检索结果-南通市图书馆

Effective photon mass in nuclear matter and finite nuclei

在线全文

cnki会议

学校读者我要写书评

暂无评论

Effective photon mass in nuclear matter and finite nuclei

CCAST“不稳定核反应”研讨会

作者： Bao-Xi Sun, Xiao-Fu Lu, Peng-Nian Shen, En-Guang Zhao Institute of High Energy Physics. The Chinese Academy of Sciences, P.O.Box 918(4), Beijing 100039. china Institute of Theoretical Physics, The Chinese Academy of Sciences, Beijing 100080, china Department of Physics, Sichuan University, Chengdu 610064, china. center of Theoretical nuclear Physics. national laboratory of heavy ion accelerator,lanzhou 730000, china Department of Physics, Tsinghua University, Beijing 100084, china and china center of Advanced Science and Technology (World laboratory), Beijing 100080, china

＜正＞ Electromagnetic field in nuclear matter and nuclei are studied In the nuclear matter,because theexpectation value of the electric charge density operator is not zero,different in vacuum,the U（1）local gauge symmetry of electric charge is spontaneously broken and consequently,the photon gainsan effective mass through the Higgs mechanism An alternative way to study the effective mass of

关键词：

Dense coding scheme using superpositions of Bell-states and its NMR implementation

在线全文

cnki会议

学校读者我要写书评

暂无评论

Science china(Physics,Mechanics & Astronomy) 2005年第1期48卷 57-67页

作者： ZHANG Jingfu, XIE Jingyi, DENG Zhiwei & LU Zhiheng Key laboratory for Quantum Information and Measurements, Department of Physics, Tsinghua University, Beijing 100084, china center for Quantum Information, Tsinghua University, Beijing 100084, china Department of Materials Science and Engineering, Beijing Normal University, Beijing 100875, china Testing and Analytical center, Beijing Normal University, Beijing 100875, china Department of Physics, Beijing Normal University, Beijing 100875, china Key laboratory for Quantum Information and Measurements Department of Physics Tsinghua University Beijing 100084 China center for Quantum Information Tsinghua University Beijing 100084 China Department of Materials Science and Engineering Beijing 100875 China Testing and Analytical center Beijing Normal University Beijing 100875 China Department of Physics Beijing Normal University Beijing 100875 China

Dense coding using superpositions of Bell-states is proposed. The generalized Grover's algorithm is used to prepare the initial entangled states, and the reverse process of the quantum algorithm is used to determine the entangled state in the decoding measurement. Compared with the previous schemes, the superpositions of two Bell-states are exploited. Our scheme is demonstrated using a nuclear magnetic resonance (NMR)quantum computer. The corresponding manipulations are obtained. Experimental results show a good agreement between theory and experiment. We also generalize the scheme to transmit eight messages by introducing an additional two-state system.

关键词： dense coding, superpositions of Bell-states, generalized Grover's algorithm, nuclear magnetic res-onance, quantum computer.

Lithosphere types in North china:Evidence from geology and geophysics

在线全文

学校读者我要写书评

暂无评论

Science china Earth Sciences 2005年第11期48卷 1809-1827页

作者： QIU Ruizhao1,2, DENG Jinfu3, ZHOU Su3, LI Jinfa4, XIAO Qinghui1,5, WU Zongxu6 & LIU Cui3 1. Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, china 2. Development and Research center, china Geological Survey, Beijing 100037, china 3. china University of Geosciences, Beijing 100083, china 4. china University of Geosciences, Wuhan 430074, china 5. Information center of Ministry of Land and Resources, Beijing 100812, china 6. Institute of Geology, State Seismological Bureau, Beijing 100029, china Institute of Geology Chinese Academy of Geological Sciences Beijing China Development and Research center China Geological Survey Beijing China china University of Geosciences Beijing China china University of Geosciences Wuhan China Information center of Ministry of Land and Resources Beijing China Institute of Geology State Seismological Bureau Beijing China

On the basis of the characteristics of geology and geophysics in North china, three types of lithosphere, namely, the cratonic, the orogenic and the rift lithospheres can be classified. In terms of petrological method (based on the information from Precambrian rock assemblages, igneous activities, deep-seated enclaves, etc.) and the relationship between seismic velocity and rock compositions, the crust-mantle petrological and chemical structure models can be set up. Researching results indicate that the geology and geophysics of North china platform bears the similar characteristics in comparison with those of the global typical cratons. The Eerduosi(Ordos) block located in the west of the North china Platform is a remnant of cratonic lithosphere after the North china platform had undergone “activation” in Mesozoic and “reconstruction” in Cenozoic times. The continental crust consists mainly of TTG rock assemblage while the subcontinental lithosphere mantle mainly consists of strongly depleted harzburgite. The craton was finally formed in late Archaean and early Proterozoic, and has been kept in stability up to present; its crustal-mantle petrological structures of lithosphere can be set up as a reference for the study of North china craton and even Sino-Korean craton. In the Mesozoic period, the middle and east areas of North china platform were activated in the Yanshanian orogenic process, the continental crust was reformed by material and heat-transfer of convective mantle and the original crustal TTG component was reconstructed to be granitic crust, and the subcontinental lithosphere man- tle was replaced by the Yanshanian harzburgite-lherzolite. The Yanshan-Taihang Mountains were the remnants of orogenic lithosphere after the rifting in eastern North china in Cenozoic. The present thickness of continental crust and lithosphere in the Yanshan-Taihang Mountains is not equal to their thickness during the Yanshanian orogenic movement because they had undergone the

关键词： lithospheric types,evidence of geology and geophysics,crust-mantle petrological structure,deep process

Improved Glauber model for the reactions induced by Halo Nuclei and Stable Nuclei

在线全文

学校读者我要写书评

暂无评论

Improved Glauber model for the reactions induced by Halo Nuc...

CCAST“放射性束物理”研讨会

作者： Wenjun Guo, Huanqing Jiang, Jianye Liu Wei zuo, Zhongzhou Ren, Xiguo Lee, Zenghua Li1. center of Theoretical nuclear Physics, national laboratory of heavy ion accelerator,lanzhou 730000, P.R.china2. Institute of Modem Physics, The Chinese Academy of Sciences, lanzhou 730000, P.R.china 3.Institute of High Energy Physics, The Chinese Academy of Sciences, Beijing 100039, P.R.china4.Physics department of Nanjing University, Nanjing 210008, P.R.china

＜正＞We develop the method for the calculation of the total reaction cross sections induced by thehalo nuclei and stable nuclei. This approach is based on the Glauber theory, which is valid for thereactions at high energies. It is extended for reactions at low energy and at the intermediate energy bycorrecting with the quantum correction and Coulomb correction under the assumption of the effectivenuclear density distribution. The calculated results for the total reaction cross section induced by stablenuclei agrees well with the experimental data within 10 percent accuracy. The comparison between thenumerical results and the experimental data for the neutron halo nucleiand the proton halo nucleiindicates a satisfactory agreement after considering the halo structure of these nuclei, which implies thequite different mean fields for the reactions induced by halo nuclei and stable nuclei. The halo nucleondistributions and the root mean square radii of these nuclei can be extracted from above ***, it is clear to see that the medium correction of the nucleon-nucleon collision has little effecton the total reaction cross sections induced by the halo nuclei due to the very weak binding and the veryextended density distribution, which is quite different from the reactions induced by the stable nucleiwith the salient medium correction.

关键词： total reaction cross section improved Glauber theory halo nuclei

Properties of nuclear Matter in A Nonlinear Realized Approach of the SU(2) Chiral Symmetry Spontaneous Breaking

在线全文

cnki会议

学校读者我要写书评

暂无评论

Properties of Nuclear Matter in A Nonlinear Realized Approac...

CCAST“第二届粒子物理、核物理及宇宙学前沿问题”研讨会

作者： Xiao-Fu Lu , Bao-Xi Sun, Yu-Xin Liu, Hua Guo, En-Guang Zhao Institute of Theoretical Physics, The Chinese Academy of Sciences, Beijing 100080, china Department of Physics, Sichuan University, Chengdu 610064, china School of Physics, Peking University, Beijing 100871, china Institute of High Energy Physics, The Chinese Academy of Sciences, P.O. Box 918(4),Beijing 100039, china center of Theoretical nuclear Physics, national laboratory of heavy ion accelerator, lanzhou 730000, china

A nonlinear realization of SU(2) chiral symmetry spontaneous breaking approach is developed in the composite operator formalism. The properties of nuclear matter, the pion and the quark condensates in nuclear matter are evaluated. The calculated results show that the saturation properties of nuclear matter can be reproduced well with the approach. Meanwhile, the expectation value of (?)2 becomes nonzero in the nuclear matter with minimal density pN - 0.235/m-3, and the quark condensate decreases monotonously with the increasing of the nuclear matter density. It indicates that the chiral symmetry is restored gradually as the nuclear matter density increases.

关键词： net Chiral Symmetry Spontaneous Breaking Properties of nuclear Matter in A Nonlinear Realized Approach of the SU

Sum rules on quantum hadrodynamics

在线全文

cnki会议

学校读者我要写书评

暂无评论

Sum rules on quantum hadrodynamics

CCAST“不稳定核反应”研讨会

作者： Bao-Xi Sun, Xiao-Fu Lu, Peng-Nian Shen, En-Guang Zhao Institute of High Energy Physics, The Chinese Academy of Sciences. P.O.Box 918(4), Beijing 100039, china Institute of Theoretical Physics, The Chinese Academy of Sciences, Beijing 100080. china Department of Physics, Sichuan University, Chengdu 610064, china center of Theoretical nuclear Physics, national laboratory of heavy ion accelerator.lanzhou 730000. china Department of Physics. Tsinghua University. Beijing 100084. china china center of Advanced Science and Technology(World laboratory). Beijing 100080,china

＜正＞ A new method,sum rules on quantum hadrodynaznics,is developed to solve thenuclear many—body *** differences between this method and the relativis-tic Hartree—Fock approximation are *** theory with off-shell p...

关键词：

Improvement of tribological behavior of a Ti-Al-V alloy by nitrogen ion implantation

在线全文

cnki会议

学校读者我要写书评

暂无评论

Rare Metals 2006年第Z1期25卷 309-314页

作者： LIU Yanzhang ZU Xiaotao QIU Shaoyu HUANG Xinquan Department of Applied Physics University of Electronic Science and Technology of China Chengdu 610054 China national Key laboratory for nuclear Fuel and Materials P.O. Box 436(4) Chengdu 610041 China Department of Applied Physics University of Electronic Science and Technology of China Chengdu 610054 China National Key Laboratory for Nuclear Fuel and Materials P.O. Box 436(4) Chengdu 610041 China National Key Laboratory for Nuclear Fuel and Materials P.O. Box 436(4) Chengdu 610041 China

The tribological properties especially wear and hardness of a Ti-Al-V alloy with nitrogen implantation (energy 60 keV) were investigated. The implantation was carried out at fluences range from 1×1016 to 4×1017 ions/cm2. Glancing angle X-ray diffraction (GAXRD) and X-ray photoelectron spectroscopy (XPS) analyses were performed to obtain surface characterization of the implanted sample. The unimplanted and implanted samples were also annealed at 600 ℃ in order to understand the influence of annealing on the tribological properties of Ti-Al-V. The hardness shows significant improvement at the higher fluence. After annealing at 600 ℃, the friction coefficient exhibits a relative decrease for the nitrogen-implanted samples. In addition, the wear rates of the implanted samples exhibits a great decrease after annealing at 600 ℃. Nature of the surface and reason for the variation and improvement in wear resistance were discussed in detail.

关键词： nitrogen ion implantation Ti-Al-V alloy phase formation tribological properties

Cells therapy for Parkinson's disease-so close and so far away

在线全文

学校读者我要写书评

暂无评论

Science china(Life Sciences) 2009年第7期52卷 610-614页

作者： REN ZhenHua & ZHANG Yu Cell Therapy center,Xuanwu Hospital,Capital Medical University and Key laboratory of Neurodegeneration,Ministry of Education,Beijing 100053,china Cell Therapy center Xuanwu Hospital Capital Medical University and Key Laboratory of Neurodegeneration Ministry of Education Beijing China

One of the strategies of treating Parkinson's disease(PD) is the replacement of lost neurons in the substantia nigra with healthy dapamingergic *** sources for cells range from autologous grafts of dopamine secreting cells,fetal ventral mesencephalon tissue,to various stem cell *** the past quarter century,many experimental replacement therapies have been tried on PD animal models as well as human patients,yet none resulted in satisfactory outcomes that warrant wide *** progress in stem cell biology has shown that nuclear transfer embryonic stem cells(ntES) or induced pluripotent stem cells(iPS) derived cells can be used to successfully treat rodent PD models,thus solving the problem of immunorejection and paving the way for future autologous transplantations for treating ***,however,post mortem analysis of patients who received fetal brain cell transplantation revealed that implanted cells are prone to degeneration just like endogenous neurons in the same pathological area,indicating long-term efficacy of cell therapy of PD needs to overcome the degenerating environment in the brain.A better understanding of neurodegeneration in the midbrain appeared to be a necessary step in developing new cell therapies in Parkinson's *** is likely that future cell replacement will focus on not only ameliorating symptoms of the disease but also trying to slow the progression of the disease by either neuroprotection or restoring the micro-environment in the midbrain.

关键词： Parkinson’s disease dopamine neurons cell replacement transplantation stem cell fetal ventral mesencephalon carotid body embryonic stem cells nuclear transfer embryonic stem cells induced pluripotent stem cells

nuclear Symmetry Energy from Brueckner Approach with Three-body Force

在线全文

学校读者我要写书评

暂无评论

Nuclear Symmetry Energy from Brueckner Approach with Three-b...

CCAST“放射性束物理”研讨会

作者： W. Zuo, U. Lombardo, A. Lejeune center of Theoretical nuclear Physics, national laboratory of heavy ionaccelerator, lanzhou 730000, P.R. china Institute of Modern Physics, Academia Sinica, lanzhou 730000, P. R. china INFN-LNS, 44 Via S. Sofia, I-95123 Catania, Italy Institut de Physique, B5 Sart-Tilman, B-4000 Liege 1, Belgium

＜正＞A microscopic three-body force is introduced in the Brueckner-Hartree-Fock ap-proach and its effects on the the nuclear symmetry energy and the proton fractionin the β-equlibrium matter have been investigated. It is shown that the three-bodyforce leads to a decisive improvement of the saturation properties for symmetricnuclear matter and a large enhancement of the symmetry energy at high density.

关键词：