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Journal of Rare Earths 2024年第7期42卷 1240-1249,I0002页

作者： Ziyao Wang Haitao Fu xiufeng zhan Bo tong Guofeng Ma H.t.(Bert)Hintzen Institute of Innovative Science and technology Shenyang UniversityShenyang110044China College of Mechanical Engineering Shenyang UniversityShenyang110044China Faculty of Applied Sciences Delft University of Technology2629 JBDelftthe Netherlands

A novel Eu^(2+)-Eu^(3+)co-activated ratiometric thermo-sensitive phosphor was developed and synthesized by solid-state *** valence state of Eu,photoluminescence and thermo-sensitive performance of the phosphor prepared either in ambient air or carbothermally were investigated and *** phosphor shows high sensitivity(Sa=0.0173 K^(-1),S_(r)=0.461%/K)and superior signal discriminability(Δν∼10380 cm^(−1)).the thermo-sensitive performance is subject to the dual effects of different thermo-responses by Eu^(2+)versus Eu^(3+)combined with energy transfer from Eu^(2+)to Eu^(3+),so that the sensitivity of the phosphor in the temperature range presents a non-monotonic *** development of the BaAl_(2)B_(2)O_(7):Eu^(2+),Eu^(3+)phosphor is not only expected to be relevant for application in the field of temperature sensing,but also of reference significance for improving the sensitivity by means of energy transfer between co-activator ions over a wider temperature range of Eu^(2+)-Eu^(3+)co-activated ratiometric thermo-sensitive phosphors.

关键词： Photoluminescence Ratiometric thermo-response Phosphor Eu^(2+)/Eu^(3+) Rare earths

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Miniaturized, Shared Electric and Magnetic Dipole, Pattern Diversity Iot Antenna for Sub-6 GHz Applications

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Chinese Journal of Electronics 2024年第5期33卷 1224-1233页

作者： zhan WANG Yuandan DONG University of Electronic Science and technology of China

By using a novel meta-resonator structure, a miniaturized, surface mountable, shared aperture, and hybrid electric/magnetic dipole pattern diversity antenna is proposed for Internet of things（Iot） applications. By exploring the shared electric（E-dipole） and magnetic dipole（M-dipole） structures, a novel t-shaped split-ring resonator（SRR） with even and odd modes is presented and studied by current distributions and equivalent *** and omnidirectional（monopole-like） patterns are achieved by exciting the M-dipole and E-dipole modes of the t-shaped SRR, respectively. to validate the proposed design, this shared aperture metamaterial-inspired pattern diversity antenna with a small size of 0.295λ0× 0.0065λ0× 0.115λ0is fabricated and measured. the measured overlapped-10 dB bandwidth is from 3.40 GHz to 3.63 GHz（7.0%, covering the LtE B42 band） and the port isolation is greater than 23 dB. Both two modes achieve a good radiation efficiency better than-0.79 d B（>83.0%）.

关键词： Antenna measurements Dipole antennas Surface mount technology Switches Size measurement Aperture antennas Internet of things Electric/magnetic dipoles Internet of things (Iot) Metamaterial-based/inspired antenna LOW-PROFILE PAtCH ANtENNA RECONFIGURABLE ANtENNA MICROStRIP ANtENNA RADIAtION-PAttERN HIGH-GAIN FREQUENCY ARRAY

Context‑dependent antioxidant defense system(ADS)‑based stress memory in response to recurrent environmental challenges in congeneric invasive species

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Marine Life Science & technology 2024年第2期6卷 315-330页

作者： Hanxi Li xuena Huang Aibin zhan Research Center for Eco-Environmental Sciences Chinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China

Marine ecosystems are facing escalating environmental fluctuations owing to climate change and human activities,imposing pressures on marine *** withstand recurring environmental challenges,marine organisms,especially benthic species lacking behavioral choices to select optimal habitats,have to utilize well-established strategies such as the antioxidant defense system(ADS)to ensure their ***,understanding of the mechanisms governing the ADS-based response is essential for gaining insights into adaptive strategies for managing environmental *** we conducted a com-parative analysis of the physiological and transcriptional responses based on the ADS during two rounds of'hypersalinity-recovery'challenges in two model congeneric invasive ascidians,Ciona robusta and *** results demonstrated that *** exhibited higher tolerance and resistance to salinity stresses at the physiological level,while *** demonstrated heightened responses at the transcriptional *** observed distinct transcriptional responses,particularly in the utilization of two superoxide dismutase(SOD)*** Ciona species developed physiological stress memory with elevated total SOD(t-SOD)and glutathione(GSH)responses,while only *** demonstrated transcriptional stress *** regulatory distinctions within the Nrf2-Keap1 signalling pathway likely explain the formation disparity of transcriptional stress memory between both Ciona *** findings support the'context-dependent stress memory hypothesis',emphasizing the emergence of species-specific stress memory at diverse regulatory levels in response to recurrent environmental *** results enhance our understanding of the mechanisms of environmental challenge manage-ment in marine species,particularly those related to the ADS.

关键词： Antioxidant defense Ascidian Biological invasion Environmental stress Stress memory

Dislocation density-me diate d creep ageing behavior of an Al-Cu-Li alloy

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Journal of Materials Science & technology 2024年第7期174卷 204-217页

作者： Chang Zhou Lihua zhan Chunhui Liu Minghui Huang College of Mechanical and Electrical Engineering Central South UniversityChangsha 410083China State Key Laboratory of Precision Manufacturing for Extreme Service Performance Central South UniversityChangsha 410083China Light Alloys Research Institute Central South UniversityChangsha 410083China

Creep aging is well-known to be a time-dependent,coupled process of deformation and precipitation strengthening for age-hardening *** existing mechanisms are mainly attributed to those interac-tions between atomic diffusion and dislocation ***,an understanding of the relationship between dislocation density and a special multistage creep behavior,i.e.,double steady creep feature,is still far *** we investigate the effect of various dislocation density levels on such an abnormal multistage creep of an Al-Cu-Li *** find that the increased dislocation densities enable an apparent time decrease(from 6.2 h to 0.8 h)of their first steadyⅡ-*** yield strength of post-aged sam-ples increases from 425.0 MPa to 580.0 MPa while the corresponding elongation decreases from 12.3%to 7.3%for the creep-aged samples#1 to#*** results also reveal that a great difference in dislocation configuration,tailored by various density levels,results in varying creep processes of theⅡ-*** stage is closely related to the nucleation and early growth of t_(1)*** number densities(maximum:2.9×10^(19)m^(-3))and the average length(maximum:21.3 nm)of t_(1)precipitates are much smaller than those of the stable peak-aged t_(1)phases,suggesting that creepⅡ-stage of all three creep-aged samples is dominant by the nucleation and initial growth of those t_(1)*** study provides valuable insights into the dislocation density-mediated creep deformation of an Al-Cu-Li alloy.

关键词： Dislocation density Al-Cu-Li alloy Creep ageing t_(1)precipitation

Electro-optic 3D snapshot of a laser wakefield accelerated kilo-ampere electron bunch

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Light(Science & Applications) 2024年第5期13卷 823-834页

作者： Kai Huang zhan Jin Nobuhiko Nakanii tomonao Hosokai Masaki Kando Kansai Institute for Photon Science(KPSI) National Institutes for Quantum Science and Technology(QST)KyotoJapan. Laser Accelerator R&D Innovative Light Sources DivisionRIKEN SPring-8 CenterHyogoJapan. SANKEN Osaka UniversityOsakaJapan

Laser wakefield acceleration,as an advanced accelerator concept,has attracted great attentions for its ultrahigh acceleration gradient and the capability to produce high brightness electron *** three-dimensional(3D)density serves as an evaluation metric for the particle bunch quality and is intrinsically related to the applications of an *** its significance,this parameter has not been experimentally measured in the investigation of laser wakefield *** report on an electro-optic 3D snapshot of a laser wakefield electron bunch at a position outside the *** 3D shape of the electron bunch was detected by simultaneously performing optical transition radiation imaging and electro-optic *** 3D structures to a few micrometer levels were reconstructed using a genetic *** electron bunch possessed a transverse size of less than 30 *** current profile shows a multi-peak *** main peak had a duration oft>1 *** maximum electron 3D number density was~9×10^(21)m^(-3).this research demonstrates a feasible way of 3D density monitoring on femtosecond kilo-ampere electron bunches,at any position of a beam transport line for relevant applications.

关键词： laser acceleration field

On the Well-Posedness Problem of the Anisotropic Porous Medium Equation with a Variable Diffusion Coefficient

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Journal of Partial Differential Equations 2024年第2期37卷 135-149页

作者： zhan Huashui School of Mathematics and Statistics Xiamen University of TechnologyXiamen 361024China

the initial-boundary value problem of an anisotropic porous medium equation■is *** with the usual porous medium equation,there are two different characteristics in this *** lies in its anisotropic property,another one is that there is a nonnegative variable diffusion coefficient a(x,t)*** a(x,t)may be degenerate on the parabolic boundary∂Ω×(0,t),instead of the boundedness of the gradient|∇u|for the usual porous medium,we can only show that∇u∈L^(∞)(0,t;L^(2)_(loc)(Ω)).Based on this property,the partial boundary value conditions matching up with the anisotropic porous medium equation are discovered and two stability theorems of weak solutions can be proved naturally.

关键词： Anisotropic porous medium equation variable diffusion coefficient stability partial boundary condition

Bridging microstructure and crystallography with the crack propagation behavior in ti-6Al-4V alloy fabricated via dual laser beam bilateral synchronous welding

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Journal of Materials Science & technology 2024年第7期174卷 1-14页

作者： tingyan Yan Yuan Liu Jianfeng Wang Yong Zheng xiaohong zhan College of Materials Science and technology Nanjing University of Aeronautics and AstronauticsNanjing 211106China

the microstructure evolution and crack propagation behavior were systematically and thoroughly inves-tigated inα/βti-6Al-4V alloy obtained under the inhomogeneous heating effect of a coupled dual laser beam via a combination of postmortem electron backscattering diffraction analyses and numerical *** effect of microstructural attributes(grain size,grain boundary,dislocation)on the fracture property and crack propagation behavior was investigated based on thermodynamic and crystallographic analyses,as well as the examinations of dislocation density and the Burgers *** quantifying the degree of variant selection using the degree of variant selection(DVS)equation,it was found that the higher the energy input,the weaker the variant selection,as the secondaryαphase suppresses further dislocation-induced variant selection via autocatalytic nucleation and *** proportion of high an-gle grain boundaries(HAGBs)concentrated around 60°gradually increases with improving cooling rate,mainly due to the change in the tendency of martensite transformation to be *** grain refine-ment was the primary mechanism for the enhancement of ti-6Al-4V alloy t-joints,while the suppression of crack propagation by HAGBs also played a crucial role in improving strength and *** crack propagation direction frequently changes when the order is approximately parallel to the short axis ofαmartensite grains,forming a zigzag propagation *** above findings should shed light on optimiz-ing dual laser beam bilateral synchronous welding(DLBSW)technology to tailor the microstructure and improve the mechanical properties of ti-6Al-4V alloy t-joints.

关键词： ti-6Al-4V alloy Microstructure Grain refinement Crack propagation Dual laser beam bilateral synchronous welding

Anomalous response to creep deformation from dislocation density during electrically assisted creep aging

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Rare Metals 2024年第10期43卷 5268-5283页

作者： Chang Zhou Li-Hua zhan Chun-Hui Liu Ming-Hui Huang College of Mechanical and Electrical Engineering Central South University Light Alloys Research Institute State Key Laboratory of Precision Manufacturing for Extreme Service PerformanceCentral South University

Adding numerous dislocations into metallic materials before the forming stage significantly enhances their deformability. However, this beneficial effect of dislocation defects may not have a simple monotonic relationship with increased dislocation density during electroplastic deformation. this is due to the complex interactions among the drifting electrons, dislocations and solute atoms. this study explores the effect of diverse initial dislocation densities on creep deformation during electrically aided creep aging of an aluminum–lithium alloy. Surprisingly, we discovered a threshold value for the dislocation density that affects electroplastic creep, i.e., an enhanced effect from dislocations weakens when exceeding this density threshold(an anomalous response to creep). Microstructural data also reveal that such an anomalous response originates mainly from differences in various dislocation density-tailored configurations, which can influence the dislocation motions and precipitation kinetics of the strengthening t1precipitates under the same action of pulsed currents. this study provides important insights into the dislocation density-mediated electroplastic creep of an aluminum–lithium alloy.

关键词： Al–Cu–Li alloy Creep aging Dislocation density Pulsed currents

A study of the effect of local scour on the flow field near the spur dike

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theoretical & Applied Mechanics Letters 2024年第2期14卷 98-105页

作者： Yu-tian Li Jie-Min zhan Wing-Hong Onyx Wai Department of Industrial Design School of Industrial Design and Ceramic ArtFoshan UniversityFoshan 528000China Department of Applied Mechanics and Engineering Shenzhen Campus of Sun Yat-sen UniversityShenzhen 518107China Department of Civil and Environmental Engineering The Hong Kong Polytechnic UniversityHong Kong 999077China

the flow field near a spur dike such as down flow and horseshoe vortex system(HVS)are susceptible to the topographic changes in the local scouring process,resulting in variation of the sediment transport with *** this study,large eddy simulations with fixed-bed at different scouring stages were conducted to investigate the changes in flow *** results imply that the bed deformation leads to an increase in flow rate per unit area,which represent the capability of sediment transportation by water,in the scour ***,the intensity of turbulent kinetic energy and bimodal motion near the sand bed induced by the HVS were also ***,the peak moments between the two sediment transport mechanisms were ***,understanding the complex feedback mechanism between topography and flow field is essential for the local scour problem.

关键词： Spur dike Local scour Large eddy simulation Down flow Horseshoe vortex system

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Bond behavior of the interface between concrete and basalt fiber reinforced polymer bar after freeze–thaw cycles

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Frontiers of Structural and Civil Engineering 2024年第4期18卷 630-641页

作者： Li HONG Mingming LI Congming DU Shenjiang HUANG Binggen zhan Qijun YU Department of Structural Engineering Hefei University of TechnologyHefei 230009China Key Laboratory of Performance Evolution and Control for Engineering Structures Tongji UniversityShanghai 200092China Engineering Research Center of Low-carbon technology and Equipment for Cement-based Materials(Ministry of Education) Hefei University of TechnologyHefei 230009China Hefei Cement Research&Design Institute Corporation Ltd. Hefei 230051China

the shear bond of interface between concrete and basalt fiber reinforced polymer(BFRP)bars during freeze–thaw(F–t)cycles is crucial for the application of BFRP bar-reinforced concrete structures in cold *** this study,48 groups of pull-out specimens were designed to test the shear bond of the BFRP-concrete interface subjected to F–t *** effects of concrete strength,diameter,and embedment length of BFRP rebar were investigated under numerous F–t *** results showed that a larger diameter or longer embedment length of BFRP rebar resulted in lower interfacial shear bond behavior,such as interfacial bond strength,initial stiffness,and energy absorption,after the interface goes through F–t ***,higher concrete strength and fewer F–t cycles were beneficial for enhancing the interfacial bond ***,a three-dimensional(3D)interfacial model based on the finite element method was developed,and the interfacial bond behavior of the specimens was analyzed ***,a degradation bond strength subjected to F–t cycles was predicted by a proposed mechanical *** predictions were fully consistent with the tested *** model demonstrated accuracy in describing the shear bond behavior of the interface under numerous F–t cycles.

关键词： F-t cycle interface shear bond strength bond stress−slip curves bond degradation