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Mechanical behaviors and energy absorption properties of Y/Cr and Ce/Cr coated open-cell nickel-based alloy foams

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Rare Metals 2018年第8期37卷 650-661页

作者： Zhi-Li Hu Qiu Pang Guo-Qiang Ji gao-hui wu State Key Laboratory of Advanced Welding and Joining HarbinInstitute of TechnologyHarbin 150001China Hubei Key Laboratory of Advanced Technology of Automobile Components Wuhan University of TechnologyWuhan 430070China School of Mechanical and Electrical Engineering Wuhan Donghu UniversityWuhan 430212China Materials Test Department China National Analytical CenterGuangzhou 510070China

In this study, Y-and Ce-modified Cr coatings applied by pack cementation method were prepared on the surface of open-cell nickel-based alloy foam. The morphologies and microstructures of Y- and Ce-modified Cr coatings with various Y and Ce contents were investigated in detail. Then, the effects of Y and Ce addition on the mechanical properties of open-cell nickel-based alloy foams were analyzed and compared. Simultaneously, the energy absorption capacity and energy absorption efficiency of the Y- and Ce-modified Cr coated alloy foams were discussed and compared at the room and high temperatures. The results show that Cr coatings containing minor amounts of rare earth element （Y and Ce） are well adhered to the nickel-based foam struts. Especially, the microstructure of the 2 wt% Ce-modified Cr coating is denser and uniform. In addition, the compressive strength and plateau stress of Y- and Ce-modified Cr coated alloy foams firstly increase and then decrease by increasing the Y and Ce contents at room and high temperatures. The energy absorption capacity of Y/Cr and Ce/Cr coated alloy foams increases linearly with the strains increasing. The Ce/Cr coated alloy foams can absorb more energy than Y/Cr coated alloy foams in the plateau and densification regions at room temperature. Compared to those at room temperature, the Y- and Ce-modified Cr coated alloy foams show higher energy absorption efficiency when deforma- tion within 10%-30% at high temperature.

关键词： Open-cell nickel-based alloy foam Y-modified Cr coating Ce-modified Cr coating Pack cementation Mechanical properties

Mechanical Property of M40J_f/5A06Al Composite at Elevated Temperatures

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Acta Metallurgica Sinica(English Letters) 2015年第9期28卷 1175-1182页

作者： Da-Guang Li Guo-Qin Chen Long-Tao Jiang Xiu Lin gao-hui wu School of Materials Science and Engineering Harbin Institute of Technology State Key Laboratory of Advanced Welding and Joining Harbin Institute of Technology Heilongjiang Academy of Industrial Technology

In this work, aluminum alloy with a high concentration of magnesium （5A06） was reinforced with 55 vol% unidirectional ultra-high modulus and highly graphitized carbon fiber （M40J） using pressure infiltration method. The effect of temperature on the bending strength of the Cf/A1 composites was investigated from room temperature to 500 ℃. The experimental results showed that the strength of M40Jf/5A06A1 composites was not affected by temperature from room temperature to 200 ℃. The bending strength of the composite at 300 ℃ was decreased by 30% compared with that at room temperature. In order to evaluate the extent of interface weakening, the length of fiber pullout was measured. The results showed that the pullout length reached the maximum at 300 and 500 ℃, which indicated weak interface at the corre- sponding temperature. The DSC curve presented obvious heat absorption peak at around 300 ℃, which may be attributed to the dissolution of the interfacial product （A13Mg2） phases at the C/A1 interface. The bending fracture surfaces of the composites after three-point bending tests were observed by SEM, plastic-viscous flow of the matrix were observed at the samples tested at 500 ℃. The predominant mechanisms for high-temperature damage of M40Jf/5A06A1 composites are matrix softening caused by dislocation recovery and interface weakening caused by the dissolution of interfacial products.

关键词： Carbon fiber Aluminum Metal matrix composites High-temperature properties Fiberpullout length

Electrical Discharge Machining of Al2024-65 vol%SiC Composites

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Acta Metallurgica Sinica(English Letters) 2017年第5期30卷 447-455页

作者： Wen-Shu Yang Guo-Qin Chen Ping wu Murid Hussain Jia-Bing Song Rong-Hua Dong gao-hui wu Department of Materials Science and Engineering HarbinInstitute of TechnologyHarbin 150001China Northwest Institute of Nuclear Technology Xi'an 710024China Department of Chemical Engineering COMSATS Instituteof Information TechnologyM.A.Jinnah BuildingDefenceRoadOff Raiwind RoadLahore 54000Pakistan Beijing Institute of Aerospace Control Devices Beijing 100039China

In the present work, the wire electrical discharge machining（WEDM） process of the 65 vol% SiCp/2024 Al composite prepared by pressure infiltration methods has been investigated. The microstructure of the machined composite was characterized by scanning electron microscope, the average surface roughness（Ra）, X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy（TEM） techniques. Three zones from the surface to the interior（melting zone, heat affected zone and un-affected zone） were found in the machined composites, while the face of SiC particles on the surface toward the outside was ‘‘cut＇＇ to be flat. Increase in Al and Si but decrease in C and O were observed in the core areas of the removed particles. Si phase, which was generated due to the decomposition of SiC, was detected after the WEDM process. The irregular and spherical particles were further observed by TEM. Based on the microstructure observation, it is suggested that the machining mechanism of 65 vol% SiCp/2024 Al composite was the combination of the melting of Al matrix and the decomposition of SiC particles.

关键词： Metal matrix composites SiCp/Al composite Metal infiltration Wire electrical discharge machining(WEDM) SiC decomposition Machining mechanism

Microstructural evolution and thermal conductivity of diamond/Al composites during thermal cycling

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International Journal of Minerals,Metallurgy and Materials 2021年第11期28卷 1821-1827页

作者： Ping-ping Wang Guo-qin Chen Wen-jun Li hui Li Bo-yu Ju Murid Hussain Wen-shu Yang gao-hui wu School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China Qiqihar Xiangke New Material Co. Ltd.Qiqihar 161005China Key Laboratory of Advanced Structure-Function Integrated Materials and Green Manufacturing Technology School of Material Science and EngineeringHarbin Institute of TechnologyHarbin 150001China Beijing Institute of Spacecraft System Engineering Beijing 100094China Department of Chemical Engineering COMSATS University IslamabadLahore CampusDefence RoadOff Raiwind RoadLahore 54000Pakistan

The microstructural evolution and performance of diamond/Al composites during thermal cycling has rarely been *** the present work,the thermal stability of diamond/Al composites during thermal cycling for up to 200 cycles was ***,the thermal conductivity(λ)of the composites was measured and scanning electron microscopy of specific areas in the same samples was carried out to achieve quasi-in situ *** interface between the(100)plane of diamond and the Al matrix was well bonded with a zigzag morphology and abundant needle-like Al4C3 *** contrast,the interface between the(111)plane of diamond and the Al matrix showed weak bonding and debonded during thermal *** debonding length increased rapidly over the first 100 thermal cycles and then increased slowly in the following 100 ***λof the diamond/Al composites decreased abruptly over the initial 20 cycles,increased afterward,and then decreased monotonously once more with increasing number of thermal *** in theλof the Al matrix and the corresponding stress concentration at the diamond/Al interface caused by thermal mismatch,rather than interfacial debonding,may be the main factors influencing the decrease inλof the diamond/Al composites,especially in the initial stages of thermal cycling.

关键词： metal-matrix composites diamond stability thermal mismatch stress

Research progress on the characterization and repair of graphene defects

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International Journal of Minerals,Metallurgy and Materials 2020年第9期27卷 1179-1190页

作者： Bo-yu Ju Wen-shu Yang Qiang Zhang Murid Hussain Zi-yang Xiu Jing Qiao gao-hui wu School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China Key Laboratory of Advanced Structure-Function Integrated Materials and Green Manufacturing Technology Harbin Institute of TechnologyHarbin 150001China Department of Chemical Engineering COMSATS University IslamabadLahore CampusDefence RoadOff Raiwind RoadLahore 54000Pakistan State Key Laboratory of Advanced Welding and Jointing Harbin Institute of TechnologyHarbin 150001China

Graphene has excellent theoretical properties and a wide range of applications in metal-based composites. However, because of defects on the graphene surface, the actual performance of the material is far below theoretical expectations. In addition, graphene containing defects could easily react with a matrix alloy, such as Al, to generate brittle and hydrolyzed phases that could further reduce the performance of the resulting composite. Therefore, defect repair is an important area of graphene research. The repair methods reported in the present paper include chemical vapor deposition, doping, liquid-phase repair, external energy graphitization, and alloying. Detailed analyses and comparisons of these methods are carried out, and the characterization methods of graphene are introduced. The mechanism, research value, and future outlook of graphene repair are also discussed at length. Graphene defect repair mainly relies on the spontaneous movement of C atoms or heteroatoms to the pore defects under the condition of applied energy. The repair degree and mechanism of graphene repair are also different according to different preparations. The current research on graphene defect repair is still in its infancy, and it is believed that the problem of defect evolution will be explained in more depth in the future.

关键词： graphene metal matrix composites defect repair characterization repair mechanism

Deformation treatment and microstructure of graphene-reinforced metal matrix nanocomposites: A review of graphene post-dispersion

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International Journal of Minerals,Metallurgy and Materials 2020年第7期27卷 888-899页

作者： Yong Mei Pu-zhen Shao Ming Sun Guo-qin Chen Murid Hussain Feng-lei Huang Qiang Zhang Xiao-sa gao Yin-yin Pei Su-juan Zhong gao-hui wu State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China Institute of Defense Engineering AMSPLABeijing 100036China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China Department of Chemical Engineering COMSATS University IslamabadLahore CampusLahore 54000Pakistan State Key Laboratory of Advanced Brazing Filler Materials&Technology Zhengzhou Research Institute of Mechanical Engineering Co.Ltd.Zhengzhou 450001China

Graphene/aluminum(Gr/Al)composites have attracted the attention of researchers all over the world due to their excellent ***,graphene agglomerates easily because of the van der Waals force between graphite sheets,thereby affecting the performance of the *** the agglomeration of graphene and dispersing it uniformly in the Al matrix is a key *** the preparation process,predispersion treatment and deformation treatment can play important roles in graphene *** have conducted a series of research and literature reviews of the graphene predispersion and consolidation of ***,they paid less attention to post-deformation *** review summarizes different deformation treatments involved in the preparation process of Gr/Al composites and the evolution of the microstructure during the *** on deformation parameters is expected to further improve the properties of Gr/Al composites and would provide a deep understanding of the strengthening effect of graphene.

关键词： graphene/aluminum composites deformation treatment dispersion microstructure

Influence of soaking Malus domeri(Bois)*** on gut microbiota and metabolites of long-living elderly individuals in Hezhou city,Guangxi,China

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Food Science and Human Wellness 2024年第3期13卷 1311-1321页

作者： hui Nie Zhongyang gao Yanghe Luo Yajuan Wang Feiyang wu Guangqing Mu Xiaomeng wu School of Food Science and Technology Dalian Polytechnic UniversityDalian 116034China Dalian Probiotic Function Research Key Laboratory Dalian Polytechnic UniversityDalian 116034China Guangxi Key Laboratory of Health Care Food Science and Technology Hezhou UniversityHezhou 542899China

To investigate the effects of drinking the soaking of Malus domeri(Bois)*** on gut microbiota and metabolites of long-living elderly individuals in Hezhou city,Guangxi,*** has been reported that longevity is closely related to metabolism and the gut *** 16S rRNA sequencing and liquid chromatography-mass spectrometry(LC-MS)were used to analysis fecal samples and explore the factors affecting longevity in the ***,we discovered,that elderly individuals who had been drinking the soaking of ***(Bois)*** for a long time exhibited higher diversity of the gut microbiota than without drinking the soaking,*** proportions of Ruminococcaceae and Prevotella were decreased in those who did not drink this *** addition,a total of 106 metabolites were characterized,and the people of long-lived people(>90 years old)and elderly people(<90 years old)who drinking soaking of ***(Bois)*** significantly altered the gut microbiota and upregulated levels of haplopine,farnesol,genipic acid,momordicinin,2-hydroxyestrone,hydroxyphenyllactic acid,caffeic acid,sophoraflavanone B,and soyasaponin *** preliminarily determined that ***(Bois)*** consumption may be an important factor affecting longevity in this area.

关键词： Longevity Malus domeri(Bois)Chev.leaves Gut microbiota Metabolomics

Research on a Monte Carlo global variance reduction method based on an automatic importance sampling method

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Nuclear Science and Techniques 2024年第5期35卷 200-215页

作者： Yi-Sheng Hao Zhen wu Shen-Shen gao Rui Qiu hui Zhang Jun-Li Li Department of Engineering Physics Tsinghua UniversityBeijing 100084China Key Laboratory of Particle and Radiation Imaging of Ministry of Education Beijing 100084China Nuctech Company Limited Beijing 100084China

Global variance reduction is a bottleneck in Monte Carlo shielding *** global variance reduction problem requires that the statistical error of the entire space is *** study proposed a grid-AIS method for the global variance reduction problem based on the AIS method,which was implemented in the Monte Carlo program *** proposed method was validated using the VENUS-Ⅲ international benchmark problem and a self-shielding calculation *** results from the VENUS-Ⅲ benchmark problem showed that the grid-AIS method achieved a significant reduction in the variance of the statistical errors of the MESH grids,decreasing from 1.08×10^(-2) to 3.84×10^(-3),representing a 64.00% *** demonstrates that the grid-AIS method is effective in addressing global *** results of the selfshielding calculation demonstrate that the grid-AIS method produced accurate computational ***,the grid-AIS method exhibited a computational efficiency approximately one order of magnitude higher than that of the AIS method and approximately two orders of magnitude higher than that of the conventional Monte Carlo method.

关键词： Monte Carlo Global variance reduction Reactor shielding Automatic importance sampling

Rapid Antidepressant-Like Potential of Chaihu Shugan San Depends on Suppressing Glutamate Neurotransmission and Activating Synaptic Proteins in Hippocampus of Female Mice

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Chinese Journal of Integrative Medicine 2024年第8期30卷 692-700页

作者： LU Chao gao Zi-wei XING Shan WANG hui-hui HUANG Yun-ke ZHOU Hang wu Lei Department of Chinese Medicine Preparations Affiliated Hospital of Nanjing University of Chinese MedicineJiangsu Province Hospital of Chinese MedicineNanjing210029China College of Chinese Medicine Nanjing University of Chinese MedicineNanjing210046China Department of Chinese Medicine Women’s HospitalSchool of MedicineZhejiang UniversityHangzhou310000China

Objective To explore the rapid antidepressant potential and the underlying mechanism of Chaihu Shugan San(CSS)in female *** Liquid chromatography mass spectrometry(LC-MS)/MS was used to determine the content of main components in CSS to determine its *** C57BL/6J mice were randomly divided into 4 groups,including control(saline),vehicle(saline),CSS(4 g/kg)and ketamine(30 mg/kg)*** were subjected to irregular stress stimulation for 4 weeks to establish the chronic mild stress(CMS)model,then received a single administration of *** hours later,the behavioral tests were performed,including open field test,tail suspension test(TST),forced swimming test(FST),novelty suppression feeding test(NSF),and sucrose preference test(SPT).Western blot analysis was used to detect the expression levels of N-methyl-D-aspartate receptor(NMDA)subtypes[N-methyl-D-aspartate receptor 1(NR1),NR2A,NR2B],synaptic proteins[synapsin1 and post synaptic density protein 95(PSD95)],and brain-derived neurotrophic factor(BDNF).Moreover,the rapid antidepressant effect of CSS was tested by pharmacological technologies and optogenetic interventions that activated glutamate receptors,*** Compared with the vehicle group,a single administration of CSS(4 g/kg)reversed all behavioral defects in TST,FST,SPT and NSF caused by CMS(P<0.05 or P<0.01).CSS also significantly decreased the expressions of NMDA subtypes(NR1,NR2A,NR2B)at 2 h in hippocampus of mice(all P<0.01).In addition,similar to ketamine,CSS increased levels of synaptic proteins and BDNF(P<0.05 or P<0.01).Furthermore,the rapid antidepressant effects of CSS were blocked by transient activation of NMDA receptors in the hippocampus(all P<0.01).Conclusion Rapid antidepressant effects of CSS by improving behavioral deficits in female CMS mice depended on rapid suppression of NMDA receptors and activation of synaptic proteins.

关键词： Chaihu Shugan San female rapid antidepressant potential N-methyl-D-aspartate receptor synapticprotein optogenetic Chinesemedicine