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Subsurface macro-inclusions and solidified hook character in aluminum-killed deep-drawing steel slabs

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International Journal of Minerals,Metallurgy and Materials 2014年第6期21卷 531-543页

作者： Xiao-xuan Deng lin-ping li Xin-hua Wang Yun-qing ji Chen-xi ji Guo-sen Zhu School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Shougang Research Institute of Technology Shougang Group

Subsurface macro-inclusions and hooks are detrimental to the surface quality of deep-drawing steel sheets. However, little is known about the relationship between macro-inclusions and hooks. Thus, in this work, two ultralow carbon （ULC） steel slabs and two low carbon （LC） aluminum-killed steel slabs were sampled to study the relationship between hooks and subsurface macro-inclusions, which were detected on the cross-sections of steel samples with an area of 56058 mm2 using an automated scanning electron microscopy/energy-disper-sive X-ray spectroscopy system. Results show that subsurface inclusions larger than 200 μm were almost entrapped by hook structures, whereas the location of other inclusions smaller than 200μm had no obvious dependence on the location of solidified hooks. Furthermore, the number density （ND） of subsurface inclusions larger than 200μm decreased from 0.02 to 0 cm-2 in ULC steel as the mean hook depth decreased from 1.57 to 1.01 mm. Similar trends were also observed in LC steel. In addition, the detected inclusions larger than 200μm were concentrated in the region near the slab center （3/8 width-5/8 width）, where hook depths were also larger than those at any other locations. Therefore, minimizing the hook depth is an effective way to reduce inclusion-induced sliver defects in deep-drawing steels.

关键词： low carbon steel aluminum-killed steel steel sheet deep drawing inclusions hooks

Mechanical properties of hot-pressed high-entropy diboride-based ceramics

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Journal of Advanced Ceramics 2020年第4期9卷 503-510页

作者： ji-xuan liu Xiao-Qin Shen Yue Wu Fei li Yongcheng liang Guo-Jun Zhang State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and EngineeringCollege of SciencesInstitute of Functional MaterialsDonghua UniversityShanghai201620China

High-entropy ceramics attract more and more attention in recent ***,mechanical properties especially strength and fracture toughness for high-entropy ceramics and their composites have not been comprehensively *** this work,high-entropy(Ti0.2Zr0.2Hf0.2Nb0.2Ta 0.2)B2(HEB)monolithic and its composite containing 20 vol%SiC(HEB–20SiC)are prepared by hot *** addition of SiC not only accelerates the densification process but also refines the microstructure of HEB,resulting in improved mechanical *** obtained dense HEB and HEB–20SiC ceramics hot pressed at 1800℃exhibit four-point flexural strength of 339±17 MPa and 447±45 MPa,and fracture toughness of 3.81±0.40 MPa·m1/2 and 4.85±0.33 MPa·m1/2 measured by single-edge notched beam(SENB)*** deflection and branching by SiC particles is considered to be the main toughening mechanisms for the HEB–20SiC *** hardness Hv0.2 of the sintered HEB and HEB–20SiC ceramics is 23.7±0.7 GPa and 24.8±1.2 GPa,*** the increase of indentation load,the hardness of the sintered ceramics decreases rapidly until the load reaches about 49 N,due to the indentation size *** on the current experimental investigation it can be seen that the room temperature bending strength and fracture toughness of the high-entropy diboride ceramics are within ranges commonly observed in structure ceramics.

关键词： high-entropy ceramics high-entropy diboride flexural strength fracture toughness indentation size effect

Dielectric thin films for GaN-based high-electron-mobility transistors

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Rare Metals 2015年第6期34卷 371-380页

作者： Yan-Rong li Xing-Zhao liu Jun Zhu ji-Hua Zhang lin-xuan Qian Wan-li Zhang State Key Laboratory of Electronic Thin Films and Integrated Devices School of Microelectronics and Solid-State Electronics University of Electronic Science and Technology of China

The effects of dielectric thin films on the performance of GaN-based high-electron-mobility transistors （HEMTs） were reviewed in this work. Firstly, the nonpolar dielectric thin films which act as both the surface passivation layers and the gate insulators of the high-frequency GaN-based high-electron-mobility transistors were presented. Furthermore, the influences of dielectric thin films on the electrical properties of two-dimensional electron gas （2DEG） in the A1GaN/GaN hetero-structures were ana- lyzed. It was found that the additional in-plane biaxial tensile stress was another important factor besides the change in surface potential profile for the device perfor- mance improvement of the A1GaN/GaN HEMTs with dielectric thin films as both passivation layers and gate dielectrics. Then, two kinds of polar gate dielectric thin films, the ferroelectric liNbO3 and the fluorinated A1203, were compared for the enhancement-mode GaN-based HEMTs, and an innovative process was proposed. At last, high-permittivity dielectric thin films were adopted as passivation layers to modulate the electric field and accordingly increase the breakdown voltage of GaN-based HEMTs. Moreover, the polyimide embedded with Cr particles effectively increased the breakdown voltage of GaNbased HEMTs. Finally, the effects of high-permittivity dielectric thin films on the potential distribution in the drift region were simulated, which showed an expanded electric field peak at the drain-side edge of gate electrode.

关键词： GaN-based HEMTs Surface passivation Gate dielectrics Enhancement-mode HEMTs High-permittivity field plate

Free vibration analysis of functionally graded material beams based on Levinson beam theory

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Applied Mathematics and Mechanics(English Edition) 2016年第7期37卷 861-878页

作者： xuan WANG Shirong li School of Hydraulic Energy and Power Engineering Yangzhou University School of Civil Science and Engineering Yangzhou University

Free vibration response of functionally graded material （FGM） beams is studied based on the Levinson beam theory （LBT）. Equations of motion of an FGM beam are derived by directly integrating the stress-form equations of elasticity along the beam depth with the inertial resultant forces related to the included coupling and higherorder shear strain. Assuming harmonic response, governing equations of the free vibration of the FGM beam are reduced to a standard system of second-order ordinary differential equations associated with boundary conditions in terms of shape functions related to axial and transverse displacements and the rotational angle. By a shooting method to solve the two-point boundary value problem of the three coupled ordinary differential equations, free vibration response of thick FGM beams is obtained numerically. Particularly, for a beam with simply supported edges, the natural frequency of an FGM Levinson beam is analytically derived in terms of the natural frequency of a corresponding homogenous Euler-Bernoulli beam. As the material properties are assumed to vary through the depth according to the power-law functions, the numerical results of frequencies are presented to examine the effects of the material gradient parameter, the length-to-depth ratio, and the boundary conditions on the vibration response.

关键词： functionally graded material (FGM) beam Levinson beam theory (LBT),free vibration shooting method natural frequency

A high entropy silicide by reactive spark plasma sintering

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Journal of Advanced Ceramics 2019年第1期8卷 148-152页

作者： Yuan QIN ji-xuan liU Fei li Xiaofeng WEI Houzheng WU Guo-Jun ZHANG State Key Laboratory for Modification of Chemical Fibers and Polymer Materials Institute of Functional Materials College of Materials Science and Engineering Donghua University Department of Materials Loughborough University

A high-entropy silicide(HES),(Ti_(0.2) Zr_(0.2) Nb_(0.2) Mo_(0.2) W_(0.2))Si_2 with close-packed hexagonal structure is successfully manufactured through reactive spark plasma sintering at 1300 ℃ for 15 *** elements in this HES are uniformly distributed in the specimen based on the energy dispersive spectrometer analysis except a small amount of zirconium that is combined with oxygen as impurity particles. The Young's modulus, Poisson's ratio,and Vickers hardness of the obtained(Ti_(0.2) Zr_(0.2) Nb_(0.2) Mo_(0.2) W_(0.2))Si_2 are also measured.

关键词： high-entropy ceramics high-entropy silicide spark plasma sintering silicide

NONliNEAR ANALYSIS OF A 5-LAYER BEAM-liKE PIEZOELECTRIC TRANSFORMER NEAR RESONANCE

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Acta Mechanica Solida Sinica 2014年第2期27卷 195-201页

作者： Hairen Wang xuan Xie Yuantai Hu ji Wang Purple Mountain Observatory Chinese Academy of Sciences Department of Mechanics Huazhong University of Science and Technology Piezoelectric Device Laboratory Department of Mechanics and Engineering Science School of Mechanical Engineering and Mechanics Ningbo University

The paper examines the weakly nonlinear behavior of a 5-layer beam-like piezo- electric transformer operating near resonance, where the main structure of the device consists of properly poled and electroded flexible piezoceramic four-layers separated by a central metallic layer. Nonlinear effects of the large deflection to induce the incidental implane extension near res- onance are considered, which is shown that on one side of the resonant frequency the output-input relation becomes nonlinear, and the other side output voltage experiences jumps.

关键词： piezoelectric transformer resonance nonlinear vibration jump multi-valuedness

Novel design of a personnel safety system for Hefei light Source-Ⅱ

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Nuclear Science and Techniques 2019年第6期30卷 114-121页

作者： Zi-Yu Huang Ke xuan Chuan li ji-Gang Wang Gong-Fa liu National Synchrotron Radiation Laboratory University of Science and Technology of China

The Hefei light Source-Ⅱ(HLS-Ⅱ) is a vacuum ultraviolet synchrotron light source. The personnel safety system (PSS), which is a personnel access control system, is a crucial part of the HLS-Ⅱ, as it protects the staff and users at HLS-Ⅱfrom radiation damages. The prior version of HLS-Ⅱ PSS was based on an access control system called SiPass. This lacked the personnel management function. Meanwhile, as the prior PSS is a turn-key system, it was not effective for sharing information. To overcome these drawbacks, the novel design of PSS for HLS-Ⅱ is proposed based on the Siemens redundant programmable logic controller under the Experimental Physics and Industrial Control System. The proposed PSS consists of a safety interlock system, access control system, and a radiation monitoring system. The safety interlock system is used to define the interlock logic. The access control system is designed to restrict the access of staff and users at HLS-Ⅱ, and to provide a personnel management function. The radiation monitoring system is used to monitor the radiation dose rate in both the light source and the surrounding areas. This paper details the architecture and the specific design of the novel PSS. The off-line test results demonstrate that the proposed system has achieved the design objectives.

关键词： Personnel safety system Personnel management Redundant programmable logic controller PROFINET Experimental Physics and Industrial Control System

Burden of mental disorders and risk factors in the Western Pacific region from 1990 to 2021

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World Journal of Psychiatry 2025年第1期15卷 93-105页

作者： Ya-Xin Xu Xiao-xuan Niu Wen-Chang jia jing Wen Xue-lin Cheng Yan Han Ming-Hui Peng jing Zhou Yao liu Sun-Fang jiang Xiao-Pan li Department of Health Management Centre Zhongshan HospitalFudan UniversityShanghai 200030China Department of General Practice Zhongshan HospitalFudan UniversityShanghai 200030China Department of Nutrition Zhongshan HospitalFudan UniversityShanghai 200032China School of Public Health Fudan UniversityShanghai 200032China

BACKGROUND The burden of mental disorders(MD)in the Western Pacific Region(WPR)re-mains a critical public health concern,with substantial variations across demogra-phics and *** To analyze the burden of MD in the WPR from 1990 to 2021,along with associated risk factors,to reveal changing trends and emerging *** We used data from the Global Burden of Disease 2021,analyzing prevalence,incidence,and disability-adjusted life years(DALYs)of MD from 1990 to *** methods included age-standardisation and uncertainty analysis to address variations in population structure and data *** Between 1990 and 2021,the prevalence of MD rose from 174.40 million cases[95%uncertainty interval(UI):160.17-189.84]to 234.90 million cases(95%UI:219.04-252.50),with corresponding DALYs increasing from 22.8 million(95%UI:17.22-28.79)to 32.07 million(95%UI:24.50-40.68).During this period,the burden of MD shifted towards older age *** and anxiety disorders were predominant,with females showing higher DALYs for depressive and anxiety disorders,and males more affected by conduct disorders,attention-deficit hyperactivity disorder,and autism spectrum ***,New Zealand,and Malaysia reported the highest burdens,whereas Vietnam,China,and Brunei Darussalam reported the ***,childhood sexual abuse and bullying,and intimate partner violence emerged as significant risk *** This study highlights the significant burden of MD in the WPR,with variations by age,gender,and *** coronavirus disease 2019 pandemic has exacerbated the situation,emphasizing the need for a coordinated response.

关键词： Mental disorders Western pacific region Global Burden of Disease Risk factors Disability-adjusted life years

Knowledge mapping visualization analysis of the military health and medicine papers published in the Web of Science over the past 10 years

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Military Medical Research 2018年第2期5卷 129-139页

作者： xuan-ming Zhang xuan Zhang Xu Luo Hai-tao Guo li-qun Zhang ji-wei Guo Southwest Hospital Third Military Medical UniversityChongqing 400038China Department of Clinical Laboratory Xinqiao HospitalThird Military Medical UniversityChongqing 400037China

Background:Military medicine is a research field that seeks to solve the medical problems that occur in modern war conditions based on public medicine ***:We explore the main research topics of military health and medical research in the Web of Science?core collection(Wo SCC)from 2007 to 2016,and the goal of this work is to serve as a reference for orientation and development in military health and *** on Cite Space III,a reference co-citation analysis is performed for 7921 papers published in the Wo SCC from 2007 to *** addition,a cluster analysis of research topics is performed with a comprehensive analysis of high-yield authors,outstanding research institutions and their cooperative ***:Currently,the research topics in military health and medicine mainly focus on the following seven aspects:mental health diagnoses and interventions,an army study to assess risk and resilience in service members(STARRS),large-scale military action,brain science,veterans,soldier parents and children of wartime,and wound *** also observed that the annual publication rate increased with *** S,Greenberg N,Fear NT,Smith TC,Smith B,Jones N,Ryan MAK,Boyko EJ,Hull L,and Rona RJ were the top 10 authors in military health and medicine *** top 10 institutes were the Uniformed Services University of the Health Sciences,the United States Army,the United States Navy,Kings College London,Walter Reed National Military Medical Center,Boston University,Walter Reed Army Institute of Research,Walter Reed Army Medical Center,Naval Health Research Center,and the VA Boston Healthcare ***:We are able to perform a comprehensive analysis of studies in military health and medicine research and summarize the current research climate and the developmental trends in the Wo ***,further studies and collaborations are needed ***,our findings provide valuable information and new perspectives and shape future resear

关键词： Military health Military medicine Knowledge mapping Cite Space