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Electromagnetic wave absorbing properties of TMCs(TM=Ti,Zr,Hf,Nb and Ta)and high entropy(Ti0.2Zr0.2Hf0.2Nb0.2Ta0.2)C

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Journal of Materials Science & Technology 2021年第15期74卷 105-118页

作者： Yanchun Zhou Biao Zhao Heng Chen Huimin Xiang fu-zi dai Shijiang Wu Wei Xu Science and Technology on Advanced functional Composite Laboratory Aerospace Research Institute of Materials&Processing TechnologyBeijing100076China Henan Key Laboratory of Aeronautical Materials and Application Technology School of Material Science and EngineeringZhengzhou University of AeronauticsZhengzhou450046China Key Laboratory of Advanced Ceramics and Machining Technology of Ministry of Education School of Materials Science and EngineeringTianjin UniversityTianjin300072China zibo Firstar New Material Incoqjorated Co.Ltd. Zibo255000China Shanghai Chenhua Science and Technology Coloration Ltd. Shanghai201804China

Electromagnetic wave(EMW)absorbing materials play a vital role in modern communication and information processing technologies to inhibit information leakage and prevent possible damages to environment and human ***,most of EMW absorbing materials are either composites of two or more phases or in the form of nanosheets,nanowires or nanofibers in order to enhance the EMW absorption performance through dielectric loss,magnetic loss and dielectric/magnetic loss ***,the combination of complex shapes/multi phases and nanosizes may compound the difficulties of materials processing,composition and interfaces control as well as performance maintenance during ***,searching for single phase materials with good stability and superior EMW absorbing properties is *** achieve this goal,the EMW absorbing properties of transition metal carbides TMCs(TM=Ti,Zr,Hf,Nb and Ta)and high entropy(Ti_(0.2)Zr_(0.2)Hf_(0.2)Nb_(0.2)Ta_(0.2))C which belong to ultrahigh temperature ceramics,were investigated in this *** to the good electrical conductivity and splitting of d orbitals into lower energy t2glevel and higher energy eglevel in TMC6octahedral arrangement,TMCs(TM=Ti,Zr,Hf,Nb and Ta)exhibit good EMW absorbing ***,Hf C and Ta C exhibit superior EMW absorbing *** minimum reflection loss(RLmin)value of Hf C is-55.8 d B at 6.0 GHz with the thickness of 3.8 mm and the effective absorption bandwidth(E_(AB))is 6.0 GHz from 12.0 to 18.0 GHz at thickness of 1.9 mm;the RL_(minvalue)of Ta C reaches-41.1 d B at 16.2 GHz with a thickness of 2.0 mm and the EABis 6.1 GHz with a thickness of 2.2 ***,the electromagnetic parameters,i.e.,complex permittivity and permeability are tunable by forming single phase solid solution or high entropy(Ti_(0.2)Zr_(0.2)Hf_(0.2)Nb_(0.2)Ta_(0.2))*** R_(Lminvalue)of high entropy(Ti_(0.2)Zr_(0.2)Hf_(0.2)Nb_(0.2)Ta_(0.2))C is-38.5 d B at 9.5 GHz with the thickness of 1.9 mm,and the EA

关键词： Transition metal carbides High entropy ceramics Microwave absorption Electromagnetic parameters Electronic structure Crystal field theory

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Effects of Ti-and Nb-based transition element from single to multiple compound oxides and carbon-based composite additives on Mg-MgH2 hydrogen storage material

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Tungsten 2025年第1期7卷 32-49页

作者： Li-Rong Xiao Chen Chen Shuo Wang zi-Yin dai Hideo Kimura Cui Ni Chuan-Xin Hou Xue-Qin Sun Si-Jie Guo Wei Du Xiu-Bo Xie School of Environmental and Material Engineering Yantai University Bosch HUAYU Steering Systems (Yantai) Co. Ltd.Ytp/MFE University of Tennessee Knoxville Shandong Key Laboratory of Eco-Environmental Science for the Yellow River Delta Shandong University of Aeronautics

MgH2is considered as a promising hydrogen storage material for its high hydrogen storage capacity,low cost and abundant resource ***,the low kinetics and high enthalpy formation of MgH2limit its wide *** the perspective of adding catalysts to enhance the hydrogen storage properties of Mg-MgH2,this article elaborated the main catalysts based on Ti and Nb transition elements,including single oxide catalysts,binary oxides catalysts（combined with Ni,Na,Sr,V,etc.）,multiple catalysts bound to carbon,and composite catalysts with Ti and Nb elements combined with MXene ***,the main pathways of various catalysts to reduce the reaction activity and broaden the hydrogen desorption channel were also *** Ti-based catalysts can enhance the reactive sites of the matrix by forming multivalent states,while Nb-based catalysts broaden the hydrogen reaction channels by forming tiny *** improving the size structure and enhancing the grain size stability,combined with carbon materials should be the future considerations.

关键词： Catalysts Mg-based hydrogen storage alloys Solid hydrogen storage Transition metal elements

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A monolithic 3D IGZO-RRAM-SRAM-integrated architecture for robust and efficient compute-in-memory enabling equivalent-ideal device metrics

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Science China(Information Sciences) 2025年

作者： Shengzhe YAN Zhaori CONG zi WANG Zhuoyu dai Zeyu GUO Zhihang QIAN Xufan LI Xu ZHENG Chuanke CHEN Nianduan LU Chunmeng DOU Guanhua YANG Xiaoxin XU Di GENG Jinshan YUE Lingfei WANG Ling LI Ming LIU Institute of Microelectronics of the Chinese Academy of Sciences University of Chinese Academy of Sciences

Abstract Compute-in-memory (CIM) based on various devices such as static random access memory (SRAM) and resistive random access memory (RRAM) and other emerging devices such as indium-gallium-zinc-oxide (IGZO) transistor, magnetoresistive RAM (MRAM), and ferroelectric RAM (FeRAM) has been explored for better performance and energy efficiency on neural networks applications. However, CIM based on a single-type device suffers a variety of non-ideal metrics to reach the simultaneous optimal accuracy, density, and energy efficiency. This work presents equivalent-ideal CIM (Eq-CIM), a monolithic 3D(M3D) IGZO-RRAM-SRAM integrated architecture for robust and efficient compute-in-memory enabling equivalent-ideal device metrics. To overcome the non-ideality (variation, endurance, temperature, etc.) of the single-type devices, system-technology co-optimization (STCO) is performed. This work highlights the non-ideality-aware functionality breakdown for robust high accuracy and simultaneous high density/efficiency, by utilizing 2T0C IGZO for temporal activation storage, RRAM for high-density weight storage, and SRAM for accurate CIM. Device-to-algorithm variation transfer is applied to analyze the system-level accuracy. We benchmark Eq-CIM architecture on CIFAR-10/ImageNet, with 5.06×storage density and 5.05×/2.45×area/energy efficiency compared with single-type-device-based CIM, and high robustness (<0.27%accuracy loss) from-40℃ to 120℃.

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带拼接板螺栓连接耗能梁段的可恢复功能钢框筒结构抗震性能研究

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工程力学 2025年第1期42卷 83-102页

作者：连鸣戴子琳程倩倩西安建筑科技大学土木工程学院西安710055 西安建筑科技大学结构工程与抗震教育部重点实验室西安710055 中国建筑西北设计研究院有限公司西安710018

为了提升传统钢框筒结构的延性和耗能能力，提出采用拼接板螺栓连接的可恢复功能剪切耗能型钢框筒结构(FTS-SRSL)，该结构结合了可更换剪切型耗能梁段和钢框筒结构具有良好的抗震性能。该文对一个2/3缩尺的单层单跨FTS-SRSL子结构试件... 详细信息

为了提升传统钢框筒结构的延性和耗能能力，提出采用拼接板螺栓连接的可恢复功能剪切耗能型钢框筒结构(FTS-SRSL)，该结构结合了可更换剪切型耗能梁段和钢框筒结构具有良好的抗震性能。该文对一个2/3缩尺的单层单跨FTS-SRSL子结构试件进行了往复加载试验，试验结果表明，FTS-SRSL子结构试件具有良好的抗震性能，结构损伤集中于耗能梁段，且耗能梁段可实现更换。在试验的基础上，以耗能梁段长度比、耗能梁段腹板加劲肋间距、螺栓直径、翼缘拼接板和腹板拼接板厚度为参数，利用ABAQUS建立了15个足尺的单层单跨FTS-SRSL有限元模型，探究各模型的抗震性能，包括承载力、刚度、耗能以及塑性变形能力。有限元分析结果表明：改变拼接板螺栓连接的剪切型耗能梁段长度比会显著影响结构的承载力、刚度及耗能，建议FTS-SRSL中的拼接板螺栓连接剪切型耗能梁段长度比取0.73~1.09;改变耗能梁段腹板加劲肋间距对结构的承载力、刚度和耗能影响较小，基于该文的分析结果，建议FTS-SRSL中的拼接板螺栓连接剪切型耗能梁段腹板加劲肋间距取e/4~e/3(e为耗能梁段长度)，且间距应满足我国抗规的规定;改变翼缘拼接板和腹板拼接板厚度对结构的承载力、刚度及耗能基本无影响;改变螺栓直径对结构承载力、刚度及耗能影响较小。

关键词：可更换耗能梁段拼接板螺栓连接钢框筒结构抗震性能参数分析

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Lattice QCD Study of the σ Meson

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Chinese Physics Letters 2011年第8期28卷 43-46页

作者： fu zi-Wen Key Laboratory of Radiation Physics and Technology(Ministry of Education) Sichuan UniversityInstitute of Nuclear Science and TechnologySichuan UniversityChengdu 610064

We study theσmeson in 2+1 flavor full quantum chromodynamics(QCD)with sufficiently light u and d *** point−to-point correlator is measured for theσchannel in the“Asqtad”improved staggered fermion *** attention is paid to its disconnected diagram and bubble *** chiral extrapolation,we obtain theσmass with 706±53 MeV,which is close to the observedσmeson within error,and is heavier than theππ*** simulations are carried out with MILC 2+1 flavor gauge configurations at lattice spacing of a≈0.15 fm.

关键词： meson QCD gauge

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Lattice QCD Calculation of ππ Scattering Length

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Communications in Theoretical Physics 2012年第1期57卷 78-84页

作者： fu zi-Wen Key Laboratory of Radiation Physics and Technology(Sichuan University) Ministry of EducationInstitute of Nuclear Science and TechnologySichuan UniversityChengdu 610064China

We study s-wave pion-pion scattering length in lattice QCD for pion masses ranging from 330 MeV to 466 MeV. In the ＂Asqtad＂ improved staggered fermion formulation, we measure full ππ four-point correlators for isospin I = 0 and 2 channels, and use chiral perturbation theory at next-to-leading order to extrapolate our simulation results. Extrapolating to the physical pion mass yields scattering lengths as mna01=2 = -0.041 6（2） and mna01= 0.186（2） for isospin I = 2 and 0 channels, respectively. Our lattice simulation for ππ scattering length in I = 0 channel is an exploratory study, where we include the disconnected contribution, and our preliminary result is near to its experimental value. These simulations are carried out with MILC 2 ＋ 1 flavor gauge configurations at lattice spacing a ≈0.15 fm.

关键词： lattice QCD energy shift scattering length four point function

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Gamma-Ray Burst Afterglows with Energy Injection: Homogeneous Versus Wind External Media

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Chinese Physics Letters 2001年第8期18卷 1153-1155页

作者： WANG Wei dai zi-Gao Department of Astronomy Nanjing UniversityNanjing 210093 National Astronomical Observatory Chinese Academy of SciencesBeijing 100012

Assuming an adiabatic evolution of a gamma-ray burst(GRB)fireball interacting with an external medium,we calculate the hydrodynamics of the fireball with an energy injection from a strongly magnetic millisecond pulsar through magnetic dipole radiation,and obtain the light curve of the optical afterglow from the fireball by synchrotron *** results are given both for a homogeneous external medium and for a wind ejected by GRB *** calculations are also available in both ultra-relativistic and non-relativistic ***,the observed R-band light curve of GRB000301C can be well fitted in our model,which might provide a probe of the properties of GRB progenitors.

关键词： Wind relativistic fitted

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Study on detinning process of a reflow conductor roll

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Rare Metals 2005年第4期24卷 325-329页

作者： fu Hanguang dai Mingshan fu Hanfeng Department of Mechanical Engineering Tsinghua University Beijing 100084 China Baoshan Iron ＆ Steel Co. Ltd. Shanghai 201900 China

Adhering tin is the main reason of a reflow conductor roll which works in an electroplating tin line （ETL）. A det- inning agent whose main composition is NaOH and KOH and assistant composition is Na2PbO2 or K2PbO2 and NaNO3 or NaNO2 has excellent detinning effects when the temperature of detinning solution is 40-80℃ and the temperature of the reflow conductor roll reaches 40-70℃. After the adhering tin layer of the reflow conductor roll is removed, the roughness of the reflow conductor roll can resume to 4.0 μm, its service life increases by 80%, and the repairing cost decreases by 90%.

关键词： electroplating tin reflow conductor roll detinning agent roughness

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Multiband fitting to three long GRBs with Fermi/LAT data:structured ejecta sweeping up a density-jump medium

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Research in Astronomy and Astrophysics 2011年第9期11卷 1046-1066页

作者： Si-Yi Feng zi-Gao dai Department of Astronomy Nanjing University Nanjing 210093 China Key Laboratory of Modern Astronomy and Astrophysics （Nanjing University） Ministry of Education Nanjing 210093 China

We present broadband （radio, optical, X-ray and GeV） fits to the afterglow light curves and spectra of three long-duration gamma-ray bursts （GRBs 080916C, 090902B, and 090926A） detected by the Gamma-Ray Burst Monitor and Large Area Telescope （LAT） instruments on the Fermi satellite. Using the observed broadband data, we study the origin of the high energy emission, and suggest that the early-time GeV emission and the late-time radio, optical, and X-ray afterglows can be under- stood as being due to synchrotron emission from an external forward shock caused by structured ejecta propagating in a wind bubble jumping to a homogeneous density medium. If the ceasing time for a majority of the energy injection is assumed to be close to the deceleration time of the forward shock, the structured ejecta with con- tinuous energy injection towards the forward shock can well explain the early rising feature of the GeV mission from these bursts, and the density-jump medium can ac- count for some particular plateaus or flares in the late afterglows. From our fits, we find that, on one hand, the external shock origin of the GeV photons will make the optical depth not have a significant contribution to the early LAT rising part, which will loosen the strong constraint of lower limits of the Lorentz factor. On the other hand, these Fermi-LAT events preferentially occur in a low-density circumburst environment, in which case the Klein-Nishina cutoff will significantly suppress the Self- Synchrotron Compton radiation. Such an environment might result from superbubbles or low-metallicity progenitor stars （which have a low mass-loss rate at late times of stellar evolution） of type Ib/c supernovae.

关键词： gamma-rays: bursts -- gamma-rays: theory

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Estimate of an environmental magnetic field of fast radio bursts

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Research in Astronomy and Astrophysics 2016年第3期16卷 11-16页

作者： Wei-Li Lin zi-Gao dai School of Astronomy and Space Science Nanjing University Key Laboratory of Modern Astronomy and Astrophysics (Nanjing University) Ministry of Education

Fast radio bursts （FRBs） are a type of newly-discovered transient astronomical phenomenon. They have short durations, high dispersion measures and a high event rate. However, due to unknown dis- tances and undetected electromagnetic counterparts at other wavebands, it is difficult to further investigate FRBs. Here we propose a method to study their environmental magnetic field using an indirect method. Starting withdispersion measures and rotation measures （RMs）, we try to obtain the parallel magnetic field component ^-B ││ which is the average value along the line of sight in the host galaxy. Because both RMs and redshifls are now unavailable, we demonstrate the dependence of ^-B ││ on these two separate quantities. This result, if the RM and redshift of an FRB are measured, would be expected to provide a clue towards understanding an environmental magnetic field of an FRB.

关键词： radio continuum: general -- pulsars: general -- galaxies: magnetic fields -- Galaxy: structure

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