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On B(5,20)2-Groups

Algebra Colloquium 2024年第3期31卷 429-440页

作者： E.A.Alhassan y.L.Tan y.li School of Mathematical Sciences Jiangsu UniversityZhenjiangJiangsu 212013China Department of Mathematics Brock UniversitySt.CatharinesOntario L2S 3A1Canada

A finite group G is said to be a B(n,k)group if for any n-element subset[a_(1),…,a_(n)]of G,|{a_(i)a_(j)|1≤i,j≤n}|≤*** is of interest to characterize the structure of B(n,k)groups for n(n+1)/2≤k≤n^(2)-*** B(5,k)groups for 15≤k≤19 have been investigated by several *** this paper,we give a complete characterization of B(5,20)2-groups by showing there are five classes of such groups which are nontrivial and nonabelian.

关键词： B(n,k)groups small squaring property central extension GAP

A　k－ε－PDF　Two－Phase　Turbulence　Model　for　Simulating　Sudden－Expansion　Particle－Laden　Flows

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Journal of Thermal Science 1996年第1期5卷 34-38页

作者： y.li L.X.Zhou DepartmentofEngineeringMechanics TsinghuaUniversityBeijingChina DepartmentofEngineeringMechanics Ts

A k - ε-PDF model based on statistical theory for turbulent gas-particle flows is proposed,and a numerical procedure combining the finite difference and finite fluctuating-velocity -group methods is *** obtained statistically averaged equations have the same form as those obtained by using the Reynolds *** the k -ε-PDF model (PDF particle turbulence model combined with the k - ε gas turbulence model),many terms,such as the diffusion term in particle Reynolds Stress equations,can be accurately calculated for verifying the second-moment-closure *** k - ε- PDF model is used to simulate sudden-expansion particle-laded *** of the predictions using both k -ε-PDF and the k - ε- kp models with experimental results shows that the k - ε-PDF model give more reasonable non-isotropic features of particle turbulence.

关键词： turbulent gas-particle flows statistical theory turbulence models nonisotropic turbulence.

THEORy DEPOSITION MODEL AND INFLUENCING FACTORS DURING PROCESS OF PREPARING MICRO-LAyER LAMINATE By EBPVD

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Acta Metallurgica Sinica(English Letters) 2004年第3期17卷 283-287页

作者： L.P.Shi X.D.He y.li Center for Composite Materials Harbin Institute of TechnologyHarbin 150001 ChinaCenter for Composite Materials Harbin Institute of TechnologyHarbin 150001 ChinaCenter for Composite Materials Harbin Institute of TechnologyHarbin 150001 China

This paper briefly introduces the characteristics of electron beam physical vapor depo-sition (EBPVD) technique and the whole process of preparing micro--layer compositelaminate. And several major influencing factors are presented and discussed. It wasfound that residual gas pressure should be low enough to guarantee the unobstructedtransporfation of vapor steam and electron beam; the evaporation method and evapo-ration speed are up to the different vapor pressure deficit of compositions of raw mate-rials; and the substrate temperature could have great influence on the microstructureof the micro--layer laminates.

关键词： micro-layer composite material EBPVD residual gas pressure evaporation method and speed,substrate temperature

Recent advancements toward gapless neural-electrode interface post-cochlear implantation

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Neural Regeneration Research 2021年第9期16卷 1805-1806页

作者： Crystal y.li Rahul Mittal Jenna Bergman Jeenu Mittal Adrien A.Eshraghi Department of Otolaryngology University of Miami Miller School of MedicineMiamiFLUSA Department of Neurological Surgery University of Miami Miller School of MedicineMiamiFLUSA Department of Biomedical Engineering University of MiamiCoral GablesFLUSA

Cochlear implants(CI) are widely used to provide auditory rehabilitation to individuals with moderate to severe sensorineural hearing loss(Eshraghi et al., 2012). The scala tympani(ST) of the cochlea is the site of im... 详细信息

关键词： cochlear al. auditory

REVIEW OF THE RESEARCHES ON MAGNETOSTRICTIVE MATERIALS

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Acta Metallurgica Sinica(English Letters) 1998年第5期11卷 313-319页

作者： y.li Chong-OhKim

The recent evolution in researeh on the magnetostrictive materials is briefly reviewed.A cotnpaboon of the relative preperties between bulk and thin film materialS, and theeNcts of addition of elements on the magnetic... 详细信息

关键词： magnetostriction rare-earth metal transition metal

Hardness-thermal stability synergy in nanograined Ni and Ni alloys:Superposition of nanotwin and low-energy columnar boundary

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Journal of Materials Science & Technology 2023年第6期137卷 123-131页

作者： F.H.Duan y.lin Q.li J.H.Luan J.Lu J.Pan y.li Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Laboratory of Nanomaterials&Nanomechanics Department of Mechanical EngineeringCity University of Hong KongHong KongChina State Key Laboratory of Material Processing and Die&Mould Technology and School of Materials Science and Engineering Huazhong University of Science and TechnologyWuhan 430074China Department of Materials Science and Engineering City University of Hong KongHong KongChina Centre for Advanced Structural Materials Greater Bay Joint DivisionShenyang National Laboratory for Materials ScienceCity University of Hong Kong Shenzhen Research InstituteShenzhen 518057China City U-Shenzhen Futian Research Institute Shenzhen 518045China

Refining grains into nanoscale can significantly strengthen and harden metallic materials;however,nanograined metals generally exhibit low thermal stability,hindering their practical *** this work,we exploit the superposition of the contribution of nanotwins,low-angle grain boundaries,and microalloying to tailor superior combinations of high hardness and good thermal stability in Ni and Ni *** the nanotwinned Ni having a twin thickness of∼2.9 nm and grain size of 28 nm,it exhibits a hardness over 8.0 GPa and an onset coarsening temperature of 623 K,both of which are well above those of nanograined ***/Mo microalloying can further improve the onset coarsening temperature to 773 K without comprising *** analyses reveal that high hardness is achieved via strengthen-ing offered by extremely fine ***,the superior thermal stability is mainly ascribed to the low driving force for grain growth induced by the low-angle columnar boundary architecture and to the additional pinning effect on the migration of twin/columnar boundaries provided by minor Re/Mo *** present work not only reveals a family of nanotwinned metals possessing the combination of ultra-high hardness and high thermal stability but also provides a strategy for tailoring properties of metallic materials by pairing low-angle grain boundaries and twin boundaries.

关键词： Nanotwin Thermal stability Hardness Low-angle grain boundary Microalloying

Research on high bandwidth power supply

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Radiation Detection Technology and Methods 2022年第3期6卷 409-417页

作者： P.liu F.L.Long y.li Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049People’s Republic of China University of Chinese Academy of Sciences Beijing 100049People’s Republic of China

Background Fourth-generation photon sources like Free Electron Lasers(FEL)and Diffraction-limited Storage Rings(DLSR)have high requirements for beam *** the case of DLSR sources,a set of high-performance fast orbit feedback system(FOFB)is needed to correct the beam orbit quickly and *** FOFB system has four key components,which is BPM,orbit feedback calculation,fast correction magnet and fast corrector power *** FOFB gives the correction command and controls the fast corrector power supply to drive the fast correction magnet to correct the beam quickly and *** corrector power supply has an important impact on the performance of *** corrector power supply needs to have high bandwidth and low output current *** The new GaN power device is used to solve the restriction of the high-speed *** switching frequency of the power supply is increased to 300 *** control system is designed to improve the bandwidth and optimize the output current *** modeling analysis of the key parts of the system is given and the simulation experiments are carried out with *** and conclusion The test results showed that bandwidth of the designed power supply is 20 *** step response time is 18us and output current ripple is lower than 1 mA.

关键词： Photon source FOFB High bandwidth MATLAB GaN

The Tendency of the Market and Technology of the Magnetic Materials in Korea

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Journal of Materials Science & Technology 2000年第2期16卷 217-220页

作者： C.O.Kim and y.li (Engineering College, Chungnam National University, Korea) Chungnam Natl Univ Coll Engn Taejon South Korea

The magnetic materials industry in Korea started from the production of the ferrite and alnico magnet at the end of 1970s. At that time, most electronic company in Korea imported the equipment parts and made them up. As one of electronic equipments, its development dropped behind other countries. In 1980s, with the revaluing upward of Japanese yen and the increment of the domestic need in Korea, several new magnet manufacturing plants were built up.

关键词： The Tendency of the Market and Technology of the Magnetic Materials in Korea

Formation,characteristics and control of sludge in Al-containing magnesium alloys:An overview

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Journal of Magnesium and Alloys 2022年第3期10卷 643-658页

作者： y.Fu G.G.Wang A.Hu y.li K.B.Thacker J.P.Weiler H.Hu Department of Mechanical Automotive and Materials EngineeringUniversity of Windsor401 Sunset AveWindsorON N9B 3P4Canada Global Technology Centre Meridian Lightweight Technologies25 MacNab AveStrathroyON N7G 4H6Canada

Sludge consisting of heavy element phases and oxides is often generated during the casting operation of aluminum(Al)and magnesium(Mg)*** the help of the well-established Sludge Factor(SF)formula,it is relatively easy to control the sludge generation in aluminum *** formation mechanisms and characteristics of sludge in die casting magnesium alloys are still *** ensure the production of high quality die cast components at a low cost,a full understanding of sludge in die casting Mg alloys and its proper control measures need to be developed,since excessive sludge formation affects deleteriously material and operation cost,and casting *** the present report,the formation,characteristics and control of Mg die-casting sludge,based on the established knowledge of sludge formation and sludge factor in Al die casting alloys,are *** work on characterization and assessment of sludge in die cast Mg alloys are *** principles for control of sludge in ingot production in association with die casting of Mg alloys are *** assessment of Mg oxide and intermetallics relevant to sludge formation in Mg alloys are highlighted.

关键词： Sludge Magnesium alloys Die casting Al-Mn(-Fe)intermetallics Magnesium oxide Microstructure characterization