perovskite *** with rhodium(Rh)and carbon(C)causes crystal lattice contraction,internal stress,and significant oxygen *** changes notably improve tribocatalytic efficiency under solar irradiation,with Rh-doped SrTiO_(3) demonstrating an impressive degradation rate of approximately 88% for Rhodamine B(RhB),along with reaction rate constants near 0.9 h^(-1) at 554 nm and a noticeable *** study highlights that defects introduced by doping are integral to this process,boosting catalytic activity through energy state modification and enhancing surface redox radical ***,these defects are instrumental in generating a flexoelectric field,which markedly influences the separation of electron-hole pairs under solar *** findings illuminate the complex interplay between material composition,defect states,and environmental conditions,paving the way for advanced strategies in environmental remediation through optimized tribocatalytic activity.

关键词： tribocatalysis SrTiO_(3)(STO) doping-induced defects blueshift flexoelectric field

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Comparative analysis of empirical and deep learning models for ionospheric sporadic E layer prediction

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Earth and Planetary physics 2025年第1期9卷 10-19页

作者： BingKun Yu PengHao Tian XiangHui Xue Christopher JScott HaiLun Ye JianFei Wu Wen Yi TingDi Chen XianKang Dou Institute of Deep Space Sciences Deep Space Exploration LaboratoryHefei 230088China CAS Key Laboratory of Geospace Environment School of Earth and Space SciencesUniversity of Science and Technology of ChinaHefei 230026China Hefei National Laboratory University of Science and Technology of ChinaHefei 230088China Department of Meteorology University of ReadingReading RG66BBUK

Sporadic E(Es)layers in the ionosphere are characterized by intense plasma irregularities in the E region at altitudes of 90-130 *** they can significantly influence radio communications and navigation systems,accurate forecasting of Es layers is crucial for ensuring the precision and dependability of navigation satellite *** this study,we present Es predictions made by an empirical model and by a deep learning model,and analyze their differences comprehensively by comparing the model predictions to satellite RO measurements and ground-based ionosonde *** deep learning model exhibited significantly better performance,as indicated by its high coefficient of correlation(r=0.87)with RO observations and predictions,than did the empirical model(r=0.53).This study highlights the importance of integrating artificial intelligence technology into ionosphere modelling generally,and into predicting Es layer occurrences and characteristics,in particular.

关键词： ionospheric sporadic E layer radio occultation ionosondes numerical model deep learning model artificial intelligence

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Dynamic mechanical behavior and nonlinear hyper-viscoelastic constitutive model of SiO_(2) particle-reinforced silicone rubber composite:experimental and numerical investigation

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Acta Mechanica Sinica 2024年第6期40卷 100-114页

作者： Xihuang Zhang Xuexing Wu He Yang Ying Chen Xiangli Cheng Bo Liu Hui Zhao Institute of Electronic Engineering China Academy of Engineering PhysicsMianyang621999China State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China

SiO_(2)-particle reinforced silicon rubber composite(SP-RSRC)is a widely utilized material that offers shock absorption protection to various engineering structures in impact *** paper presents a comprehensive investigation of the mechanical behavior of SP-RSRC under various strain rates,employing a combination of experimental,theoretical,and numerical ***,quasi-static and dynamic compression tests were performed on SP-RSRC utilizing a universal testing machine and split Hopkinson pressure bar(SHPB)*** stress-strain relationships of SP-RSRC were obtained for strain rates ranging from 1×10^(−3) to 3065 s^(−1).The results indicated that the composite showed evident strain rate sensitivity,along with ***,a nonlinear visco-hyperelastic constitutive model was developed,consisting of a hyperelastic component utilizing the 3rd-order Ogden energy function and a viscous component employing a rate-dependent relaxation time *** model accurately characterized the dynamic mechanical response of SP-RSRC,effectively mitigating the challenge of calibrating an excessive number of material parameters inherent in conventional viscoelastic ***,the simplified rubber material(SRM)model,integrated within the LS-DYNA software,was chosen to depict the mechanical properties of SP-RSRC in numerical *** parameters of the SRM model were further calibrated based on the strain-stress relationships of SP-RSRC,as predicted by the developed nonlinear visco-hyperelastic constitutive ***,an inverse ballistic experiment using a single-stage air gun was conducted for *** simulations of SHPB experiments and the inverse ballistic experiment were then performed,and the reliability of the calibrated SRM model was verified by comparing the results of experiments and numerical *** study offers a valuable reference for the utilization of SP-RSRC in the realm of impact protection.

关键词： Silicone rubber composites Dynamic mechanical properties Nonlinear visco-hyperelastic constitutive model Inverse ballistic experiment

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