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The dynamical properties of Rydberg hydrogen atom near a metal surface

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Science china(physics,Mechanics & Astronomy) 2005年第6期48卷 667-675页

作者： GE Meihua1, ZHANG Yanhui1, WANG Dehua2. DU Mengli3 & LIN Shenglu1 1. College of physics and electronics, Shandong Normal University, Jinan 2.0014,{2. 2. Department of Mathematics and physics, Shandong Institute of Architecture and Engineering, Jinan 2.0014,{2. 3. Institute of Theoretical physics, chinese academy of sciences, beijing 100080,{2. College of physics and electronics Shandong Normal University Jinan China Department of Mathematics and physics Shandong Institute of Architecture and Engineering Jinan China Institute of Theoretical physics Chinese Academy of Sciences Beijing China

The dynamical properties of Rydberg hydrogen atom near a metal surface are presented by using the methods of phase space analysis and closed orbit theory. Transforming the coordinates of the Hamiltonian, we find that the phase space of the system is divided into vibrational and rotational region. Both the Poincaré surface of section and the closed orbit theory verify the same conclusion clearly. In this paper we choose the atomic principal quantum number as n = 2.. The dynamical character of the exited hydrogen atom depends sensitively on the atom-surface distance d. When d is sufficiently large, the atom-surface potential can be expressed by the traditional van der Waals force and the system is integrable. When d becomes smaller, there exists a critical value dc. For d > dc, the system is near-integrable and the motion is regular. While chaotic motion appears for d electron might be captured onto the metal surface.

关键词： Rydberg hydrogen atom, van der Waals interaction, Poincaré surface of section, closed orbit theory, chaos.

Atomic force microscopy studies of SrTiO_(3)(001)substrates treated by chemical etching and annealing in oxygen

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Science china(physics,Mechanics & Astronomy) 2005年第4期48卷 459-468页

作者： WANG Xu1, FEI Yiyan1, LU Huibin1, JIN Kui-juan1, ZHU Xiangdong1,3, CHEN Zhenghao1, ZHOU Yueliang1 & YANG Guozhen1 1. beijing National laboratory for Condensed Matter {2.,Institute of {2.,chinese academy of sciences,beijing 100080,china 2. Department of {2.,University of California, Davis,California,USA beijing National laboratory for Condensed Matter {2. Institute of Physics Chinese Academy of Sciences Beijing China Department of physics University of California Davis USA

The SrTiO3 (001) substrates treated by chemical etching in NH4F-buffered HF solution and annealing in oxygen ambient have been studied by an atomic force microscopy (AFM). The SrTiO3 substrates with TiO2.termineted and atomically smooth surfaces and single unit cell steps have been obtained. The surface morphologies of SrTiO3 substrates strongly depend on the treated conditions and the quality of the substrates.

关键词： SrTiO3, AFM, surface morphology, surface defects.

Studies on BEPC upgrade from pretzel to double-ring

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Science china(physics,Mechanics & Astronomy) 2010年第11期53卷 2084-2089页

作者： ZHANG Chuang Institute of High Energy physics,chinese {2. of sciences,beijing 100049,china Institute of High Energy physics Chinese Academy of Sciences Beijing China

physics opportunity in the charm and τ energy region calls for higher luminosity of the beijing {2.-Positron Collider (BEPC).The BEPC has experienced continuous improvement since its completion in ***,as a major upgrading project of the BEPC,aims at enhancing its luminosity of factor 30–100,following the principle of "one machine,two purposes" as adopted in BEPC,so that both high energy physics and synchrotron radiation experiments can be carried out with *** the BEPC to BEPCII,the double-ring scheme with multi-bunch e +-e-collision in the large crossing angle was studied in comparison with the single-ring pretzel *** the dedicated synchrotron radiation operation,artful "bridges" are designed to connect two halves of the outer ring in both the southern and the northern crossing *** paper reviews the studies on the BEPC upgrade from pretzel to double-ring structure of BEPCII.

关键词： collider storage ring high energy physics synchrotron radiation

Fabrication of atomically smooth SrRuO_3 thin films by laser molecular beam epitaxy

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Science china(physics,Mechanics & Astronomy) 2008年第7期51卷 745-749页

作者： LIU GuoZhen1, HE Meng1, JIN KuiJuan1, YANG GuoZhen1, Lü HuiBin1, ZHAO Kun2. ZHENG ShiJian3 & MA XiuLiang3 1 beijing National laboratory for Condensed Matter {2., Institute of {2., chinese academy of sciences, beijing 100080, china 2.Department of Mathematics and {2., china University of Petroleum, beijing 102.49, china 3 Shenyang National laboratory for Materials Science, Institute of Metal Research, chinese academy of sciences, Shenyang 110016, china beijing National laboratory for Condensed Matter {2. Institute of Physics Chinese Academy of Sciences Beijing China Department of Mathematics and physics China University of Petroleum Beijing China Shenyang National laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences Shenyang China

High-quality SrRuO3 (SRO) thin films and SrTiO3/SRO bilayer were grown epitaxially on SrTiO3 (STO)(001) substrates by laser molecular beam epitaxy. The results of in situ observation of reflection high-energy electron diffraction and ex situ X-ray diffraction θ -2. scan indicate that the SRO thin films have good crystallinity. The measurements of atomic force microscopy and scan tunneling microscopy reveal that the surface of the SRO thin film is atomically smooth. The resistivity of the SRO thin film is 300 μΩ·cm at room temperature. Furthermore, the transmission electron microscopy study shows that the interfaces of STO/SRO and SRO/STO are very clear and no interfacial reaction layer was observed. The experimental results show that the SRO thin film is an excellent electrode material for devices based on perovskite oxide materials.

关键词： SrRuO3 thin film laser molecular beam epitaxy surface morphology

MICROSTRUCTURE STUDY ON 16.5mol% CeO_2.ZrO_2.BY MEANSOF TRANSMISSION electron MICROSCOPE

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Acta Metallurgica Sinica(English Letters) 1997年第3期10卷 174-178页

作者： L-F. Li Z. Zhang and Y Y Li(Cryogenic laboratory chinese academy of sciences,{2., china)(Institute of Metal Research, chinese academy of sciences, Shenyang 110015, china) Cryogenic Lab Chinese Acad of Sciences Beijing China

The microstructure of a fine-grained 16.5mol% CeO2.stabilized tetragonal zirconia polycrystal (Ce-TZP has been investigated by TEM and it is shown that the mi-crostructures of samples fractured at 2.8, 77 and 4.2.K change significantly. At 2.8K there is no stress-induced martensite but a few anti-phase boundaries (APBs) in tetragonal (t) parent phase. With a decrease in temperature, monoclinic (m) product or mariensite within retained t-phase appears. The morphologies are characterized as lenticular and block-like at 77 K and as lenticular and butterfly-like at 4.2.K. The relationship between microstructure and mechanical properties is also discassed in this paper.

关键词： microstructure stress-induced martensite mechanical property

Microstructure and Wear Resistance Evolution of HVOFSprayed WC-(W,Cr)_2.-Ni Coating with Post Heat Treatment In Air Atmosphere

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稀有金属材料与工程 2012年第S1期41卷 388-393页

作者： Hou Guoliang1,2.Zhou Huidi1,An Yulong1,2.Liu Guang1,2.Chen Jianmin1,Chen Jie1,2.1 State Key laboratory of Solid Lubrication,Lanzhou Institute of Chemical physics,{2. academy of sciences,Lanzhou 730000,china 2.Graduate University,{2. academy of sciences,beijing 100049,china chinese Acad Sci Lanzhou Inst Chem Phys State Key Lab Solid Lubricat Lanzhou 730000 Peoples R China chinese Acad Sci Grad Univ Beijing 100049 Peoples R China

WC-(W,Cr)2.-Ni coating was prepared on 1Cr18Ni9Ti stainless steel and C-2.6 Ni-base Hastelloy by high velocity oxy-fuel(HVOF)*** effect of post heat treatment in air atmosphere on the microstructure,phase composition,microhardness,fracture toughness,and wear resistance of HVOF-sprayed WC-(W,Cr)2.-Ni coating was *** microstructure and phase composition of the coatings were analyzed by means of field emission scanning electron microscopy(FESEM)and X-ray diffraction(XRD).The microhardness and fracture toughness of the coatings were measured using a microhardness tester and a Vickers hardness ***,dry friction and wear behavior of the coatings sliding against Si3N4 ball was investigated using an oscillating friction and wear tester;and the worn surfaces of the coatings were analyzed by means of scanning electron microscopy(SEM).It was found that heat treatment within 500-800°C resulted in crystallization of amorphous phase in as-sprayed coating,generating nanoscale new phases such as NiWO4,CrWO4 and ***,heat treatment led to increase of the microhardness of as-sprayed coating,and the highest microhardness was obtained after heat treatment at 800°*** fracture toughness and wear resistance of the as-sprayed coating increased with increasing heat treatment temperature up to 700°C but tended to decrease with further elevating *** other words,the mechanical properties and wear resistance of the as-sprayed coatings were worsened owing to excessive growth of oxidation grains and depletion of ductile Ni binder after heat treatment above 700°*** it was suggested that as-sprayed ceramic composite coating should be post heat treated in air at a moderate temperature of 700°C so as to achieve the optimized mechanical properties and wear resistance.

关键词： HVOF WC-(W,Cr)2.-Ni coating post heat treatment microstructure wear resistance

Superconductivity at 36 K in gadolinium-arsenide oxides GdO_(1-x)F_xFeAs

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Science china(physics,Mechanics & Astronomy) 2008年第6期51卷 719-722页

作者： CHENG Peng, FANG Lei, YANG Huan, ZHU XiYu, MU Gang, LUO HuiQian, WANG ZhaoSheng & WEN HaiHu National laboratory for Superconductivity, Institute of physics,{2., beijing 100190, china beijing National laboratory for Condensed Matter physics, Institute of physics,{2., beijing 100190, china National laboratory for Superconductivity Institute of Physics Chinese Academy of Sciences Beijing China beijing National laboratory for Condensed Matter {2. Institute of Physics Chinese Academy of Sciences Beijing China

In this paper we report the fabrication and superconducting properties of GdO1-xFxFeAs. It was found that when x is equal to 0.17, GdO0.83F0.17FeAs is a su-perconductor with the onset transition temperature Tcon ≈ 36.6 K. Resistivity anomaly near 130 K was observed for all samples up to x = 0.17, and such a phenomenon is similar to that of LaO1-xFxFeAs. Hall coefficient indicates that GdO1-xFxFeAs is conducted by electron-like charge carriers.

关键词： iron-based superconductor high-temperature superconductor

Adsorption behavior of hexadecyltrimethylammonium bromide (CTAB) to mica substrates as observed by atomic force microscopy

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Science china Chemistry 2005年第2期48卷 101-106页

作者： ZHAO Feng1,2. DU Yukou1, YANG Ping1, LI Xingchang2.& TANG Ji’an2.1. Chemistry and Chemical Engineering Department, Suzhou University, Suzhou 2.5006, china 2. Key laboratory of Colloid and Interface Science, Institute of Chemistry,{2., beijing 100080, china Correspondence should be addressed to Tang Ji’an (email: jatang@***) Chemistry and Chemical Engineering Department Suzhou University Suzhou China Key laboratory of Colloid and Interface Science Institute of Chemistry Chinese Academy of Sciences Beijing China

Atomic force microscopy is employed to study the adsorption behavior of CTAB to mica surfaces. Results show that conformational transitions from globular micelles→cylindrical micelles→flat films are observed in the process of the adsorption of CTAB to mica at twice the bulk critical concentration. However, in 0.5 cmc CTAB solution, the adsorbed CTAB molecules to mica form the layered film structures, and apparent conformational transitions do not appear. Meanwhile, the phenomena of the adsorption of CTAB to mica and the dissociation of mica sur- faces are periodically observed.

关键词： atomic force microscopy (AFM), micelle, behavior of adsorption, the dissociation of mica surfaces.

Characterization of GLUT4-containing vesicles in 3T3-L1 adipocytes by total internal reflection fluorescence microscopy

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Science china(Life sciences) 2009年第7期52卷 665-671页

作者： WANG Yan1,2.ZHANG JinZhong1,2.CHEN Yu1,2.JIANG Li1,2.JI Wei1,2.& XU Tao1 1 National laboratory of Biomacromolecules,Institute of Biophysics,{2. academy of sciences,beijing 100101,china 2.Graduate University of chinese academy of sciences,beijing 100049,china National laboratory of Biomacromolecules Institute of Biophysics Chinese Academy of Sciences Beijing China Graduate University of chinese academy of sciences Beijing China

Insulin-responsive GLUT4(glucose transporter 4) translocation plays a major role in regulating glucose uptake in adipose tissue and *** or not there is a specialized secretory GSV(GLUT4 storage vesicle) pool,and more importantly how GSVs are translocated to the PM(plasma membrane) under insulin stimulation is still under *** the present study,we systematically analyzed the dynamics of a large number of single GLUT4-containing vesicles in 3T3-L1 adipocytes by TIRFM(total internal reflection fluorescence microscopy).We found that GLUT4-containing vesicles can be classified into three groups according to their mobility,namely vertical,stable,and lateral GLUT4-containing *** these groups,vertical GLUT4-containing vesicles exclude transferrin receptors and move towards the PM specifically in response to insulin stimulation,while stable and lateral GLUT4-containing vesicles contain transferrin receptors and show no insulin *** data demonstrate that vertical GLUT4-containing vesicles correspond to specialized secretory GSVs,which approach the PM directly and bypass the constitutive recycling pathway.

关键词： GLUT4 IRAP-pHluorin GSV transferring TIRFM