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Refraction of light in media

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science china(physics,Mechanics & Astronomy) 2007年第5期50卷 591-600页

作者： ZHANG Tao key laboratory of beam technology and material modification of Ministry of Education, institute of low energy nuclear physics, beijing normal university, beijing 100875, china beijing Radiation Center, beijing 100875, china key laboratory of beam technology and material modification of Ministry of Education Institute of Low Energy Nuclear Physics Beijing Normal University Beijing China beijing Radiation Center Beijing China

The roles of the magnetic field and electric field of the light are investigated when the light is refracted in the medium. The model of the electron cloud conductor is presented. Electron cloud in a molecule is treated as a conductor and the Faraday’s Law is applied to this conductor that is in the alternating magnetic field of the light. dBM/dt of the light gives rise to an alternating induced current on the electron cloud conductor, and the light exchanges energy, i.e. the refractive energy, with the elec- tron cloud conductor. Formulas of refractive index, which is the ratio of light speed in vacuum to that in the medium, are derived with this model. These formulas are tested with several mediums and Langevin’s diamagnetic susceptibility of helium gas, and the results are in good agreement with the measured data. The anisotropy and the nonlinearity of the refractive index are explained with the theory described in this work.

关键词： refractive index, light, speed, medium, propagation

Structural and mechanical properties of amorphous carbon films deposited by the dual plasma technique

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Journal of university of science and technology beijing 2008年第5期15卷 622-626页

作者： Yaohui Wang,Xu Zhang,Xianying Wu,Huixing Zhang,and Xiaoji Zhang key laboratory of the Ministry of Education of china for beam technology and material modification,Institution of low energy nuclear physics,beijing normal university beijing Radiation Center,beijing 100875,china key laboratory of the Ministry of Education of china for beam technology and material modification Institution of Low Energy Nuclear Physics Beijing Normal University beijing Radiation Center Beijing 100875 China

Direct current metal filtered cathodic vacuum arc （FCVA） and acetylene gas （C2H2） were wielded to synthesize Ti-containing amorphous carbon films on Si （100）. The influence of substrate bias voltage and acetylene gas on the microstructure and mechanical properties of the films were investigated. The results show that the phase of TiC in the （111） preferential crystallographic orientation exists in the film,and the main existing pattern of carbon is sp2. With increasing the acetylene flow rate,the contents of Ti and TiC phase of the film gradually reduce; however,the thickness of the film increases. When the substrate bias voltage reaches -600 V,the internal stress of the film reaches 1.6 GPa. The micro-hardness and elastic modulus of the film can reach 33.9 and 237.6 GPa,respectively,and the friction coefficient of the film is 0.25.

关键词： metal containing amorphous carbon amorphous carbon films filtered arc acetylene flow rate bias voltage structure and properties

Optimal reactions for the synthesis of superheavy nucleus ^(270)Hs

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science china(physics,Mechanics & Astronomy) 2006年第6期49卷 641-648页

作者： LIU Zuhua1,3 & BAO Jingdong1,2 1. key laboratory of beam technology and material modification of Ministry of Education, beijing normal university, beijing 100875, china 2. physics department, beijing normal university, beijing 100875, china 3. china institute of Atomic energy, beijing 102413, china key laboratory of beam technology and material modification of Ministry of Education Beijing Normal University Beijing China china institute of Atomic energy Beijing China physics department Beijing Normal University Beijing China

The superheavy nucleus 270Hs is expected to be a “double-magic” deformed nucleus. We have calculated its cross sections of evaporation residue for the reactions 248Cm(26Mg,4n)270Hs, 244Pu(30Si,4n)270Hs, 238U(36S,4n)270Hs and 226Ra(48Ca,4n)270Hs using a two-parameter Smoluchowski equation. It is found from our results that 226Ra(48Ca,4n)270Hs and 238U(36S,4n)270Hs are two optimal reactions for the synthesis of the superheavy nucleus 270Hs due to their large negative Q-values.

关键词： diffused fusion barrier,Smoluchowski equation,superheavy nuclei.

Complete multiple round quantum dense coding with quantum logical network

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Chinese science Bulletin 2007年第9期52卷 1162-1165页

作者： LI ChunYan1,2,LI XiHan1,2,DENG FuGuo1,2,3,ZHOU Ping1,2 & ZHOU HongYu1,2,3 1 key laboratory of beam technology and material modification of Ministry of Education,beijing normal university,beijing 100875,china 2 institute of low energy nuclear physics,and department of material science and engineering,beijing normal university,beijing 100875,china 3 beijing Radiation Center,beijing 100875,china key laboratory of beam technology and material modification of Ministry of Education Beijing Normal University Beijing China institute of low energy nuclear physics and Department of Material Science and Engineering Beijing Normal University Beijing China beijing Radiation Center Beijing China

We present a complete multiple round quantum dense coding scheme for improving the source ca-pacity of that introduced recently by Zhang et al. The receiver resorts to two qubits for storing the four local unitary ope... 详细信息

关键词：量子通信多重量子紧凑编码量子逻辑网络量子纠缠

Synthesis of superheavy nuclei with ^(238)U target

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science china(physics,Mechanics & Astronomy) 2009年第10期52卷 1482-1488页

作者： LIU ZuHua1,3 & BAO JingDong2,4 1 key laboratory of beam technology and material modification of Ministry of Education,beijing normal university,beijing 100875,china 2 department of physics,beijing normal university,beijing 100875,china 3 china institute of Atomic energy,beijing 102413,china 4 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 Beijing Normal University Beijing China china institute of Atomic energy Beijing China department of physics Beijing Normal University Beijing China Center of Theoretical nuclear physics National Laboratory of Heavy Ion Accelerator of Lanzhou Lanzhou China

The production of superheavy nuclei with Z=108-116 via hot fusion reactions of the neutron-rich projectiles with 238U target is systematically *** results show that the production cross sections of superheavy nuclei do not decrease monotonously as the atomic number Z *** cross sections of the superheavy nuclei at Z = 112 and 115 are enhanced as compared with the whole Z-trend in synthesis of the superheavy nuclei,which clearly illustrates that the reactions with large negative Q-value and shell correction are more favorable to synthesize superheavy nuclei.

关键词： superheavy nuclei fusion reaction cross section 238U target

Exotic structure of the third excited state in^(21)Na

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Chinese science Bulletin 2005年第23期50卷 2677-2680页

作者： LI Xihan1,2,3, LIANG Yujie1,2,3, DENG Fuguo1,2,3, LIU Zuhua1,4 & ZHOU Hongyu1,2,3 1. key laboratory of beam technology and material modification of Minister of Education, beijing normal university, beijing 100875, china 2. institute of low energy nuclear physics, and department of material science and engineering, beijing normal university, beijing 100875, china 3. beijing Radiation Center, beijing 100875, china 4. china institute of Atomic energy, beijing 102413, china key laboratory of beam technology and material modification of Minister of Education Beijing Normal University Beijing 100875 China institute of low energy nuclear physics Department of Material Science and Engineering Beijing Normal University Beijing 100875 China beijing Radiation Center Beijing 100875 China china institute of Atomic energy Beijing 102413 China

The probability of the last proton being out of the binding potential, P and the root-mean-square (rms) ra- dius (1/2= of the third excited state in 21Na are calcu- lated by means of asymptotic normalization coefficient (ANC) method with the experimental date existing. The results are P=54.73% and 1/2=5.28 fm respectively. The P value and the contribution of the asymptotic part to the 1/2 are compared with those of several other low energy states in 21Na. It is found that the valence particle in the third excited state has an obvious larger P than those of other states. The density distribution of the valence proton in this state is also compared with the nucleons in the nuclear core 20Ne, and a far extended tail can be seen clearly. These results show that the third ex- cited state in 21Na is a proton halo state.

关键词：钠第三激发态外部结构有效半径密度分布渐近标准化系数

Collision dynamics of He@C_(60)+He@C_(60) at low energies

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science china(physics,Mechanics & Astronomy) 2008年第7期51卷 765-772页

作者： ZHAO Qiang1,2, ZHANG FengShou1,2,3 & ZHOU HongYu1,2 1 key laboratory of beam technology and material modification of Ministry of Education, institute of low energy nuclear physics, beijing normal university, beijing 100875, china 2 beijing Radiation Center, beijing 100875, china 3 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 Institute of Low Energy Nuclear Physics Beijing Normal University Beijing China beijing Radiation Center Beijing China Center of Theoretical nuclear physics National Laboratory of Heavy Ion Accelerator of Lanzhou Lanzhou China

A semi-empirical molecular dynamics model is developed. The central collisions of C60+C60 and He@C60+He@C60 at different incident energies are investigated based on this model. It is found that the dimer structures have been produced at proper incident energies and these fullerene dimers could be formed by a self-assembly of C60 fullerene and He@C60. The He atom has a significant effect at higher incident energy and this embedded He atom can enhance the stability of the dimer structure.

关键词： C60 He@C60 collision molecular dynamics

Anomalous magnetotransport in LaMn_(1-x)Te_xO_3

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science china(physics,Mechanics & Astronomy) 2009年第7期52卷 987-992页

作者： TAN GuoTai1,2, CHEN ZhengHao3 & ZHANG XiaoZhong4,5 1 key laboratory of beam technology & materials modification of the Ministry of Education, institute of low energy nuclear physics, beijing normal university, beijing 100875, china 2 beijing Radiation Center, beijing 100875, china 3 laboratory of Optical physics, institute of physics, Chinese Academy of sciences, beijing 100080, china 4 key laboratory of Advanced materials of the Ministry of Education, department of materials science and engineering, Tsinghua university, beijing 100084, china 5 beijing National Center for Electron Microscopy, Tsinghua university, beijing 100084, china key laboratory of beam technology & materials modification of the Ministry of Education Institute of Low Energy Nuclear Physics Beijing Normal University Beijing China beijing Radiation Center Beijing China laboratory of Optical physics Institute of Physics Chinese Academy of Sciences Beijing China key laboratory of Advanced materials of the Ministry of Education Department of Materials Science and Engineering Tsinghua University Beijing China beijing National Center for Electron Microscopy Tsinghua University Beijing China

The LaMn1-xTexO3+δ (x=0.1, 0.2, 0.3) were synthesized using solid-state reaction method for the first time. X-ray photoemission spectrum (XPS) shows that in the samples the Te ions have a valence of Te4+, and Mn3+ ions are partly converted into Mn2+ and Mn4+ due to the excess oxygen and Te doping. The magnetotransport associated with Mn2+, Mn3+ and Mn4+ was investigated. The experimental results show that the samples are insulator at 0 T when the amount of Mn3+ is much larger or less than the sum of Mn2+ and Mn4+; by contrast, the samples display metal to insulator transition with increasing temperature when the amount of Mn3+ is close to the sum of Mn2+ and Mn4+. These anomalous magnetotransport behaviors were analyzed in the frame of the double-exchange (DE) mechanism.

关键词： colossal magnetoresistance La-Te-Mn-O magnetotransport

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 214122,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 China beijing Radiation Center Beijing China School of science Jiangnan University Wuxi China College of physics and technology Guangxi Normal University Guilin China institute of Modern physics Chinese Academy of Sciences Lanzhou China Center of Theoretical nuclear physics National Laboratory of Heavy Ion Accelerator of Lanzhou Lanzhou 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 + 82 208 Pb → 117 288 X are also calculated and discussed.

关键词： superheavy nuclei transport theory shell effect cross sections