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Dispersion and Damage of Carbon Nanotubes in Carbon Nanotube/7055Al Composites During High-Energy Ball Milling Process

2005 6th International Conference on ASIC

作者： R.yang G.H.Li y.z.Xu y.F.Chao z.M.Tang y.H.yang B.K.Ma D.H.Huang P.Xu S.G.Shen C.L.Lin C.L.Wu F.z.yan D.J Han y.L.Ren L.K.yu I.M.Cai X.N.Tian y.z.ji D.S.Du C.Huang Beijing Normal University Beijing Institute of Microelectronics Technology Institute of Computing Technology CAS China Aerospace Corporation

＜正＞*** Device physics and Integrated Device and Circuit Simulation of "Dual Carrier Field Effect Transistor" （DCFET） with effective channel length of 5-30nm had been presented in Ref.[1].Two dimensional approximation methods had been used in these studies. Recently,two dimensional exact numerical simulation had been carried out for mesa type SOI switching "Vertical Dual Carrier Field Effect Transistor" （VDCFET）.This exact method is presented in this paper *** details are reported in Ref.[2]. Shown in Fig.1 is the mesa SOI switching N channel *** comparison of the simulation results of the approximate physical method and of the exact numerical method shall be discussed and are shown to be in good *** on these simulation results,mesa type SOI switching VDCFET with effective channel of 30nm was designed and fabricated by

关键词： Fabrication FETs Application specific integrated circuits Physics Ion implantation Poisson equations Differential equations Numerical simulation Space charge Voltage

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Acta Metallurgica Sinica(English Letters) 2021年第2期34卷 196-204页

作者： S.Bi B.L.Xiao z.H.ji B.S.Liu z.y.Liu z.y.Ma Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of Sciences72 Wenhua RoadShenyang 110016China School of Material Science and Engineering University of Science and Technology of China72 Wenhua RoadShenyang 110016China AVIC Manufacturing Technology Institute Beijing 100024China

High-energy ball milling(HEBM)combined with powder metallurgy route was used to fabricate carbon nanotube(CNT)reinforced 7055 Al *** powder morphology evolution processes(HEBM-1 and HEBM-2)were designed to investigate the dispersion and damage of CNTs during HEBM ***-1 evolution process involved powder fl attening,cold-welding and fracture,while HEBM-2 evolution process consisted of powder fl attening and *** HEBM-1,the repetitive fracture and cold-welding process was effective for dispersing ***,the powder fl attening process in HEBM-2 was unsuccessful in dispersing CNTs due to two reasons:(1)the thickness of fl aky Al powders exceeded the critical value,and(2)the clustered CNTs embedded in fl aky Al powders could not be *** of the broadening of D band and the appearance of a new defect-related D’band,product of I D/I G and full width half maximum of D band,rather than I D/I G,was used to evaluate the actual damage of *** indicates that the damage of CNTs was severe in powder fl attening and fracture stages,while the damage of CNTs was small in powder cold-welding stage.

关键词： Metal matrix composites Carbon nanotubes Powder evolution Dispersion and damage Powder metallurgy

RESEARCH ON LASER DIRECT DEPOSITION PROCESS OF Ti-6Al-4V ALLOy

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Acta Metallurgica Sinica(English Letters) 2007年第3期20卷 171-180页

作者： S.y. Gao y.z. zhang L.K. Shi B.L. Du M.z. Xi H.z. ji Mechanical Engineering College Yanshan University O~mhuangdao 066004 China Beijing General Research Institute for Nonferrous Metals Beijing 100088 China

Laser direct deposition （LDD） of metallic components is an advanced technology of combining CAD/CAM （computer aided design/computer aided manufacturing）, high power laser, and rapid prototyping. This technology uses laser beam to melt the powders fed coaxiaUy into the molten pool by the laser beam to fabricate fuUy dense metallic components. The present article mainly studies the LDD of Ti-6Al-4V alloy, which can be used to fabricate aircraft components. The mechanical properties of the Ti-6Al-4V alloy, fabricated by LDD, are obtained using the tension test, and the oxygen content of used powders and deposited specimens are measured. In the present article, it can be seen that the mechanical properties obtained using this method are higher than the ones obtained by casting, and equal to those got by wrought anneal. One aircraft part has been made using the LDD process. Because of this aircraft part, with sophisticated shape, the effect of the laser scanning track on the internal soundness of the deposited part was discussed.

关键词： laser direct deposition Ti-6Al-4V alloy mechanical property depositing process aircraft component

Oxidation behavior and microstructural evolution of FeCoNiTiCu five-element high-entropy alloy nanoparticles

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Journal of Materials Science & Technology 2024年第10期177卷 133-141页

作者： H.Bai R.Su R.z.zhao C.L.Hu L.z.ji y.J.Liao y.N.zhang y.X.Li X.F.zhang Key Laboratory for Anisotropy and Texture of Materials(MOE) School of Materials Science and EngineeringNortheastern UniversityShenyang110819China Institute of Advanced Magnetic Materials College of Materials and Environmental EngineeringHangzhou Dianzi UniversityHangzhou310012China

High-entropy alloys(HEAs)have attracted extensive attention ascribed to their unique physical and chemical properties induced by the cocktail ***,their oxidation behaviors,in particular at nanoscale,are still lack because of multi-element complexity,which could also be completely differ-ent from the bulk *** this work,we synthesized FeCoNiTiCu five-element HEA nanopar-ticles(NPs)with uniform elemental distribution by arc-discharging approach,and further investigated their oxidation behaviors at 250 ℃,and 350 ℃.The morphology,structure and element distribution of NPs were analyzed by transmission electron microscopy(TEM),energy dispersive spectroscopy(EDS)and electron energy loss spectroscopy(EELS).The surface oxidation in FeCoNiTiCu NPs during the high-temperature process can induce nanoscale pores at core/shell interfaces by Kirkendall effect,and even the eventual coalescence into a single ***,the oxidation states of NPs with diameters(d)varying from 60 to 350 nm were analyzed in detail,revealing two typical configurations:hollow(dyolk-shell structures(d>150 nm).The experimental results were complemented by first-principles calculations to investigate the diffusion behaviors of five elements,evidencing that the surface oxidation strongly alters the surface segregation preferences:(1)in the initial stage,Cu and Ni appear to prefer segregating on the surface,while Co,Ti and Fe tend to stay in the bulk;(2)in the oxidation process,Cu prefers to stay in the center,while Ti segregates to the surface ascribed to the reduced po-tential *** study gives new insights into oxidation of nanoscale HEA,and also provides a way for fabrication of high-entropy oxides with controllable architectures.

关键词： High-entropy alloy Nanoparticles Oxidation Kirkendall effect Exchange bias effect

Decreased levels of phosphorylated synuclein in plasma are correlated with poststroke cognitive impairment

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Neural Regeneration Research 2025年第9期20卷 2598-2610页

作者： yi Wang yuning Li yakun Gu Wei Ma yuying Guan Mengyuan Guo Qianqian Shao Xunming ji jia Liu Department of Clinical Laboratory Beijing Bo’ai HospitalChina Rehabilitation Research CenterCapital Medical UniversityBeijingChina Beijing Institute of Brain Disorders Laboratory of Brain DisordersMinistry of Science and TechnologyCollaborative Innovation Center for Brain DisordersBeijing Advanced Innovation Center for Big Data-based Precision MedicineCapital Medical UniversityBeijingChina Department of Neurosurgery Xuanwu HospitalCapital Medical UniversityBeijingChina

Poststro ke cognitive impairment is a major secondary effect of ischemic stroke in many patients;however,few options are available for the early diagnosis and treatment of this *** aims of this study were to(1)determine the specific relationship between hypoxic andα-synuclein during the occur of poststroke cognitive impairment and(2)assess whether the serum phosphorylatedα-synuclein level can be used as a biomarker for poststro ke cognitive *** found that the phosphorylatedα-synuclein level was significantly increased and showed pathological aggregation around the cerebral infa rct area in a mouse model of ischemic *** addition,neuronalα-synuclein phosphorylation and aggregation were observed in the brain tissue of mice subjected to chronic hypoxia,suggesting that hypoxia is the underlying cause ofα-synuclein-mediated pathology in the brains of mice with ischemic *** phosphorylatedα-synuclein levels in patients with ischemic stroke were significantly lower than those in healt hy subjects,and were positively correlated with cognition levels in patients with ischemic ***,a decrease in serum high-density lipoprotein levels in stroke patie nts was significantly correlated with a decrease in phosphorylatedα-synuclein *** ischemic stroke mice did not show significant cognitive impairment or disrupted lipid metabolism 14 days after injury,some of them exhibited decreased cognitive function and reduced phosphorylatedα-synuclein *** together,our results suggest that serum phosphorylatedα-synuclein is a potential biomarker for poststroke cognitive impairment.

关键词： biomarker high-density lipoprotein ischemic stroke phosphorylatedα-synuclein poststroke cognitive impairment

Experimental and numerical study of the effect of pulsatile flow on wall displacement oscillation in a flexible lateral aneurysm model

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Acta Mechanica Sinica 2019年第5期35卷 1120-1129页

作者： L.z.Mu X.y.Li Q.z.Chi S.Q.yang P.D.zhang C.J.ji y.He G.Gao School of Energy and Power Engineering Dalian University of TechnologyDalian 116024China School of Biomedical Engineering Capital Medical UniversityBeijing 100069China The First Affiliated Hospital of University of Science and Technology of China Hefei 230036China

This study experimentally and numerically investigated the effect of pulsatile flow of different frequencies and outflow resistance on wall deformation in a lateral aneurysm.A method for constructing a flexible aneurysm model was developed,and a self-designed piston pump was used to provide the pulsatile flow conditions.A fluid-structure interaction simulation was applied for comparison with and analysis of experimental *** maximum wall displacement oscillation increased as the pulsation frequency and outflow resistance increased,especially at the aneurysm *** is an obvious circular motion of the vortex center accompanying the periodic inflow fluctuation,and the pressure at the aneurysm dome at peak flow increased as the pulsatile flow frequency and terminal flow resistance *** results could explain why abnormal blood flow with high frequency and high outflow resistance is one of the risk factors for aneurysm rupture.

关键词： Lateral aneurysm In vitro experiment Pulsatile flow Wall displacement oscillation Fluid-structure interaction simulation

The correlationship between the metabolizable energy content,chemical composition and color score in different sources of corn DDGS

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Journal of Animal Science and Biotechnology 2014年第3期5卷 340-347页

作者： yong-z jie jian-y zhang Li-H zhao Qiu-G Ma Cheng ji State Key Laboratory of Animal Nutrition College of Animal Science and TechnologyChina Agricultural University

Background： This study was conducted to evaluate the apparent metabolizable energy （AME） and true metabolizable energy （TME） contents in 30 sources of corn distillers dried grains with solubles （DDGS） in adult roosters, and establish the prediction equations to estimate the AME and TME value based on its chemical composition and color score. Methods： Twenty-eight sources of corn DDGS made from several processing plants in 11 provinces of China and others imported from the United States. DDGS were analyzed for their metabolizable energy （ME） contents, measured for color score and chemical composition （crude protein, crude fat, ash, neutral detergent fiber, acid detergent fiber）, to predict the equation of ME in DDGS. A precision-fed rooster assay was used, each DDGS sample was tube fed （50 g） to adult roosters. The experiment was conducted as a randomized incomplete block design with 3 periods. Ninety-five adult roosters were used in each period, with 90 being fed the DDGS samples and 5 being fasted to estimate basal endogenous energy losses. Results： Results showed that the AME ranged from 5.93 to 12.19 MJ/kg, TME ranged from 7.28 to 13.54 MJ/kg. Correlations were found between ME and ash content （-0.64, P 〈 0.0]） and between ME and yellowness score （0.39, P 〈 0.05） of the DDGS samples. Furthermore, the best-fit regression equation for AME content of DDGS based on chemical composition and color score was AME = 6.57111 ＋ 0.5]475 GE - 0.10003 NDF ＋ 0.1 3380 ADF ＋ 0.07057 fat - 0.57029 ash - 0.02437 L （R^2 = 0.70）. The best-fit regression equation for TME content of DDGS was TME = 7.92283 ＋ 0.51475 GE - 0.10003 NDF ＋ 0.13380 ADF ＋ 0.07057 fat - 0.57029 ash - 0.02437 L （R2 = 0.70）. Conclusions： This experiment suggested that measuring the chemical composition and color score of a corn DDGS sample may provide a quality parameter for identifying corn DDGS sources energy digestibility and metabolizable energy content.

关键词： Metabolizable energy Distillers dried grains with solubles Rooster Predictive equation

A novel friction stir diffusion bonding process using convex-vortex pin tools

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Journal of Materials Science & Technology 2020年第13期47卷 23-30页

作者： S.D.ji Q.Wen z.W.Li College of Aerospace Engineering Shenyang Aerospace UniversityShenyang 110136China State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China

In this work,a novel friction stir diffusion bonding(FSDB)method was proposed to eliminate hook when joining thin *** tools,with several convex-vortex pins were innovatively designed to improve the diffusion bonding effect of the lap *** showed that sound joints,excellently bonded at the lap interface and without hook,were *** lap interfaces on the joints welded using the T-tool and F-tool almost remained intact,thereby indicating that they were formed by diffusion *** material flow behavior was also simulated by FLUENT software and the results showed that the material flow along thickness was significantly enhanced by increasing the pin *** joint welded by the T-tool showed shear fracture *** bonding was formed at the lap interface when using the F-tool and thus the joint showed tensile fracture.

关键词： Friction stir diffusion bonding Convex-vortex pin Hook Material flow Failure

DIFFUSION　PHENOMENA　AND　MICROSTRUCTURE　STABILITy　OF　Ni－Cr－Al－y－Si　COATING　ON　THENi_3Al　BASED　ALLOy　SUBSTRATE

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Acta Metallurgica Sinica(English Letters) 1996年第6期9卷 635-639页

作者： z.P. Xing y.F. Han y.L. ji and M.G. yan(Beijing Institute of Aeronautical Materials, Beijing 100095, ) Beijing Inst of Aeronautical Materials Beijing China

In this paper, Ni-Cr-Al-y-Si coating deposited by vacuum are deposition on the Ni_3Alalloy IC6, the typical use of which is for turbine blades and vanes, was *** results of the tests show that the tensile properties at room temperature and stress rupture properties at 1100℃ of the IC6 alloy were not obviously influenced by the coatings. At annealing state, limited element interdiffusion was observed. After stress rupture testing for 252 h at 1100℃/90 MPa, however,significant interdiffusion of Mo, Cr and Al took place between the coating layer and the *** element diffustion did not result in the formation of brittle phases on the coating/substrate interface. No cracking and spallation in the coating were *** it can be concluded that the Ni-Cr-Al-y-Si overlay coating was successful for protecting the IC6 alloy.

关键词： M-Cr-Al-y coating Ni_3Al based alloy microstructure stability vskip 0.6cm

Optical Anisotropy of InAs Monolayer in (311)-Oriented GaAs Matrix

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Chinese Physics Letters 1997年第12期14卷 932-935页

作者： y.H.Chen z.yang XU Bo WANG zhan-guo LIANG ji-ben Department of Physics Hong Kong University of Science and TechnologyClear Water BayKowloonHong Kong Laboratory of Semiconductor Materials Science lnstitute of SemiconductorsChinese Academy of SciencesBeijing 100083 On leave from Laboratory of Semiconductor Materials Science Institute of SemiconductorsChineseAcademy of SciencesBeijing 100083

In-plane optical anisotropy which comes from the heavy hole and the light hole transitions in an InAs monolayer inserted in(311)-oriented GaAs matrix is observed by reflectance difference *** observed steplike density of states demonstrates that the InAs layer behaves like a two-dimensional quantum well rather than isolated quantum *** magnitude of the anisotropy is in good agreement with the intrinsic anisotropy of(311)orientation quantum wells,indicating that there is little structural or strain anisotropy of the InAs layer grown on(311)-oriented GaAs surface.

关键词： anisotropy quantum reflectance