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Surface modification of γ-Al_2._3 by sodium ions

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Chinese Science Bulletin 2001年第3期46卷 188-193页

作者： DENG Feng, YUE Yong, DU Youru, YE Chaohui, KONG Yuhua, WANG Guoxing & LI Xiaoding1. Laboratory of Magnetic Resonance and atomic and Molecular physics, Wuhan {2. of physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, china 2. Hubei {2. of Chemistry, Wuhan 430074, china Laboratory of Magnetic Resonance and atomic and Molecular physics Wuhan Institute of Physics and Mathematics Chinese Academy of Sciences Wuhan China Hubei institute of Chemistry Wuhan China

1H/2.Na double resonance NMR techniques were employed to study the modification of surface hydroxyls on Y-Al2.3 by sodium ions. 1H-2.Na cross polarization (CP) experiment can resolve three kinds of sodium cations that are closely associated with surface hydroxyl groups, while the signal of deposited salt-Na2.O3, which is not connected to surface hydroxyl groups, is completely suppressed. 1H{2.Na} spin echo double resonance experiments reveal the surface modification in more detail. At low Na+ coverage (5%, 10%), the acidic hydroxyl groups are preferentially coordinated with sodium ions, while both the acidic and the basic hydroxyl groups are accessible for sodium ions at highcoordination that causes proton of the OH groups to be easily dissolved, which is evidenced by the fact that with calcination temperature of the catalysts increasing, the acidic hydroxyl groups are preferentially removed and only the basic hydroxyl groups remain when the calcination temperature is raised to 600℃.

关键词： surface modification γ-Al2.3 NMR hydrodesulfu-rization catalyst.

Monte Carlo simulation of an antiproton annihilation detector system

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Chinese Science Bulletin 2009年第19期54卷 3494-3500页

作者： ZHANG ZhongDong1,2.1 institute of nuclear {2., Forschungszentrum Jülich, D-52.2. Jülich, Germany 2.State nuclear Power Technology Corporation Ltd., beijing 100140, china institute of nuclear {2. Forschungszentrum Jülich D-52425 Jülich Germany State nuclear Power Technology Corporation Ltd. Beijing 100140 China

A renewed antiproton annihilation detector system has been developed for the ATRAP (Antihydrogen Trap Collaboration) experiment at CERN (European Organization for nuclear Research). It counts the antihydrogen atoms and determines the annihilation vertex of the atoms. This diagnostic element will allow to optimize the production of cold antihydrogen sufficiently to permit the optical observations and measurements. Extensive Monte Carlo simulations concerning the detector system have been developed. Different event generators as well as different geometry representations were established and evaluated. Real-time measurement with the detector system was performed and the results are calibrated via the Monte Carlo simulations.

关键词：反质子仿真模拟 CERN

Approximation analytical solutions for a unified plasma sheath model by double decomposition method

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nuclear Science and Techniques 1998年第4期9卷 193-197页

作者： Fang Jin-Qing (china institute of {2. energy beijing 1024.3.

A anified plasma sheath model and its potential equation are proposed. Any higher-ordor-approximation analytical solutions for the unified plasma sheath potential equa tiop are derived by double decomposition method.

关键词：等离子体屏蔽模型双分解方法近似分析

Nano-Structure Observed in Highly Doped Silicon Crystalline

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Journal of Materials Science & Technology 1993年第3期9卷 232-234页

作者： Zhiheng LU department of physics,{2. Normal University,{2.,100875,chinaDachan WANG Yan LUO institute of Low energy nuclear physics,{2. Normal University,{2.,100875,china

It was reported that due to the non-linear electrical phenomena,the super-saturated arsenic in silicon single crystalline precipitates during post processing at low temperatures to form different *** structure with sp... 详细信息

关键词： nano-structure silicon semiconductor materials

Shell effect and capture cross sections in the synthesis of superheavy nuclei

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Science china(physics,Mechanics & Astronomy) 2009年第10期52卷 1489-1493页

作者： DU SaiSai1,2.BIAN BaoAn1,2.3,LIU Min1,2.4,FENG ZhaoQing5,6 & ZHANG FengShou1,2.6 1 Key Laboratory of Beam Technology and Material Modification of Ministry of Education,College of nuclear Science and Technology,beijing Normal University,beijing 100875,china 2.beijing Radiation Center,beijing 100875,china 3 School of Science,Jiangnan University,Wuxi 2.412.,china 4 College of physics and Technology,Guangxi Normal University,Guilin 541004,china 5 institute of Modern physics,Chinese Academy of Sciences,Lanzhou 730000,china 6 Center of Theoretical nuclear physics,National Laboratory of Heavy Ion Accelerator of Lanzhou,Lanzhou 730000,china Key Laboratory of Beam Technology and Material Modification of Ministry of Education College of Nuclear Science and Technology Beijing Normal University Beijing 100875 China beijing Radiation Center Beijing 100875 China School of Science Jiangnan University Wuxi 214122 China College of physics and Technology Guangxi Normal University Guilin 541004 China institute of Modern physics Chinese Academy of Sciences Lanzhou 730000 China Center of Theoretical nuclear physics National Laboratory of Heavy Ion Accelerator of Lanzhou Lanzhou 730000 China

The shell effect is included in the improved isospin dependent quantum molecular dynamics model in which the shell correction energy of the system is calculated by using the deformed two-center shell model. A switch function is introduced to connect the shell correction energy of the projectile and the target with that of the compound nucleus during the dynamical fusion process. It is found that the calculated capture cross sections reproduce the experimental data quantitatively at the energy near the Coulomb barrier. The capture cross sections for reaction 35 80 Br + 82.2.8 Pb → 117 2.8 X are also calculated and discussed.

关键词： superheavy nuclei transport theory shell effect cross sections

Control of Melt Structures on Cu-Au Mineralization in Basic-Ultrabasic Complexes of Northern china

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Acta Geologica Sinica(English Edition) 2000年第4期74卷 786-794页

作者： YUAN Wanming institute of High energy {2., Chinese Academy of Sciences, beijing 100080and MO Xuanxue china University of Geoscienses, beijing 100083 institute of High energy {2. Chinese Academy of Sciences Beijing 100080 china University of Geoscienses Beijing 100083 [?]3Yuan Wanming Born in April 1956 graduated from Hebei College of Geology in 1982. He was once engaged in teaching in Hebei College of Geology for many years and acquired M.Sc and Ph.D degrees in petrology at china University of Geosciences (Wuhan) and china University of Geosciences ({2.) in 1989 and 1997 respectively. Dr. Yuan now works with the institute of High energy physics Chinese Academy of Sciences doing postdoctoral research work. His interests are mainly nuclear techniques and their applications to geology. E-mail: panm@***.

Based on systematic analyses of 72.samples of different basic-ultrabasic rocks, the present paper discusses the relationship between melt structure and Cu and Au mineralization. It is found that if the NBO/T, NBO, M2., FeO and MgO values are relatively high and the T, M3+, Fe2.3 and CaO values are low the basic-ultrabasic melt will be favourable to Cu (Ni) mineralization, but if the former are low and the latter are high it is favourable to Au metallization. Cu ions occupy dominantly octahedra in basic-ultrabasic melt and the higher the NBO/T, NBO and M2. values, the more the octahedra in the melt. Au element mainly takes the form of Au+ ions in basic-ultrabasic melt and the Au+ ions constitute tetrahedral sites together with Fe3+ ions. Therefore, low M2. and high Fe3+, i.e. high oxygen fu-gacity, can promote the enrichment of Au+ ions and Au mineralization. Components NT (other than Au+), Al2.3 and SiO2.in basic-ultrabasic melt have no effect on metallogenetic species. As mentioned above, in relevant diagrams distribution areas of the characteristic values of ore-free melt and those of ore-forming melt are overlapped in different degrees, which possibly indicates that not all the magmas have mineralizing ability. It can be well distinguished whether basic-ultrabasic rocks are favourable to Cu or Au mineralization or they are just ore-free rocks by analysing integrated diagrams of the characteristic values of the magmatic melt structure.

关键词： melt structure Cu-Au mineralization basic-ultrabasic complex

Integrated Numerical Experiment of an Intense RF Linac for CIAE Far-Infrared FEL

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Chinese journal of nuclear physics 1997年第2期19卷 121-127页

作者： Fu Shinian Chen Yinbao Huang Zhibin china institute of atomic energy,P.O.Box 2.5(17),beijing {2. 中国原子能科学院北京

An L band RF linac is now under installation at CIAE to provide intense electronbeam for a far-infrared free-electron laser *** linac consists of a DC thermionicgun,a subharmonic prebuncher,a buncher,an accelerating section and a beam transport *** the INEX(Integrated Numerical Experiment)conducted for prediction of the perfor-mance of the complex and the comparison of some of the simulation results with available ex-perimental data,it shows that the beam quality can satisfy our FEL requirements.

关键词： RF linac Free electron laser Integrated numerical experiments

A scheme for the RCP pattern of the nano-structure

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Communications in Nonlinear Science and Numerical Simulation 2001年第4期6卷 201-204页

作者： Guangwu YAN, Hongxue QU and Bing YAN department of Mathematics, Jilin University, Changchun 130012. china {2. of atomic and Molecular physics, Jilin University. Changchun 13002., china department of Mathematics Juin University Changchun 130012 China Inst. of Atom. and Molecular physics Jilin University Changchun 130023 China

A new scheme for the Random-Continuous-Pile (RCP) pattern is proposed to simulate a two-dimensional structure The RCP pattern is plotted.

关键词： RCP pattern. Maxwell distribution balls-filling

Systematic study of survival probability of excited superheavy nuclei

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Science china(physics,Mechanics & Astronomy) 2011年第S1期54卷 109-113页

作者： XIA ChengJun1, SUN BaoXi1, ZHAO EnGuang2.3 & ZHOU ShanGui2.3 1College of Applied Sciences, beijing University of Technology, beijing 10012., {2. 2.3} of Theoretical physics, Chinese Academy of Sciences, beijing 100190, {2. 3Center of Theoretical nuclear physics, National Laboratory of Heavy Ion Accelerator, Lanzhou 730000, {2. Chinese Acad Sci Inst Theoret Phys Beijing 100190 Peoples R China beijing Univ Technol Coll Appl Sci Beijing 100124 Peoples R China Ctr Theoret Nucl Phys Natl Lab Heavy Ion Accelerator Lanzhou 730000 Peoples R China

The stability of excited superheavy nuclei (SHN) with 100 Z 134 against neutron emission and fission is investigated by using a statistical model. In particular, a systematic study of the survival probability against fission in the 1n-channel of these SHN is made. The present calculations consistently take the neutron separation energies and shell correction energies from the calculated results of the finite range droplet model which predicts an island of stability of SHN around Z = 115 and N = 179. It turns out that this island of stability persists for excited SHN in the sense that the calculated survival probabilities in the 1n-channel of excited SHN at the optimal excitation energy are maximized around Z = 115 and N = 179. This indicates that the survival probability in the 1n-channel is mainly determined by the nuclear shell effects.

关键词： survival probability superheavy elements island of stability neutron emission fission