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High-resolution photofragment translational spectro- scopy for the UV photodissociation of C_2H_5I

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Science china Chemistry 2007年第4期50卷 476-482页

作者： BI WeiBin, XU XiLing, HUANG JianGou, XIAO DaoQing & ZHU QiHe beijing National laboratory for Molecular Sciences, State key laboratory of Molecular Reaction Dynamics, Institute of Chemistry, chinese academy of Sciences, beijing 100080, china 1. beijing National laboratory for Molecular Sciences State Key Laboratory of Molecular Reaction Dynamics Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China

The photodissociation of ethyl iodide at 279.71, 281.73. 3.4.02 and 3.4.67 nm has been studied on our new mini-photofragment translational spectrometer with a total flight path of only 5 cm. Some vibra-tional peaks are firstly resolved in the TOF spectra of I*(2P1/2) and I(2P3.2) channels. These vibrational peaks are assigned to the excitation states (ν2 = 0, 1, 2,…) of the umbrella mode (ν2, 540 cm-1) of the photofragment C2H5, and the distribution of the vibrational states is obtained. The dissociation energy has been determined to be D0(C-I)=2.3.4 ± 0.03.eV. The energy partitioning of the available energy (Eavl=ET+Eint=ET+EV,R) calculated from our experimental data E int /E avl= 22.1% at 281.73.nm, 22.4% at 3.4.02 nm for the I* channel, and E int /E avl= 25.2% at 279.71 nm, 25.9% at 3.4.67 nm for the I channel, seem to be more reliable.

关键词： photofragment translational spectroscopy C_2H_5I photodissociation vibrational state distribution energy partitioning dissociation energy

Surface effects of monolayer-protected gold nanoparticles on the redox reactions between ferricyanide and thiosulfate

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Science china Chemistry 2005年第5期48卷 424-430页

作者： LI Di1, SUN Chunyan1, HUANG Yunjie1, LI Jinghong1,2 & CHEN Shaowei3.1. State key laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, chinese {3. of Sciences, Changchun 13.022, china 2. Department of Chemistry, Tsinghua University, beijing 100084, china 3. Department of Chemistry, University of California, Santa Cruz, Santa Cruz, CA 95064, USA 1. State key laboratory of Electroanalytical Chemistry Changchun Institute of Applied Chemistry Chinese Academy of Sciences 130022 Changchun China 2. Department of Chemistry Tsinghua University 100084 Beijing China 3. Department of Chemistry University of California 95064 Santa Cruz Santa Cruz CA USA

Electron transfer through the self-assembled monolayers (SAMs) on gold nanopar-ticles is investigated by using the monolayer protected gold nanoclusters (MPCs) as elec-tron-transfer mediators. 3.Mercaptopropionic acid (MPA) and 11-meraptoundecanoic acid (MUA) MPCs were employed to catalyze the redox reaction between potassium ferricyanide and sodium thiosulfate. The catalytic mechanism was proposed that the MPCs act as diffusing elec-tron-mediators and electron transfers to and from the MPCs surface. Therefore the electron transfer rate through the capping layers would be proportional to the MPCs catalyzed reaction rate, which was monitored by the UV absorbance of ferricyanide. The calculated apparent rate constant was orders of magnitude smaller than that of the maximum of tunneling current, which was attributed to the splited energy level of the nanoscale particles.

关键词： electron transfer, three-dimensional self-assembled monolayers, redox reaction, electron transfer mediator, surface effect.

Mitochondrial membrane fusion and ATP synthesis both compete for interfacial △pH of PMF,but not △Ψ:An Inter-play between membrane fusion and energy coupling of mitochondria

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生物物理学报 2009年第S1期25卷 217-218页

作者： Shusen Liu State key laboratory of Biomembrane and Membrane Biotechnology, Instutute of Zoology, chinese {3. of Sciences, beijing, 100101, china

Although some fusogenic proteins have been established to tether two opposite outer or inner mitochondrial membranes into contact, a prerequisite for whole mitochondrial fusion events,

关键词： Mitochondrial membrane fusion Protein-tethering Lipid-bilayer-mixing and fusion Interfacial △pH of PMF.Inter-play between membrane fusion and ATP synthesis.

Light collection of the POLAR detector

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Science china(Physics,Mechanics & Astronomy) 2010年第S1期53卷 43-46页

作者： DONG YongWei,LI YanGuo,WU BoBing,ZHANG YongJie & ZHANG ShuangNan key laboratory of Particle Astrophysics,Institute of High energy Physics,{3. academy of Sciences,beijing 100049,china 1. key laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China

POLAR is a compact polarimeter dedicated to measuring the polarization of GRBs between 50-3.0 *** light collection of 200 mm×6 mm×6 mm plastic bars has been simulated and optimized in order to get uniform response to X-rays at different points along one single *** to the Monte Carlo results,the amplitude uniformity strongly depends on the level of polishing of the scintillator surface and the covering.A uniformity of 89% is achieved with a prototype constructed by a non position-sensitive PMT and an array of 4×4 bars.

关键词： plastic scintillator light collection gamma-ray burst polarimeter

SVOM gamma ray monitor

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Science china(Physics,Mechanics & Astronomy) 2010年第S1期53卷 40-42页

作者： DONG YongWei,WU BoBing,LI YanGuo,ZHANG YongJie & ZHANG ShuangNan key laboratory of Particle Astrophysics,Institute of High energy Physics,{3. academy of Sciences,beijing 100049,china 1. key laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China

The space-based multi-band astronomical Variable Object Monitor(SVOM) mission is dedicated to the detection,localization and broad-band study of gamma-ray bursts(GRBs) and other high-energy transient *** gamma ray monitor(GRM) onboard is designed to observe GRBs up to 5 *** this instrument,one of the key GRB parameters,Epeak,can be easily measured in the hard X-ray *** can achieve a detection rate of 100 GRBs per year which ensures the scientific output of SVOM.

关键词： gamma-ray burst Epeak triple phoswich

Lunar ~3.e estimations and related parameters analyses

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Science china Earth Sciences 2010年第8期53卷 1103-1114页

作者： LI DiHui, LIU HeGuang, ZHANG WeiGuo, LI Yun & XU ChuanDong Center for Space Science and Applied Research, chinese academy of Sciences, beijing 100190, {3. 1. Center for Space Science and Applied Research Chinese Academy of Sciences Beijing 100190 China

As a potential nuclear fuel, 3.e element is significant for both the solution of impending human energy crisis and the conservation of natural environment. Lunar regolith contains abundant and easily extracted 3.e. Based on the analyses of the impact factors of 3.e abundance, here we have compared a few key assessment parameters and approaches used in lunar regolith 3.e reserve estimation and some representative estimation results, and discussed the issues concerned in 3.e abundance variation and 3.e reserve estimation. Our studies suggest that in a range of at least meters deep, 3.e abundance in lunar regolith is homogeneously distributed and generally does not depend on the depth; lunar regolith has long been in a saturation state of 3.e trapped by minerals through chemical bonds, and the temperature fluctuation on the lunar surface exerts little influence on the lattice 3.e abundance. In terms of above conclusions and the newest lunar regolith depth data from the microwave brightness temperature retrieval of the "ChangE-1" Lunar Microwave Sounder, a new 3.e reserve estimation has been presented.

关键词： lunar regolith 3.e abundance reserve estimation maturity granularity composition solar wind flux CELMS

EFFECT OF PARTICLE SIZE ON THE FILMING PROCESS OF POLYSTYRENE LATEX STUDIED BY AFM

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chinese Journal of Polymer Science 2002年第6期20卷 509-515页

作者： Xiao-zhong Qu Yi Shi Liu-sheng Chen Xi-gao Jin State key laboratory of Polymer Physics & Chemistry, Center for Molecular Science,Institute of Chemistry, chinese {3. of Sciences, beijing 100080 china chinese Acad Sci Inst Chem Ctr Mol Sci State Key Lab Polymer Phys & Chem Beijing 100080 Peoples R China

The film formation process of micro-PS particles (diameter 742 nm) and nano-PS particles (diameter 29 nm) was studied by atomic force microscopy and differential scanning calorimetry. During a step heating process, the particles were annealed for 0.5 h at each selected temperature. It was found that the deformation and interdiffusion temperatures of the micro-PS particles are ca. 120-13.degreesC and 140-150degreesC, that of the nano-PS particles are 90degreesC and 100-110degreesC respectively. The DSC traces of nano-PS particles showed that there was an exothermic peak near T-g after annealing for 0.5 h at the selected temperatures below 90degreesC; otherwise, the exothermic peak disappeared after annealing at 100degreesC or above. Compared with the micro-PS particles, the sintering process of nano-PS particles occurs at much lower temperature determined by the confined state of polymer chains with higher conformational energy in nano-particles, and completes in a much narrower temperature range driven mainly by the larger total surface energy.

关键词： polystyrene latex filming process particle size effect

Relative importance of water, energy, and heterogeneity in determining regional pteridophyte and seed plant richness in china

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Journal of Systematics and Evolution 2011年第2期49卷 95-107页

作者： 1,2,3.Sheng-Bin CHEN § 1 Gao-Ming JIANG 3.Zhi-Yun OUYANG 3.Wei-Hua XU 3.Yi XIAO 1 (State key laboratory of Vegetation and Environmental Change, Institute of Botany, chinese {3. of Sciences, beijing 100093. china) 2 (Graduate University of the chinese {3. of Sciences, beijing 100049, china) 3.(State key laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, chinese {3. of Sciences, beijing 100085, china) (State key laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Beijing 100093 China) (Graduate University of the chinese academy of Sciences Beijing 100049 China) (State key laboratory of Urban and Regional Ecology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China) *Correspondence: Gao-Ming JIANG *Correspondence: Sheng-Bin CHEN *Correspondence: ?Author for correspondence. E-mail: jianggm@*** Tel.: 86-10-6283.506 Fax: 86-10-82596146.

Environmental variables, such as ambient energy, water availability, and environmental heterogeneity have been frequently proposed to account for species diversity gradients. How taxon-specific functional traits define large-scale richness gradients is a fundamental issue in understanding spatial patterns of species diversity, but has not been well documented. Using a large dataset on the regional flora from china, we examine the contrast spatial patterns and environmental determinants between pteridophytes and seed plants which differ in dispersal capacity and environmental requirements. Pteridophyte richness shows more pronounced spatial variation and stronger environmental associations than seed plant richness. Water availability generally accounts for more spatial variance in species richness of pteridophytes and seed plants than energy and heterogeneity do, especially for pteridophytes which have high dependence on moist and shady environments. Thus, pteridophyte richness is disproportionally affected by water-related variables; this in turn results in a higher proportion of pteridophytes in regional vascular plant floras (pteridophyte proportion) in wet regions. Most of the variance in seed plant richness, pteridophyte richness, and pteridophyte proportion explained by energy is included in variation that water and heterogeneity account for, indicating the redundancy of energy in the study extent. However, heterogeneity is more important for determining seed plant distributions. Pteridophyte and seed plant richness is strongly correlated, even after the environmental effects have been removed, implying functional linkages between them. Our study highlights the importance of incorporating biological traits of different taxonomic groups into the studies of macroecology and global change biology.

关键词： habitat heterogeneity pteridophytes seed plants species richness water-energy hypothesis.

Laser Remelting of Plasma Sprayed NiCrAlY and NiCrAlY-Al_2O_3.Coatings

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Journal of Materials Science & Technology 2001年第5期17卷 525-528页

作者： Yingna WU, Gang ZHA NC, Bingchun ZHANG, Zhongchao FENG and Yong LIANG Institute of Metal Research, chinese academy of Sciences, Shenyang 110016, china Fangjun LIU {3. laboratory for High energy Density Beam Processing Technology, beijing Aeronautical Manu chinese Acad Sci Inst Met Res Shenyang 110016 Peoples R China beijing Aeronaut Mfg Technol Res Inst Key Lab High Energy Dens Beam Proc Technol Beijing 100024 Peoples R China

Two types of plasma sprayed coatings (NiCrAlY and NiCrAlY-A12O3. were remelted by a 5 kW cw CO2 laser. With increasing laser power and decreasing traverse speed in the ranges of 200-700 W and 5-3. mm/s respectively, the melted track grew in width and depth. In the optimum range of laser parameters, a homogeneous remelted layer without voids, cavities, unmelted particles and microcracks was formed. On the surface of remelted layers, Al203.and YAIO3.were detected. As a result of isothermal oxidation tests, weight gains of laser remelted coatings were obviously lower than that only plasma sprayed, especially laser remelted NiCrAlY-Al2O3.coatings. The effects of laser remelting and incorporation of A12O3.second phase in N1CrAlY matrix on high temperature oxidation resistance were discussed.

关键词： Ni Laser Remelting of Plasma Sprayed NiCrAlY and NiCrAlY-Al2O3.Coatings TBCS Al