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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,beijing National Laboratory for {2. Matter physics,institute of physics,chinese academy of sciences,beijing 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

An Explicit Function Expression for dc Bias and Temperature Dependence of Magnetoresistances in Magnetic Tunnel Junctions

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Journal of Materials Science & Technology 2002年第6期18卷 497-501页

作者： Xiufeng HANState Key Laboratory of Magnetism, institute of physics and center of {2. Matter physics, chinese academy of sciences, beijing 100080, china chinese Acad Sci Inst Phys State Key Lab Magnetism Beijing 100080 Peoples R China chinese Acad Sci Ctr Condensed Matter Phys Beijing 100080 Peoples R China

An explicit function expression for the bias voltage or/and temperature dependences of tunnel magnetoresistance ratio and resistances were obtained with a unique set of intrinsic parameters. Two of these intrinsic parameters are the Curie temperature TC and the density of state (DOS) for itinerant majority and minority electrons ξ(ρM/ρm), which are the eigen parameters of ferromagnetic electrodes. Others are the spin-dependent matrix-element ratio (i.e., |Td|2.|TJ|2.) and the anisotropic-wavelength-cutoff energy ECγ of spin-wave spectrum in magnetic tunnel junction (MTJ), which are the structure parameters of an MTJ. These intrinsic parameters can be predetermined using the experimental measurement or, in principle, using the first-principle calculation method for an MTJ with the three key layers of FM/I/FM. Furthermore, a series of experimental data for an MTJ, for example, a spin-valve-type MTJ of Ta (5 nm)/Ni79Fe2.(2. nm)/lr2.Mn78(12.nm)/Co75Fe2.(4 nm)/AI(0.8 nm)-oxide/Co75Fe2.(4 nm)/Ni79Fe2.(2. nm)/Ta (5 nm) in this work, can be self-consistently evaluated and explained using such concise explicit function formulations.

关键词： Magnetic tunnel junction TMR Spin-electron transport Magnon excitation Spin-polarization Magnetotransport

CHEMICAL STRUCTURE DEPENDENCE OF THE INTERNAL ENERGY CONTRIBUTION IN RUBBER ELASTICITY

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chinese Journal of Polymer Science 2001年第5期19卷 447-449页

作者： Juan Sun Xiao-zhen Yang Polymer physics Laboratory center for Molecular {2., institute of Chemistry chinese academy of sciences beijing 100080 china 中科院化学所高分子物理及化学国家重点实验室北京

Conformational elasticity theory recently developed has been used to explore the internal energy contribution to the elastic force f(e)/f as a function of strain for poly(cis-1,4-isoprene) and poly(trans-1,4-isoprene). Calculated f(e)/f values are in good agreement with those obtained experimentally. Results show that behavior of f(e)/f is mainly contributed by chemical structure, or intramolecular interaction, supporting the experimental observations, and that the internal energy contribution is strain dependent.

关键词： conformational elasticity theory internal energy contribution poly(cis-1,4-isoprene) poly(trans-1,4-isoprene)

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 Technology beijing, beijing 100083,{2. 2. beijing National Laboratory for condensed Matter physics, institute of physics, chinese academy of sciences, beijing 100080,{2.) School of Material Science and Engineering University of Science and Technology Beijing Beijing 100083 China beijing National Laboratory for condensed Matter {2. 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.

Anomalous Hall effect in perpendicular CoFeB thin films

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chinese physics B 2014年第4期23卷 9-17页

作者：朱涛 institute of physics and {2. National Laboratory for condensed Matter physics Chinese Academy of Sciences

Our recent research achievements in the perpendicular magnetic anisotropy （PMA） properties of the CoFeB sand- wiched by MgO and tantalum layers are summarized. We found that the PMA behaviors of Ta/CoFeB/MgO and MgO/CoFeB/Ta thin films are different. The larger PMA in the latter film is related to the lower magnetization of CoFeB deposited on MgO. Furthermore, we have demonstrated a large anomalous Hall effect in perpendicular CoFeB thin fihn. Our results show large anomalous Hall resistivity, large longitudinal resistivity, and low switching field can be achieved, all at the same time, in the perpendicular CoFeB thin film. Anomalous Hall effect with high and linear sensitivity is also found in an MgO/CoFeBFFa thin film with a thick MgO layer, which opens a door tbr future device applications of perpendicular ferromagnetic thin films.

关键词： anomalous Hall effect perpendicular magnetic anisotropy magnetic properties of interfaces

The gravity wave instability induced by photochemistry in summer polar mesopause region

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chinese Science Bulletin 2000年第3期45卷 267-272页

作者： center for Space Science and Applied Research, chinese academy of sciences,{2., china Laboratory of Numeric Study of Heliospheric physics, chinese academy of sciences,{2., china center for Space Science and Applied Research Chinese Academy of Sciences Beijing China Laboratory of Numeric Study of Heliospheric physics Chinese Academy of Sciences Beijing China

The effect of diabatic process due to the photochemical heating and cooling on the gravity wave propagation in middle atmosphere is studied. A linear gravity wave model which considers the diabatic process is established. The unstable region and the growth rate of the gravity wave caused by photochemistry are calculated. And the comparison between the model and the adiabatic gravity wave theory of pure dynamics is made. The results indicate that the photochemical heating process can induce the instability of gravity wave at mesopause. The intensity of the instability becomes stronger as the temperature decreases. The temperature feature and the altitude characteristics of the instability are consistent with the observation. Therefore, the instability of the gravity wave induced by photochemistry may be an important mechanism in polar mesopause region in summer.

关键词： photochemistry instability gravity wave growth rate.

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, beijing 100083, china Laboratory of Soft Matter physics, beijing 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 Matter {2. 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.

PREPARATION OF BISPHENOL A EPOXY RESIN WATERBORNE DISPERSIONS BY THE PHASE INVERSION EMULSIFICATION TECHNIQUE

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chinese Journal of Polymer Science 2000年第1期18卷 33-38页

作者： Zhen-zhong Yang De-lu Zhao Polymer physics Laboratory, institute of Chemistry,{2., beijing 100080, china 中科院化学所高分子物理及化学国家重点实验室北京

The phase inversion emulsification technique (PIET) is an effective physical method for preparing waterborne dispersions of polymer resins. Some results concerning the preparation of bisphenol A epoxy resin waterborne dispersions by PIET in our laboratory were summarized. Electrical properties, rheological behavior and morphological evolution during phase inversion progress were systematically characterized. The effects of the emulsifier concentration and emulsification temperature on phase inversion progress and the structural features of the waterborne particles were studied as well. The deformation and break up of water drops in a shear field were analyzed in terms of micro-theology, while the interaction and coalescence dynamics of water drops were discussed in terms of DLVO theory and Smoluchowski effective collision theory, respectively. Based on the experimental results and theoretical analysis, a physical model of phase inversion progress was suggested, by which the effects of the parameters on phase inversion progress and the structural features of the waterborne particles were interpreted and predicted.

关键词： phase inversion emulsification waterborne dispersions epoxy resin mechanism physical model

The size effect on transport properties of colossal magnetoresistance materials La_(0.67)Ca_(0.33)MnO_3

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Science china(physics,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 physics,center for Optoelectronics Materials and Devices,Zhejiang Sci-Tech University,Hangzhou 310018,{2. 2.National Laboratory for condensed Matter physics,institute of physics,chinese academy of sciences,beijing 100080,{2. 3 Department of physics,Peking University,beijing 100875,{2. Department of physics Center for Optoelectronics Materials and Devices Zhejiang Sci-Tech University Hangzhou China National Laboratory for condensed Matter physics Institute of Physics Chinese Academy of Sciences Beijing China Department of physics Peking University Beijing China

High quality La0.67Ca0.33MnO3 (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