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β-delayed proton decays near the proton drip line

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 {3., Chinese Academy of Sciences, Lanzhou 73.000, {2. 2. nuclear physics department, china institute of atomic energy, Beijing 1024.3. {2. 3. department of Technical {3., Peking University, Beijing 100871, {2. 4. Shanghai institute for {13. Research, Shanghai 2.1800, {2. 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 93.d 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 {2. 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.

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Electronic structure and magnetism of R(Fe,Si)_(12. (R=Y,Nd)

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Science china(physics,Mechanics & Astronomy) 2006年第2期49卷 195-202页

作者： SUN Guang’ai1, CHEN Bo1, DU Honglin2. FAN Zhijian1, GAO Tao3.& QI Xinhua3.. institute of nuclear {2. and Chemistry, china Academy of Engineering {2., Mianyang 62.900, china 2. department of {2., Peking university, Beijing 100871, china 3. institute of {13. and Molecular {2., Sichuan University, Chengdu 610065, china 1. institute of nuclear {2. and Chemistry China Academy of Engineering Physics Mianyang 621900 China 2. department of physics Peking university Beijing 100871 China 3. institute of atomic and Molecular {2. Sichuan University Chengdu 610065 China

The newly developed full-potential linearized augmented plane wave (LAPW) and local orbitals (lo) based on standard APW methods are briefly introduced, and the structure and magnetic properties of R(Fe, Si)12.compounds (R = Y, Nd) are calculated using the method. The distribution of Si at different sites is analyzed based on total energy of one crystal unit with structure having been optimized. The characters of magnetic mo-ments, total density of states (TDOS) and partial density of states (PDOS) for different crystal sites Si occupies are obtained and analyzed. The results show that the total mag-netic moments of RFe10Si2.(R = Y, Nd) are larger than those of RFe10M2.(M = Ti, V, Cr, Mn, Mo and W) and the hybridization mechanism is seen as follows. Si(8j) reduce the mag-netic moments of Fe at three sites, however, Si(8f) mainly reduce the magnetic moments of Fe(8i) and Fe(8j) atoms. The Curie temperature is markedly enhanced by the introduc-tion of Si atoms according to spin fluctuation of DOS at Fermi level.

关键词： (L)APW+lo method R(Fe Si)12.R = Y Nd) magnetic moment Density of state.

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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. {3. {2., Beijing Normal University, Beijing 100875, china 3. china institute of atomic energy, Beijing 1024.3. 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 {2. {3. 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(3.Si,4n)2.0Hs, 2.8U(3.S,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(3.S,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.

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Isospin-dependent relativistic microscopic optical potential in the Dirac Brueckner-Hartree-Fock method

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Science china(physics,Mechanics & Astronomy) 2004年第2期47卷 189-198页

作者： RONG Jian1 & MA Zhongyu1,2.3.1. china institute of atomic energy, Beijing 1024.3. {2. 2. Center of nuclear Theoretical physics, National Laboratory of Heavy Ion Accelerator of Lanzhou, Lan-zhou 73.000, {2. 3. institute of Theoretical physics, Chinese Academy of Sciences, Beijing 100080, {2. Correspondence should be addressed to Rong Jian (email: jrong@***) 1. china institute of atomic energy 102413 Beijing China 2. Center of nuclear Theoretical physics National Laboratory of Heavy Ion Accelerator of Lanzhou 730000 Lanzhou China 3. institute of Theoretical physics Chinese Academy of Sciences 100080 Beijing China

The relativistic microscopic optical potential in the asymmetric nuclear matter is studied in the framework of the Dirac Brueckner-Hartree-Fock method. A new decomposition of the Dirac structure of the nuclear self-{2. in nuclear matter is adopted. The self-{2. of a nucleon with E > 0 in nuclear matter is calculated with the G matrix in the Hartree-Fock approach. The optical potential of a nucleon in the nuclear medium is identified with the nucleon self-{2.. The {2. and asymmetric parameter dependence of the relativistic optical potentials for proton and neutron are discussed. The resulting Schroedinger equivalent potentials have reasonable behaviors of the {2. dependence. The asymmetric parameter dependence of relativistic optical potentials and Schroedinger potentials are emphasized.

关键词： Dirac Brueckner Hartree-Fock, relativistic microscopic optical potential, asymmetric nuclear matter, isospin-dependence.

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Exotic structure of the third excited state in^(2.)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 {2. nuclear physics, and department of Material Science and Engineering, Beijing Normal University, Beijing 100875, china 3. Beijing Radiation Center, Beijing 100875, china 4.{13., Beijing 1024.3. china Key Laboratory of Beam Technology and Material Modification of Minister of Education Beijing Normal University Beijing 100875 China institute of Low energy {2. {3. and Department of Material Science and Engineering Beijing Normal University Beijing 100875 China Beijing Radiation Center Beijing 100875 China china institute of {2. {3. 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 2.Na are calcu- lated by means of asymptotic normalization coefficie... 详细信息

The probability of the last proton being out of the binding potential, P and the root-mean-square (rms) ra- dius (2.1/2. of the third excited state in 2.Na are calcu- lated by means of asymptotic normalization coefficient (ANC) method with the experimental date existing. The results are P=54.73. and 2.1/2.5.2. fm respectively. The P value and the contribution of the asymptotic part to the 2.1/2.are compared with those of several other low energy states in 2.Na. 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 2.Ne, and a far extended tail can be seen clearly. These results show that the third ex- cited state in 2.Na 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

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A template of rat brain based on fMRI T2. imaging

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Progress in Natural Science:Materials International 2005年第6期15卷 502-506页

作者： HU Zhenghui1, WU Yigen2. WANG Xiaochuan3. WANG Jianzhi3. CHEN Feiyan1 and TANG Xiaowei1*(1. department of physics and Bio-X Laboratory, Zhejiang University, Hangzhou 3.002., {2. 2. institute of High energy physics and Key Laboratory of nuclear Analysis Techniques, Chinese Academy of Sciences,Beijing 10003., {2. 3. department of Pathophysiology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 43.03., {2.) department of physics and Bio-X Laboratory Zhejiang University Hangzhou 310027 China institute of High energy {2. and Key Laboratory of {3. Analysis Techniques Chinese Academy of Sciences Beijing 100039 China department of Pathophysiology Tongji Medical College Huazhong University of Science and Technology Wuhan 430030 China

The development of functional magnetic resonance imaging (fMRI) technology has made it possible to carry out functional brain imaging experiments in small animals. Usually, group data is required to form the assessment of population, which can not only increase the sensitivity of the overall experiment, but also allow the generalization of the conclusion to the whole population. In order to average the signals of functional brain images from different subjects, it is necessary to put all the mapping images into the same standard space (template image). However, up to now, most animal brain templates remain unavailable and it must be done by ourselves. In this study, a template image based on the brains of eight male Wistar rats is obtained, and it is successfully used in our present Alzheimer disease (AD)-like rat model studies as template for spatially normalizing images to the same stereotaxical space. The fMRI results processed with statistical parametric mapping (SPM99) software are in agreement with the results from immunohistochemical experiment, which proves that this method is universally applicable to the pathologic models of other small animals and to human brain lesion studies.

关键词： fMRI animal model atlas template normalization T*2.

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PIXE and INAA studies on ancient potteries from Guangfulin relics in Shanghai

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Progress in Natural Science:Materials International 2007年第11期17卷 1348-1356页

作者： Lin Jiawei1, Cheng Huansheng1, Zhang Zhengquan1, Zhang Bin1, Feng Songlin2. Song Jian3. Gao Menghe4 and Zhu Dan1(1. Applied Ion Beam physics Laboratory, Key Laboratory of the Ministry of Education, institute of Modern physics, Fudan University, Shanghai 2.043., china 2. Key Laboratory of nuclear Analytical Techniques, institute of High energy physics, Beijing 10003., china 3. Shanghai Museum, Shanghai 2.0003. china 4. department of Cultural Heritage and Museology, Fudan University, Shanghai 2.043., china) Applied Ion Beam physics Laboratory Key Laboratory of the Ministry of Education Institute of Modern Physics Fudan University Shanghai 200433 China Key Laboratory of nuclear Analytical Techniques Institute of High Energy Physics Beijing 100039 China Shanghai Museum Shanghai 200003 China department of Cultural Heritage and Museology Fudan University Shanghai 200433 China

This paper reports the study of ancient potteries unearthed from the Guangfulin site in Shanghai. From the external features of these potteries, archeologists can classify them into two different cultural types: Liangzhu culture (local culture) and a new culture which might be derived elsewhere, but they can not recognize whether they were produced in the same place. Proton induced X-ray emission (PIXE) and instrumental neutron activation analysis (INAA) were used to measure the chemical compositions of the samples and the results were analyzed using multivariate statistics. We found that the two methods can complement each other and their database can be mutually referenced in the study of ancient potteries. Experimental results show that the compositions of the potteries from the two cultural types are different, which means that the materials for ancient potteries of new culture originate from elsewhere. This supports the archaeologists’ speculation that a group of ancient people migrated to Shanghai from some other places 4000 years ago.

关键词： PIXE INAA factor analysis Guangfulin ancient pottery

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Full fermion-boson vertex function derived in terms of symmetry relations in Abelian gauge theory

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Science china(physics,Mechanics & Astronomy) 2008年第9期51卷 1206-1213页

作者： HE HanXin china institute of atomic energy, Beijing 1024.3. {2. china institute of {2. {3. Beijing 102413 China

Nonperturbative studies such as confinement and dynamical chiral symmetry breaking need the nonperturbative interacting vertex functions. In this paper, an approach to determining the full fermion-boson vertex function in four-dimensional Abelian gauge theory is presented: this full vertex function is derived in terms of a set of normal (longitudinal) and transverse Ward-Takahashi relations for the fer-mion-boson (vector) and axial-vector vertices in the momentum space in the case of massless fermion. Such a derived fermion-boson vertex function should be sat-isfied both perturbatively and nonperturbatively. The fact that such a derived full fermion-boson vertex function to one-loop order holds indeed is proven and the nonperturbative form of this vertex is also under discussion.

关键词： symmetry Ward-Takahashi relations full fermion-boson vertex function

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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 University, Nanjing 2.0093. {2. 2. china institute of atomic energy, Beijing 1024.3. {2. physics department of Nanjing University Nanjing China china institute of {2. {3. 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.

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Synthesis of superheavy nuclei with ^(2.8)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.{3. of {2.,Beijing Normal University,Beijing 100875,china 3.6},Beijing 1024.3.china 4 Center of Theoretical nuclear {2.,National Laboratory of Heavy Ion Accelerator of Lanzhou,Lanzhou 73.000,china Key Laboratory of Beam Technology and Material Modification of Ministry of Education Beijing Normal University Beijing 100875 China department of physics Beijing Normal University Beijing 100875 China china institute of {2. {3. Beijing 102413 China Center of Theoretical nuclear physics National Laboratory of Heavy Ion Accelerator of Lanzhou Lanzhou 730000 China

The production of superheavy nuclei with Z=108-116 via hot fusion reactions of the neutron-rich projectiles with 2.8U 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 2.8U target

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