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Journal of Iron and Steel Research International 2024年第11期31卷 2611-2621页

作者： Bo feng Hao-kun Yang xiao-hui Li xiao-wei feng Tian-lai Chen Guo-feng Li Guangdong Provincial Key Laboratory of Metal Toughening Technology and Application Institute of New MaterialsGuangdong Academy of SciencesGuangzhou 510000GuangdongChina Smart Manufacturing Division Hong Kong Productivity CouncilHong Kong 999077China School of Mechatronic Engineering and Automation Foshan UniversityFoshan 510168GuangdongChina Foshan Tongbao Electrical Precision Alloy Co. Ltd.Foshan 510168GuangdongChina

Accumulative roll bonding(ARB)is a severe plastic deformation method to prepare the metallic composite material by physical method at room to elevate temperature,without the generation of additional waste solid or *** the physical characteristicsmulti-material and hybrid structure,the mechanical and function properties of the ARB composite material,like Al/steel,Al/Mg,Al/Cu,etc.,shall have the"1+1>2"effect on the mechanical and functional properties,including the remarkable properties that include lightweight,high strength,thermal/electrical conductivity,electromagnetic shielding,and other *** deeply investigate the preparation method and microstructural evolution of various metal laminates by ARB,as well as the mechanical and functional properties of the laminate,an overview of the history of ARB technique,the breakthrough of ARB sheet properties,as well as the relative products in industries is ***-tionally,the future development of ARB technology and the utilization of composite materials in different areas will be discussed.

关键词： Accumulative roll bonding Metal-Composite material:Mechanical property Functional property:Industrial application

SYNTHESIS OF CHIRAL CONJUGATED POLYBINAPHTHYLS BY SONOGASHIRA REACTION

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Chinese Journal of Polymer Science 2006年第3期24卷 273-279页

作者：成义祥 Ling-wu Chen xiao-wei Zou Jin-feng Song College of Chemistry and Chemical Engineering Nanjing University Nanjing 210093 China

Chiral polymers P-1 and P-2 were synthesized by the polymerization of （R）-3,3＇-diiodo-2,2＇-bisbutoxy-1,1＇- binaphthyl （M- 1 ） with 2,5-di（4-ethynylphenyl）- 1,3,4-oxadiazole （M-3） and （R）-3,3＇-diethylnyl-2,2＇-bisbutoxy- 1,1 ＇-binaphthyl （M-2） with 1,2-di（4-bromophenyl）acetylene （M-4） under Sonogashira reaction, respectively. Both monomers and polymers were analyzed by NMR, MS, FT-IR, UV-Vis spectroscopy, DSC-TGA, fluorescence spectroscopy, GPC and CD spectroscopy. CD spectra of P-1 and P-2 are similar due to the same chiral center units and main chain structure. The long wavelengths CD effect of P-1 and P-2 can be regarded as the more extended conjugated structure and a highly rigid backbone in the polymer chain. Polymers have strong blue fluorescence due to the efficient energy migration from the extended n-electronic structure of the polymers to the chiral binaphthyl core and are expected to provide understanding of the relationship between molecular structure and fluorescent property of the chiral polymers.

关键词： (R)-BINOL Chiral conjugated polymer Sonogashira reaction Fluorescence.

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Mechanical properties and fracture mechanism of Fe/Cu composite sheets with Al interlayer after annealing treatment

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Journal of Iron and Steel Research International 2023年第9期30卷 1888-1895页

作者： xiao-wei feng Jia-xin Li Zhi-bin Zheng Bo feng Hao-kun Yang Institute of New Materials Guangdong Academy of SciencesGuangdong Provincial Key Laboratory of Metal Toughening Technology and ApplicationGuangzhou 510000GuangdongChina Smart Manufacturing Division Hong Kong Productivity CouncilHong Kong 999077China

The feasibility of preparing Fe/Cu composite sheet was achieved by introducing submillimeter thickness Al sheet as an interlayer by rolling at room *** shear test of the composite sheet supported that the metallurgical bonding strength between Fe/(Al)/Cu interface was stronger than that of Cu sheet at the initial *** further 300 or 600℃ annealing treatments,the interlayer subsequently exhibited brittle shear fracture,and the shear strength significantly dropped under the shear ***,the tensile test pointed out that the tensile fracture mechanism changed from fracture as a whole structure to interlayer-to-layer delamination mode after annealing *** microstructure and X-ray diffraction observations proved that the formation of Cu–Al intermetallic compounds(IMCs)along the interlayer resulted in brittle fracture,rather than that of Fe–Al IMCs after annealing,especially under 600℃ annealing *** investigation of the effect of the rolling process and annealing treatment on the mechanical properties of the Fe/(Al)/Cu composite sheet shall provide instruction for high-quality composite metallic sheet fabrication.

关键词： Composite sheet Fe/Cu Interlayer Intermetallic compound Fracture

Experimental research on HEL and failure properties of alumina under impact loading

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Defence Technology（防务技术） 2016年第3期12卷 272-276页

作者： xiao-wei feng Jing-zhen CHANG Yong-gang LU Institute of Systems Engineering China Academy of Engineering Physics

A series of plate impact experiments on alumina was conducted using a light gas gun in order to further investigate Hugoniot elastic limit(HEL)and failure properties of alumina under shock *** velocity interferometer system for any reflector(VISAR)was used to record the rear-free surface velocity histories of the alumina *** to the experimental results,the HELs of tested alumina samples with different thicknesses were measured,and the decay phenomenon of elastic wave in shocked alumina was studied.A phenomenological expression between HEL and thickness of sample was presented,and the causes of the decay phenomenon were *** propagation of failure wave in shocked alumina was *** velocity and delayed time of failure wave propagation were *** physical mechanism of the generation and propagation of failure was further discussed.

关键词： Plate impact experiment Alumina Hugoniot elastic limit Failure wave

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Microstructure and nanoindentation hardness of shot-peened ultrafine-grained low-alloy steel

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Journal of Iron and Steel Research International 2019年第5期26卷 472-482页

作者： xiao-wei feng Juan Xie Wen-ying Xue Yong-feng Shen Hong-bo Wang Zhen-yu Liu Institute of Systems Engineering of China Academy of Engineering Physics Mianyang 621999 Sichuan China Key Laboratory for Anisotropy and Texture of Materials (MOE) School of Materials Science and Engineering Northeastern University Shenyang 110819 Liaoning China The State Key Lab of Rolling and Automation Northeastern University Shenyang 110819 Liaoning China

The effect of shot peening (SP) on microstructure and hardness of ultrafine-grained (UFG) low-alloy steel was investigated. With increasing shot-peening time from 0.5 to 1.5 h, grain size of UFG low-alloy steel decreases from 400 to 280 nm at surface whilst that of the layer with a depth of 160μm decreases from (230 ± 15) to (75 ± 5) nm. Interestingly, nanoindentation shows that hardness increases linearly with increasing the SP duration, reaching a value as high as (7.10 ± 0.1) GPa at the depth of 160 μm after the SP duration of 1.5 h. The thickness of the SP treated layer is measured as^300 μm. The Hall-Petch (H-P) relationship was established for the hardening layer. Correspondingly, abrasion resistance should be ~51% higher than that of as-prepared UFG low-alloy steel. As shown in SP processing, grain refinement is the key factor responsible for the strengthening of the studied steel.

关键词： Low-alloy steel Shot peening Grain refinement Nanoindentation Hardness

Microstructure and Mechanical Behavior of Mg-Based Bimetal Plates with High Formability Sleeve by Co-extrusion

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Acta Metallurgica Sinica(English Letters) 2024年第3期37卷 499-512页

作者： Yue-Hui Dang Sheng-Lin Liu xiao-Lei Ai xiao-wei feng Bo feng Zhuo Tian Ying-Fei Lin Huan-Tao Chen Kai-Hong Zheng School of Materials Science and Engineering Chang’an UniversityShaanxi 710064China Guangdong Key Laboratory of Metal Toughening Technology and Application Institute of New MaterialsGuangdong Academy of SciencesGuangzhou 510650China

In this study,microstructure and mechanical behavior of two types of Mg-based bimetal plates with a high formability sleeve were systematically studied,with a great emphasis on the effect of the interface characteristic and the sleeve fraction on the plasticity of composite *** rule of mixtures(ROM)for elongation was also *** results show that when there is no or thin diffusion layer with thickness of about 3μm,Mg-based bimetal plates have a good plasticity with elongation of about 19-24%,and the ROM predicted elongations are very close to the experimental *** contrast,with a diffusion layer about 95-155μm thick,Mg-based bimetal plates exhibit a poor plasticity with elongation of about 11-17%,and the experimental elongations largely deviate from the ROM *** plasticity of Mg-based bimetal plates increases with increasing sleeve *** study provides new insights on the plastic deformation of Mg-based bimetal composites with a high formability sleeve.

关键词： Mg-based composites Co-extrusion Microstructure Mechanical behavior Plastic deformation

On the Discrete-Time Dynamics of Cross-Coupled Hebbian Algorithm

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Journal of Computer Science & Technology 2022年第1期37卷 252-265页

作者： xiao-wei feng Xiang-Yu Kong Chuan He Dong-Hui Xu Xi'an Research Institute of High Technology Xi'an 710025China

Principal/minor component analysis(PCA/MCA),generalized principal/minor component analysis(GPCA/GMCA),and singular value decomposition(SVD)algorithms are important techniques for feature *** the convergence analysis of these algorithms,the deterministic discrete-time(DDT)method can reveal the dynamic behavior of PCA/MCA and GPCA/GMCA algorithms ***,the dynamic behavior of SVD algorithms has not been studied quantitatively because of their special *** this paper,for the first time,we utilize the advantages of the DDT method in PCA algorithms analysis to study the dynamics of SVD ***,taking the cross-coupled Hebbian algorithm as an example,by concatenating the two cross-coupled variables into a single vector,we successfully get a PCA-like DDT ***,we analyze the discrete-time dynamic behavior and stability of the PCA-like DDT system in detail based on the DDT method,and obtain the boundedness of the weight vectors and learning ***,further discussion shows the universality of the proposed method for analyzing other SVD *** a result,the proposed method provides a new way to study the dynamical convergence properties of SVD algorithms.

关键词： deterministic discrete-time(DDT)system singular value decomposition(SVD) cross-correlation matrix discrete-time dynamic behavior

Recent Advancements in Intestinal Microbiota Analyses:A Review for Non-Microbiologists

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Current Medical Science 2018年第6期38卷 949-961页

作者： xiao-wei feng Wen-ping DING Ling-yun XIONG Liang GUO Jia-ming SUN Peng xiao Department of Psychiatry Wuhan Youfu HospitalWuhan 430050China Department of Ultrasound Wuhan Women and Children's Health Care CenterWuhan 430016China Department of Plastic Surgery Union HospitalTongji Medical CollegeHuazhong University of Science and Technology Wuhan 430022China

Microbial constituents naturally inhabiting the gastrointestinal tract may influence the homeostasis of the gut *** presence or overabundance of some bacterial taxa has been reported to be associated with complex diseases,and the metabolites of certain bacteria may contribute to diverse disorders by influencing signaling ***,the study of gut microbial population has emerged as a crucial field and a new potential area of clinical significance. Advances in the methods of microbiota analysis have shed light upon the details including species diversity,microfloral activities as well as the entire gut ***,comprehensive reviews on this subject are still *** elucidating the appropriate selection strategy of the methods to address a particular research question,we comprehensively reviewed the continuously improving technologies,classical to newly developed,and dissected their relative advantages and *** addition,aiming at the rapidly advancing next-generation sequencing,we enumerated the improvements in mainstream platforms and made the horizontal and vertical comparison among ***,we demonstrated the four main-omics methods,which may provide further mechanistic insights into the role of microbiota,to propel phylotyping analysis to functional analysis.

关键词： gut microbiota methods analysis advantages drawbacks

Microstructural evolutions of Cu(Ni)/AuSn/Ni joints during reflow

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Progress in Natural Science:Materials International 2011年第4期21卷 347-354页

作者： xiao-feng wei,Ri-chu WANG,Chao-qun PENG,Yan feng,Xue-wei ZHU School of Materials Science and Engineering,Central South University,Changsha 410083,China School of Materials Science and Engineering Central South University Changsha 410083 China

Interfacial reactions of the Ni/AuSn/Ni and Cu/AuSn/Ni joints are experimentally studied at 330℃for various reflow *** microstructures and mechanical properties of the as-solidified solder joints are *** as-solidified solder matrix of Ni/AuSn/Ni presents a typical eutecticξ-(Au,Ni)5Sn+δ-(Au,Ni)Sn lamellar microstructure after reflow at 330℃for 30 *** reflow for 60 s,a thin and flat(Ni,Au)3Sn2intermetallic compound(IMC) layer is formed,and some needle-like(Ni,Au)3Sn2phases grow from the IMC layer into the solder *** the other hand,a cellular-typeξ(Cu) layer is found at the upper AuSn/Cu interface in the Cu/AuSn/Ni joint after reflow for 30 s,and a(Ni,Au,Cu)3Sn2IMC layer is also formed at the lower AuSn/Ni interface. For both joints the IMC layer grows significantly with the increase of reflow time,but the growth rate of(Ni,Au,Cu)3Sn2IMC in the Cu/AuSn/Ni joint is smaller than that of the(Ni,Au)3Sn2layer in the Ni/AuSn/Ni *** comparisons of the shear strength and fracture surface between the Ni/AuSn/Ni and Cu/AuSn/Ni joints suggest that the coupling effect of the Cu/AuSn/Ni sandwich joint is helpful to prevent the excessive growth of(Ni,Au)3Sn2,which in turn enhances the mechanical reliability of the solder joint.

关键词： Cu(Ni)/AuSn/Ni joints interfacial reaction intermetallic compound(IMC) coupling effect

Geochemical characteristics and growth suitability assessment of Scutellaria baicalensis Georgi in the Earth's critical zone of North China

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Journal of Mountain Science 2022年第5期19卷 1245-1262页

作者： LI Xia wei xiao-feng WU Jin YIN Zhi-qiang WAN Li-qin SUN Hou-yun AN Yong-long College of Water Sciences Beijing Normal UniversityBeijing 100875China China Institute of Geo-Environment Monitoring Beijing 100081China Beijing Institute of Geology for Mineral Resources Beijing 100012China Faculty of Architecture Civil and Transportation EngineeringBeijing University of TechnologyBeijing 100124China School of Water Resources&Environment China University of GeosciencesBeijing 100083China

Geochemical differentiation of soils has a series of consequences on plant and places pressure on the ecological *** quantitative evaluation of element migration in the Earth’s critical zone is a challenging *** this study,two demonstration study areas of Scutellaria baicalensis Georgi were selected,and multiple chemical weathering indexes,chemical loss fraction,mass migration coefficients and biological enrichment coefficient method were used to assess the ecological and geochemical *** results show that for the element of Fe,Zn,Se,Cu,Co,Ni,Mo and Ge,the degree of weathering and soil maturation,were greater in the rhyolitic tuff area than in the Plagioclase gneiss *** both research sites,the heavy metal level of samples in Scutellaria baicalensis Georgi did not exceed the standard *** plagioclase gneiss region’s surface soil environment was more alkaline,and the content of soil organic matter was lower,resulting in a higher bioenrichment intensity of Ge,Co,Cu,and Se elements in Scutellaria baicalensis Georgi than in the rhyolite-tuff *** elements of Cd,Nb,Mo,Pb and As are considerably enriched in the soil of the plagioclase gneiss area but lost by leaching in the soil of the rhyolite tuff area,which is connected to the interplay of elemental abundance and human impact in the parent *** study provides a good example of how to assess growth suitability of Chinese medicinal materials in the Earth’s critical zone.

关键词： Earth’s critical zone Biogeochemistry characteristics Weathering mechanism Element migration Chinese medicinal materials Chengde

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