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Biaxial tensile behavior of CoCrFeNi high-entropy alloy under dynamic and proportional loadings

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CHINESE JOURNAL OF AERONAUTICS 2024年第9期37卷 475-489页

作者： li, Haoyang Gao, liqiang Qi, lin Feng, Yajing Wang, Jingyu li, yulong Yu, Qifeng Northwestern Polytech Univ Sch Aeronaut Xian 710072 Peoples R China Northwestern Polytech Univ Shaanxi Key Lab Impact Dynam & Engn Applicat Xian 710072 Peoples R China Northwestern Polytech Univ Sch Civil Aviat Suzhou 215699 Peoples R China NPU Yangzi River Delta Res Inst Suzhou 215400 Peoples R China

The dynamic failure behavior of CoCrFeNi High-Entropy Alloy (HEA) under plane biaxial stress was investigated in detail. The dynamic biaxial tensile tests were conducted using an Electromagnetic Biaxial Split Hopkinson Tensile Bar (EBSHTB) system. For comparison, the quasi-static uniaxial and biaxial tensile tests, as well as dynamic uniaxial tensile tests, were performed respectively. A cruciform specimen suitable for large plastic deformation was designed and employed in the experiments. The Finite Element Method (FEM) verified that the improved cruciform specimen could satisfy the basic requirements. The feasibility of the proposed specimen was further confirmed through loading tests. Finally, the quasi-static and dynamic yield loci of the HEA in the first quadrant of the principal stress space were plotted. The results indicate that the alloy exhibits obvious strain hardening effect and strain rate strengthening effect, the yield locus and plastic work contours can be accurately described by Hill'48 criterion. (c) 2024 Production and hosting by Elsevier Ltd. on behalf of Chinese Society of Aeronautics and Astronautics. This is an open access article under the CC BY-NC-ND license .

关键词： High-entropy alloys Biaxial tensile test Cruciform specimen Electromagnetic split Hop- kinson bar Digital image correlation

Wear-resistant CoCrNi multi-principal element alloy at cryogenic temperature

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Science Bulletin 2024年第2期69卷 227-236页

作者： Yue Ren Qing Zhou Dongpeng Hua Zhuobin Huang yulong li Qian Jia Peter Gumbsch Christian Greiner Haifeng Wang Weimin liu State Key Laboratory of Solidification Processing Center of Advanced Lubrication and Seal MaterialsNorthwestern Polytechnical UniversityXi’an 710072China Institute for Applied Materials Karlsruhe Institute of TechnologyKarlsruhe 76131Germany IAM-ZM MicroTribology CenterμTC Karlsruhe Institute of TechnologyKarlsruhe 76131Germany Fraunhofer IWM Freiburg 79108Germany State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China

Traditional high strength engineering alloys suffer from serious surface brittleness and inferior wear performance when servicing under sliding contact at cryogenic ***,we report that the recently emerging CoCrNi multi-principal element alloy defies this trend and presents dramatically enhanced wear resistance when temperature decreases from 273 to 153 K,surpassing those of cryogenic austenitic *** temperature-dependent structure characteristics and deformation mechanisms influencing the cryogenic wear resistance of CoCrNi are clarified through microscopic observation and atomistic *** is found that sliding-induced subsurface structures show distinct scenarios at different deformation *** cryogenic condition,significant grain refinement and a deep plastic zone give rise to an extended microstructural gradient below the surface,which can accommodate massive sliding deformation,in direct contrast to the strain localization and delamination at 273 ***,the temperature-dependent cryogenic deformation mechanisms(stacking fault networks and phase transformation)also provide additional strengthening and toughening of the subsurface *** features make the CoCrNi alloy particularly wear resistant at cryogenic conditions and an excellent candidate for safety–critical applications.

关键词： Multi-principal element alloy Cryogenic temperature Wear CoCrNi

Causal relationship between hypertension and epilepsy:a mendelian randomization study

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Acta Epileptologica 2024年第1期7卷 53-59页

作者： Zhen Sun Tong Jiang Mengwen Zhang yulong li Jing Zhang Yanping Sun Xiaofeng Yu Department of Neurology The Affiliated Hospital of Qingdao UniversityQingdao266000China Department of Endocrinology and Metabolism The Affiliated Hospital of Qingdao UniversityQingdao266000China Department of Neurology Qingdao Eighth People’s HospitalQingdao266000China

Background Recent studies suggest that hypertension may increase the risk of epilepsy onset,revealing intricate interactions between cardiovascular health and neurological disorders,thus emphasizing the significance of conducting further investigations into their *** study aimed to investigate the potential causality between hypertension,either in systolic or diastolic blood pressure,and epilepsy,using a Mendelian randomization *** A two-sample Mendelian randomization design was used in this *** extracted data from the UK Biobank,FinnGen,and the International Consortium of Blood Pressure,utilizing blood pressure-related single nucleotide polymorphisms as instrumental variables to evaluate the influence of hypertension on the risk of *** variance weighted,weighted median,and MR-Egger approaches were used for *** There was a potential association between hypertension,primarily in systolic blood pressure,and an elevated epilepsy risk,while the relationship between hypertension in diastolic blood pressure and epilepsy risk remained *** analyses suggest an absence of substantial heterogeneity and confounding effects,suggesting the reliability of our *** Our study lays the groundwork for further investigations into the mechanisms of this causal relationship,which may potentially involve vascular change,neuroinflammatory pathways,and alterations in cerebral blood flow,which are crucial for understanding the complex hypertension-epilepsy nexus.

关键词： Mendelian randomization Epilepsy Hypertension Systolic blood pressure

Self-consistent and precise measurement of time-dependent radiative albedo of gold based on specially symmetrical triple-cavity Hohlraum

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Matter and Radiation at Extremes 2024年第3期9卷 57-64页

作者： Zhiyu Zhang Yang Zhao Xiaoying Han liling li Bo Qing lifei Hou yulong li YuXue Zhang Huan Zhang Xiangming liu Bo Deng Gang Xiong Min Lv Tuo Zhu Chengwu Huang Tianming Song Yan Zhao Yingjie li Lu Zhang Xufei Xie Jiyan Zhang Jiamin Yang Laser Fusion Research Center China Academy of Engineering PhysicsMianyang 621900China National Key Laboratory of Plasma Physcis Mianyang 621900China Institute of Applied Physics and Computational Mathematics Beijing 100088China

A self-consistent and precise method to determine the time-dependent radiative albedo,i.e.,the ratio of the reemission flux to the incident flux,for an indirect-drive inertial confinement fusion Hohlraum wall material is proposed.A specially designed symmetrical triple-cavity gold Hohlraum is used to create approximately constant and near-equilibrium uniform radiation with a peak temperature of 160 *** incident flux at the secondary cavity waist is obtained from flux balance analysis and from the shock velocity of a standard *** results agree well owing to the symmetrical radiation in the secondary cavity.A self-consistent and precise time-dependent radiative albedo is deduced from the reliable reemission flux and the incident flux,and the result from the shock velocity is found to have a smaller uncertainty than that from the multi-angle flux balance analysis,and also to agree well with the result of a simulation using the HYADES opacity.

关键词： precise cavity radiative

An octopamine-specific GRAB sensor reveals a monoamine relay circuitry that boosts aversive learning

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National Science Review 2024年第05期 186-201页

作者： Mingyue Lv Ruyi Cai Renzimo Zhang Xiju Xia Xuelin li Yipan Wang Huan Wang Jianzhi Zeng Yifei Xue Lanqun Mao yulong li State Key Laboratory of Membrane Biology School of Life SciencesPeking University State Key Laboratory of Brain and Cognitive Science Institute of Biophysics Chinese Academy of Sciences PKU-IDG/Mc Govern Institute for Brain Research Yuanpei College Peking University Peking-Tsinghua Center for life Sciences Academy for Advanced Interdisciplinary Studies Peking University Peking University–Tsinghua University–National Institute of Biological Sciences Joint Graduate Program Academy for Advanced Interdisciplinary Studies Peking University Institute of Molecular Physiology Shenzhen Bay Laboratory College of Chemistry Beijing Normal University Chinese Institute for Brain Research

Octopamine（OA）,analogous to norepinephrine in vertebrates,is an essential monoamine neurotransmitter in invertebrates that plays a significant role in various biological functions,including olfactory associative ***,the spatial and temporal dynamics of OA in vivo remain poorly understood due to limitations associated with the currently available methods used to detect *** overcome these limitations,we developed a genetically encoded GPCR activation-based（GRAB） OA sensor called *** sensor is highly selective for OA and exhibits a robust and rapid increase in fluorescence in response to extracellular *** GRABOA1.0,we monitored OA release in the Drosophila mushroom body（MB）,the fly's learning center,and found that OA is released in response to both odor and shock stimuli in an aversive learning *** OA release requires acetylcholine（ACh） released from Kenyon cells,signaling via nicotinic ACh ***,we discovered that OA amplifies aversive learning behavior by augmenting dopamine-mediated punishment signals via Octβ1R in dopaminergic neurons,leading to alterations in synaptic plasticity within the ***,our new GRABOA1.0sensor can be used to monitor OA release in real time under physiological conditions,providing valuable insights into the cellular and circuit mechanisms that underlie OA signaling.

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Equation of state for boron nitride along the principal Hugoniot to 16 Mbar

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Matter and Radiation at Extremes 2024年第5期9卷 77-86页

作者： Huan Zhang Yutong Yang Weimin Yang Zanyang Guan Xiaoxi Duan Mengsheng Yang Yonggang liu Jingxiang Shen Katarzyna Batani Diluka Singappuli Ke Lan Yongsheng li Wenyi Huo Hao liu yulong li Dong Yang Sanwei li Zhebin Wang Jiamin Yang Zongqing Zhao Weiyan Zhang liang Sun Wei Kang Dimitri Batani National Key Laboratory of Plasma Physics Laser Fusion Research CenterChina Academy of Engineering PhysicsMianyang 621900China HEDPS Center for Applied Physics and Technologyand College of PhysicsPeking UniversityBeijing 100871China HEDPS Center for Applied Physics and Technologyand School of EngineeringPeking UniversityBeijing 100871China Institute of Plasma Physics and Laser Microfusion Hery 2301-497 WarszawaPoland Universitéde Bordeaux CNRSCEACELIA(Centre Lasers Intenses et Applications)UMR 5107F-33405 TalenceFrance Institute of Applied Physics and Computational Mathematics Beijing 100094China

The thermodynamic properties of boron nitride under extreme pressures and temperatures are of great interest and importance for materials science and inertial confinement fusion physics,but they are poorly understood owing to the challenges of performing experiments and realizing ab initio ***,we report the first shock Hugoniot data on hexagonal boron nitride at pressures of 5–16 Mbar,using hohlraum-driven shock waves at the SGIII-p laser facility in *** density functional theory molecular dynamics calculations closely match experimental data,validating the equations of state for modeling the shock response of boron nitride and filling a crucial gap in the knowledge of boron nitride properties in the region of multi-Mbar pressures and eV *** results presented here provide fundamental insights into boron nitride under the extreme conditions relevant to inertial confinement fusion,hydrogen–boron fusion,and high-energy-density physics.

关键词： boron Hugoniot extreme

弱电网下基于电网电压前馈的并网逆变器阻抗重塑控制策略

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电工技术学报 2024年第8期39卷 2553-2566页

作者：杨明杨倬李玉龙朱军河南理工大学电气工程与自动化学院河南省煤矿装备智能检测与控制重点实验室焦作454003

弱电网下,锁相环在基波以上频段引入的负阻特性,会降低系统输出阻抗的相位,严重影响系统稳定性。鉴于此,该文通过系统控制框图等效变换,推导得到可以消除锁相环负阻特性的电网电压前馈函数,进而提出一种基于电网电压前馈控制的并网逆变... 详细信息

弱电网下,锁相环在基波以上频段引入的负阻特性,会降低系统输出阻抗的相位,严重影响系统稳定性。鉴于此,该文通过系统控制框图等效变换,推导得到可以消除锁相环负阻特性的电网电压前馈函数,进而提出一种基于电网电压前馈控制的并网逆变器阻抗重塑控制策略。同时,为了提高该策略的普适性,该文利用函数近似和多目标约束为电网电压前馈函数的优化提供两种设计方法,并从系统基波电流跟踪性能、并网功率因数等方面进行误差分析,从而证明其函数优化设计方法的可行性。理论分析表明,优化后的电网电压前馈控制策略,可以有效地对系统输出阻抗相位特性进行重塑,很大程度上拓宽了系统对电网阻抗的适应范围。最后,通过仿真与实验验证所提控制策略的有效性。

关键词：弱电网并网逆变器阻抗重塑锁相环稳定性

基于电容电压全前馈的并网逆变器高鲁棒性稳定控制策略

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高电压技术 2024年第9期50卷 4171-4183,I0024页

作者：杨明李玉龙杨倬朱军解宝河南省煤矿装备智能检测与控制重点实验室(河南理工大学电气工程与自动化学院) 焦作454003 光伏系统教育部工程研究中心(合肥工业大学) 合肥230009

虽然并网逆变器采用电容电压全前馈控制策略,能够有效抑制电网电压背景谐波对并网电流的影响。但是在弱电网工况环境下,由于锁相环、数字控制延时等因素与电网阻抗相互耦合,导致逆变器稳定较差、在阻抗交截频域中呈现弱无源性,易引发系... 详细信息

虽然并网逆变器采用电容电压全前馈控制策略,能够有效抑制电网电压背景谐波对并网电流的影响。但是在弱电网工况环境下,由于锁相环、数字控制延时等因素与电网阻抗相互耦合,导致逆变器稳定较差、在阻抗交截频域中呈现弱无源性,易引发系统谐波振荡甚至失稳问题。鉴于此,该文借助无源性理论和阻抗分析方法,深度揭示了影响系统各频带阻抗特性的主导因素,进而提出了一种基于电容电压全前馈的并网逆变器高鲁棒性稳定控制策略。理论分析表明:所提控制策略不仅能有效地拓宽系统输出阻抗稳定范围,还可以保证改进后的系统输出阻抗具有较高的幅值增益。最后,通过仿真和实验验证了所提控制策略的有效性。

关键词：弱电网电容电压全前馈数字控制延时锁相环并网逆变器无源性理论

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黄精乌鸡膏营养组分及其对不同免疫状态小鼠肠道黏膜形态和免疫性能的影响

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食品与发酵工业 2024年第13期50卷 55-63,71页

作者：张敏冯景刘喆李玉龙陕西中医药大学基础医学院陕西咸阳712046

为探究黄精乌鸡膏(jellied black-bone chicken with rhizoma polygonati,JBR)营养组分及免疫调控作用,该研究采用代谢组方法检测了JBR营养和功能性物质组成状况,用于探讨其潜在生物学调节作用,进而分析了JBR对不同免疫状态C57BL/6小鼠... 详细信息

为探究黄精乌鸡膏(jellied black-bone chicken with rhizoma polygonati,JBR)营养组分及免疫调控作用,该研究采用代谢组方法检测了JBR营养和功能性物质组成状况,用于探讨其潜在生物学调节作用,进而分析了JBR对不同免疫状态C57BL/6小鼠体重、肠道黏膜形态及免疫性能的影响。结果表明,相比普通乌鸡膏,JBR中多种必须氨基酸和功能性物质含量显著提高,KEGG通路分析显示JBR具有调控营养代谢和免疫性能的潜在作用。动物试验结果显示,JBR可显著改善环磷酰胺处理及脂多糖(lipopolysaccharide,LPS)攻毒导致的小鼠肠黏膜损伤,因此可对环磷酰胺导致的小鼠体重降低产生显著缓解效应。此外,JBR可抑制环磷酰胺+LPS攻毒导致的脾脏NF-κB高表达,并可降低环磷酰胺+LPS处理导致的脾脏和血清TNF-α高表达,抑制免疫抑制小鼠的急性炎症反应并缓解炎症导致的脾脏组织损伤,脾淋巴细胞增殖活性、外周血半数溶血值和NK细胞活力等免疫指标均显示JBR可显著提高免疫抑制小鼠的免疫功能,并可改善LPS攻毒导致的免疫异常。JBR具有调控营养代谢和免疫性能作用,可显著改善免疫抑制小鼠的小肠黏膜组织形态和免疫性能,有利于免疫抑制小鼠更好的应对LPS诱导的脾脏急性炎症反应,缓解急性炎症导致的脾脏损伤。

关键词：黄精乌鸡膏代谢组 C57BL/6小鼠肠道黏膜形态免疫功能

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