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Optimization of ferroelectricity and endurance of hafnium zirconium oxide thin films by controlling element inhomogeneity

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Journal of Advanced Ceramics 2024年第7期13卷 1023-1031页

作者： Fei Yan Ke Cao Yang Chen Jiajia liao Min liao Yichun Zhou Shaanxi Key Laboratory of High-Orbits-Electron Materials and Protection Technology for Aerospace School of Advanced Materials and NanotechnologyXidian UniversityXi’an 710126China Xi’an Key Laboratory of Reconfigurable Chip and Materials School of Advanced Materials and NanotechnologyXidian UniversityXi’an 710126China Frontier Research Center of Thin Films and Coatings for Device Applications Academy of Advanced Interdisciplinary ResearchXidian UniversityXi’an 710126China

Ferroelectric thin films based on HfO2 have garnered increasing attention worldwide,primarily due to their remarkable compatibility with silicon and scalability,in contrast to traditional perovskite-structured ferroelectric ***,significant challenges remain in their widespread commercial utilization,particularly concerning their notable wake-up effect and limited *** address these challenges,we propose a novel strategy involving the inhomogeneous distribution of Hf/Zr elements within thin films and explore its effects on the ferroelectricity and endurance of Hf_(0.5)Zr_(0.5)O_(2) thin *** techniques such as grazing incidence X-ray diffraction,transmission electron microscopy,and piezoresponse force microscopy,we investigated the structural characteristics and domain switching behaviors of these *** experimental results indicate that the inhomogeneous distribution of Hf/Zr contributes to improving the frequency stability and endurance while maintaining a large remnant polarization in Hf_(0.5)Zr_(0.5)O_(2) ferroelectric thin *** adjusting the distribution of Zr/Hf within the Hf_(0.5)Zr_(0.5)O_(2) thin films,significant enhancements in the remnant polarization(2Pr>35μC/cm2)and endurance(>109)along with a reduced coercive voltage can be ***,the fabricated ferroelectric thin films also exhibit high dielectric tunability(≥26%)under a low operating voltage of 2.5 V,whether in the wake-up state or *** study offers a promising approach to optimize both the ferroelectricity and endurance of HfO_(2)-based thin films.

关键词： ferroelectric capacitors thin films ferroelectricity hafnium zirconium oxide

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挤压态FGH4096合金的热变形行为及热加工图

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材料导报 2019年第12期33卷 2047-2054页

作者：陈龙司家勇刘松浩廖凯中南林业科技大学机电工程学院

为了获得挤压态FGH4096合金的热加工最佳工艺参数,利用Gleeble 3180D热模拟实验机对热挤压后的FGH4096合金进行了高温压缩实验,研究了其在变形温度1020~1140℃、应变速率0.001~1.0s^-1、压下量50%条件下的高温变形行为,分析了应变速率... 详细信息

为了获得挤压态FGH4096合金的热加工最佳工艺参数,利用Gleeble 3180D热模拟实验机对热挤压后的FGH4096合金进行了高温压缩实验,研究了其在变形温度1020~1140℃、应变速率0.001~1.0s^-1、压下量50%条件下的高温变形行为,分析了应变速率和变形温度对流变应力的影响,并基于双曲正弦模型与动态材料模型建立相应的本构方程和热加工图。结果表明,该合金的热变形激活能为1128.79kJ/mol;优化的热加工工艺参数范围为变形温度1049~1080℃、应变速率0.005~0.013s^-1,在该区域内合金的能量耗散率峰值为64%。通过微观组织分析发现,此区域内金相组织发生完全动态再结晶,合金的晶粒细小且均匀。

关键词： FGH4096合金挤压态热压缩本构模型热加工图

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喀斯特山区不同植被类型土壤有机碳的变化

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应用生态学报 2011年第9期22卷 2253-2258页

作者：廖洪凯龙健贵州师范大学贵州省山地环境重点实验室贵阳550001

研究了贵州西南部典型喀斯特山区不同植被类型下常规土壤及小生境土壤中有机碳及不同粒径土壤颗粒有机碳的变化.结果表明:不同植被类型下,常规及小生境土壤有机碳含量均表现为:裸地<草丛<灌木林<乔木林,常规土壤变幅在7.18～43.42g·kg... 详细信息

研究了贵州西南部典型喀斯特山区不同植被类型下常规土壤及小生境土壤中有机碳及不同粒径土壤颗粒有机碳的变化.结果表明:不同植被类型下,常规及小生境土壤有机碳含量均表现为:裸地<草丛<灌木林<乔木林,常规土壤变幅在7.18～43.42g·kg-1,土面和石坑土壤有机碳变幅分别为6.62～46.47g·kg-1和9.01～52.07g·kg-1;颗粒有机碳(POC)/矿物结合态有机碳(MOC)值均为:裸地<草丛<乔木林<灌木林,同一植被类型下,与常规及土面相比,石坑中土壤POC/MOC值最高;植被在由裸地-草丛-灌木林-乔木林的变化过程中,不同粒径土壤颗粒有机碳含量增加,而土壤有机碳主要以砂粒及粉砂粒有机碳形式存在,说明喀斯特地区土壤的固碳能力及有机碳稳定性较弱,土壤易受外界干扰而引发有机碳流失,土壤质量存在下降或退化的风险.

关键词：喀斯特植被类型小生境有机碳土壤颗粒

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Interface property of dissimilar Ti-6Al-4V/AA1050 composite laminate made by non-equal channel lateral co-extrusion and heat treatment

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Defence Technology（防务技术） 2024年第3期33卷 197-208页

作者： Juan liao Mengmeng Tian Xin Xue School of Mechanical Engineering and Automation Fuzhou UniversityFuzhou 350116China

The purpose of this paper is to examine the effect of processing parameters and subsequent heat treatments on the microstructures and bonding strengths of Ti-6Al-4V/AA1050 laminations formed via a non-equal channel lateral co-extrusion *** microstructural evolution and growth mechanism in the diffusion layer were discussed further to optimize the bonding quality by appropriately adjusting process *** electron microscopes(SEM),energy dispersive spectrometer(EDS),and X-ray diffraction(XRD)were used to characterize interfacial diffusion *** shear test was used to determine the mechanical properties of the interfacial diffusion *** experimental results indicate that it is possible to co-extrusion Ti-6Al-4V/AA1050 compound profiles using non-equal channel lateral *** heat treatment processes affect the thickness of the diffusion *** the temperature and time of heat treatment increase,the thickness of the reaction layers increases ***,the shear strength of the Ti-6Al-4V/AA1050 composite interface is proportional to the diffusion layer *** is observed that a medium interface thickness results in superior mechanical performance when compared to neither a greater nor a lesser interface *** characterization of all heat treatments reveals that the only intermetallic compound observed in the diffusion layers is TiAl_(3).Due to the inter-diffusion of Ti and Al atoms,the TiAl_(3) layer grows primarily at AA1050/TiAl_(3) interfaces.

关键词： Shear strength Co-extrusion Heat treatment Microstructure Intermetallic compounds

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Assessing Soil Water Retention Characteristics and Their Spatial Variability Using Pedotransfer Functions

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Pedosphere 2011年第4期21卷 413-422页

作者： liao kai-Hua1, XU Shao-Hui2,.2, WU Ji-Chun1, JI Shu-Hua2 and LIN Qing2 XU Shao-Hui WU Ji-Chun JI Shu-Hua LIN Qing Department of Hydrosciences Nanjing University Nanjing 210093 (China) Department of Environmental Science Qingdao University Qingdao 266071 (China)

A total of 107 soil samples were taken from the city of Qingdao,Shandong Province,*** water retention data at 2.5,6,10,33,100,300,and 1 500 kPa matric potentials were measured using a pressure membrane *** linear regression (MLR) was used to develop pedotransfer functions (PTFs) for single point estimation and van Genuchten parameter estimation based on readily measurable soil properties,i.e.,MLR-based point (MLRP) PTF and MLR-based parametric (MLRV) *** double cross-validation method was used to evaluate the accuracy of PTF estimates and the stability of the PTFs developed in this *** performance of MLRP and MLRV PTFs in estimating water contents at matric potentials of 10,33,and 1 500 kPa was compared with that of two existing PTFs,the Rawls PTF and the Vereecken *** addition,geostatistical analyses were conducted to assess the capabilities of these PTFs in describing the spatial variability of soil water retention *** showed that among all PTFs only the Vereecken PTF failed to accurately estimate water retention *** the MLRP PTF can be used to predict retention characteristics through traditional statistical analyses,it failed to describe the spatial variability of soil water retention *** the MLRV and Rawls PTFs failed to describe the spatial variability of water contents at a matric potential of 10 kPa,they can be used to quantify the spatial variability of water contents at matric potentials of 33 and 1 500 kPa.

关键词： double cross-validation method multiple linear regression soil water content van Genuchten parameter

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基于能量分层协调控制的能量路由器

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太阳能学报 2018年第5期39卷 1388-1395页

作者：刘凯陈才学文军朱厚达廖凯湘潭大学信息工程学院

提出一种能量路由器的能量协调控制方法,该方法包含3个层次：第1层,能量路由器根据当地直流母线电压进行协调控制;第2层,为保障重要负载的工作时间,依据储能电池SOC值对不同负载进行切除;第3层,为提高应对突发故障的能力,依据上层指令... 详细信息

提出一种能量路由器的能量协调控制方法,该方法包含3个层次：第1层,能量路由器根据当地直流母线电压进行协调控制;第2层,为保障重要负载的工作时间,依据储能电池SOC值对不同负载进行切除;第3层,为提高应对突发故障的能力,依据上层指令或并网情况对储能量进行优化控制。同时为改善光伏发电中恒压控制与MPPT之间切换易导致系统不稳定问题,提出一种自由无缝切换方法,提高系统的稳定性。为验证能量路由器能量协调控制方法正确性,在Matlab/Simulink仿真平台上搭建典型能量路由器系统,对控制方法进行系统仿真,仿真结果证明所提控制策略可行。

关键词：能源互联网能量路由器分层控制恒压控制

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Synergistic extraction and separation of thorium from rare earths in chloride media using mixture of Cextrant 230 and Cyanex 923

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Journal of Rare Earths 2024年第4期42卷 759-767页

作者： Hui Wang Shengting Kuang Wuping liao School of Rare Earths University of Science and Technology of ChinaHefei230026China Institute of Material and Chemistry Ganjiang Innovation AcademyChinese Academy of SciencesGanzhou341000China State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun130022China

In order to lower the usage of expensive Cyanex 923 and increase the extraction capacity of the system of Cextrant 230,the synergistic extraction of thorium from chloride media by a mixture of Cextrant 230 and Cyanex 923 was *** maximum synergistic enhancement coefficient(R)of 1.53 is obtained at 1:1 molar ratio of Cextrant 230/Cyanex *** syne rgistic extracted species of Th^(4+)is determined as ThCl_(4)·2Cextrant 230·Cyanex *** synergistic extraction of Th^(4+)is an entropy-driven exothermic *** loading capacity of 0.60 mol/L mixed extractant for thorium is about 17.10 g/L(calculated as ThO_(2)),and the loaded thorium in the organic phase can be effectively stripped by distilled *** comparison,rare earth cations are barely extracted under the similar conditions,suggesting that the mixtures can be applied to separate thorium from rare earths.A cascade extraction process was developed based on the synergistic extraction system to separate thorium from the hydrochloric acid leaching of *** content of thorium in the leaching solution decreases obviously from 19.90 mg/L to1.4μg/L by 3 stages of extraction,which is superior to sole Cextrant 230 or Cyanex *** introduction of Cextrant 230 into the extraction system not only lowers the usage of Cyanex 923 but also enhances the selective extraction of thorium at low acidity,implying that the synergistic extraction system can selectively extract thorium more efficiently and economically than the sole systems.

关键词： Synergistic extraction Cextrant 230 Cyanex 923 Thorium Rare earths

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Application of plant DNA metabarcoding of lake sediments for monitoring vegetation compositions on the Tibetan Plateau

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Science China Earth Sciences 2024年

作者： kai WU kai LI Weihan JIA Kathleen R.STOOF-LEICHSENRING Ulrike HERZSCHUH Jian NI Mengna liao Fang TIAN College of Life Sciences Zhejiang Normal University Polar Terrestrial Environmental Systems Research Group Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research Institute of Environmental Science and Geography University of Potsdam Institute of Biochemistry and Biology University of Potsdam College of Resource Environment and Tourism Capital Normal University

Benefiting from the rapid development of environmental DNA (eDNA) technologies,sedimentary DNA (sedDNA)emerges as a promising tool for monitoring plant compositions in remote *** Tibetan Plateau (TP),renowned for its harsh environment and numerous ponds and lakes,presents a potentially demanding region for the application of sedDNA on vegetation ***,we used the g and h universal primers for the P6 loop region of the chloroplast trn L (UAA)intron to amplify plant DNA in surface sediments from 59 ponds and small lakes on the southwestern *** applicability and limitations of using plant DNA metabarcoding for modern vegetation monitoring and palaeo-vegetation reconstructions have been assessed by comparing sedDNA,pollen,and vegetation survey *** results showed that plant DNA metabarcoding recorded 186 terrestrial taxa,of which 30.1%can be identified at the species *** plant sedDNA approach can effectively disclose the dominant plant taxa (including Asteraceae,Cyperaceae and Poaceae) and significant vegetation assemblages in the vicinity of the investigated *** number of taxa and taxonomic resolution of plant sedDNA exceeded that of pollen analysis(75 taxa detected,5.3%can be identified at species level).Unlike pollen that retains a broad spectrum of regional plant signals(including Pinus and Artemisia),plant sedDNA mirrors very local plants,underscoring its utility in local vegetation monitoring and *** conclude,plant DNA metabarcoding of (small) lake sediments warrant increased attention in the future for local vegetation monitoring and reconstructions on the TP.

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Thermodynamic property of sandwich cylindrical shell structure with metallic wire mesh:Numerical modeling and experimental analysis

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Chinese Journal of Aeronautics 2024年第1期37卷 138-152页

作者： Xin XUE Guojian SHEN Juan liao Institute of Metal Rubber&Vibration Noise School of Mechanical Engineering and AutomationFuzhou UniversityFuzhou 350116China Fujian Shuikou Power Generation Group Co. LTDFuzhou 350000China

As a new addition to lightweight composite structures,the sandwich cylindrical shell with a metallic wire mesh core has emerged as a promising solution for thermodynamic performance analysis at elevated *** intricate interwoven cellular formations within the metallic wire mesh pose difficulties for thermo-mechanical modeling and property ***,the constitutive models employed to characterize hysteresis phenomena were presented,comprising isotropic elasticity,Bergstrom-Boyce model,Ogden hyper-elasticity,and parameter identification through mechanical examinations at varying ***,the finite element modeling of cylindrical shell structures was determined for modal and steady-state dynamic ***,the experimental procedures were carried out,including the preparation of the sandwich cylindrical shell and the dynamic testing *** first-order natural frequency of the cylindrical shell structure is close to the resonance frequency of the dynamic test results,with a maximum error of 6.5%,demonstrating the accuracy of the simulation *** compared to the solid-core cylindrical shell,the average insertion loss of the sandwich cylindrical shell structure within the frequency range of 10–1000 Hz at room temperature is up to 11.09 ***,at elevated temperatures,the average insertion loss of the sandwich cylindrical shell decreases but fluctuates as the temperature changes.

关键词： Energy dissipation Metallic matrix composites Numerical analysis Sandwich structure Thermodynamic properties

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浅埋大断面黄土隧道防塌方实时监测预警

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现代隧道技术 2014年第2期51卷 11-15,22页

作者：马士伟韩学诠廖凯中铁西南科学研究院有限公司成都611731 中国铁路工程总公司北京100038

为减少隧道塌方对工程的损害,文章依托大断面浅埋黄土隧道工程实例,提出了隧道防塌方实时预警的思路和方法,给出了隧道防塌方预警基准值的确立原则和预警分级标准,开发出了隧道防塌方预警系统(软、硬件),并进行了现场试验。结果表明:该... 详细信息

为减少隧道塌方对工程的损害,文章依托大断面浅埋黄土隧道工程实例,提出了隧道防塌方实时预警的思路和方法,给出了隧道防塌方预警基准值的确立原则和预警分级标准,开发出了隧道防塌方预警系统(软、硬件),并进行了现场试验。结果表明:该系统软、硬件性能可靠,能适应隧道复杂施工环境;测试仪器数据采集、传输正常;软件系统数据能根据监测数据变化,实现分级报警。

关键词：大断面黄土隧道塌方实时监测预警

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