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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 100124, china 2Institute of Theoretical physics, Chinese Academy of Sciences, beijing 100190, china 3Center of Theoretical nuclear physics, National Laboratory of Heavy Ion Accelerator, Lanzhou 730000, china beijing university of Technology College of Applied Sciences Beijing China (GRID:grid.28703.3e) (ISNI:***) Chinese Academy of Sciences Institute of Theoretical Physics Beijing China (GRID:grid.9227.e) (ISNI:***) National Laboratory of Heavy Ion Accelerator Center of Theoretical Nuclear Physics Lanzhou China (GRID:grid.450259.f) (ISNI:0000 0004 1804 2516)

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

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 310027, china 2. Institute of High energy physics and Key Laboratory of nuclear Analysis Techniques, Chinese Academy of Sciences,beijing 100039, china 3. Department of Pathophysiology, Tongji Medical College, Huazhong university of Science and Technology, Wuhan 430030, china) Department of physics and Bio-X Laboratory Zhejiang University Hangzhou 310027 China Institute of High energy physics and Key Laboratory of nuclear 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.

A note on the discovery of a 2M_⊙ pulsar

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Research in Astronomy and Astrophysics 2011年第6期11卷 687-691页

作者： Xiao-Yu Lai Ren-Xin Xu school of physics and State Key Laboratory of nuclear physics and Technology Peking University Beijing 100871 China

It is conventionally thought that the state equation of dense matter softens and thus cannot result in high maximum mass if pulsars are quark stars and that a recently discovered 2M⊙ pulsar （PSR J1614–2230） may make pulsars unlikely to be quark stars. However, this standard point of view would be revisited and updated if quark clustering could occur in cold quark matter because of the strong coupling be- tween quarks at realistic baryon densities in compact stars. It can be argued that the state equation of clustered quark matter stiffens to support compact stars with maxi- mum mass Mmax 2M⊙. In this brief note, it is demonstrated that large parameter space ranges are allowed for Mmax 2M⊙ in a Lennard-Jones model of clustered quark matter and the newly measured highest mass of PSR J1614–2230 would be meaningful for constraining the number of quarks inside a single quark-cluster to be Nq ≤ 103.

关键词： dense matter — elementary particles — pulsars: general — stars: neutron

Track Fading and Its Applications in Archaeology, Tectonics and Geothermal Chronology in china

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Journal of Earth Science 2013年第4期24卷 645-651页

作者：郭士伦袁万明陈宝流黄慰文刘顺生 Department of nuclear physics China Institute of Atomic Energy school of Earth Sciences and Resourses China University of Geosciences Department of Radioisotopes China Institute of Atomic Energy Institute of Vertebrate Paleontology and Paleoanthropology Chinese Academy of Sciences Guangzhou Institute of Geochemistry Chinese Academy of Sciences

Track fading is a basic phenomenon in track science and has been the source of informa- tion in geosciences. This article summarizes the knowledge of track fading and gives some examples of successful applications of track fading in archaeology, tectonics and geothermal chronology in china. The applications of track fading are classified into 5 modes：（1） mode of complete fading （annealing）; （2） mode of partial fading; （3） use of the dependence of track fading on time and temperature; （4） use of the differences of track fading between coexisting minerals; and （5） use of fading-reduced track length. Track fading mechanisms hints that scientists in geothermal chronology should adopt microprobes for quantitative elemental analysis to determine the detailed chemical compositions of each mineral grain or at least of the grains from each position of geological structures in order that one becomes well aware of the relation between the track fading behavior and chemical compositions of the mineral used.

关键词： track fading archaeology tectonics geothermal chronology.

Correlation of Behavior Changes and BOLD Signal in Alzheimer-like Rat Model

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Acta Biochimica et Biophysica Sinica 2004年第12期36卷 803-810页

作者： Zheng-Hui HU#, Xiao-Chuan WANG1#, Li-Yun LI3, Mai-Li LIU3, Rong LIU1, Zhiqun LING1, Qing TIAN1, Xiao-Wei TANG, Yi-Gen WU2*, and Jian-Zhi WANG1* Department of physics and Bio-X disciplinary Laboratory, Zhejiang university, Hangzhou 310027,china 1 Department of Pathophysiology, Tongji Medical College, Huazhong university of Science and Technology, Wuhan 430030, china 2Institute of High energy physics and Key Laboratory of nuclear Analysis Techniques, Chinese Academy of Sciences, P.O. Box 918, beijing 100039, china 3Wuhan Institute of physics and Mathematics, State Key Laboratory of Magnetic Resonance and Atomic and Molecular physics, Chinese Academy of Sciences, Wuhan 430071, china Department of physics and Bio-X disciplinary Laboratory Zhejiang UniversityHangzhou 310027China Department of Pathophysiology Tongji Medical College Huazhong University of Science and TechnologyWuhan 430030 China Wuhan Institute of physics and Mathematics State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Chinese Academy of SciencesWuhan 430071 China Institute of High energy physics and Key Laboratory of nuclear Analysis Techniques Chinese Academy of SciencesP.O. Box 918 Beijing 100039 China

To explore a potential means for the early diagnosis of Alzheimer disease, we studied the relationship of resting T2* signal and tau hyperphosphorylation/spatial memory deficit. The rat model with tau hyperphosphorylation and spatial memory deficit was established by bilateral hippocampi injection of isoproterenol (IP). Then, the correlative alteration between resting T2* signal and spatial memory retention was assessed with blood oxygenation level dependent (BOLD) functional magnetic resonance imaging (fMRI) study and Morris Water Maze test, and Western blot was employed to confirm tau hyperphosphorylation. The analysis showed following results. (1) Tau phosphorylation at Ser396/Ser404 and Ser199/Ser202 was signifi- cantly increased in IP-injected rats as detected by PHF-1 and tau-1, respectively. (2) An AD-like spatial memory retention disturbance was induced at 24 h after isoproterenol injection. (3) A sensitivity threshold of resting T2* signal intensity, which separated the IP-treated rats from vehicle control, was obtained by applying linear regression analysis, and an estimated sensitivity statistical threshold was at 32.62. These results suggest that resting T2* signal may serve as a noninvasive quantitative marker in predicting AD-like spatial memory deficits and tau hyperphosphorylation.

关键词： Alzheimer disease (AD) functional magnetic resonance imaging (fMRI) isoproterenol (IP) Morris Water Maze diagnosis

A study of constraints on the constitutive relationships of electromagnetic medium based on generally acknowledged truths

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Science china(physics,Mechanics & Astronomy) 2005年第5期48卷 541-548页

作者： GUO Huiping1, LIU Xueguan1,2, YIN Hongcheng2, CHAO Zengming2 & HUANG Peikang2 1. school of Electronics and Information engineering, Soochow university, Suzhou 215021, china 2. National Electromagnetic Scattering Laboratory, beijing 100854, china school of Electronics and Information engineering Soochow University Suzhou China National Electromagnetic Scattering Laboratory Beijing China

The study of constraints on the constitutive relationships of electromagnetic media is of great importance in the aspects of the medium characteristics analysis, the new article material synthesis and the medium parameters reconstruction, etc. According to the fact that the constitutive relationships should not conflict with the general physical laws, the constraints that the constitutive relationships of electromagnetic medium must satisfy have been summarized in this paper. These constraints include determinacy principle, objectivity principle, causality principle and permission principle. And the parameter constraints of the arbitrary linear homogenous time-invariant medium are obtained following the minimum energy consumption principle. This work provides a new way of ascertaining the constitutive relationships of the electromagnetic medium.

关键词： electromagnetic medium, medium parameter constraint, generally acknowledged truths, energy conservation principle, minimum energy consumption principle.

Simulation of nuclei morphologies for binary alloy

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Science china Mathematics 2010年第11期53卷 2927-2936页

作者： LI DaMing1, & ZHANG PingWen2 1Department of Mathematics, Shanghai Jiaotong university, Shanghai 200240, china 2Key Lab of Mathematics and Applied Mathematics, Center for Applied physics and Technology and school of Mathematical Sciences, Peking university, beijing 100871, china Department of Mathematics Shanghai Jiaotong University Key Lab of Mathematics and Applied Mathematics Center for Applied Physics and Technology and School of Mathematical Sciences Peking University

We study the critical nuclei morphologies of a binary alloy by the string method. The dynamic equation of the string, connecting the metastable phase (liquid) and stable phase (solid), is governed by Helmholtz free energy for the binary alloy system at a given temperature. The stationary string through the critical nucleus (saddle point) is obtained if the relaxation time of the string is su?ciently large. The critical nucleus radius and energy barrier to nucleation of a pure alloy with isotropic interface energy in two and three dimensions are calculated, which are consistent with the classical nucleation theory. The critical nuclei morphologies are sensitive to the anisotropy strength of interface energy and interface thickness of alloy in two and three dimensions. The critical nucleus and energy barrier to nucleation become smaller if the anisotropy strength of the interface energy is increased, which means that it is much easier to form a stable nucleus if the anisotropy of the interface energy is considered.

关键词： nucleation crystal morphology string method

Relativistic description of second-order correction to nuclear magnetic moments

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Relativistic description of second-order correction to nucle...

A DOMINANT DEFECT AT THE Si/SiO_2 INTERFACE IN MOS STRUCTURE

第十三届全国核结构研讨会暨第九次全国“核结构与量子力学”专题讨论会

作者： Li Jian~(1 1)) Yao Jiangming~(2 2)) Meng Jie~(1,3 3)) 1(State Key Laboratory for nuclear physics and Technology,school of physics,Peking university,beijing 100871,china) 2(school of Physical Science and Technology,Southwest university,Chongqing 400715,china) 3(school of physics and nuclear energy engineering,beihang university,beijing 100191,china)

Using the single particle states and residual interaction derived from the relativistic point-coupling model with PC-F1 parameter set,the second-order core polarization corrections to nuclear magnetic moments of double-closed shell nuclei plus or minus one nucleon with A = 15,17,39 and 41 have been studied and compared with previous non-relativistic *** has been found that the second-order corrections are *** these corrections,the relativistic description of isoscalar magnetic moments for nuclei with A= 15 and A = 39, becomes *** the isovector magnetic moments of nuclei with A = 15 and A = 39,the negative second-order corrections improve the description significantly,while the positive corrections for nuclei with A = 17 and A = 41 still worsen the description.

关键词： second-order core polarization magnetic moments relativistic point-coupling model residual interaction

来源： cnki会议评论

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Science china Mathematics 1989年第12期32卷 1458-1468页

作者：陈开茅卢殿通 Department of physics Peking University Institute of Low energy nuclear physics of beijing Normal university

The interface defects at the Si/SiO_2 interface in ρ-type silicon (111) MOS structures have been studied by the DLTS method. A dominant defect H_(it),(0.503) at the Si/SiO_2 interface has been found. Its characteristics are (i) the average hole ionization Gibbs free energy △G_p≥0.503 eV; (ii) by changing the gate bias when the distance from Fermi level to the top of Si valence band at the Si/SiO_2 interface is less than △G_p there is still the strong DLTS peak; (iii) its hole apparent activation energy increases with the dectease of the height of semiconductor surface potential barrier; and (iv) its hole capture process causes the multiexponential capacitance transience as a function of pulse width and the H_(it)(0.503) level are very difficult to be fully filled with the holes introduced by thepulst with alimited width. All above show that there is a continuous transition energy band between the energy bands of the covalent crystal silicon and the SiO_2 in the Si/SiO_2 systems formed by thermal oxidation; the dominant defect H_(it)(0.503) is distributed in the transition region, and the distance of H_(it)(0.503) level from the top of the valence band increases with the distance from the silicon surface.

关键词： interface defects MOS structure physics model of Si/SiO_2 interface.