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A Novel Poly(3-hexylthiophene) Engineered Interface for Electrochemical Monitoring of Ascorbic Acid During the Occurrence of Glutamate-Induced Brain Cytotoxic Edemas

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Research 2024年第1期2023卷 301-313页

作者： Zexuan Meng Yuchan Zhang Lu Yang Shuang zhao Qiang Zhou Jiajia Chen Jiuxi Sui Jian Wang lizhong Guo Luyue Chang Jialing He Guixue Wang Guangchao Zang Institute of Life Science and Laboratory of Tissue and Cell BiologyLab Teaching and Management CenterChongqing Medical UniversityChongqing 400016China Key Laboratory for Biorheological Science and Technology of Ministry of Education State and Local Joint Engineering Laboratory for Vascular ImplantsBioengineering College of Chongqing UniversityChongqing 400030China Jinfeng Laboratory Chongqing 401329China Department of Pathophysiology Chongqing Medical UniversityChongqingChina

Although neuroelectrochemical sensing technology offers unique benefits for neuroscience research,its application is limited by substantial interference in complex brain environments while ensuring biosafety requirements.In this study,we introduced poly(3-hexylthiophene)(P3HT)and nitrogen-doped multiwalled carbon nanotubes(N-MWCNTs)to construct a composite membrane-modified carbon fiber microelectrode(CFME/P3HT-N-MWCNTs)for ascorbic acid(AA)detection.The microelectrode presented good linearity,selectivity,stability,antifouling,and biocompatibility and exhibited great performance for application in neuroelectrochemical sensing.Subsequently,we applied CFME/P3HT-N-MWCNTs to monitor AA release from in vitro nerve cells,ex vivo brain slices,and in vivo living rat brains and determined that glutamate can induce cell edema and AA release.We also found that glutamate activated the N-methyl-d-aspartic acid receptor,which enhanced Na^(+) and Cl^(−) inflow to induce osmotic stress,resulting in cytotoxic edema and ultimately AA release.This study is the first to observe the process of glutamate-induced brain cytotoxic edema with AA release and to reveal the mechanism.Our work can benefit the application of P3HT in in vivo implant microelectrode construction to monitor neurochemicals,understand the molecular basis of nervous system diseases,and discover certain biomarkers of brain diseases.

关键词： release microelectrode Engine

High-entropy-alloy nanoparticles with 21 ultra-mixed elements for efficient photothermal conversion

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National Science Review 2022年第6期9卷 124-134页

作者： Yijun Liao Yixing Li Rongzhi zhao Jian Zhang lizhong zhao Lianze Ji Zhengyu Zhang Xiaolian Liu Gaowu Qin Xuefeng Zhang Key Laboratory for Anisotropy and Texture of Materials (MOE) School of Materials Science and EngineeringNortheastern University Institute of Advanced Magnetic Materials College of Materials and Environmental EngineeringHangzhou Dianzi University

Multi-metallic nanoparticles have been proven to be an efficient photothermal conversion material, for which the optical absorption can be broadened through the interband transitions(IBTs), but it remains a challenge due to the strong immiscibility among the repelling combinations. Here, assisted by an extremely high evaporation temperature, ultra-fast cooling and vapor-pressure strategy, the arc-discharged plasma method was employed to synthesize ultra-mixed multi-metallic nanoparticles composed of 21 elements(FeCoNiCrYTiVCuAlNbMoTaWZnCdPbBiAgInMnSn), in which the strongly repelling combinations were uniformly distributed. Due to the reinforced lattice distortion effect and excellent IBTs, the nanoparticles can realize an average absorption of >92% in the entire solar spectrum(250 to 2500 nm). In particular, the 21-element nanoparticles achieve a considerably high solar steam efficiency of nearly 99%under one solar irradiation, with a water evaporation rate of 2.42 kg m-2h-1, demonstrating a highly efficient photothermal conversion performance. The present approach creates a new strategy for uniformly mixing multi-metallic elements for exploring their unknown properties and various applications.

关键词： high-entropy alloy nanoparticle ultra-mixing arc-discharged method photothermal conversion

Simultaneous enhancement of coercivity and electric resistivity of Nd-Fe-B magnets by Pr-Tb-Al-Cu synergistic grain boundary diffusion toward high-temperature motor rotors

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Journal of Materials Science & Technology 2023年第23期154卷 54-64页

作者： Jiayi He Jinwen Hu Bang Zhou Haoyang Jia Xiaolian Liu Zhenhua Zhang Lin Wen lizhong zhao Hongya Yu Xichun Zhong Xuefeng Zhang Zhongwu Liu School of Materials Science and Engineering South China University of Technology Guangzhou 510640 China Institute of Advanced Magnetic Materials Hangzhou Dianzi University Hangzhou 310012 China

To high-power permanent magnetic motors,it is critical for Nd-Fe-B magnets to maintain the desirable coercivity at high-temperature operating conditions.To address this,two approaches have been proven effective:(1)enhancing the room temperature coercivity;(2)reducing the eddy current loss.However,these two items are difficult to be simultaneously achieved.Here,the grain boundary diffusion(GBD)of the Pr-Tb-Al-Cu-based source is applied to enhance the coercivity and electric resistivity at room temperature from 1101 kA m-1 and 2.13×10–6Ωm to 1917 kA m-1 and 2.60×10–6Ωm,and those at 120°C from 384 kA m-1 and 4.31×10–6Ωm to 783 kA m-1 and 4.86×10–6Ωm,respectively.Such optimization is ascribed to the improved formation depth of Tb-rich 2:14:1 shells with large magnetocrystalline anisotropy and the increased intergranular Pr-based oxides with high electric resistivity,induced by the coordination effects of Tb and Pr,as proven by the atomic-scale observations and the first principles calculations.It thus results in the simultaneously improved output power and energy efficiency of the motor because of the combination of magnetic thermal stability enhancement and eddy current loss reduction,as theoretically confirmed by electromagnetic simulation.

关键词： Nd-Fe-B Grain boundary diffusion Coercivity Electrical resistivity Eddy current loss

Micromagnetic investigation by a simplified approach on the demagnetization field of permanent magnets with nonmagnetic phase inside

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Frontiers of Materials Science 2019年第3期13卷 323-333页

作者： Wei LI lizhong zhao Zhongwu LIU School of Materials Science and Engineering South China University of TechnologyGuangzhou 510640China Innovative Center for Advanced Materials Hangzhou Dianzi UniversityHangzhou 310012China

A simplified analysis method based on micromagnetic simulation is proposed to investigate effects of nonmagnetic particles on the demagnetizing field of a permanent magnet By applying the additivity law of the demagnetizing field,the complicated demagnetizing field of the real magnet could be analyzed by only focusing on the stray field of the reserved magnet For a magnet with nonmagnetic particles inside,the particle size has no significant effect on the maximum value of the demagnetization field,but the area of the affected region by the particle is proportional to the particle size.A large particle produces a large affected area overlapped with those influenced by other particles,which leads to the large demagnetization field.With increasing the length of the particle along the magnetization direction,the demagnetization field on the pole surface increases.The pole surface with a convex shape will increase the demagnetization field.The demagnetizing field near the nonmagnetic particle will be further increased by the large macroscopic demagnetizing field near the pole surface.This work suggests some practical approaches to optimize the microstructure of permanent magnets.

关键词： demagnetizing field additivity micromagnetic simulation nonmagneticphase nucleation process

基于等效物理模型的脉冲电解微加工精度及定域性表征研究

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机械工程学报 2024年第5期60卷 378-389页

作者：赵传军王冀鹏许立忠燕山大学机械工程学院秦皇岛066004

针对脉冲微细电解加工多场耦合模型求解复杂、定域性难以量化表征的问题,基于电极/溶液GCS双电层模型,建立脉冲电解加工等效物理模型。利用该等效物理模型,分析双电层极化电压及各支路等效电流的瞬态响应规律,得到两种提高脉冲电解加工... 详细信息

针对脉冲微细电解加工多场耦合模型求解复杂、定域性难以量化表征的问题,基于电极/溶液GCS双电层模型,建立脉冲电解加工等效物理模型。利用该等效物理模型,分析双电层极化电压及各支路等效电流的瞬态响应规律,得到两种提高脉冲电解加工精度的方法:缩短脉宽和控制极化电压。分别揭示两种精度提高方法的作用机理,并建立其精度预测方程。根据工件分解电压特性,定义阳极加工区和过切区边界;通过对极化峰值电压随极间距变化规律的研究,采用加工区极化峰值电压差描述电解定域性,并建立定域性表征参数模型。利用Matlab对影响定域性工艺参数进行数值仿真分析,并通过微孔电解加工实验对理论分析结果进行验证。

关键词：脉冲电解加工等效模型定域性表征仿真分析精度预测

Micromagnetic simulation on magnetic properties of Nd2Fe14B/α-Fe nanocomposites with Fe nanowires as the soft phase

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Frontiers of Materials Science 2018年第4期12卷 348-353页

作者： Wei LI lizhong zhao Zhongwu LIU School of Materials Science and Engineering South China University of TechnologyGuangzhou 510640China

Fe nanowire array with strong shape anisotropy was employed as the soft phase in Nd-Fe-B based nanocomposites. The effects of the Fe nanowire distribution on magnetic properties of the nanocomposites were investigated by micromagnetic simulation. The results indicate that the shape anisotropy of Fe wires added in the same direction as the uniaxial magnetocrystalline anisotropy of the hard phase cannot increase the coercivity of the nanocomposite. When the nanowires are distributed perpendicular to the easy axis of the hard phase, the shape anisotropy of soft phase can retard the moments from rotating to the full reversed direction, leading to enhanced coercivity. In addition, with increasing the nanowire diameter, the coercivity of the nanocomposite decreases, but the dipolar interaction shows different roles in magnetic reversal of nanocomposite for different distributions of nanowires. The current results suggest that the coercivity of the Nd2Fe14B/α-Fe nanocomposite can be enhanced by introducing the soft magnetic nanowire array with the diameter less than the exchange length and with the long axis along the direction other than the easy axis of hard phase.

关键词： Nd 2 Fe 14 B/α-Fe nanocomposite micromagnetic simulation Fe nanowires shape anisotropy exchange coupling

Grain boundary construction and properties enhancement for hot deformed(Ce,La,Y)-Fe-B magnet by a two-step diffusion process

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Journal of Materials Science & Technology 2023年第34期165卷 253-261页

作者： Xuefeng Liao Weiwei Zeng lizhong zhao Qing Zhou Jiayi He Wei Li Xiangyi Liu Hongya Yu Xiaolian Liu Haoyang Jia Jean-Marc Greneche Xuefeng Zhang Zhongwu Liu School of Materials Science and Engineering South China University of TechnologyGuangzhou 510640China Institute of Advanced Magnetic Materials College of Materials&Environmental EngineeringHangzhou Dianzi UniversityHangzhou 310018China Guangdong Provincial Key Laboratory of Rare Earth Development and Application Institute of Resources Utilization and Rare Earth DevelopmentGuangdong Academy of SciencesGuangzhou 510640China School of Materials Science and Engineering Nanchang Hangkong UniversityNanchang 330063China Institut des Molécules et Matériaux du Mans IMMM CNRS UMR-6283 Le Mans UniversitéAvenue MessiaenLe Mans F-72085Cedex 9France

The rare earth-iron-boron magnets based on high abundance rare earths(REs)show potential for costeffective permanent magnets but their hard magnetic properties have to be greatly improved.The grain boundary diffusion process(GBDP)is known as an effective way to improve the coercivity of Nd-Fe-B magnets,however,the conventional diffusion method faces a challenge for Ce-based magnets since there is no enough continuous GB layer as the diffusion channel.Here,a two-step(Nd-Cu doping followed by Nd-Cu diffusion)GBDP was introduced for hot deformed(Ce,La,Y)-Fe-B magnet,and the excellent magnetic properties ofμ0Hc=0.63 T,μ0Mr=0.68 T,and(BH)max=72.4 kJ/m^(3)were achieved.The Nd-Cu doping helps the formation of RE-rich GB layer,and then it acts as the diffusion channel for increasing the ef-ficiency of the subsequent Nd-Cu diffusion and results in the increased volume fraction of continuously distributed GB phase,whose paramagnetism was verified by 57Fe Mössbauer spectrometry.Those paramagnetic GB phases help to form the discontinuous domain walls,as observed by Lorentz transmission electron microscopy,and break the magnetic exchange coupling of RE2Fe14B grains.It thus contributes to the coercivity enhancement of the hot deformed magnet with two-step diffusion,which is further proved by micromagnetic simulation.This study proposes a potential technique to prepare anisotropic hot deformed(Ce,La,Y)-Fe-B magnet with high cost-performance.

关键词： High abundance rare earth Hot deformed RE-Fe-B magnets Grain boundary diffusion process Magnetic properties Grain boundary phase

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基于双PSD的三维测角传感器精度分析

红外与激光工程 2024年第2期53卷 98-108页

作者：赵文赫白杨杨王劲凯张立中长春理工大学机电工程学院吉林长春130022 长春理工大学空间光电技术国家地方联合工程研究中心吉林长春130022

在机载光电转台、多自由度摇摆台等系统中,对于一些运动体与基座间没有确定的回转轴的柔性支撑、并联支撑平台,需要考虑非接触三轴角度测量方法,目前大部分的光电非接触三轴角度测量方案系统复杂,占用空间大,无法适用于如机载、星载等... 详细信息

在机载光电转台、多自由度摇摆台等系统中,对于一些运动体与基座间没有确定的回转轴的柔性支撑、并联支撑平台,需要考虑非接触三轴角度测量方法,目前大部分的光电非接触三轴角度测量方案系统复杂,占用空间大,无法适用于如机载、星载等载荷对体积、质量敏感的场景。为此,文中提出了基于双位置敏感探测器(PSD)的非接触三轴角度测量方案,使用准直镜头汇聚、双面反射光楔反射,将光源在两片PSD上汇聚成像,利用PSD上的光斑位置坐标反解出三轴角度。描述了其工作原理以及传感器构成,分析了因两片PSD的相对位置偏移产生的误差,提出了对应补偿方法以减少焊装产生的PSD位置偏移对测量精度的影响。主要对采集的PSD模拟信号值的抖动噪声进行FIR滤波处理,分析了滤波器的相频响应特性,并在MCU中测量相位滞后时间以及滤波器的响应带宽,验证了该数字滤波器在系统内拥有较好的实时传输特性。自准直测量单元总质量为230 g,尺寸为50 mm×50 mm×50 mm。实验结果表明,34阶FIR滤波器将角度测量的误差减小至60%,在±2°测量范围内单轴测量时,方位角、俯仰角、横滚角的误差均方根分别为0.003°、0.007°、0.017°,组合测量时分别为0.006°、0.009°、0.021°,文中所提出的三维测角传感器精度较高,满足机载等场景的使用要求。

关键词：三轴姿态角度测量非接触测量位置敏感探测器滤波带宽响应频率

Enhanced magnetic properties in chemically inhomogeneous Nd-Dy-Fe-B sintered magnets by multi-main-phase process

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Journal of Rare Earths 2021年第5期39卷 558-564页

作者： Xiaolian Liu Mengjie Pan Pei Zhang Tianyu Ma lizhong zhao Lingwei Li College of Materials&Environmental Engineering Hangzhou Dianzi UniversityHangzhou 310018China State Key Laboratory of Silicon Materials Key Laboratory of Novel Materials for Information Technology of Zhejiang ProvinceDepartment of Materials Science and EngineeringZhejiang UniversityHangzhou 310027China

Homogeneous substitution of Dy for Nd in the hard magnetic 2:14:1 phase can effectively enhance coercivity to ensure the high temperature operation,however,inevitably deteriorate remanence at expense.In this work,we performed a comparative investigation of the two magnets prepared by multimain-phase(co-sintering Nd_(2)Fe_(14)B and(Nd,Dy)_(2)Fe_(14)B powders)and single-main-phase(sintering(Nd,Dy)_(2)Fe_(14)B powders)approaches.The comparative investigation reveals that at the same Dy substitution level(2.16 wt%),such chemically inhomogeneous multi-main-phase magnet possesses better roomtemperature magnetic properties as well as thermal stability than those of the single-main-phase one with homogenous Dy distribution in the matrix grains.Room-temperature magnetic properties H_(Cj)=1664 kA/m,B_(r)=1.33 T and(BH)_(max)=350.4 kJ/m^(3)for the multi-main-phase magnet are all better than those for the single-main-phase magnet with H_(Cj)=1536 kA/m,B_(r)=1.29 T and(BH)_(max)=318.4 kj/m^(3).In addition,over the temperature range from 295 to 423 K,both the temperature coefficients of coercivity and remanence for the multi-main-phase magnet are also lower than that for the single-main-phase magnet.Such superior magnetic performance is attributed to the short-range magnetic interactions inside individual 2:14:1 phase grains and the long-range magnetostatic interactions between adjacent grains with inhomogeneous Dy distribution.Our work provides a feasible approach of enhancing coercivity and retaining energy product simultaneously in the Nd-Dy-Fe-B permanent magnets.

关键词： Permanent magnet Nd-Fe-B magnet Multi-main-phase Magnetic properties Thermal stability Microstructure