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Electron localization of H_2^+ in a dc electric field

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Chinese Physics B 2017年第1期26卷 170-175页

作者： z M Jia z N zeng W T Tang R x Li State Key Laboratory of High Field Laser Physics Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai 201800 China Signal and Information Processing Jingchu University of Technology Jingmen 448000 China

A dc electric field is utilized to steer the electron motion after the molecular ion H2-＋ is excited by an ultrashort ultraviolet laser pulse. The numerical simulation shows that the electron localization distribution and the dissociation control ratio are dependent on the polarization direction and amplitude of the dc electric field. Most electrons of the dissociation state move opposite to the dc electric field and stabilize at the dressed-up potential well, for the dressed-down well is occupied by the electrons of the 1 sσg state.

关键词： dissociation localization time dependent Schrdinger equation Coulomb potential ultraviolet laser pulse

xPS INVESTIGATION OF NITROGEN IONS IMPLANTED INTO ALUMINUM ALLOY BY PLASMA BASED ION IMPLANTATION

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Acta Metallurgica Sinica(English Letters) 1999年第5期12卷 771-776页

作者： zhan, z.J. Ma, x.x. xia, L.F. Sun, Y. Harbin Inst of Technology Harbin China

Aluminum alloy 2024 has been implanted with nitrogen ions at various doses by plasma based ion implantation. The introduction of energetic ions causes structural change within the near surface region of the solid. The samples have been characterized by x-ray Photoelectron Spectroscopy at various depths. The chemical states of Al and N were identified by deconvolution of the recorded xPS spectra. After plasma based ion implanted nitrogen into aluminum, not only the AlN precipitates but also super saturated solution of nitrogen forms. The presence of aluminum in different chemical states is corresponding to Al, AlN and Al2O3. The majority of nitrogen is in the form of the supersaturated solution. With the increase of nitrogen dose, the amount of AlN precipitates increases.

关键词： Aluminum compounds Ion implantation Nitrides Nitrogen Plasma devices Wear of materials

EFFECTS OF zIRCONIUM ON MICROSTRUCTURES AND MECHANICAL PROPERTIES OF MICROALLOYED STEELS

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Acta Metallurgica Sinica(English Letters) 2006年第5期19卷 319-327页

作者： T．H．xi x. Chen P.H. Li z.x. Yuan Technology Center of Wuhan Iron ＆ Steel （Group） Corp. Wuhan 430080 China School of Materials and Metallurgy Wuhan University of Science and TechnologyWuhan 430081 China

The effects of zr on the microstructures and mechanical properties of microalloyed steels have been investigated by mechanical tests and microstructural observations. The microstructures in the zr-doped steels are ferrite plus pearlite, which is similar to those in the zr-free steel. With the increase in the zr content, the lamellar structure reduces and even disappears. Sulfides and silicates that exist in the zr-free steel are modified into fine oxides in the zr-bearing steel. When the zr contents range from 0.01wt% to 0.03wt%, the low temperature toughness of the steel can be substantially improved while its room-temperature strength and ductility have no apparent change. The refinement of ferrite grain size by the addition of zirconium is one of the main reasons for this toughness improvement.

关键词： zirconium microalloyed steel microstructure mechanical property

Distinct Electrical and Mechanical Responses of a Cu-10Fe Composite Prepared by Hot-Pressed Sintering and Post Treatment

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Acta Metallurgica Sinica(English Letters) 2024年第2期37卷 255-265页

作者： x.Y.Yue S.Y.Peng x.zhang C.N.He Y.z.Tian Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education) School of Materials Science and EngineeringNortheastern UniversityShenyang110819China School of Materials Science and Engineering and Tianjin Key Laboratory of Composite and Functional Materials Tianjin UniversityTianjin300350China Research Centre for Metallic Wires Northeastern UniversityShenyang110819China

A Cu-10wt%Fe composite was prepared through hot-pressed sintering,and the material was subsequently solution *** hot-pressed sintered and solution treated materials were rolled and *** precipitation behavior and performance changes were systematically studied by using scanning electron microscopy and transmission electron *** contrast to the hot-pressed sintered specimen,the solution treatment significantly affects the thermal stability and properties of the Cu-10wt%Fe *** Cu-10wt%Fe composite was prepared after solid solution,cold rolling and aging at 773 K for 1 h,and it obtained excellent tensile strength of 494 MPa,uniform elongation of 16.3%,electrical conductivity of 51.1%IACS and softening temperature of 838 *** for the distinct difference in thermal stability and properties between hot-pressed sintered and solution treated specimens were *** findings provide a theoretical basis for designing high-performance Cu-based in-situ composites by post treatment.

关键词： Cu-Fe composite Hot-pressed sintering Thermal stability Strength Electrical conductivity

Active metal brazing of SiO2–BN ceramic and Ti plate with Ag–Cu–Ti＋BN composite filler

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Journal of Materials Science & Technology 2017年第11期33卷 1392-1401页

作者： z.W.yang C.L.Wang Y.Wang L.x.zhang D.P.Wang J.C.Feng Tianjin Key Lab of Advanced Joining Technology School of Materials Science and Engineering Tianjin University Tianjin 300072 China State Key Lab of Advanced Welding andJoining Harbin Institute of Technology Harbin 150001 China

SiO2–BN ceramic and Ti plate were joined by active brazing in vacuum with Ag–Cu–Ti＋BN composite *** effect of BN content,brazing temperature and time on the microstructure and mechanical properties of the brazed joints was *** results showed that a continuous Ti N–Ti B2reaction layer formed adjacent to the SiO2–BN ceramic,whose thickness played a key role in the bonding *** Ti–Cu compound layers,Ti2Cu,Ti3Cu4,Ti Cu2and Ti Cu4,were observed to border Ti substrate due to the strong affinity of Ti and Cu compared with *** central part of the joint was composed of Ag matrix,over which some fine-grains *** added BN particles reacted with Ti in the liquid filler to form fine Ti B whiskers and Ti N particles with low coefficients of thermal expansion（CTE）,leading to the reduction of detrimental residual stress in the joint,and thus improving the joint *** maximum shear strength of 31 MPa was obtained when 3 wt%BN was added in the composite filler,which was 158%higher than that brazed with single Ag–Cu–Ti filler *** morphology and thickness of the reaction layer adjacent to the parent materials changed correspondingly with the increase of BN content,brazing temperature and holding *** on the correlation between the microstructural evolution and brazing parameters,the bonding mechanism of SiO2–BN and Ti was discussed.

关键词： SiO2–BN ceramic BN particles Microstructure Mechanical properties

Derimorphisms over Algebras and Applications

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Algebra Colloquium 2023年第2期30卷 193-204页

作者： x.Cao S.H.Liu x.S.Lu z.J.Ye z.R.Yu Y.H.zhang School of Mathematical Sciences Shanghai Jiao Tong University 800 Dongchuan RoadShanghai 200240China MoE Key Lab of Scientific and Engineering Computing Shanghai Jiao Tong University 800 Dongchuan RoadShanghai 200240China

The new concept"derimorphism"generalizing both derivation and homomor-phism is *** a derimorphism is invertible,its inverse is a Rota-Baxter *** general theory of derimorphism is *** classification of all derimorphisms over an associative unital algebra is *** to the nonexistence of nontriv-ial positive derivations,it is shown that nontrivial positive derimorphisms do exist over any pair of opposite orderings over R[x],the lattice-ordered full matrix algebra and upper triangular matrix algebra over a totally ordered field.

关键词： derimorphism Rota-Baxter operator opposite orderings positive derimor-phism

Stability analyses of the mass abrasive projectile high-speed penetrating into a concrete target Part III: Terminal ballistic trajectory analyses

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Acta Mechanica Sinica 2015年第4期31卷 558-569页

作者： H.Wu x.W.Chen Q.Fang x.z.Kong L.L.He Institute of Systems Engineering China Academy of Engineering Physics State Key Laboratory for Disaster Prevention & Mitigation of Explosion & Impact PLA University of Science and Technology

During the high-speed penetration of projectiles into concrete targets （the impact velocity ranges from 1.0 to 1.5 km/s）, important factors such as the incident oblique and attacking angles, as well as the asymmetric abrasions of the projectile nose induced by the target-projectile interactions, may lead to obvious deviation of the terminal ballistic tra- jectory and reduction of the penetration efficiency. Based on the engineering model for the mass loss and nose-blunting of ogive-nosed projectiles established, by using the Differ- ential Area Force Law （DAFL） method and semi-empirical resistance function, a finite differential approach was pro- grammed （PENTRA2D） for predicting the terminal ballistic trajectory of mass abrasive high-speed projectiles penetrating into concrete targets. It accounts for the free-surface effects on the drag force acting on the projectile, which are attributed to the oblique and attacking angles, as well as the asymmetric nose abrasion of the projectile. Its validation on the prediction of curvilinear trajectories of non-normal high-speed pene- trators into concrete targets is verified by comparison with available test data. Relevant parametric influential analyses show that the most influential factor for the stability of ter- minal ballistic trajectories is the attacking angle, followed by the oblique angle, the discrepancy of asymmetric nose abrasion, and the location of mass center of projectile. The terminal ballistic trajectory deviations are aggravated as the above four parameters increase.

关键词： Projectile Penetration Concrete Massabrasion Terminal ballistic trajectory

A pathway to improve low-cycle fatigue life of face-centered cubic metals via grain boundary engineering

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Journal of Materials Science & Technology 2022年第18期113卷 82-89页

作者： x.J.Guan z.P.Jia S.M.Liang F.Shi x.W.Li Department of Materials Physics and Chemistry School of Materials Science and EngineeringNortheastern UniversityShenyang 110819China State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819China Key Laboratory for Anisotropy and Texture of Materials Ministry of EducationNortheastern UniversityShenyang 110819China

To probe a pathway to improve the low-cycle fatigue life of face-centered cubic(FCC)metals via grain boundary engineering(GBE),the tension-tension fatigue tests were carried out on the non-GBE and GBE Cu-16 at.%Al alloys at relatively high stress *** results indicate that the cyclic strain localiza-tion and cracking at grain boundaries(GBs)can be effectively suppressed,especially at increased stress amplitude,by an appropriate GBE treatment that can result in a higher resistance to GB cracking and a greater capability of compatible ***,the sensitivity of fatigue life to stress amplitude can be weakened by GBE,and the low-cycle fatigue life of Cu-16 at.%Al alloys is thus distinctly improved.

关键词： Cu-Al alloy Grain boundary engineering Fatigue life Crack nucleation Stress amplitude

A new scale for optimized cryogenic magnetocaloric effect in ErAl_2@Al_2O_3 nanocapsules

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Journal of Materials Science & Technology 2018年第5期34卷 848-854页

作者： F.Wei S.Ma L.yang Y.Feng J.z.Wang A.Hua x.G.zhao D.Y.Geng z.D.zhang Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of Sciences

The Er Al2@Al2O3 nanocapsules with Er Al2core and Al2O3 shell were synthesized by modified arc-charge *** typical core-shell structure of the nanocapsules was confirmed by high resolution transmission electron microscopy and x-ray photoelectron *** electron microscopy analysis shows the irregular sphere of the nanocapules with an average diameter of 26 *** investigation revealed the Curie temperature of Er Al2@Al2O3 nanocapsules at 20 K and the typical superparamagnetic behavior between blocking temperature and Curie *** on the blocking temperature and average diameter,the magnetocrystalline anisotropy constant of Er Al2@Al2O3nanocapsules was estimated to illustrate the magnetic contribution to *** large-SMof 14.25 J/（kg K）was obtained under 50 k Oe at 5 K.A vital parameter β was introduced in the present work to scale the optimized magnetic characteristics and the optimized mechanism was discussed in detail according to classical superparamagnetic *** results demonstrate that the optimal-SMwill be obtained when the magnetic parameter β is close to the theoretical coefficient.

关键词： Nanocapsules Magnetocaloric effect Superparamagnetic property Cryogenic refrigeration