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Adsorption and reaction of CO and O_2 on the Ag/Pt(110) surface studied by photoemis-sion electron microscopy

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Chinese Science Bulletin 2001年第12期46卷 998-1002页

作者： HUANG Weixin & BAO XinheState Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China State Key Laboratory of Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian China

The Ag/Pt(110) model catalyst was prepared by evaporating silver on Pt(110). Adsorption and reaction of CO and O2 on Ag/Pt(110) surface were studied in situ by photo-emission electron microscopy.(PEEM) during the pressure range of 10-5-10-2 Pa at 480 K. The Ag/Pt(110) surface consisted of Pt(110), AgPt interface and Ag area after annealing at 500 K. The dosing pressure of CO and O2 had a larger influence on their adsorption on the Ag area than on the Pt(110) and AgPt interface. Small Pt clusters formed on the Ag area and AgPt interface, which had a stronger ability to adsorb CO than Pt(110) terrace. The existence of Ag had an obvious influence on the kinetic of CO oxidation on Pt(110). No pattern was observed on the AgPt interface under the same condition when the formation of reaction-diffusion waves occurred on Pt(110).

关键词： silver Pt(110) carbon monoxide oxygen adsorption reaction photoemission electron microscopy.

Phase-separated structures in binary mixed monolayers investigated by atomic force microscopy

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Chinese Science Bulletin 1995年第23期40卷 1963-1967页

作者：吴海明肖守军陆祖宏韦珏 National Laboratory of Molecular and Biomolecular Electronics Southeast University Nanjing 210096 Center for Advanced Studies in Science and Technology of Microstructures Nanjing 210093 China

Two-dimensional domain structures are normally formed at the air-water interface due to phase separation in mixed monolayers, in which their components are incompletely miscible. This provides us a chance for studying some quasi-two-dimensional phenomena in physics, such as phase separation and phase transition. On the other hand, mixed monolayers provide us a way of assembling several kinds of functional molecules into

关键词： mixed monolayer film domain atomic force microscopy.

Structure of neurofilaments studied with scanning tunneling microscopy

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Chinese Science Bulletin 1998年第21期43卷 1805-1809页

作者： Jie Liu Xiangjun Tong Shijin Pang Zhonghe Zhai Beijing Univ Coll Life Sci Beijing 100871 Peoples R China Chinese Acad Sci Inst Phys Ctr Condensed Matter Phys Beijing Lab Vacuum Phys Beijing 100080 Peoples R China

Neurofilaments (NFs) were isolated from bovine spinal cord. The structure of purified NFs was studied by scanning tunneling microscopy.(STM). The STM images showed that NF was composed of a long core filament and numerous sidearms flanking the rod regularly. The diameter of the rod was about 10 nm (10.2±0.8 nm). Most of the sidearms were short and the distance between two adjacent sidearms was approximately 10 nm. There were some long sidearms between two proximal core filaments. The distance between two adjacent long sidearms was 21 nm. A three-quarter-staggered fashion of native NF structure was put forward.

关键词： neurofilament intermediate filament scanning tunneling microscopy.

Investigations of the mechanism of liquid-crystal alignment onrubbed polyimide films

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Chinese Science Bulletin 1996年第7期41卷 611-615页

作者：吴海明朱扬明杨晓敏陆祖宏韦钰罗棋孙政明 National Laboratory of Molecular and Biomolecular Electronics Southeast University Nanjing 210096 China State Key Laboratory of Solid State Microstructures Nanjing University Nanjing 210093 China

Liquid crystals (LCs) can be easily oriented by surfaces on a macroscopic scale. Thisphenomenon, known as alignment or anchoring, plays a dominant role in the fabrication ofLC devices. Studying the alignment technique of LCs is of great importance from bothpractical and theoretical points of view. Recently, rubbed polyimide-coated glass substrates have been widely used in LC align-ment. A general belief about the mechanism by which such a polymer alignment methodworks is that alignment acts through the interaction between LC molecules and orientedpolymer chains. This assumption was demonstrated by Barmentlo et al. through surfacesecond-harmonic-generation and optical phase retardation measurements. However, theseoptical techniques can only provide the macroscopic and average information because

关键词： polyimide rubbed film liquid crystal atomic force microscopy scanning tunneling microscopy.

Two-dimensional crystallization and preliminary electron crystallographic result of partially purified Fo from porcine mitochondria

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Chinese Science Bulletin 2002年第4期47卷 323-325页

作者： ZHANG Xujia SUN Jingchuan YANG Hui LI Huilin HUANG Youguo YANG Fuyu Institute of Biophysics Chinese Academy of SciencesBeijing 100101China Life Science Division Berkeley National LaboratoryBerkeleyCA 94720USA

After removal of cytoplasmic sector F1 from submitochondrial particles of F0F1-ATP synthase complex with guanidine hydrochloride, the transmembranc sector F0 was specifically extracted from the stripped membranes in the presence of detergent CHAPS and partially purified. Two-dimensional crystals were produced by the reconstitu-tion of the partially purified F0 into asolectin and microdi-alysis. The obtained crystals are able to diffract to 2 nm. The projection map of the negatively stained crystal shows that the crystal has p4212 symmetry, lattice constant, a = b = 14.4 nm. A unit cell contains four F0 molecules.

关键词： membrane protein proton channel F0 two-dimensional crystal electron microscopy.

The Transformation of Clay Minerals in Triassic Mudstone of North Shaanxi Province During Burial Metamorphism

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Science China Chemistry 1993年第6期36卷 729-739页

作者：张立飞王启明任磊夫 Department of Geology Peking University Beijing 100871 PRC

According to the analysis of X-ray diffraction and the investigation under electron microscope (SEM, TEM) of clay minerals, the transformation of clay minerals in Triassic mudstone during burial metamorphism has been studied in detail. Berthierine, the mixed layer of illite and chlorite, and the changeable texture from berthierine to chlorite have been first discovered in the paper; and then it is considered that the transformation of clay minerals during burial metamorphism is shown in the following reaction: Smectite+ Kaolinite + K^+ = lllite + Chlorite + Quartz. The metamorphic temperature of the above reaction is about 160—220℃, according to the calculation of oxygen isotope geothermometry of illite and quartz. The study of crystallinity and polytype of illite and chlorite shows that the different indexes have varied in regular way, and have certain functional relationship between them.

关键词： clay minerals burial metamorphism X-ray diffraction electron microscopy.

Assemble four-arm DNA junctions into nanoweb

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Chinese Science Bulletin 2001年第19期46卷 1618-1621页

作者： ZHOU Chunqing TAN Zukun WANG Chen BAI Chunli CAO Enhua STM Lab Institute of ChemistryChinese Academy of SciencesBeijing 100080China Institute of Biophysics Chinese Academy of SciencesBeijing 100101China

DNA is of structural polymorphism, which is useful in nanoarchitecture; especially, four-arm DNA junctions can be used to assemble nanowebs. The static four-arm DNA junctions were designed and synthesized. One-arm DNA and two-arm DNA came out simultaneously with the four-arm DNA junction’s formation. A new method, termed the two-step method, was proposed and the productivity of four-arm DNA junctions was increased. A nanoweb was assembled successfully, but it showed irregularity itself. It was not the same as we expected. We consider that it is a result from the flexibility of four-arm DNA junction.

关键词： nucleic acid self-assembly nanotechnology atomic force microscopy.

Subcellular localization of the stripe disease-specific protein encoded by rice stripe virus (RSV) in its vector,the small brown planthopper,Laodel-phax striatellus

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Chinese Science Bulletin 2001年第21期46卷 1819-1822页

作者： WU Aizhong ZHAO Yan QU Zhicai SHEN Daleng PAN Chongguang SU Deming School of Life Sciences Fudan UniversityShanghai 200433China College of Agronomy Shanghai Jiaotong UniversityShanghai 201101China

The stripe disease-specific protein (SP) encoded by the rice stripe virus (RSV) was successfully used as a localization signal of the virus in its vector, the small brown lanthopper, Laodelphax striatellus Fallen. Immunogold particles in large numbers were detected in various parts of the viruliferous females: the ovum, surface of chorion, the mid-gut lumen, and the columnar cells. Whereas there was noneof these particles in the non-viruliferous females and males, and testis of viruliferous males. Endosymbionts (mycetocytes) were abundant, harboring ovaries of both viruliferous and non-viruliferous females, but none in the testis of males. The results provided us with the direct proof that RSV is a ciruculative and propagative plant virus and it was transovarially transmitted alongside with endosymbionts of its vector. Therefore, we deem it a nice lead for future studies on the mechanism of RSV transmission and functioning of its viral proteins.

关键词： Laodelphax striatellus rice stripe virus midgut ovary immunogold labeling immunoelectron microscopy.

Study on Electrical Property of Polyaniline Composite Film

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Journal of China Textile University(English Edition) 1998年第2期15卷 5-8页

作者：张清华金惠芬景遐斌耿延侯 China Textile Univ Shanghai China

Polyaniline was synthesized by chemically oxidative *** means of infrared spectroscopy,the dif-ference between its intrinsic state structure and its dopedstate structure was determined for researching the rela-tionship between macromolecular structure and conduc-tive property before and after *** morphologyof solution-processed polyblends with the electricallyconductive polyaniline-camphor sulfonic acid complex(PAn-CSA)was investigated by using scanning *** conductive percolation threshold of thecomposite films is about 2.8%.

关键词： polyaniline conductive film scanning electron microscopy.