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Design of HIRFL-CSRm Accelerating system

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Design of HIRFL-CSRm Accelerating system

Electron localization of H_2^+ in a dc electric field

The Second Asian Particle Accelerator Conference

作者： w.z. zhang D.S. zhang w.L. zhanInstitute of Modem Physics Chinese Academy of Sciences

＜正＞ An ion cooler-storage ring HIRFL-CSR has being constructed at *** consists of tworings-main ring（CSRm）and experimental ring（CSRe）.For the CSRm,two RF systems willbe employed,one is for RF stacking,and another is for beam *** the presentpaper,the designed parameters of CSRm accelerating system are described as well as the

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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

A Model of Tangential Contact Damping Considering Asperity Interaction and Lateral Contact

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Acta Mechanica Solida Sinica 2018年第6期31卷 758-774页

作者： w.P.Fu z.Q.Gao w.wang J.B.wu School of Mechanical and Precision Instrument Engineering Xi'an University of TechnologyXi'an 710048 China

A precise tangential contact damping model is proposed,which includes the lateral contact of the upper-lower asperities and the interaction of adjacent *** effects of the normal static preload,frequency,and amplitude of tangential displacement on the tangential contact damping were analyzed by simulation,***,the results of simulation are verified by *** tangential contact damping of considering the interaction and lateral contact of asperity is very close to the experimental results.

关键词： Asperity Lateral contact Interaction Tangential contact damping

Analysis of Contact Melting Driven by Surface Heat Flux Around a Cylinder

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Journal of Thermal Science 2008年第1期17卷 64-68页

作者： Y.S.zhao w.z.Chen F.R.Sun z.Y.Chen Faculty of Thermal Engineering College of Power and ShippingNaval University of EngineeringWuhan 430033China Faculty of Thermal Engineering College of Power and ShippingNaval University of EngineeringWuhan 430033China Professor

The contact melting of phase change material around a moving horizontal cylindrical heat source, which descended under its own weight, is investigated in this article. A melting model under constant surface heat flux is established. The analytical results for thickness and pressure distributions inside melt layer and steady melting velocity are obtained by using contact melting theory. The melting law is discussed, and compared with that of contact melting driven by temperature difference. It is found that quasi-steady melting velocity is determined by heat flux of heat source, and the variation of heat source density has less effect on melting velocity.

关键词： Contact melting horizontal cylinder phase change phenomena

Surface modification of tungsten oxide by oxygen vacancies for hydrogen adsorption

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Journal of Materials Science & Technology 2022年第22期117卷 23-35页

作者： Q.zhang F.w.Tang z.zhao z.R.Nie X.Y.Song Faculty of Materials and Manufacturing Key Laboratory of Advanced Functional MaterialsMinistry of Education of ChinaBeijing University of TechnologyBeijing 100124China

A model for describing the adsorption process of hydrogen on surface of tungsten oxide was proposed based on the first-principle calculations. Multiple factors such as type of active surface, adsorption site and distribution of oxygen vacancies were considered to evaluate the hydrogen adsorption capability of tungsten oxide. The adsorption Gibbs free energies, electronic structures and bonding characteristics under various conditions were examined to reveal the influence of oxygen vacancies on the surface. It is found that the capability of hydrogen adsorption of tungsten oxide can be significantly enhanced by adjusting the oxygen vacancy on the outermost layer of certain active surfaces. The modeling predicts that the surface structure stability and gas adsorption ability of tungsten oxide can be simultaneously improved through the formation of w–H bonds. The proposed strategy for moderating surface provides a new approach to obtain excellent gas-sensitive metal oxide materials.

关键词： Metal oxide Gas-sensitive material Surface adsorption Oxygen vacancy First-principles calculation

Fabrication and Characterization of a 2×2 Microfiber Knot Resonator Coupler

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Chinese Physics Letters 2012年第8期29卷 96-98页

作者： A.A.Jasim A.z.zulkifli M.z.Muhammad H.Ahmad S.w.Harun Department of Electrical Engineering University of Malaya 50603 Kuala LumpurMalaysia Photonics Research Center Department of PhysicsUniversity of Malaya50603 Kuala LumpurMalaysia

A 2×2 microfiber knot resonator(MKR)coupler is *** hybrid device is obtained by forming a knot within the coupling region of a microfiber coupler with a 50:50 splitting *** microfiber coupler is successfully fabricated by laterally fusing and tapering two optical fibers using a flame-brushing *** coupler has an overlapping length of 40 mm with a uniform waist of around 5μ*** an MKR structure,the coupler produces a resonant response at both output *** free spectral range of the output spectrum from both ports is obtained at 0.2 nm at a knot diameter of 260μ*** resonance extinction ratio of the device varies from 2 to 6 dB while the calculated Q factor and finesse are~25646 and 3.3,respectively,at both output ports.

关键词： technique fiber resonator

OXIDATION BEHAVIOR OF KOVAR ALLOY IN CONTROLLED ATMOSPHERE

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Acta Metallurgica Sinica(English Letters) 2008年第6期21卷 409-418页

作者： D. w. Luo z.S. Shen School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

Controlled oxidation experiments were performed on Kovar alloy by changing oxidation atmosphere, temperature, and exposure time to produce films with different oxide type and thickness. The results indicated that single Fe3O4 and single FeO were respectively obtained when Kovar alloy was oxidized in N2-2.31%H2O-0.95%H2 at 500℃ and in N2-2.31%H2O-0.5%H2 at 1000℃, and all kinetic curves followed linear relation; mixed oxides of FeO and Fe3O4 formed when Kovar was oxidized in N2-2.31%H2O at 1000℃and parabolic kinetics were obeyed. Analysis of metallographic cross section of oxides indicated that oxygen diffusion inward through the oxide scale is responsible for intergranular oxide, which had formed beneath the oxide scales when the oxide products were mixed oxides of FeO and Fe3O4, and which did not occur when the oxide was single FeO or Fe3O4. The oxidation model was also established.

关键词： Kovar alloy, Oxidation Controlled atmosphere H2-H2O-N2

The Novel Mechanical Property of Tongue of a woodpecker

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Journal of Bionic Engineering 2009年第3期6卷 214-218页

作者： P zhou X Q Kong C w wu z Chen National Key Laboratory for Structural Analysis of Industrial Equipment Dalian University of Technology Department of Civil and Environmental Engineering University of Missouri

Biomaterials such as bone,teeth,nacre and silk are known to have superior mechanical properties due to their specific nanocomposite *** we report that the woodpecker's tongue exhibits a novel strength and flexibility due to its special composite micro/*** tongue consists of a flexible cartilage-and-bone skeleton covered with a thin layer tissue of high strength and *** the interface between the cartilage-and-bone skeleton and the tissue layer,there is a hierarchical fiber-typed *** is this special design of the tongue that makes the woodpeckers efficient in catching the insects inside *** special micro/nanostructures of the woodpecker's tongue show us a potential method to enhance the interfacial connection between soft and hard material layers for bio-inspired composite system designs.

关键词： woodpeckcr hyoid cartllage multilevel structure tensile strength

Mesoporous Carbon-Tin Nanocomposites as Anode Materials for Li-ion Battery

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Journal of Materials Science & Technology 2008年第4期24卷 657-660页

作者： z. w.z.ao z.P.Guo P. Yao H.K.Liu Institute for Superconducting and Electronic Materials University of Wollongong NSW 2522 Australia ARC Centre of Excellence for Electromaterials Science University of Wollongong NSW 2522 Australia Centre for Analysis and Measurement Tianjin University Tianjin 300072 China

A new mesoporous carbon-tin （MC-Sn） nanocomposite has been successfully prepared via a two-step method. From the transmission electron microscopy （TEM） observations, the tin nanoparticles were decorated on the as-prepared mesoporous carbons. The mesoprous structure of the carbon can effectively buffer the volume changes during the Li-Sn alloying and de-alloying cycles. The as-prepared MC/Sn nanocomposite electrodes exhibited extremely good cycling stability, with the specific capacity of Sn in the composite electrode calculated to be 959.7 mAh-g-1, which amounts to an impressive 90.9% of the theoretical value （990 mAh-g-1）. The reversible capacity after 200 cycles is 96.1% of the first cycle reversible capacity, i.e., the capacity fade rate is only 0.0195% per cycle, which is even better than that of commercial graphite-based anodes.

关键词： Mesoporous Carbon Tin Nanocomposites Lithium ion battery