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Theoretical study of the interaction mechanism of single-electron halogen bond complexes H_3C…Br-Y(Y=H,CN,NC,CCH,C_2._3)

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Science china Chemistry 2010年第1期53卷 216-225页

作者： LI ZhiFeng1,SHI XiaoNing1,TANG HuiAn1 & ZHANG JunYan2.1College of Life Science and Chemistry,Tianshui Normal University,Tianshui 741001,china 2.1} {2. of chemical physics,chinese academy of sciences,lanzhou 730000,china 1. College of Life Science and Chemistry Tianshui Normal University Tianshui 741001 China2. Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou 730000 China

The characteristics and structures of single-electron halogen bond complexes H3C…Br-Y(Y = H,CCH,CN,NC,C2.3) have been investigated by theoretical calculation *** geometries were optimized and frequencies calculated at the B3LYP/6-31.++G *** interaction energies were corrected for basis set superposition error(BSSE) and the wavefunctions obtained by the natural bond orbital(NBO) and atom in molecule(AIM) analyses at the MP2.6-31.++G *** each H3C…Br-Y complex,a single-electron Br bond is formed between the unpaired electron of the CH3(electron donor) radical and the Br atom of Br-Y(electron acceptor);this kind of single-electron bromine bond also possesses the character of a"three-electron bond".Due to the formation of the single-electron Br bond,the C-H bonds of the CH3 radical bend away from the Br-Y moiety and the Br-Y bond elongates,giving red-shifted single-electron Br bond *** effects of substituents,hybridization of the carbon atom,and solvent on the properties of the complexes have been *** strengths of single-electron hydrogen bonds,single-electron halogen bonds and single-electron lithium bonds have been *** addition,the single-electron halogen bond system is discussed in the light of the first three criteria for hydrogen bonding proposed by Popelier.

关键词： single-electron halogen bond single-electron hydrogen bond single-electron lithium bond MP2 DFT NBO AIM

Fabrication of Ni-decorated helical ribbon composite microstructure from self-assembled lipid tubule by electroless metallization

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Science china Chemistry 2006年第3期49卷 238-245页

作者： FU Yubin1.2. ZHANG Lide1.& ZHENG Jiyong2.1. institute of solid State {2., china academy of sciences, Hefei 2.0031. china 2. Luoyang Ship Material Research institute, Luoyang 471.39, china 1. institute of {1. State {2. China Academy of Sciences Hefei 230031 China 2. Luoyang Ship Material Research {1. Luoyang 471039 China

Lipid molecules can self-assemble into a tubular structure, which is formed by tightly wound helical ribbons. Lipid tubules are utilized as a precursor to fabricate a novel Ni-decorated helical ribbon composite microstructure in a high yield by electroless deposition. The microstructure carries Ni nanoparticles on the flat face and wires at the edge of helical ribbon, in which the average size of nanoparticles is about 40―60 nm, and the wires are of a layered structure strongly correlated with a multi-bilayer structure in the lipid membrane. Compared with the tubular precursor, the Ni-decorated composite microstructure becomes short and irregular shapes due to the breakage in the deposition, and its formation is largely bound up with the tubular helical structure and the different catalytic process. Finally, the helical composite microstructure would have a potential application in the development of electric active materials.

关键词： molecular self-assembly, lipid tubule, helical ribbon, electroless deposition, nanoparticles and wires, composite microstructure.

Progress and development in thermodynamic theory of friction and wear

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Science china(Technological {1.) 2009年第4期52卷 844-849页

作者： DAI ZhenDong1.& XUE QunJi2.1.{1. of Bio-inspired Structure and Surface Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 2.001., china 2.State Key {2. of solid lubrication, chinese academy of sciences, lanzhou 71.000, china 1. institute of Bio-inspired Structure and Surface Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China 2. State Key {1. of solid {2. Chinese Academy of Sciences Lanzhou 710000 China

Tribology theory lags well behind engineering needs because of those complex and multi-dimensional characteristics associated with friction and wear. The mechanism of friction is reviewed and discussed from a static thermodynamics perspective; research methods on the process of friction and wear and thermodynamic studies within the field of tribology are also reviewed. We propose that entropy can be a critical parameter in describing the evolution of friction and wear, and the entropy balance equation could be considered as a fundamental cornerstone for a systematic tribology theory. Applications of irreversible thermodynamic theory of tribology to various fields are reviewed.

关键词： friction and wear irreversible thermodynamics entropy generation multi-factor coupling

Three Novel Eremophilanolides from Ligularia virgaurea ***

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chinese {1. Letters 2004年第12期15卷 1441-1444页

作者： Quan Xiang WU Yan Ping SHI Li YANG State Key laboratory of Applied Organic Chemistry, {1. University,{2. lanzhou institute of chemical physics chinese academy of sciences (CAS) {1. 730000 State Key laboratory of Applied Organic Chemistry Lanzhou University lanzhou {1. of {2. physics Chinese Academy of Sciences (CAS)

From the alcoholic extract of the whole plant of Ligularia virgaurea spp. oligocephala,three novel eremophilane sesquiterpene lactones, 6α, 1.α-dihydroxy-1.oxoeremophila- 7(1.),8(9)-dien-8, 1.0}olide, 6β, 1.α-dihydroxy-1.oxoeremophila-7 (1.), 8 (9)-dien-8, 1.0}olide and1.α-diydroxy-1.oxoeremophila-7(1.), 8 (9)-dien-8, 1.0}olide were isolated. Their structure s wereelucidated by various, spectroscopic methods including intensive 2. NMR techniques (COSY,HMQC, HMBC and ~1.-~1. NOESY) and HR-MS.

关键词： Ligularia virgaurea spp oligocephala Compositae sesquiterpene lactones eremophilanolides.

Wet-chemical synthesis and characteristics of Au nanoshell

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Science china Chemistry 2005年第5期48卷 431-435页

作者： LIU Zhongxin1.2. SONG Hongwei1. YU Lixin1.2. YANG Linmei1.2.& PAN Guohui1.2.1. Key laboratory of Excited State physics, Changchun {2. of Optics, Fine Mechanics and physics, chinese academy of sciences, Changchun 1.0033, china 2. Graduate School of the chinese academy of sciences, Beijing 1.0039, china 1. Key laboratory of Excited State {1. Changchun Institute of Optics Fine Mechanics and Physics Chinese Academy of Sciences 130033 Changchun China 2. Graduate School of the{1. 100039 Beijing China

Gold nanoshells were prepared by an easy wet-chemical method, with Ag nanoparticles used as the templates. Transmission electron microscopy (TEM) indicated that the shells were sphere in shape, the size was homogenous, being about {1. nm, and no hard ag-glomerates were observed. The plasma resonance absorption of gold was tuned from visible to near-infrared (NIR) with the increased volume of HAuCl4. The temperature grads (?T) of the gold nanoshell hydrosol under the exposure of an 808-nm optical fiber laser with different power den-sities were measured. The highest ?T was 30℃ (5 W/cm{1. irradiation area was {1.cm{1.. This kind of gold nanoshell hydrosol is a promising material to be used in biomedicine such as photo-thermal cancer therapy, and its special photothermal convert property will photothermally trigger drug release.

关键词： wet-chemical synthesis, Au, nanoshell, NIR absorption, photothermal conversion.

Interfacial behaviors of PMMA-PEO block copolymers at the air/water interface

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Science china Chemistry 2005年第6期48卷 567-573页

作者： CHENG Caixia1. JIAO Tifeng2. TANG Rupei1. LIU Minghua2.& XI Fu1.1. State Key laboratory of Polymer physics and Chemistry, Joint laboratory of Polymer Science and Materials, institute of Chemistry, chinese academy of sciences, Beijing 1.0080, china 2. CAS Key laboratory of Colloid and Interface Science, institute of Chemistry, chinese academy of sciences, Beijing 1.0080, china 1. State Key laboratory of Polymer {1. and Chemistry Joint Laboratory of Polymer Science and Materials Institute of Chemistry Chinese Academy of Sciences 100080 Beijing China 2. CAS Key {1. of Colloid and Interface Science Institute of Chemistry Chinese Academy of Sciences 100080 Beijing China

Diblock copolymer of PMMA2.1.b-PEO1.4 and triblock copolymer of PMMA1.0}-b- PEO2.7-b-PMMA1.0} were synthesized and their interfacial properties at the air-water interface were investigated, where both blocks of polyethylene oxide (PEO) and poly(methyl methacrylate) (PMMA) are surface active but the former is soluble in water while the latter is not. Both the block copolymers could form monolayers with two obvious transition regions. The first transition point is around 1. mN/m, which could be assigned to the pancake-brush change of the PEO chains. The other is around 1. mN/m, which could be ascribed to the condensed packing of PMMA. The surface morphological changes during the compression of the Langmuir monolayers are inves-tigated by using the AFM and SEM methods for the films deposited at different surface pressure or molecular areas. At a lower surface pressure, a typical morphology of PEO-con- taining lipopolymers is observed. Upon compression, sphere-dominant morphologies were observed. While the diblock copolymer is easy to folding, the triblock copolymer is in favor of formation of circular domains through vesiculation.

关键词： PMMA-PEO, block copolymers, monolayer, Langmuir-Blodgett films, AFM.

Structures and physical properties of rigid polyurethane foams with water as the sole blowing agent

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Science china Chemistry 2006年第4期49卷 363-370页

作者： LI Xiaobin1.2. CAO Hongbin1.& ZHANG Yi1.1. {1. of Process Engineering, chinese academy of sciences, Beijing 1.0080,{2. 2. Graduate School of the chinese academy of sciences, Beijing 1.0039,{2. 1. institute of Process Engineering Chinese Academy of Sciences Beijing 100080 China 2. Graduate School of the{1. Beijing 100039 China

Rigid polyurethane foams blown by varying water level were prepared in this study. The structures and physical properties of rigid polyurethane foams blown by water were measured with FT-IR, universal testing machine (Instron3365), scanning electron microscope (SEM) and differential scanning calorimeter (DSC). The results show that polyurea and polybiuret were the typical charac- teristics, and the cream time and gel time were shorter for the fully water blown rigid foams than that for the fully cyclopentane blown foams. The density of foam samples decreased from 45.0 kg/m3 to 2..4 kg/m3 with the increase of water level from 3 pph to 7 pph. Compressive strength exhibited the similar behavior with density. The average cell size of foam samples ranged from 2.1.μm to 356 μm with the increase of water level from 3 pph to 7 pph, respectively. At the same time, poorer dimen- sional stability was encountered with the increase of average cell size due to fast diffusion rate of CO2.out of the foam. The results of thermal analysis show that the glass transition temperature (Tg) shifted to a higher temperature with the increase of isocyanate level when more water was used as chemical blowing agent.

关键词： polyether polyol, polyurethane rigid foam, compressive strength, dimensional stability, cell size, glass transition temperature.

Gasdynamic characteristics of toroidal shock and detonation wave converging

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Science china({1.,Mechanics & Astronomy) 2005年第6期48卷 739-749页

作者： TENG Honghui1.2.& JIANG Zonglin2.1. Key laboratory of High Temperature Gas Dynamics, institute of Mechanics, {2. academy of Sci- ences, Beijing 1.0080, china 2. Graduate University of chinese academy of sciences, Beijing 1.0039, china 1. Key laboratory of High Temperature Gas Dynamics Institute of Mechanics Chinese Academy of Sciences 100080 Beijing China 2. Graduate University of{1. 100039 Beijing China

The modified CCW relation is applied to analyzing the shock, detonation wave converging and the role of chemical reactions in the process. Results indicate that the shock wave is strengthened faster than the detonation wave in the converging at the same initial Mach number. Euler equations implemented with a detailed chemical reaction model are solved to simulate toroidal shock and detonation wave converging. Gasdynamic characteristics of the converging are investigated, including wave interaction patterns, observable discrepancies and physical phenomena behind them. By comparing wave diffractions, converging processes and pressure evolutions in the focusing area, the different effects of chemical reactions on diffracting and converging processes are discussed and the analytic conclusion is demonstrated through the observation of numerical simulations.

关键词： converging, CCW relation, shock wave, detonation wave.

Preparation of InSb nanocrystals embedded in SiO_2.thin films

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chinese Science Bulletin 1998年第19期43卷 1610-1615页

作者： ZHU Kaigui 1. SHI Jianzhong 1. WEI Yanfeng 2.and ZHANG Lide 1.1. {1. of solid State {2., chinese academy of Science, Hefei 2.0031. china 2. State Key laboratory of Surface {2., Fudan University, Shanghai 2.0433, china institute of {1. State {2. Chinese Academy of Science Hefei China State Key laboratory of Surface {1. Fudan University Shanghai China

InSb nanocrystals embedded in SiO 2.thin films were prepared by rf magnetron cosputtering technique. THe observation by transmission electron microscope showed that InSb nanocrystals dispersed uniformly in SiO-2.matrices. InSb nanocrystals with different sizes can be obtained by changing the annealing condition. The average size of InSb nanocrystals depended on annealing temperature and time, but not on the t 1.3 rules. X-ray photoelectron spectroscopy and X-ray diffraction were also applied to the analyses of the composite thin films.

关键词： InSb nanocrystals radio-frequency sputtering quantum confinement.