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Optimization of the imaginary time step evolution for the Dirac equation

Science China(physics,Mechanics & Astronomy) 2011年第2期54卷 231-235页

作者： LI FangQiong1,ZHANG Ying2,LIANG HaoZhao2,3 & MENG Jie4,2,5 1Guizhou university for Nationalities,Guiyang 550025,China 2State Key Lab Nuclear physics & Technology,School of physics,Peking university,Beijing 100871,China 3Institut de Physique Nucle’aire,IN2P3-CNRS and Universite’ Paris-Sud,F-91406 Orsay Cedex,France 4School of physics and Nuclear Energy Engineering,Beihang university,Beijing 100191,China 5department of physics,university of stellenbosch,stellenbosch,south africa 1. Guizhou university for Nationalities Guiyang 550025 China2. State Key Lab Nuclear Physics & Technology School of Physics Peking University Beijing 100871 China3. Institut de Physique Nucléaire IN2P3-CNRS and Université Paris-Sud F-91406 Orsay Cedex France4. School of Physics and Nuclear Energy Engineering Beihang University Beijing 100191 China5. Department of Physics University of Stellenbosch Stellenbosch South Africa

Taking the single neutron levels of 12C in the Fermi sea as examples,the optimization of the imaginary time step(ITS) evolution with the box size and mesh size for the Dirac equation is *** the weakly bound states,in order to reproduce the exact single-particle energies and wave functions,a relatively large box size is *** long as the exact results can be reproduced,the ITS evolution with a smaller box size converges faster,while for both the weakly and deeply bound states,the ITS evolutions are less sensitive to the mesh ***,one can find a parabola relationship between the mesh size and the corresponding critical time step,i.e.,the largest time step to guarantee the convergence,which suggests that the ITS evolution with a larger mesh size allows larger critical time step,and thus can converge faster to the exact *** conclusions are very helpful for optimizing the evolution procedure in the future self-consistent calculations.

关键词： Dirac equation Schrdinger-like equation imaginary time step method convergence

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中共二十届三中全会为非洲发展带来重大机遇

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当代世界 2024年第8期 78-79页

作者： [南非]谭哲理南非哲理中非国际交流智库

2024年7月15—18日,中国共产党第二十届中央委员会第三次全体会议召开,审议通过了《中共中央关于进一步全面深化改革、推进中国式现代化的决定》(下称《决定》)。中共中央总书记习近平作了重要讲话。作为平等伙伴关系下的朋友和兄弟,非... 详细信息

2024年7月15—18日,中国共产党第二十届中央委员会第三次全体会议召开,审议通过了《中共中央关于进一步全面深化改革、推进中国式现代化的决定》(下称《决定》)。中共中央总书记习近平作了重要讲话。作为平等伙伴关系下的朋友和兄弟,非洲国家认识到,中共二十届三中全会及其决定不仅对中国意义重大,也为非中合作带来更多机遇。

关键词：中国式现代化中共中央总书记全面深化改革三中全会重大机遇《决定》中央委员会习近平

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Convergence for Imaginary Time Step evolution in the Fermi and Dirac seas

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Science China(physics,Mechanics & Astronomy) 2010年第2期53卷 327-330页

作者： LI FangQiong1,ZHANG Ying2 & MENG Jie2,3,4 1Guizhou university for Nationalities,Guiyang 550025,China 2State Key Lab Nucl. Phys. & Tech.,School of physics,Peking university,Beijing 100871,China 3School of physics and Nuclear Energy Engineering,Beihang university,Beijing 100191,China 4department of physics,university of stellenbosch,stellenbosch,south africa 1. Guizhou university for Nationalities Guiyang 550025 China2. State Key Lab Nucl. Phys. & Tech. School of Physics Peking University Beijing 100871 China3. School of Physics and Nuclear Energy Engineering Beihang University Beijing 100191 China4. Department of Physics University of Stellenbosch Stellenbosch South Africa

The convergence for the Imaginary Time Step (ITS) evolution with time step is investigated by performing the ITS evolution for the Schrdinger-like equation and the charge-conjugate Schrdinger-like equation deduced from Dirac equation for the single proton levels of 12C in both the Fermi and Dirac seas. For the guaranteed convergence of the ITS evolution to the "exact" results,the time step should be smaller than a "critical" time step Δtc for a given single-particle level. The "critical" time step Δtc is more sensitive to the quantum numbers |κ| than to the energy of the single-particle level. For the single-particle levels with the same κ,their "critical" time steps are in the same order. For the single-particle levels with similar energy,a relatively small (large) "critical" time step for larger (smaller) |κ| is needed. These conclusions can be used in the future self-consistent calculation to optimize the evolution procedure.

关键词： Dirac equation Schrdinger-like equation Imaginary Time Step method convergence

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Selected issues at the interface between nuclear physics and astrophysics as well as the standard model

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中国科学：物理学、力学、天文学英文版 2011年第S1期54卷 119-123页

作者： MENG Jie1,2,3, NIU ZhongMing1, LIANG HaoZhao1 & SUN BaoHua2,4 1State Key Laboratory of Nuclear physics and Technology, School of physics, Peking university, Beijing 100871, China 2School of physics and Nuclear Energy Engineering, Beihang university, Beijing 100191, China 3department of physics, university of stellenbosch, stellenbosch, south africa 4Justus-Liebig-Universita¨t Giessen, Heinrich-Buff-Ring 14, Giessen 35392, Germany 1. State Key Laboratory of Nuclear physics and Technology School of Physics Peking University Beijing 100871 China 2. School of physics and Nuclear Energy Engineering Beihang University Beijing 100191 China 3. department of physics University of Stellenbosch Stellenbosch South Africa 4. Justus-Liebig-Universit?t Giessen Heinrich-Buff-Ring 14 Giessen 35392 Germany

The density functional theory (DFT) with a minimal number of parameters allows a very successful phenomenological description of ground state properties of nuclei all over the periodic table. The recent developments on the application of the covariant density functional theory as well as its extensions by the group in Beijing for a series of interests and hot topics in nuclear astrophysics and nuclear structure are reviewed, including the rapid neutron-capture process, Th/U chronometer, and isospin corrections for superallowed β transitions.

关键词： rapid neutron-capture process nuclear chronometer isospin symmetry-breaking corrections

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Micromorphology of Surface Crusts in the Knersvlakte,south africa

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Journal of Mountain Science 2009年第2期6卷 189-196页

作者： Sarah-Jane C.Fox Anthony J.Mills Rosa M.Poch department of Soil Science Stellenbosch UniversityStellenbosch South Africa department of Environment and Soil Science University of LleidaRovira Roure 191 Lleida

Soils in the Knersvlakte are particularly prone to crusting and have lower inherent infiltrability than other soils across western southern africa. Micromorphological techniques were used to examine the structure and porosity of soil crusts in the Knersvlakte to ascertain why crusting is so intense in this region. Quantile regression using boundary lines was employed to examine the relationships between infiltrability and soil properties for all samples （n = 67）. This analysis showed that infiltrability is potentially maximal at low water- dispersible ＇clay plus silt＇ content and low silt content （r^2 = 0.72 and 0.64; respectively, n = 67）（Figure 2）. The strength of crusts, pH, EC, clay mineralogy, and water-dispersible clay, silt and ＇clay plus silt＇ content were compared, and a pore analysis using optical microscopy was undertaken on images of six soil thin sections （n = 6）（circular and parallel polarizers）. Pore analysis was further undertaken on five horizontal slices of equal dimensions taken through each soil thin section. The porosity samples with low infiltrability （〈 100 mm·hr^-1, n = 4） had greater crust strength, lower porosity （both total and in the least porous slice） and greater water-dispersible ＇day plus silt＇ and silt content than the porosity samples with high infiltrability （〉 100mm·hr^-1, n = 2）. The porosity samples with low infiltrability showed a trend of lower pH and greater water dispersible clay percentage. Porosity varied within the porosity samples due to the presence of dense clay/silt bands （〈 0.5 mm in width） with relatively few air vesicles. The porosity samples with horizontal slices of low porosity （but large numbers of air vesicles） had low infiltrability, while those without slices of low porosity （and relatively few air vesicles） had high infiltrability. We conclude that the intense crusting and resultant low infiltrability of soils in the Knersvlakte appears to be related to the formation of thin, dense clay/silt bands in the

关键词： Infiltrability optical microscopy porosity air vesicles

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The phase transition and classification of critical points in the multistability chemical reactions

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Communications in Nonlinear Science and Numerical Simulation 2000年第1期5卷 36-43页

作者： Chunhua ZHANG Fugen WU Chunyan WU and Fa OU department of physics, Guangdong university of Technology, Guangzhou510090, China department of Applied physics, south China university of Technology, Guangzhou 510641, China department of physics Guangdong University of Technology Guangzhou 510090 China department of Applied physics South China University of Technology Guangzhou 510641 China

In this paper, we study the phase transition and classification of critical points in multistability chemical reaction systems. Referring to the spirit of Landau's theory of phase transitions, this paper deals with the varied transitions and critical phenomena in multistable chemical systems. It is demonstrated that the higher the order of the multistability, the wider the variety of phase transitions will be. A classification scheme of critical points according to the stability criterion and the thermodynamic potential continuity is suggested. It is useful for us to study critical phenomena especially in the non-equilibrium systems including the multi-Stable chemical ones.

关键词： nonlinear chemistry non-equilibrium phase transition critical points

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Calculation of Inelastic Neutron Scattering on ^(11)B

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Chinese journal of nuclear physics 1995年第3期17卷 265-267页

作者： Xie Wen-fang department of physics,Guangdong university of Technology,Guangzhou 510090Ruan Wen-ying department of physics,south China university of Technology,Guangzhou 510641 广东工业大学物理系广东广州 510090 华南理工大学物理系广东广州

The microscopic DWBA was used to calculate the inelastic neutron scattering on 11B to 2.14MeV excited state and some energy dependent parameters were used to improve the *** inte-grated inelastic cross sections and the angular distributions of the 11B（n,n′）11B*（2.14 MeV excitedstate）were given for the incident neutrons whose energy varies from 7.54 MeV to 20.0 *** also given for the experimental blank data.

关键词： Inelastic neutron scattering Microscopic DWBA Integrated cross section Angular distribution

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Top 10 Influential Events in carbon neutrality and climate change response for 2023

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Frontiers in Energy 2024年第1期18卷 1-3页

作者： Research Institute of Carbon Neutrality of Shanghai Jiao Tong university Research Institute of Carbon Neutrality Shanghai Jiao Tong UniversityShanghai 200240China

In 2023, the global community intensified its efforts towards achieving carbon neutrality and addressing climate change, witnessing several impactful events. Research Institute of Carbon Neutrality, Shanghai Jiao Tong university compiled the Top 10 Events (in chronological order) in the field of global carbon neutrality and climate change response for 2023, to share with readers these significant moments that document the ongoing ambition and collective efforts of human society.

关键词： neutral collective intensified

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A　FUZZY　NEURAL　NETWORK　DECISION　MODEL　ON　THE　OPERATION　PROCESS　OF　ELECTRIC　FURNACE　FOR　CLEANING　SLAG　AND　ITS　APPLICATION

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中国有色金属学会会刊：英文版 1995年第3期5卷 21-24页

作者： Peng, Xiaoqi Mei, Chi Zhou, Jiemin Tang, Ying(department of Applied physics and Heat Engineering,Central south university of Technology, Changsha 410083) Central south Univ of Technology Changsha China

ＡＦＵＺＺＹＮＥＵＲＡＬＮＥＴＷＯＲＫＤＥＣＩＳＩＯＮＭＯＤＥＬＯＮＴＨＥＯＰＥＲＡＴＩＯＮＰＲＯＣＥＳＳＯＦＥＬＥＣＴＲＩＣＦＵＲＮＡＣＥＦＯＲＣＬＥＡＮＩＮＧＳＬＡＧＡＮＤＩＴＳＡＰＰＬＩＣＡＴＩＯＮ￥Ｐｅｎｇ，... 详细信息

ＡＦＵＺＺＹＮＥＵＲＡＬＮＥＴＷＯＲＫＤＥＣＩＳＩＯＮＭＯＤＥＬＯＮＴＨＥＯＰＥＲＡＴＩＯＮＰＲＯＣＥＳＳＯＦＥＬＥＣＴＲＩＣＦＵＲＮＡＣＥＦＯＲＣＬＥＡＮＩＮＧＳＬＡＧＡＮＤＩＴＳＡＰＰＬＩＣＡＴＩＯＮ￥Ｐｅｎｇ，Ｘｉａｏｑｉ；Ｍｅｉ，Ｃｈｉ；Ｚｈ...

关键词： fuzzy neural network electric furnace for cleaning slag IDSS

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Effective-Medium Theory for Two-Phase Random Composites with and Interfacial Shell

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Journal of Materials Science & Technology 2000年第4期16卷 367-369页

作者： Qingzhong XUE (department of physics, university of Petroleum, Dongying 257062, China) department of physics University of Petroleum Dongying 257062 China

According to the Bruggeman theory and Maxwell-Garnett theory, the effective dielectric constant of a two-phase random composite with an interfacial shell is presented. The nonlinearity of the theory is obvious. Especially, the theory is suited to study the dielectric properties of two-phase random composites with a spherical interfacial shell. The theoretical results on dielectric properties of polystyrene-barium titanate composites with an interfacial shell are in good agreement with experimental data.

关键词： Zhang Effective-Medium Theory for Two-Phase Random Composites with and Interfacial Shell Wang

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