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Journal of Iron and Steel Research(International) 2024年第4期31卷 945-955页

作者： Yuan Zhang Xiang Liu chang-jun Wang chang Liu School of Material Science and Engineering Kunming University of Science and TechnologyKunming 650093YunnanChina Central Iron&Steel Research Institute Co. Ltd.Beijing 100081China

PH13-8Mo stainless steel powder with high sphericity and well fluidity was prepared by the plasma rotating electrode *** formed parts with ultra-high purity were manufactured by selective laser *** tensile and impact mechanical properties of the printed parts under three heat treatment regimes were compared to those without heat *** microstructure,grain orientation and phase composition were characterized by electron-backscatter diffraction,X-ray diffraction and transmission electron *** characterization results reveal that the addition of heat treatment makes the grains enlarge,and after different heat treatments,the average grain size from 1.51μm in the printed state increases to 2.78,3.09 and 2.06μm,*** formed parts are mainly composed of martensite and retained ***,the NiAl and M23C precipitates form,which are the major strengthening phases of PH13-8Mo stainless *** optimal heat treatment process is 925℃×1 h water cooling(WC)+0℃×2 h air cooling(AC)+540℃×4 h *** this heat treatment process,PH13-8Mo formed parts have the optimal comprehensive mechanical properties:the tensile strength,yield strength and impact energy KU2 are 1492 MPa,1432 MPa and 63 J,*** strengthening and toughening via heat treatment are mainly attributed to dislocation strengthening,the formation of NiAl and M23Co precipitates and the change of volume fraction of the retained austenite.

关键词： High-strength stainless steel-Selective laser melting-Heat treatment Microstructure Mechanical property

Generalized polynomial chaos expansion by reanalysis using static condensation based on substructuring

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Applied Mathematics and Mechanics(English Edition) 2024年第5期45卷 819-836页

作者： D.lee S.chang J.lee Department of Automotive Engineering Hanyang UniversitySeoul 04763Republic of Korea School of Mechanical Engineering Chungnam National UniversityDaejeon 34134Republic of Korea Department of Mechanical Robotics and Energy EngineeringDongguk UniversitySeoul 04620Republic of Korea

This paper presents a new computational method for forward uncertainty quantification(UQ)analyses on large-scale structural systems in the presence of arbitrary and dependent random *** method consists of a generalized polynomial chaos expansion(GPCE)for statistical moment and reliability analyses associated with the stochastic output and a static reanalysis method to generate the input-output data *** the reanalysis,we employ substructuring for a structure to isolate its local regions that vary due to random *** allows for avoiding repeated computations of invariant substructures while generating the input-output data *** substructuring with static condensation further improves the computational efficiency of the reanalysis without losing ***,the GPCE with the static reanalysis method can achieve significant computational saving,thus mitigating the curse of dimensionality to some degree for UQ under high-dimensional *** numerical results obtained from a simple structure indicate that the proposed method for UQ produces accurate solutions more efficiently than the GPCE using full finite element analyses(FEAs).We also demonstrate the efficiency and scalability of the proposed method by executing UQ for a large-scale wing-box structure under ten-dimensional(all-dependent)random inputs.

关键词： forward uncertainty quantification(UQ) generalized polynomial chaos expansion(GPCE) static reanalysis method static condensation substructuring

Turning point of organoid transplantation:first-in-human trial of iPSC-derived retinal organoid grafting in patients with retinitis pigmentosa

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Science China(Life Sciences) 2024年第5期67卷 1082-1084页

作者： chang-jun Zhang Zi-Bing Jin Beijing Institute of Ophthalmology Beijing Tongren HospitalCapital Medical UniversityBeijing 100730China

The discovery of induced pluripotent stem cells(iPSCs)has revolutionized the field of disease research,providing a promising platform for studying various *** the last decade,significant progress has been made in combining iPSCs with other cutting-edge technologies to investigate disease mechanisms and develop potential treatments.

关键词： conditions patients retinitis

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Enhancing Identity Protection in Metaverse-Based Psychological Counseling System

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Computers, Materials & Continua 2024年第1期78卷 617-632页

作者： jun lee Hanna lee Seong Chan lee Hyun Kwon Department of Game Software Hoseo UniversityAsan-si31499Korea Yatav Enter Seoul04799Korea Department of Artificial Intelligence and Data Science Korea Military AcademySeoul01805Korea

Non-face-to-face psychological counseling systems rely on network technologies to anonymize information regard-ing client ***,these systems often face challenges concerning voice data leaks and the suboptimal communication of the client’s non-verbal expressions,such as facial cues,to the *** study proposes a metaverse-based psychological counseling system designed to enhance client identity protection while ensuring efficient information delivery to counselors during non-face-to-face *** proposed systemincorporates a voicemodulation function that instantlymodifies/masks the client’s voice to safeguard their ***,it employs real-time client facial expression recognition using an ensemble of decision trees to mirror the client’s non-verbal expressions through their avatar in the metaverse *** system is adaptable for use on personal computers and smartphones,offering users the flexibility to access metaverse-based psychological counseling across diverse *** performance evaluation of the proposed system confirmed that the voice modulation and real-time facial expression replication consistently achieve an average speed of 48.32 frames per second or higher,even when tested on the least powerful smartphone ***,a total of 550 actual psychological counseling sessions were conducted,and the average satisfaction rating reached 4.46 on a 5-point *** indicates that clients experienced improved identity protection compared to conventional non-face-to-face metaverse counseling ***,the counselor successfully addressed the challenge of conveying non-verbal cues from clients who typically struggled with non-face-to-face psychological *** proposed systemholds significant potential for applications in interactive discussions and educational activities in the metaverse.

关键词： Metaverse counseling system face tracking identity protection

Development of vehicle-recognition method on water surfaces using LiDAR data:SPD^(2)(spherically stratified point projection with diameter and distance)

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Defence Technology（防务技术） 2024年第6期36卷 95-104页

作者： Eon-ho lee Hyeon jun Jeon Jinwoo Choi Hyun-Taek Choi Sejin lee The Department of Mechanical Engineering Kongju National University1223-24 Cheonan-daeroCheonan 31080Republic of Korea Ocean System Engineering Research Division Korea Research Institute of Ships and Ocean Engineering(KRISO)Daejeon 34103Republic of Korea The Division of Mechanical&Automotive Engineering Kongju National University1223-24 Cheonan-daeroCheonan 31080Republic of Korea

Swarm robot systems are an important application of autonomous unmanned surface vehicles on water *** monitoring natural environments and conducting security activities within a certain range using a surface vehicle,the swarm robot system is more efficient than the operation of a single object as the former can reduce cost and save *** is necessary to detect adjacent surface obstacles robustly to operate a cluster of unmanned surface *** this purpose,a LiDAR(light detection and ranging)sensor is used as it can simultaneously obtain 3D information for all directions,relatively robustly and accurately,irrespective of the surrounding environmental *** the GPS(global-positioning-system)error range exists,obtaining measurements of the surface-vessel position can still ensure stability during platoon *** this study,a three-layer convolutional neural network is applied to classify types of surface *** aim of this approach is to redefine the sparse 3D point cloud data as 2D image data with a connotative meaning and subsequently utilize this transformed data for object classification ***,we have proposed a descriptor that converts the 3D point cloud data into 2D image *** use this descriptor effectively,it is necessary to perform a clustering operation that separates the point clouds for each *** developed voxel-based clustering for the point cloud ***,using the descriptor,3D point cloud data can be converted into a 2D feature image,and the converted 2D image is provided as an input value to the *** intend to verify the validity of the proposed 3D point cloud feature descriptor by using experimental data in the ***,we explore the feasibility of real-time object classification within this framework.

关键词： Object classification Clustering 3D point cloud data LiDAR(light detection and ranging) Surface vehicle

Reinforcement of High Impact Polystyrene by Aramid Nanoparticle Fillers Prepared via an In situ Bottom-up Approach

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Chinese Journal of Polymer Science 2024年第8期42卷 1167-1176页

作者： Xiang-jun Gong Zhi-Ping Zhao chang-Mei Sun Ying Zhang Rong-jun Qu Ying Wang School of Chemistry and Materials Science Ludong UniversityYantai 264025China

In this work,aramid nanoparticles(ANPs)were prepared in dimethyl formamide(DMF)solution containing high impact polystyrene(HIPS)via a bottom-up *** electron microscopy(TEM)images showed that the obtained ANPs were evenly distributed in the HIPS matrix without any *** composition of the ANPs,i.e.,poly(p-phenyl-p-phenylenediamine)(PPTA),was confirmed by Fourier transform infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS)and X-ray diffractometer(XRD).The ANP/HIPS composites,obtained after ethanol precipitation,were added to neat HIPS as fillers to fabricate ANP/HIPS composite *** surface roughness and the glass transition temperature(T_g)of the sheets were characterized by atomic force microscope(AFM)and differential scanning calorimetry(DSC),*** with neat HIPS,the mechanical properties of the composite sheet were significantly improved,and the Young's modulus increased from 246.55 MPa to 2025.12 MPa,the tensile strength increased from 3.07 MPa to 29.76 MPa,and the toughness increased from 0.32 N/mm^2 to 3.92 N/mm^2,with an increase rate of 721%,869%and 1125%,***,the thermal stability of the composites improved with the increase in ANP content.

关键词： High impact polystyrene PPTA nanoparticle Reinforce Mechanical property

Unraveling the complex roles of macrophages in obese adipose tissue:an overview

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Frontiers of Medicine 2024年第2期18卷 205-236页

作者： chang Peng jun Chen Rui Wu Haowen Jiang Jia Li Hangzhou Institute for Advanced Study University of Chinese Academy of SciencesHangzhou310000China State Key Laboratory of Drug Research Shanghai Institute of Materia MedicaChinese Academy of SciencesShanghai201203China University of Chinese Academy of Sciences Beijing100049China Department of Prosthodontics Shanghai Engineering Research Center of Advanced Dental Technology and MaterialsShanghai Key Laboratory of Stomatology&Shanghai Research Institute of StomatologyNational Clinical Research Center for Oral DiseasesShanghai Ninth People’s HospitalCollege of StomatologyShanghai Jiao Tong University School of MedicineShanghai200011China

Macrophages,a heterogeneous population of innate immune cells,exhibit remarkable plasticity and play pivotal roles in coordinating immune responses and maintaining tissue homeostasis within the context of metabolic *** activation of inflammatory macrophages in obese adipose tissue leads to detrimental effects,inducing insulin resistance through increased inflammation,impaired thermogenesis,and adipose tissue ***,adipose tissue macrophages also play a beneficial role in maintaining adipose tissue homeostasis by regulating angiogenesis,facilitating the clearance of dead adipocytes,and promoting mitochondrial *** the heterogeneity of macrophages in obese adipose tissue is crucial for unraveling the pathogenesis of obesity and holds significant potential for targeted therapeutic ***,the dual effects and some potential regulatory mechanisms of macrophages in adipose tissue have been elucidated using single-cell *** this review,we present a comprehensive overview of the intricate activation mechanisms and diverse functions of macrophages in adipose tissue during obesity,as well as explore the potential of drug delivery systems targeting macrophages,aiming to enhance the understanding of current regulatory mechanisms that may be potentially targeted for treating obesity or metabolic diseases.

关键词： obesity inflammation adipose tissue macrophages adipose tissue homeostasis

A buffer overflow detection and defense method based on RiSC-V instruction set extension

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Cybersecurity 2024年第2期7卷 28-43页

作者： chang Liu Yan-jun Wu Jing-Zheng Wu Chen Zhao Intelligent Software Research Center Institute of SoftwareChinese Academy of SciencesBejingChina University of Chinese Academy of Sciences BeijingChina State Key Laboratory of Computer Science Institute of SoftwareChinese Academy of SciencesBeijingChina

Buffer overflow poses a serious threat to the memory security of modern operating *** overwrites the con-tents of other memory areas by breaking through the buffer capacity limit,destroys the system execution environ-ment,and provides implementation space for various system attacks such as program control flow *** makes it a wide range of harms.A variety of security technologies have been proposed to deal with system security problems including buffer *** example,No eXecute(NX for short)is a memory management technology commonly used in Harvard *** can refuse the execution of code which residing in a specific memory,and can effectively suppress the abnormal impact of buffer overflow on control ***,in recent years,it has also been used in the field of system security,deriving a series of solutions based on NX technology,such as ExecShield,DEP,StackGuard,***,these security solutions often rely too much on the processor archi-tecture so that the protection coverage is insufficient and the accuracy is *** in the emerging system architecture field represented by RiSC-V,there is still a lack of effective solutions for buffer overflow *** the continuous rapid development of the system architecture,it is urgent to develop defense methods that are applicable to different system application environments and oriented to all executable memory spaces to meet the needs of system security ***,we propose BOP,A new system memory security design method based on RISC-V extended instructions,to build a RISC-V buffer overflow detection and defense system and deal with the buffer overflow threat in *** to this method,NX technology can be combined with program control flow analysis,and Nx bit mechanism can be used to manage the executability of memory space,so as to achieve a more granular detection and defense of buffer overflow attacks that may occur in RISC-V system

关键词： RISc-V Operating system security Buffer overflow Control flow hijacking Nx bit Xibop

Characterizing and controlling infrared phonon anomaly of bilayer graphene in optical-electrical force nanoscopy

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Light(Science & Applications) 2023年第12期12卷 2700-2710页

作者： junghoon Jahng Sunho lee Seong-Gu Hong chang jun lee Sergey G.Menabde Min Seok Jang Dong-Hyun Kim Jangyup Son Eun Seong lee Hyperspectral Nano-imaging Team Korea Research Institute of Standards and ScienceDaejeon 34113Republic of Korea Department of Aerospace Engineering University of Illinois at Urbana-ChampaignUrbanaIL 61801USA Multiscale Mechanical Properties Measurement Team Korea Research Institute of Standards and ScienceDaejeon 34113Republic of Korea School of Mechanical Engineering Chonnam National UniversityGwangju 61186Republic of Korea School of Electrical Engineering Korea Advanced Institute of Science and TechnologyDaejeon 34141Republic of Korea Functional Composite Materials Research Center Korea Institute of Science and TechnologyJeonbuk 55324Republic of Korea SKKU Advanced Institute of Nanotechnology Sungkyunkwan UniversitySuwon 16419Republic of Korea Division of Nano&Information Technology KIST SchoolUniversity of Science and TechnologySeoul 02792Republic of Korea

We,for the first time,report the nanoscopic imaging study of anomalous infrared(IR)phonon enhancement of bilayer graphene,originated from the charge imbalance between the top and bottom layers,resulting in the enhancement of E1u mode of bilayer graphene near 0.2 *** modified the multifrequency atomic force microscope platform to combine photo-induced force microscope with electrostatic/Kelvin probe force microscope constituting a novel hybrid nanoscale optical-electrical force imaging *** enables to observe a correlation between the IR response,doping level,and topographic information of the graphene *** the nanoscale spectroscopic image measurements,we demonstrate that the charge imbalance at the graphene interface can be controlled by chemical(doping effect via Redox mechanism)and mechanical(triboelectric effect by the doped cantilever)***,we can also diagnosis the subsurface cracks on the stacked few-layer graphene at nanoscale,by monitoring the strain-induced IR phonon *** approach provides new insights into the development of graphene-based electronic and photonic devices and their potential applications.

关键词： electrical force optical

Experimental and first-principles calculation of TiN growth mechanism on CeAlO_(3) surface in steel

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Journal of Iron and Steel Research(International) 2024年第2期31卷 452-463页

作者： Fei-hu He jun Peng Fang Zhang Yong-bin Wang Hong-tao chang School of Materials and Metallurgy Inner Mongolia University of Science and TechnologyBaotou014010Inner MongoliaChina

Regular TiN is harmful to the toughness of steel,and its shape and size need to be *** the behavior of TiN precipitation on CeAlO_(3) surfaces is critical for controlling the morphology and formation process of CeAlO_(3)–TiN composite inclusions in the *** results showed that TiN had a square morphology on the CeAlO3 surface,and electron backscatter diffraction phase identification results revealed the orientation relationship between CeAlO_(3) and TiN as follows:(001)_(CeAlO_(3))//(110)_(TiN),(100)_(CeAlO_(3))/(001)_(TiN),and[010]_(CeAlO_(3))/[110]_(TiN).The CeAlO3 crystal structure was studied using the first-principles calculation method,and the adsorption and growth process of TiN on the CeAlO_(3) surface were investigated from the atomic *** calculation results indicate that there is no metallic bonding present in the CeAlO_(3) *** the low-index crystal planes of CeAlO_(3),the(110)planes terminated with O and CeAlO have the highest and lowest surface energies,respectively,with values of 0.373 and 0.051 eV/Å^(2).On the high surface energy plane of CeAlO_(3),the TiN atomic permutation structure is consistent with the arrangement of Ti and N atoms in TiN(100)or(110).For the low surface energy plane of CeAlO_(3),the Ti and N atoms are arranged in a ring-like structure.

关键词： CeAlO_(3)-TiN inclusion Orientation relationship Crystal structure First principle Surface energy