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Orientational phase transition in C_(60) single crystal under high pressure

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Chinese Science Bulletin 1998年第16期43卷 1341-1344页

作者： XIE Bin+1, WANG Haiqian+1, WANG Qiang+1, HOU Jianguo+1, XU Bo+2. TAN Mingqiu+2. LI Hongnian+2.and XU Yabo+2.1. Structure Research Laboratory and Center for Fundamental physics, university of Science and Technology of China, Hefei 2.002., China 2. Depart Structure Research Laboratory and Center for Fundamental physics University of Science and Technology of China Hefei China department of physics Zhejiang University Hangzhou China

By using a piston-cylinder type hydrostatic high-pressure unit, the electrical dc conductance of bulk C 60 single crystal was measured in the pressure range of 0 to 0.6 GPa at 2.0 K. With increasing pressure, a discontinuous increase of the conductance was observed at the pressure of 0.176 GPa, which can be ascribed to the orientational ordering phase transition. In the simple cubic phase, the increase of conductance with increasing pressure is faster than that in the face-centered-cubic phase.

关键词： C 60 high pressure conductivity.

Lepton flavor violating Z-boson decays at GigaZ as a probe of supersymmetry

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Science China(physics,Mechanics & Astronomy) 2010年第11期53卷 1949-1952页

作者： YANG JinMin 1,2.1 department of physics,Henan Normal {2.,Xinxiang 453007,China 2.Institute of Theoretical physics,Chinese Academy of Sciences,Beijing 100190,China 1. department of physics Henan Normal University Xinxiang 453007 China2. Institute of Theoretical Physics Chinese Academy of Sciences Beijing 100190 China

This paper briefly reviews the lepton flavor violating Z-decays at GigaZ as a probe of supersymmetry by focusing on Z → i j in two representative supersymmetric models: the minimal supersymmetric model without R-parity and the supersymmetric seesaw *** work concludes that under the current experimental constraints from LEP and i → j γ,these rare decays can still be enhanced to reach the sensitivity of the ***,supersymmetry can be probed via these decays at GigaZ.

关键词： Z-decay GigaZ supersymmetry

Optimal reactions for the synthesis of superheavy nucleus ^(2.0)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 {2., Beijing Normal university, Beijing 100875, China 3. China Institute of Atomic Energy, Beijing 102.13, China Key Laboratory of Beam Technology Material Modification of Ministry of Education Beijing Normal University Beijing 100875 China physics department Beijing Normal University Beijing 100875 China China Institute of Atomic Energy Beijing 102413 China

The superheavy nucleus 2.0Hs is expected to be a “double-magic” deformed nucleus. We have calculated its cross sections of evaporation residue for the reactions 2.8Cm(2.Mg,4n)2.0Hs, 2.4Pu(30Si,4n)2.0Hs, 2.8U(36S,4n)2.0Hs and 2.6Ra(48Ca,4n)2.0Hs using a two-parameter Smoluchowski equation. It is found from our results that 2.6Ra(48Ca,4n)2.0Hs and 2.8U(36S,4n)2.0Hs are two optimal reactions for the synthesis of the superheavy nucleus 2.0Hs due to their large negative Q-values.

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

Probing proton halo of the exotic nucleus ^(2.)S by elastic electron scattering

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Science China(physics,Mechanics & Astronomy) 2004年第1期47卷 42-51页

作者： WANG Zaijun1 & REN Zhongzhou1’2.1. department of physics, Nanjing {2., Nanjing 2.0008, China 2. Center of Theoretical Nuclear physics, National Laboratory of Heavy-Ion Accelerator at Lanzhou, Lanzhou 730000, China Correspondence should be addressed to Ren Zhongzhou (email: zren@*** zren99@***) Received June 16, 2.03 1. department of physics Nanjing University 210008 Nanjing China 2. Center of Theoretical Nuclear physics National Laboratory of Heavy-Ion Accelerator at Lanzhou 730000 Lanzhou China

Elastic electron scattering on the exotic light nucleus 2.S is investigated in the plane wave Born approximation. The variation of the squared form factors of 2.S with momentum transfer is compared with that of 32.. It is found that the behavior of the form factors near the second minimum (with a moderate momentum transfer) is sensitive to the alteration of the charge density distribution of halo protons in 2.S. This indicates that elastic electron scattering can be a good probe of the structure of proton-halo nuclei.

关键词： elastic electron scattering, cross section, form factor, proton-halo nucleus.

Langevin Treatment of Atomic Coherence Effect on Hybrid Erbium doped Fiber Amplification

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Chinese Journal of Lasers 1999年第6期8卷 3-5页

作者： LIU Fangxin 1,3 GUO Yang 2.MING Hai 2.( 1 Structure Research Laboratory, 2.department of physics, 3 department of Astronomy and Applied physics, university of Science and Technology of China, Hefei 2.002., China) 中国科学技术大学结构研究实验室结构分析开放实验室安徽合肥 230026 中国科学技术大学物理系安徽合肥

The effects of atomic coherence on hybrid erbium doped fiber amplifier (HEDFA) pumped simultaneously by two diode lasers with different frequencies are studied by using Langevin quantum theory. The expressions of coherence and incoherence gain are derived. The theoretical results show that HEDFA has a near flat bandwidth response from 1531 to 1568 nm and large coherence gain under the conditions of low temperature and small detuning.

关键词： atomic coherence hybrid erbium doped fiber amplifier LD pump

β-delayed proton decays near the proton drip line

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Science China(physics,Mechanics & Astronomy) 2005年第3期48卷 257-267页

作者： XU Shuwei 1 , LI Zhankui 1 , XIE Yuanxiang 1 , HUANG Wenxue 1 , SHU Nengchuan 2., CHEN Yongshou 2., XU Furong 3 , WANG Kun 4 , PAN Qiangyan 1 , WANG Xudong 1 , YU Yong 1 & XING Yebing 1 1. Institute of Modern physics, Chinese Academy of Sciences, Lanzhou 730000, China 2. Nuclear physics {2., China Institute of Atomic Energy, Beijing 102.13, China 3. {2. of Technical physics, Peking university, Beijing 100871, China 4. Shanghai Institute for Nuclear Research, Shanghai 2.1800, China 1. Institute of Modern physics Chinese Academy of Sciences 730000 Lanzhou China 2. Nuclear physics department China Institute of Atomic Energy 102413 Beijing China 3. department of Technical physics Peking University 100871 Beijing China 4. Shanghai Institute for Nuclear Research 201800 Shanghai China

We briefly reviewed the experimental study on a-delayed proton decays near the proton drip line published by our group during the period of 1996―2.04, namely the first observation of the a-delayed proton decays of 9 new nuclides in the rare-earth region and the new measurements of a-delayed proton decays of 5 nuclides in the mass ～90 region near the N = Z line with the aid of the “p-?” coincidence in combination with a He-jet tape transport system. In the meantime some important experimental technique details were supplemented. The experimental results, including the half -lives, spins, parities, deformations and production reaction cross sections for the 14 nuclei were summarized and compared with the current nuclear-model predictions, and then the following points were represented. (1) The experimental half-lives for 85Mo and 92.h as well as the predicted “waiting point” nuclei 89Ru and 93Pd are 5―10 times longer than the theoretical predictions given by M?ller et al. using a macroscopic-microscopic model. It considerably influences the predictions of the abundances of the nuclides produced in the rp-process. (2. The current-model predictions are not consistent with the experimental assignments of the spins and parities for the proton drip-line nuclei 142.o and 12.Pm. However, the nuclear potential energy surface (PES) calculated by using a Woods- Saxon-Strutinsky method reproduced the experimental results. (3) The Alice code overestimated the production reaction cross sections of the studied 9 rare-earth nuclei by one order of magnitude or two, while HIVAP code overestimated them by one order of magnitude approximately.

关键词： proton drip line, β-delayed proton decay, He-jet tape transport system, "p-γ" coincidence, spin, parity, deformation, production reaction cross section.

Tungsten-182.Mssbauer experiments at liquid nitrogen temperature

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Chinese Science Bulletin 2001年第9期46卷 732-734页

作者： HUANG Runsheng, LIU Bing, ZHANG Jinrong, LIU Cong & GAO Xuekui1. physics department of Nanjing {2., Nanjing 2.0093, China 2. China Institute of Atomic Energy, Beijing 102.13, China physics department of Nanjing {2. Nanjing China China Institute of Atomic Energy Beijing China

A good 182.a Mossbauer source and an apparatus designed specially were made. 182. transmission Mossbauer experiments were successfully carried out, both of the source and absorber at liquid nitrogen temperature. It wa... 详细信息

关键词： Mossbauer effect 182. Mossbauer effect.

The refined theory of deep rectangular beams based on general solutions of elasticity

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Science China(physics,Mechanics & Astronomy) 2006年第3期49卷 291-303页

作者： GAO Yang1 & WANG Minzhong2.1. College of Science, China Agricultural university, Beijing 100083, China 2. State Key Laboratory for Turbulence and Complex Systems and department of Mechanics and Engi- neering Science, Peking university, Beijing 100871, China College of Science China Agricultural University Beijing 100083 China State Key Laboratory for Turbulence Complex Systems department of Mechanics Engineering Science Peking University Beijing 100871 China

The problem of deducing one-dimensional theory from two-dimensional the- ory for a homogeneous isotropic beam is investigated. Based on elasticity theory, the re- fined theory of rectangular beams is derived by using Papkovich-Neuber solution and Lur’e method without ad hoc assumptions. It is shown that the displacements and stresses of the beam can be represented by the angle of rotation and the deflection of the neutral surface. Based on the refined beam theory, the exact equations for the beam without transverse surface loadings are derived and consist of two governing differential equations: the fourth-order equation and the transcendental equation. The approximate equations for the beam under transverse loadings are derived directly from the refined beam theory and are almost the same as the governing equations of Timoshenko beam theory. In two ex- amples, it is shown that the new theory provides better results than Levinson’s beam the- ory when compared with those obtained from the linear theory of elasticity.

关键词： deep rectangular beams,the refined theory,Papkovich-Neuber solution,Lur'e method,governing equation

The refined theory of transversely isotropic piezoelectric rectangular beams

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Science China(physics,Mechanics & Astronomy) 2006年第4期49卷 473-486页

作者： GAO Yang1 & WANG Minzhong2.1. College of Science, China Agricultural university, Beijing 100083, China 2. State Key Laboratory for Turbulence and Complex Systems and department of Mechanics and Engi- neering Science, Peking university, Beijing 100871, China 1. College of Science China Agricultural University Beijing 100083 China 2. State Key Laboratory for Turbulence and Complex Systems and department of Mechanics and Engineering Science Peking University Beijing 100871 China

The problem of deducing one-dimensional theory from two-dimensional theory for a transversely isotropic piezoelectric rectangular beam is investigated. Based on the piezoelasticity theory, the refined theory of piezoelectric beams is derived by using the general solution of transversely isotropic piezoelasticity and Lur'e method without ad hoc assumptions. Based on the refined theory of piezoelectric beams, the exact equations for the beams without transverse surface loadings are derived, which consist of two governing differential equations: the fourth-order equation and the transcendental equation. The approximate equations for the beams under transverse loadings are derived directly from the refined beam theory. As a special case, the governing differential equations for transversely isotropic elastic beams are obtained from the corresponding equations of piezoelectric beams. To illustrate the application of the beam theory developed, a uniformly loaded and simply supported piezoelectric beam is examined.

关键词： rectangular beams, the refined theory, piezoelectric, transversely isotropic.