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Structural and magnetic properties of micropolycrystalline cobalt thin films fabricated by direct current magnetron sputtering

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International Journal of Minerals,Metallurgy and Materials 2024年第2期31卷 384-394页

作者： Kerui Song Zhou Li Mei Fang Zhu Xiao Qian Lei School of Materials Science and Engineering Central South UniversityChangsha 410083China State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China Hunan Key Laboratory of Super-Microstructure and Ultrafast Process School of Physics and electronicsCentral South UniversityChangsha 410083China Key Laboratory of Non-Ferrous Metal Materials Science and Engineering Ministry of EducationChangsha 410083China

Pure cobalt(Co)thin films were fabricated by direct current magnetron sputtering,and the effects of sputtering power and pres-sure on the microstructure and electromagnetic properties of the films were *** the sputtering power increases from 15 to 60 W,the Co thin films transition from an amorphous to a polycrystalline state,accompanied by an increase in the intercrystal pore ***,the resistivity decreases from 276 to 99μΩ·cm,coercivity increases from 162 to 293 Oe,and in-plane magnetic aniso-tropy *** the sputtering pressure decreases from 1.6 to 0.2 Pa,grain size significantly increases,resistivity significantly de-creases,and the coercivity significantly increases(from 67 to 280 Oe),which can be attributed to the increase in defect ***-pondingly,a quantitative model for the coercivity of Co thin films was *** polycrystalline films sputtered under pressures of 0.2 and 0.4 Pa exhibit significant in-plane magnetic anisotropy,which is primarily attributable to increased microstress.

关键词： cobalt thin film magnetron sputtering microstructure electromagnetic properties

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Core-shell-structured Composite ZSM-5@MCM-41 Catalysts:Fabrication,Characterization,and Enhanced Performance in Hexane Catalytic Cracking

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China Petroleum Processing & Petrochemical Technology 2023年第4期25卷 41-51页

作者： Zhu Jiale Zhu Xuedong Yang Fan State Key Laboratory of Chemical Engineering School of Chemical EngineeringEast China University of Science&TechnologyShanghai 200237China

A series of core-shell zeolites with a ZSM-5 zeolite core and a MCM-41 shell with varying shell thicknesses were successfully fabricated via a cetyltrimethylammonium bromide(CTAB)-directed sol-gel coating method in an ultradilute solution. Extensive characterization techniques, including XRD, TEM, N_(2) adsorption-desorption, NH_(3)-TPD, and IR measurements, confirmed the successful coating of a microporous ZSM-5 core with a mesoporous MCM-41 shell layer and were further employed to explore the textural properties and acidic properties of the samples. The hexane cracking results revealed a significant enhancement in olefin yields after introducing the MCM-41 shell to ZSM-5. Interestingly, a volcanic trend in olefin yields was observed with the increase in the shell thickness. In particular, the highest olefin yield of 51.5%, exceeding that of the core catalyst by 17.1%, was achieved when the shell thickness was controlled at 40 ***, the catalyst lifetime investigation revealed that the core-shell composite catalyst exhibited a minimal reduction in hexane conversion of merely 3.8% over a 120 h reaction period, significantly outperforming the 11.3% reduction exhibited by the core catalyst. This remarkable catalytic performance was attributed to the passivation of external acid sites and the introduction of more developed pore channels by the shell, which effectively mitigated unwanted side reactions. The successful synthesis of these core-shell structured catalysts presents a novel strategy for improving catalytic performance in hexane cracking, in addition to serving as a solid foundation for the design of industrial catalysts for light naphtha cracking.

关键词： catalytic cracking light olefin core-shell ZSM-5 zeolite

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New process for treating boron-bearing iron ore by flash reduction coupled with magnetic separation

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International Journal of Minerals,Metallurgy and Materials 2024年第3期31卷 473-484页

作者： Qipeng Bao Lei Guo Hong Yong Sohn Haibin Zuo Feng Liu Yongliang Gao Zhancheng Guo State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China Department of Materials Science&Engineering University of UtahUtah 84112USA China ENFI Engineering Corporation Beijing 100038China

Boron is an important industrial raw material often sourced from minerals containing different compounds that cocrystallize,which makes it difficult to separate the mineral phases through conventional *** study proposed a new treatment called flash reduction-melting separation(FRMS)for boron-bearing iron *** this method,the concentrates were first flash-reduced at the temperature under which the particles melt,and the slag and the reduced iron phases disengaged at the particle *** reduc-tion and melting effects were achieved above 1550℃.The B_(2)O_(3) content in the separated slag was over 18wt%,and the B content in the iron was less than 0.03wt%.The proposed FRMS method was tested to investigate the effects of factors such as ore particle size and tem-perature on the reduction and melting steps with and without pre-reducing the raw *** mineral phase transformation and morphology evolution in the ore particles during FRMS were also comprehensively analyzed.

关键词： ludwigite boron-bearing iron concentrate flash reduction melting separation boron

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Research on Intrusion Tolerance System Based on Behavioral Baseline and Defense-in-Depth Architecture

Research on Intrusion Tolerance System Based on Behavioral B...

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2024 International Conference on Mechatronics and Intelligent Control, ICMIC 2024

作者： Meng, Qi Wang, Xuemeng Yang, Kai Meng, Long Wang, Jiancheng Fei, Jinlong State Key Laboratory of Mathematical Engineering and Advanced Computing PLA Strategic Support Force Information Engineering University Zhengzhou China

ISBN: (数字)9781510686847

ISBN: (纸本)9781510686830

Tolerance technology is the third-generation network security technology commonly used in the world. It is derived from the category of information survival and endogenous security technology. A scholar from Carnegie Mellon University gave this survival technology a definition: the so-called "invasion survival technology".It is the ability of the system to perform its own tasks within a limited time when external attacks, failures and accidents have occurred. It assumes that we cannot detect intrusions to the system completely and correctly. When external intrusions or failures occur suddenly, we can use tolerance technology to solve the problem of survival of the system to ensure the confidentiality, integrity, and integrity of the information system. reliability and non-repudiation. In the current Internet security incidents, countless experiences and lessons tell us that it is not enough to rely on blocking and defensing for network *** on the existing network defense-in-depth architecture and the common behavior and parameter baselines of current emergency response systems, this paper designs an intrusion-tolerant system based on the behavioral baseline and network-in-depth architecture, which realizes intrusion tolerance and malicious behavior blocking under high confrontation intensity. To adapt to the maximum recovery and necessary tolerance under the attack technology of international APT organizations, and to protect the integrity and availability of the system to the greatest extent. © 2025 SPIE.

关键词： Network intrusion

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Van der Waals epitaxial growth of single-crystal molecular film

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National science Review 2024年第11期11卷 194-202页

作者： Lixin Liu Penglai Gong Kailang Liu Bingrong Huang Zhihao Zhang Yingshuang Fu Yu Wu Yinghe Zhao Meihui Wang Yongshan Xu Huiqiao Li Tianyou Zhai State Key Laboratory of Materials Processing and Die &Mould Technology School of Materials Science and EngineeringHuazhong University of Science and Technology Key Laboratory of Optic-Electronic Information and Materials of Hebei Province College of Physics Science and Technology Hebei University Wuhan National High Magnetic Field Center School of Physics Huazhong University of Science and Technology

Epitaxy is the cornerstone of semiconductor technology, enabling the fabrication of single-crystal *** advancements in van der Waals（vd W） epitaxy have opened new avenues for producing wafer-scale single-crystal 2D atomic crystals. However, when it comes to molecular crystals, the overall weak vd W force means that it is a significant challenge for small molecules to form a well-ordered structure during *** we demonstrate that the vd W epitaxy of Sb2O3molecular crystal, where the whole growth process is governed by vd W interactions, can be precisely controlled. The nucleation is deterministically modulated by epilayer–substrate interactions and unidirectional nuclei are realized through designing the lattice and symmetry matching between epilayer and substrate. Moreover, the growth and coalescence of nuclei as well as the layer-by-layer growth mode are kinetically realized via tackling the Schwoebel-Ehrlich barrier. Such precise control of vd W epitaxy enables the growth of single-crystal Sb2O3molecular film with desirable thickness. Using the ultrathin highly oriented Sb2O3film as a gate dielectric, we fabricated MoS2-based field-effect transistors that exhibit superior device performance. The results substantiate the viability of precisely managing molecule alignment in vd W epitaxy, paving the way for large-scale synthesis of single-crystal 2D molecular crystals.

关键词： van der Waals epitaxy inorganic molecular crystal layer-by-layer growth single-crystal film dielectric

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Modelling and simulation study on dynamic pollution accumulation process of composite insulator

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High Voltage 2024年第3期9卷 601-613页

作者： Zhongyi Yang Dongxiong Liu Xiangjun Zeng Caijin Fan Xin Yang Yafei Huang School of Electrical and Information Engineering Changsha University of Science and TechnologyChangshaChina State Key Laboratory of HVDC Electric Power Research InstituteCSGGuangzhouChina

With the widespread application of composite insulators in transmission lines,exploring the accumulation mechanism of pollution particles on composite insulator surfaces is of importance to ensure the safe and steady operation of the power *** the current theoretical shortcomings,this study categorises the accumulation process of particles on the insulator surface into three stages,namely‘spatial motion’,‘surface collision’,and‘surface motion’.The motion and rotation velocities in a multi-physics field are calculated in the spatial motion *** the surface collision stage,a parameter called‘neck height’is introduced to determine the optimum mechanics theory,and the normal deposition criterion is *** the surface motion stage,the sliding displacement and rolling displacement on the surface are calculated based on the rotation speed of the particles.A dynamic pollution accumulation model of the composite insulator is estab-lished based on the normal deposition criterion and tangential ***,numerical simulations are performed by using the finite element *** results show that the proposed model agrees with the actual insulator pollution accu-mulation,and the deposition model is still applicable for various types of composite insulators operating in different applied *** deposition probability of particles increases with the increasing particle *** the surface motion stage,particle displacement increases with particle size and wind velocity.

关键词： composite displacement dynamic

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Flow field analysis and particle erosion of tunnel-slope systems under coupling between runoff and fast (slow) seepage

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Deep Underground science and engineering 2024年第4期3卷 385-398页

作者： Shuai Zhang Danqing Song Ruiliang Zhang Kai Zhang Qi Zhao Suraksha Sharma Department of Hydraulic Engineering State Key Laboratory of Hydroscience and EngineeringKey Laboratory of Hydrosphere Sciences of the Ministry of Water ResourcesTsinghua UniversityBeijingChina School of Civil Engineering and Transportation State Key Laboratory of Subtropical Building ScienceSouth China University of TechnologyGuangzhouGuangdongChina Department of Geotechnical Engineering State Key Laboratory of Hydraulic and Mountain River EngineeringSichuan UniversityChengduChina Faculty of Civil Engineering and Mechanics Kunming University of Science and TechnologyKunmingYunnanChina Department of Civil and Environmental Engineering The Hong Kong Polytechnic UniversityHong KongChina Norwegian University of Science and Technology TrondheimNorway

The presence of particles on the surface of a tunnel slope renders it susceptible to erosion by waterﬂow,which is a major cause of soil and water *** this study,a nonlinear mathematical model and a mechanical equilibrium model are developed to investigate the distribution ofﬂowfields and particle motion characteristics of tunnel slopes,*** mathematical model ofﬂowfields comprises three parts:a runoff region,a highly permeable soil layer,and a weakly permeable soil *** Navier‒Stokes equation controlsﬂuid motion in the runoff region,while the Brinkman-extended Darcy equation governs fast and slow seepage in the highly and weakly permeable soil layers,*** solutions are derived for the velocity profile and shear stress expression of the modelﬂowfield under the boundary condition of continuous transition of velocity and stress at theﬂuid‒solid *** shear stress distribution shows that the shear stress at the tunnel-slope surface is the largest,followed by the shear stress of the soil interface,indicating that particles in these two locations are most vulnerable to erosion.A mechanical equilibrium model of sliding and rolling of single particles is established at theﬂuid‒solid interface,and the safety factor of particle motion(sliding and rolling)is *** analysis shows that by increasing the runoff depth,slope angle,and soil permeability,the erosion of soil particles will be aggravated on the tunnel-slope surface,but by increasing the particle diameter,particle-specific gravity,and particle stacking angle,the erosion resistance ability of the tunnel-slope surface particles will be *** study can serve as a reference for the analysis of surface soil and water loss in tunnel-slope systems.

关键词： particle erosion particle motion runoff-fast(slow)seepage coupling shear stress profile tunnel-slope system velocity profile

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Morphological observation and mineralogical analysis of basaltic debris from a Chang'e-5 drilled lunar soil sample

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Particuology 2025年第1期96卷 256-263页

作者： Hongtao Cao Meng Zou Wei Zhang Xinyang Li Rui Zhang Qing Liang Zhenzhen Zhao Dengman Feng Zizhun Wang Nailin Yue Xicheng Li Fangfei Li Qiang Zhou Li Liu Xiujuan Li Key Laboratory of Bionic Engineering Ministry of EducationJilin UniversityChangchun 130025China Key Laboratory of Automobile Materials Ministry of Education School of Materials Science&EngineeringElectron Microscopy CenterInternational Center of Future ScienceJilin Provincial International Cooperation Key Laboratory of High-Efficiency Clean Energy MaterialsJilin UniversityChangchun 130012China Synergetic Extreme Condition High-Pressure Science Center State Key Laboratory of Superhard MaterialsCollege of PhysicsJilin UniversityChangchun 130012China Deep Space Exploration Lab Beijing 100195China

This paper analyzes the morphological characteristics and mineralogy of drilled basaltic clast sample CE5Z0806YJYX004, compares the variations in Chang'e-5 samples at different depths, and conducts a comparative analysis with surface-collected samples from Chang'e-5 and Apollo missions. Interestingly, Advanced electron microscopy identified bubbles and microcracks on the surface of some constituting mineral particles, and also displays crystalline particles with distinct rock textures and spherical droplets, revealing surface phenomena formed by space weathering. Based on Raman spectroscopy analysis, the main mineral phases were identified as 49.6 vol% pyroxene, 31.4 vol% plagioclase and 8.8 vol% olivine. Apatite, ilmenite and cristobalite are also found. The results indicate that the Chang'e-5 lunar soil exhibits similar mineral compositions at different depths. In short, a comparison was made between our drilling sample and the Chang'e-5 soil samples as well as samples from the Apollo mission series, demonstrating the physical similarities and some variations.

关键词： Chang'e-5 Lunar soil Drilled sample Physical properties Mineralogy

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Synergetic effect of ZnO-doped dendritic porous silica and barium glass powder as functional bimodal fillers for dental composite applications

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Dental Materials 2025年第7期41卷 880-891页

作者： Duan, Ci Wang, Junjun Li, Maosheng Wang, Ruili State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and Engineering Donghua University Shanghai201620 China

Objective: Porous silica particles have received attention in dental composites owing to their ability to form micromechanical matrix/filler interlocking and serve as the suitable carrier materials. The aim of this work is to develop structural-functional integrated ZnO-doped dendritic porous silica (ZnO-DPS) and investigate the effects of filler morphology and formulations on the physicochemical and antibacterial properties, cytotoxicity, and radiopacity of dental composites. Methods: Various ZnO-DPS particles (ZxUy) were synthesized with a one-pot self-assembly route by adjusting the amounts of zinc nitrate hexahydrate (Z) and urea (U) in the microemulsion, respectively. Their morphology and structure were characterized by the electron microscopy, X-ray powder diffraction, X-ray photoelectron spectroscopy, and N2 adsorption and desorption isotherms. The mechanical property of dental composites containing optimal Z0.5U1.8 and its bimodal fillers with silanized barium glass powder (BGP) were measured by a universal testing machine. The real-time degree of conversion, polymerization shrinkage, antibacterial rate, cytotoxicity, and radiopacity were further evaluated. Results: The optimal Z0.5U1.8 particles with complete spherical morphology and hierarchical porous structure were obtained. Functional bimodal fillers were further formulated to address the loading limitation of Z0.5U1.8 (10 wt%). Among all materials, the Z7B53 composite (Z0.5U1.8: BGP = 7:53, wt/wt, filler loading: 60 wt%) showed excellent mechanical performance, giving large improvements of 54.3 %, 272 %, and 18.8 % for flexural strength, flexural modulus, and compressive strength, respectively, compared with the unfilled resin. Meanwhile, this composite exhibited lower shrinkage (3.43 ± 0.01 %), higher radiopacity (1.60 mm Al), and better cell viability compared to the unfilled resin and the unimodal Z7B0. The antibacterial rate of Z7B53 is 93.0 ± 1.9 %. Significance: The preparation of ZnO-DPS particl

关键词： Dental composites

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Effect of initial orientation on microstructure and mechanical properties of AZ31 Mg alloy sheets via accumulated extrusion bonding

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Progress in Natural science:Materials International 2023年第2期33卷 178-184页

作者： Xia Cao Tingzhuang Han Ji Xu Guangsheng Huang Hua Zhang Jianhui Bai Fusheng Pan Department of Mechanics and Surface Engineering Changzhou Institute of Technology Department of Aviation Manufacturing Engineering Changzhou Institute of Technology State Key Laboratory of Solidification Processing School of Materials Science & Engineering Northwestern Polytechnical University State Key Laboratory of Mechanical Transmission College of Materials Science and Engineering Chongqing University Institute for Advanced Studies in Precision Materials Yantai University

In this study, effects of initial orientation on microstructure evolution and mechanical properties of AZ31 Mg alloy sheets via accumulated extrusion bonding(AEB) was systematically studied. The samples with RD and TD parallel to extrusion direction(ED) were labeled as RED and TED, respectively. RD and TD pieces alternately stacked was named as RTED. The results revealed that under three-dimensional compressive stress, {10-12} tensile twinning dominated the first stage deformation in container. As the plunger continuous press down, dynamic recrystallization(DRX) occurred, and the newly fine DRXed grains along original and twin grain boundaries gradually consumed the matrix and twin grains. The microstructure was completely transformed into recrystallized grain structure at sizing band with an average grain size of ～0.9 μm in TED sample, smaller than that of RED *** the alloys extruded out of the die, DRXed grains significantly grew to ～4.5 μm and 3.5 μm for RED and TED samples, respectively. A laminated microstructure was obtained with average grain sizes of～4.4 μm in RD layers and 3.5 μm in TD layers for RTED sample. The AEB processed samples exhibited an ED-tilt double-peak basal texture with similar texture intensity. The tensile tests results indicated that attributed to the combined effect of grain refinement and texture evolution, the yield strength and fracture elongation of RED and TED samples was significantly improved. The heterogeneous microstructure in RTED sample induced an extra work hardening(HDI-work hardening) in tensile deformation and resulted in a further improved elongation of 32.0%.

关键词： Magnesium alloy Accumulated extrusion bonding Initial orientation Microstructure Texture Mechanical properties

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