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Research progress in the inner surface modification of metal tubes by plasma processing

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Progress in Natural science:Materials International 2006年第11期16卷 1119-1126页

作者： ZHANG Guling~ 1,2.**, WU Xingfang~1, GU Weichao~2. CHEN Guangliang~2. FENG Wenran~2. NIU Erwu~2. LI Li~2. L Guohua~2. CHEN Huan~2. FAN Songhua~2. LIU Chizi~2.and YANG Size~2.1. School of Material science and Engineering, University of science and {2. {3., {3. 100083. china 2. {3. National Laboratory for condensed matter physics, Institute of physics, Chinese Academy of sciences, beijing 100080, china) School of Material science and Engineering University of Science and Technology Beijing Beijing 100083 China beijing National Laboratory for condensed {2. {3. Institute of Physics Chinese Academy of Sciences Beijing 100080 China

The recent progress in inner surface hardening of tubes by plasma processing is summerized. Several techniques of inner surface plasma source ion implantation and deposition are introduced, and their advantages and disadvantages are discussed. The basic principles, technical features and new progress of inner surface plasma source ion implantation methods for metal tubes, which were developed in our laboratory, are described in detail. And perspectives of the future technical development for inner surface ion implantation of tubes are presented.

关键词： PSII metal tubes inner surface surface modification.

Approaches to improving critical current density of YBCO superconducting thick films deposited by electrophoresis

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science china({2.,Mechanics & Astronomy) 2004年第2期47卷 165-172页

作者： ZHU Yabin1,2. ZHOU Yueliang2. LIU Zhen2. WANG Shufang2. CHEN Zhenghao2. L?Huibin2. YANG Guozhen2. XIAO Ling3. REN Hongtao3. JIAO Yulei3.& ZHENG Minghui3.1. Department of physics, College of science, beijing Jiaotong University, beijing 100044, china 2. Laboratory of Optical physics, Institute of physics and Center for condensed {12. physics, Chinese Academy of sciences, beijing 100080, china 3. General Research Institute for Nonferrous Metals, beijing 100088, china Correspondence should be addressed to Zhu Yabin (email: ybzhu@***) Department of physics College of Science Beijing Jiaotong University Beijing China Laboratory of Optical physics Institute of physics and Center for {2. {3. physics Chinese Academy of Sciences Beijing China General Research Institute for Nonferrous Metals Beijing China

Fabrication of YBCO superconducting thick films by electrophoresis has been widely reported. However, the value of critical current density (J c) is far from what the practical application requires. The superconducting thick films are obtained using top-seeded melt growth method with different proportional Y2.aCuO5 (Y2.1) addition. High-pressure oxygen has been used in the annealing process to improve the uniformity of the oxygen content in the superconducting thick films. When 40mol% Y2.1 powder is added to the YBa2.u3.7–5 (Y12.0} powder,J c for the superconducting thick film by approaches described above reaches 7.008×103.A/cm2.(77 K, 0 T), which is greater than the value ever reported.

关键词： YBCO thick films, electrophoretic deposition, melt-textured.

High-pressure synthesis and properties of CeO_2.ZrO_2.solid solution

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Chinese science Bulletin 2001年第10期46卷 801-806页

作者： XU Dapeng, WANG Quanyong, LU Zhe, LIU Zhiguo, ZHANG Gongmu & SU Wenhui1. Department of physics, Jilin University, Changchun 13.02.1}1} 2. International Center for Materials physics, Chinese Academy of {3.s, Shenyang 110015, china 3. Center for condensed matter and radiation physics, china Center of {12. {3. and technology (World Laboratory),{13., china Department of physics Jilin University Changchun China International Center for Materials physics Chinese Academy of Sciences Shenyang China Center for condensed matter and {2. {3. China Center of Advanced Science and Technology (World Laboratory) Beijing China

Using nanoparticles of CeO2.and ZrO2.prepared by the chemical precipitation method as starting materials, the single-phase cubic Ce0.5Zr0.5O2.solid solution (c-Ce0.5Z0.5O2. has been synthesized under 3.1 GPa at 1073.K for the first time. The structure of the c-Ce0.5Zr0.5O2.has not been changed before and after annealing at 773.K for 1 h. Only an unknown EPR signal (g =1.990) has been observed in the c-Ce0.5Zr0.5O2.and not varied after annealing at 773.K for 1 h, which exhibited that there exists no Ce3. in the c-Ce0.5Zr0.5O2.and the Ce4+ has not been reduced into Ce3. after annealing. The transport mechanism is ionic for the c-Ce0.5Zr0.5O2. The bulk conductivity (a =1.2.10-5 S/cm at 82.0}K, σ=2.1 ×10-3.S/cm at 112.0}K) is the same as that of CeO2. but smaller than that of Y2.3.stabilized ZrO2. A marked curvature at T = 82.0}K has been observed in the Arrhenius plot of the bulk conductivity. The activation energy below 82.0}K is lower than that above 82.0}K, and the reason has been discussed.

关键词： CeO2.ZrO2 nanocrystalline high-pressure and -temperature solid-state reaction solid solution.

Fluorescence dynamics of interactions between polyamide PyPyPyβDp and DNA

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science china Chemistry 2006年第1期49卷 75-80页

作者： ZHANG Huijuan1,2. WANG Jin3. WU Yishi1, YUAN Gu3. AI Xicheng1, WANG Li4 & ZHANG Jianping1 1. State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of {2.s, beijing 100080, china 2. School of Life {2. and technology, beijing Institute of technology, beijing 100081, china 3. College of Chemistry and Molecular Engineering, Peking University, beijing 100080, china 4. Center for condensed matter {13., Institute of {13., Chinese Academy of {2.s, beijing 100080, china Correspondence should be addressed to Ai Xicheng and Zhang Jianping State Key Laboratory for Structural Chemistry of Unstable and Stable Species Institute of Chemistry Chinese Academy of Sciences Beijing China School of Life science and technology Beijing Institute of Technology Beijing China College of Chemistry and Molecular Engineering Peking University Beijing China Center for condensed matter {2. Institute of Physics Chinese Academy of Sciences Beijing China

The photophysical properties of the polyamide PyPyPyβDp (PPP) were investigated by means of steady-state absorption and fluorescence spectroscopies, as well as time-resolved fluo-rescence spectroscopy. It was found that the excited-state properties of PPP are very sensitive to solvents. In TKMC buffer PPP exhibited weak fluorescence with a decay time constant of 16 ps, while with the decrease of the solvent polarity PPP showed the blue-shifted peak position, increased inten-sity and lengthened life-time for its fluorescence behavior. In the presence of calf thymus DNA, it was observed that the fluorescence intensity was enhanced and the fluorescence lifetime increased from 16 to 3. ps for PPP, which verified that PPP bound into the minor groove of DNA duplex.

关键词： polyamide (PPP), calf thymus DNA (ctDNA), time-resolved fluorescence spectroscopy, recognition dynamics.

The size effect on transport properties of colossal magnetoresistance materials La_(0.67)Ca_(0.3.)MnO_3

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science china({2.,Mechanics & Astronomy) 2008年第3期51卷 251-257页

作者： LI PeiGang1,2.LEI Ming1,2.GUO YanFeng2.GUO Xi2.CHEN LeiMing2. TANG WeiHua1,2.SONG PengYun3.& CHEN JinPing3.1 Department of {2.,Center for Optoelectronics Materials and Devices,Zhejiang Sci-Tech University,Hangzhou 3.0018,china 2.National Laboratory for condensed {3. {2.,Institute of {2.,Chinese Academy of sciences,beijing 100080,china 3.Department of {2.,Peking University,beijing 100875,china Department of physics Center for Optoelectronics Materials and Devices Zhejiang Sci-Tech University Hangzhou China National Laboratory for condensed matter {2. Institute of Physics Chinese Academy of Sciences Beijing China Department of physics Peking University Beijing China

High quality La0.67Ca0.3.MnO3.(LCMO) film was deposited via a novel pulsed electron deposition technique on SrTiO3.100) single crystal substrate. The micro-bridge with different widths was fabricated by using electron beam lithography (EBL) technique and their transport properties were studied. For the micro-bridges with width of 2.and 1.5 μm,the insulator-to-metal transition temperature (TP) keeps un-changed compared with the film. For the micro-bridges with width of 1 μm,the TP shifts towards the lower temperature by 50 K. When the width decreases down to 500 nm,the insulator-to-metal transition disappears. The magnetoresistance be-havior of these micro-bridges was studied,and the results show that the low field magnetoresistance (LFMR) decreases and the high field magnetoresistances (HFMR) keep almost unchanged as the width of micro-bridge is reduced.

关键词： colossal magnetoresistance pulsed electron deposition electron beam lithography electrical transport properties

Oxygen pressure dependent electro-resistance in La_(0.9)Sr_(0.1)MnO_3.thin films grown by laser molecular beam epitaxy

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science china({2.,Mechanics & Astronomy) 2008年第3期51卷 232-236页

作者： OUYANG SiHua1,2.WANG ChunChang2.LIU GuoZhen2.HE Meng2. JIN KuiJuan2.DANG ZhiMin1 & L HuiBin2. College of Materials science and Engineering,beijing University of Chemical {2.,beijing 10002.,china 2.beijing National Laboratory for condensed matter physics,Institute of physics,Chinese Academy of sciences,beijing {12.,china College of Materials science and Engineering Beijing University of Chemical Technology Beijing China beijing National Laboratory for condensed {2. {3. Institute of Physics Chinese Academy of Sciences Beijing China

We report here studies on the influence of oxygen pressure on the electroresis-tance behavior of La0.9Sr0.1MnO3.thin films fabricated by laser molecular beam epi-taxy. It was found that the film deposited at lower oxygen pressure shows larger c-axis parameter,higher resistance,and more distinct electroresistance. These results reveal that the electroresistance of manganite thin films can be tuned by the conditions of film fabrication.

关键词： La0.9Sr0.1MnO3 thin film electroresistance effect laser molecular beam epitaxy

Pairwise entanglement and local polarization of Heisenberg model

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science china({2.,Mechanics & Astronomy) 2008年第10期51卷 1515-1522页

作者： XI XiaoQiang1,2. ZHANG Tao3. YUE RuiHong3.4 & LIU WuMing2.1 Department of Applied Mathematics and {2., Xi’an Institute of Post and Telecommunications, Xi’an 710061, china 2.beijing National Laboratory for {3. matter {2., Institute of {2., Chinese Academy of sciences, beijing 100080, china 3.Institute of Modern {2., Northwest University, Xi’an 710069, china 4 Department of {2., Ningbo University, Ningbo 3.52.1, china Department of Applied Mathematics and physics Xi’an Institute of Post and Telecommunications Xi’an China beijing National Laboratory for condensed {2. {3. Institute of Physics Chinese Academy of Sciences Beijing China Institute of Modern physics Northwest University Xi’an China Department of physics Ningbo University Ningbo China

The characteristics of pairwise entanglement and local polarization (LP) are dis-cussed by studying the ground state (states) of the Heisenberg XX model. The re-sults show that: the ground state (states) is (are) composed of the micro states with the minimal polarization (0 for even qubit and 1/2.for odd qubit); LP and the prob-ability of the micro state have an intimate relation, i.e. the stronger the LP, the smaller the probability, and the same LP corresponds to the same probability; the pairwise entanglement of the ground state is the biggest in all eigenvectors. It is found that the pairwise entanglement is decreased by the state degeneracy and the system size. The concurrence approaches a fixed value of about 0.3.12.(for odd-qubit chain) or 0.3.91 (for even-qubit chain) if the qubit number is large enough.

关键词： Heisenberg XX model local polarization pairwise entanglement

Single-molecule studies of DNA by molecular combing

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Progress in Natural science:Materials International 2007年第5期17卷 493-499页

作者： Liu Yuying, Wang Pengye and Dou Shuoxing (College of science, china Agricultural University, {2. 100083. china Laboratory of Soft matter physics, {2. National Laboratory for condensed matter physics, Institute of physics, Chinese Academy of sciences, beijing 100080, china) College of sciences China Agricultural University Beijing 100083 China Laboratory of Soft matter physics Institute of Physics Chinese Academy of Sciences Beijing 100080 China beijing National Laboratory for condensed {2. {3. Institute of Physics Chinese Academy of Sciences Beijing 100080 China

Molecular combing is a powerful method for aligning a large array of DMA molecules onto a surface. It is a process whereby DNA molecules are stretched and aligned on a glass surface by the force via fluid flow. The ability to comb up to several hundred DNAs on a single cover slip allows for a statistically significant number of measurements to be made. These features make molecular combing an attractive tool for genomic studies, such as DNA replication, DNA transcription, DNA-protein interaction and so on. In this review article, we discuss the molecular combing principle, method and its applications.

关键词： DNA molecule molecular combing DNA-protein interaction.

Model for Unidirectional Movement of Axonemal and Cytoplasmic Dynein Molecules

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Acta Biochimica et Biophysica Sinica 2006年第10期38卷 711-724页

作者： Ping XIE* Shuo-Xing DOU Peng-Ye WANG Laboratory of Soft matter physics,{2. National Laboratory for {3. matter physics,Institute of physics,Chinese Academy of sciences,{2. 100080,china Laboratory of Soft matter physics Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of SciencesBeijing 100080 China

A model for the unidirectional movement of dynein is presented based on the structuralobservations and biochemical experimental results *** this model,the binding affinity of dynein formicrotubule (MT) is independent of its nucleotide state and the change between strong and weak MT-bindingis determined naturally by the variation of relative orientation between the stalk and MT,as the stalk rotatesfollowing nucleotide-state *** the enigmatic communication from the adenosine triphosphate(ATP)-binding site in the globular domain to the far MT-binding site in the tip of the stalk,which is aprerequisite in conventional models,is not *** the present model,the previous experimentalresults such as the effect of ATP and adenosine diphosphate (ADP) bindings on dissociation of dynein fromMT,the movement of single-headed axonemal dyneins at saturating ATP concentration,the load dependenceof step-size for the movement of two-headed cytoplasmic dyneins and the dependence of stall force on ATPconcentration can be well explained.

关键词： dynein mechanism mechanochemistry molecular motor