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Threading dislocation density comparison between GaN grown on the patterned and conventional sapphire substrate by high resolution X-ray diffraction

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Science china(physics,Mechanics & Astronomy) 2010年第3期53卷 465-468页

作者： ZHANG YuChao1, XING ZhiGang2. MA ZiGuang2. CHEN Yao2. DING GuoJian2. XU PeiQiang2. DONG ChenMing3, CHEN Hong2.& LE XiaoYun1 1 School of physics and Nuclear Energy Engineering, Beihang University, Beijing 100190, china 2.Renewable Energy Laboratory, Institute of physics, chinese academy of sciences, Beijing 100190, china 3 School of Information and Communication, Tianjin Polytechnic University, Tianjin 300160, china School of physics and Nuclear Energy Engineering Beihang University Beijing China Renewable Energy Laboratory Institute of Physics Chinese Academy of Sciences Beijing China School of Information and Communication Tianjin Polytechnic University Tianjin China

GaN epifilms are grown on the patterned sapphire substrates (PSS) (0001) and the conventional sapphire substrates (CSS) (0001) by metal-organic chemical vapor deposition (MOCVD) using a novel two-step growth. High resolution X-ray diffraction (HR-XRD) is used to investigate the threading dislocation (TD) density of the GaN epifilms. The TD density is calculated from the ω-scans full width at half maximum (FWHM) results of HR-XRD. The edge dislocation destiny of GaN grown on the PSS is 2.7×108 cm-2. which is less than on the CSS. This is confirmed by the results of atomic force microscopy (AFM) measurement. The lower TD destiny indicates that the crystalline quality of the GaN epifilms grown on the PSS is improved compared to GaN epifilms grown on the CSS. The residual strains of GaN grown on the PSS and CSS are compared by Raman Scattering spectra. It is clearly seen that the residual strain in the GaN grown on PSS is lower than on the CSS.

关键词： GaN patterned sapphire substrate threading dislocation XRD

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, {2., Dalian 11602., 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.

A CONVENIENT SYNTHESIS OF β-CYCLODEXTRIN 2.AND 3-O-MONOBENZOATE

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chinese chemical Letters 1994年第8期5卷 645-646页

作者： Ai You HAO Lin Hui TONG Fu Sheng ZHANG Dao Sen JIN(lanzhou Institute of chemical {2.,chinese academy of sciences,lanzhou 730000)

CD 2.O- and 3-O-monobenzoate were synthesised by direct benzoyletion of β-CD with benzoyl chloride in alkaline equeous solution.

关键词： n

MOLECULAR STRUCTURE OF DINUCLEAR COBALT COMPLEX WITH CHELATING 1, 3-BIS (DIPHENYLPHOSPHINO ) PROPANE LIGAND

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chinese Journal of Structural Chemistry 1993年第5期 405-408页

作者： Lu Shi-Jie Yang Fan Fu Hong-XiangOSSO Laboratory, lanzhou Institute of chemical {2., chinese academy of sciences, lanzhou, 730000 chinaShi Jian-QiuFujian Institute of Research on the Structure of Matter, chinese academy of sciences, Fuzhou, 350002.china

Co2.( CO ) 6 (dppp ) Cdppp = 1,3-bis ( diphenylphosphino ) propane = Ph2.(CH2.3PPh2., Mr=698. 38, monoclinic, space group P2./c, a=14. 952.8) , b = 13.44(2., c = 16. 72.1) A. β=110.56(4)°, V=3147(9) A3, Z = 4, A=1. 47 g/cm3, λ(MoXα) = 0. 71069 A, F(000) = 142., λ(MoKα) = 11. 93 cm-1, R = 0. 032.and Rw = 0. 044 for 4553 observed independent reflections with I>4. 0σ(I). The molecular structure of the complex shows that the dppp ligand chelates one of the two cobalt atoms of the complex molecule, and there are two bridging carbonyl groups between the two cobalt atoms. The Co-Co bond length is 2. 534(3) A . The chelating dppp ligand results in the asymmetrization of the molecule.

关键词： Crystal structure Dinuclear complex Cobalt-carbonyl-dppp complex

MULTIDIMENSIONAL GAS CHROMATOGRAPHY FOR THE SEPARATION OF TCDD ISOMERS

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chinese chemical Letters 1991年第1期2卷 31-34页

作者： C.R.Jia Y.H.Qiu Q.Y.Ou lanzhou Institute of chemical {2.,chinese academy of sciences lanzhou,730000

A multidimensional gas chromatographic technique with heartcutting was used for the determination of complex isomeric mixtures of tetra- chlorodibenzo-p-dioxins(TCDDs)which could not be completely separated on a single capillary *** using so-called heartcutting technique ,only the interested single peak or section of the fraction eluting from the first column was transferred onto the second column with different stationary *** ionization detection was used as the monitor detector and electron capture detection as the main *** arrangement offers complete separation and avoids interference of the possible remained chlorinated *** separation power of multi- dimensional GC was demonstrated by the determination of TCDD isomers.

关键词： TCDD ID OC MULTIDIMENSIONAL GAS CHROMATOGRAPHY FOR THE SEPARATION OF TCDD ISOMERS DGC GAS

Enantioseparation of Novel Chiral Tetrahedral Clusters on a Chiral Stationary Phase (CSP) by High Performance Liquid Chromatography

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色谱 2004年第4期22卷 329-330页

作者： WANG Xia~1, LI Wenzhi~2. LIU Chunhui~1, CHEN Liren~1, LI Yongmin~1(1. lanzhou Institute of chemical {2., The chinese academy of sciences, lanzhou 730000, china 2. Chemistry and chemical Engineer College, Liaocheng University, Liaocheng 2.2.59, china ) lanzhou Institute of chemical {2. Chinese Academy of Sciences Lanzhou 730000 China Chemistry and chemical Engineer Colleger Liaocheng University Liaocheng 252059 China lanzhou Institute of chemical {2. Chinese Academy of Sciences 342 Tianshui Road Lanzhou 730000 China

Deposition features of Ni on self-assembled microtubule template from biolipid by electroless method

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Science china Chemistry 2004年第3期47卷 228-234页

作者： FU Yubin1,2. ZHANG Lide1, ZHENG Jiyong2. FU Shangang3 & ZHU Mingwei3 1. Institute of Solid State physics, chinese academy of sciences, Hefei 2.0031, {2. 2. Luoyang Ship Material Research Institute, Luoyang 471039, {2. 3. College of Life Science, Henan Normal University, Xinxiang 453002. {2. Institute of Solid State physics Chinese Academy of Sciences Hefei China Luoyang Ship Material Research Institute Luoyang China College of Life Science Henan Normal University Xinxiang China

Diacetylenic glycero-phosphatidylcholine is a chiral molecule with amphiphilic property, and it can self-assembly into a lipid microtubular structure. The lipid microtubule is a stable structure formed by tightly wound helical ribbons, and the ribbon-wrapping patterns have a significant effect on their chemical deposition on the microtubules. The deposition of colloidal Pd catalyst occurs mainly on the helical edge of the wound helical ribbons to form helical deposition lines of colloidal Pd particles in the interior and exterior of the lipid microtubules, resulting in an uneven chemical deposition of Ni on the microtubules. Catalyzed by as-deposited colloidal Pd, metallized Ni microtubules are characterized by a helical form, which may be in relation to inner stress due to the thickness difference or the different deposition processes. The observation of microtom shows that metallized tubules have a hollow structure. Some metallized tubules have a kind of coaxial double layer structure observed in the direct experiment evidence, indicating that metallization can occur in the inner and outer surface of the lipid tubules. Both lipid microtubules and metallized microtubules can be used as vehicles for encapsulating biological active molecules to control their release and to develop micro-components in biological and mechanical systems. Keywords molecular self-assembly - lipid microtubules - helical pattern - site-specific deposition - electroless metallization

关键词： molecular self-assembly, lipid microtubules, helical pattern, site-specific deposition, electroless metallization.

EPR STUDIES ON THE DEBROMINATION OF DIPHENYL BROMOMETHANE IN THE PRESENCE OF VIOLOGEN DERIVATIVES AS ELECTRON-TRANSFER CATALYSTS (ETC)

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chinese chemical Letters 1993年第11期4卷 959-962页

作者： Fu Tian LIU, Liang Bo FENG, Xian Da YU, and Shu Ben LI lanzhou Institute of chemical {2., chinese academy of sciences, lanzhou 730000

The active intermediate'carbon radical' was detected by the spin—trapping reagent (POBN) during the debromination of Ph_2.HBr in the presence of viologen derivatives as electron—transfer catalysts(ETC).

关键词： ETC EPR STUDIES ON THE DEBROMINATION OF DIPHENYL BROMOMETHANE IN THE PRESENCE OF VIOLOGEN DERIVATIVES AS ELECTRON-TRANSFER CATALYSTS AS

Formation of complexes of Rubisco-Rubisco activase from La^3+, Ce^3+ treatment spinach

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Science china Chemistry 2005年第1期48卷 67-74页

作者： HONG Fashui1, LIU Chao1, ZHENG Lei1, WANG Xuefeng1, WU Kang1, SONG Weiping1, Lü Shipeng1, TAO Ye2.& ZHAO Guiwen3 1. College of Life sciences, Suzhou Universty, Suzhou 2.5006, china 2. Synchrotron Radiation Laboratory, Institute of High Energy {2., The chinese academy of Science, Beijing 100039, china 3. chemical Department, University of Science and Technology of china, Hefei 2.002., china College of Life sciences Suzhou Universty Suzhou China Synchrotron Radiation Laboratory Institute of High Energy Physics The Chinese Academy of Science Beijing China chemical Department University of Science and Technology of China Hefei China

The complex of Rubisco and Rubisco activase from LaCl3-, CeCl3- treated spinach in vivo is induced. SDS-PAGE result shows that the purified proteins from LaCl3-, CeCl3- treated spinach have not only large and small subunits (55 kD, 14.4 kD) of Rubisco, but also two large subunits of 45 kD and 41 kD near the large subunits of Rubisco. Native-PAGE shows that the purified proteins from LaCl3-, CeCl3- treated spinach have not only a band of Rubisco (560 kD), but also a band of about 1100 kD, about twice distant from Rubisco, which might be a complex of Rubisco and Rubisco activase. The purified enzyme activities from LaCl3-, CeCl3-treated spinach are 1.8 and 2.8 times that of the control,the intensities of absorption and fluorescence are sig- nificantly higher than that of the purified Rubisco from the control, and the total sulfhydryl groups and available sulfhydryl groups are 36—39 –SH per mol enzyme, 14—2. –SH per mol enzyme more than those of the purified Rubisco from the control, respectively. The CD spectra show that the secondary structure of the purified enzyme from LaCl3-, CeCl3 -treated spinach is very dif- ferent from the control. The enzyme activities from LaCl3-, CeCl3- treated spinach in vivo are 1.5 and 1.9 times those of the control.

关键词： La3+, Ce3+, spinach, Rubisco, complex of Rubisco and Rubisco acitivase, spectral characteristics.