检索结果-南通市图书馆

Relativistic description of second-order correction to nuclear magnetic moments with point-coupling residual interaction

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2011年第2期54卷 204-209页

作者： LI Jian MENG Jie RING Peter YAO JiangMing ARIMA Akito State Key Laboratory for Nuclear Physics and Technology School of Physics Peking University Beijing 100871 China School of Physics and Nuclear Energy Engineering Beihang University Beijing 100191 China Department of Physics University of Stellenbosch Stellenbosch South Africa Physik-Department der Technischen Universitat Munchen D-85748 Garching Germany School of Physical Science and Technology Southwest University Chongqing 400715 China Science Museum Japan Science Foundation 2-1 Kitanomaru-koen Chiyoda-ku Tokyo 102-0091 Japan

Using the single particle states and the residual interaction derived from the relativistic point-coupling model with the PC-F1 parameter set,the second-order core polarization corrections to nuclear magnetic moments of LS closed shell nuclei ±1 nucleon with A = 15,17,39 and 41 are studied and compared with previous non-relativistic *** is found that the second-order corrections are *** these corrections,the isovector magnetic moments of the concerned nuclei are well reproduced,especially those for A = 17 and A = 41.

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

Polarization effect on the spin symmetry for anti-Lambda spectrum in ^(16)O+■ system

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2010年第9期34卷 1425-1427页

作者：宋春艳尧江明 School of Phyics and State Key Laboratory of Nuclear Physics and TechnologyPeking University School of Physical Science and Technology Southwest University

The polarization effect on the spin symmetry for anti-Lambda spectrum in 16 O＋Λ system has been studied in relativistic mean-field *** PK1 effective interaction is used for nucleon-meson couplings and G-parity symmetry with a reduction factor ξ = 0.3 is adopted for anti-Lambda-meson *** energy differences between spin doublets in the anti-Lambda spectrum are around 0.10-0.73 MeV for p Λ *** dominant components of the Dirac spinor for the anti-Lambda spin doublets are found to be near *** indicates that the spin symmetry is still well-conserved against the polarization effect from the valence antiLambda hyperon,which leads to a highly compressed cold nucleus with the central density up to 2 - 3 times of saturated density.

关键词： lambda and anti-lambda hypernuclei relativistic mean field spin symmetry

Microscopic analysis of spherical to γ-soft shape transitions in Zn isotopes

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2011年第2期54卷 222-226页

作者： VRETENAR Dario Physics Department Faculty of ScienceUniversity of Zagreb

The rapid transition between spherical and γ-soft shapes in Zn isotopes in the mass A 70 region,is analyzed using excitation spectra and collective wave functions obtained by diagonalization of a five-dimensional Hamiltonian for quadrupole vibrational and rotational degrees of freedom,with parameters determined by constrained self-consistent relativistic mean-field calculations for triaxial *** microscopic potential energy surfaces,together with the characteristic collective observables,illustrate a rapid transition from near spherical shape at the N = 40 subshell,to γ-soft deformed shapes for lighter *** calculated spectra display fingerprints of a second-order shape phase transition that can be approximately described by the E(5) analytic solution.

关键词： quantum phase transitions E(5) critical-point symmetry five-dimensional Hamiltonian

Guiding of 60 keV O^(6+) ions along capillaries in an Al_2O_3 membrane

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2014年第4期57卷 659-662页

作者： XI FaYuan LV HuiYi National Defence Key-Subject Laboratory of Nuclear Waste and Environment Safety Southwest University of Science and Technology

The guiding of 60 keV O6+ions along capillaries in an Al2O3 membrane is *** charge state distribution and the angular distribution of the ions transmitted through the capillaries are *** ion guiding ability of the concerned capillaries for the used projectile ions is analyzed,and is compared with other results using PC and alumina *** agreement is *** studies on material influence on the ion guiding power of the capillaries are needed.

关键词： guiding 60 keV O6+ ions capillaries Al2O3

Comparison of cavities and extended defects formed in helium-implanted 6H-SiC at room temperature and 750 ℃

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2020年第7期29卷 399-405页

作者： Qing Liao Bingsheng Li Long Kang Xiaogang Li State Key Laboratory for Environment-friendly Energy Materials Southwest University of Science and TechnologyMianyang 621010China Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China

The formation of cavities in silicon carbide is vitally useful to“smart-cut”and metal gettering in semiconductor in*** this study,cavities and extended defects formed in helium(He)ions implanted 6H-SiC at room temperature(RT)and 750℃ followed by annealing at 1500℃are investigated by a combination of transmission electron microscopy and high-resolution electron *** observed cavities and extended defects are related to the implantation tempera*** distributed cavities and extended defects are observed in the helium-implanted 6H-SiC at RT,while homogeneously distributed cavities and extended defects are formed after He-implanted 6H-SiC at 750℃.The possible reasons are discussed.

关键词： He implantation cavities extended defects transmission electron microscopy recrystallization

CFD Simulation of Local and Global Mixing Time in an Agitated Tank

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2017年第1期30卷 118-126页

作者： LI Liangchao XU Bin Key Laboratory of Testing Technology for Manufacturing Process of Ministry of Education Southwest University of Science and TechnologyMianyang 621010China

The Issue of mixing efficiency in agitated tanks has drawn serious concern in many industrial processes. The turbulence model is very critical to predicting mixing process in agitated tanks. On the basis of computational fluid dynamics（CFD） software package Fluent 6.2, the mixing characteristics in a tank agitated by dual six-blade-Rushton-turbines（6-DT） are predicted using the detached eddy simulation（DES） method. A sliding mesh（SM） approach is adopted to solve the rotation of the impeller. The simulated flow patterns and liquid velocities in the agitated tank are verified by experimental data in the literature. The simulation results indicate that the DES method can obtain more flow details than Reynolds-averaged Navier-Stokes（RANS） model. Local and global mixing time in the agitated tank is predicted by solving a tracer concentration scalar transport equation. The simulated results show that feeding points have great influence on mixing process and mixing time. Mixing efficiency is the highest for the feeding point at location of midway of the two impellers. Two methods are used to determine global mixing time and get close result. Dimensionless global mixing time remains unchanged with increasing of impeller speed. Parallel, merging and diverging flow pattern form in the agitated tank, respectively, by changing the impeller spacing and clearance of lower impeller from the bottom of the tank. The global mixing time is the shortest for the merging flow, followed by diverging flow, and the longest for parallel flow. The research presents helpful references for design, optimization and scale-up of agitated tanks with multi-impeller.

关键词： agitated tank mixing time computational fluid dynamics(CFD) detached eddy simulation(DES) numerical simulation

Tensor Coupling Effects on Spin Symmetry in the Anti-Lambda Spectrum of Hypernuclei

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2011年第9期28卷 80-83页

作者： SONG Chun-Yan YAO Jiang-Ming MENG Jie State Key Laboratory of Software Development Environment and School of Physics and Nuclear Energy EngineeringBeihang UniversityBeijing 100191 School of Physical Science and Technology Southwest UniversityChongqing 400715 State Key Laboratory of Nuclear Physics and Technology School of PhysicsPeking UniversityBeijing 100871 School of Physics and Nuclear Energy Engineering Beihang UniversityBeijing 100191 Department of Physics University of StellenboschStellenboschSouth Africa

Effects ofΛΛω−tensor coupling on the spin symmetry ofΛspectra inΛ−nucleus systems are studied using relativistic mean-field *** 12C+Λas an example,it is found that the tensor coupling enlarges the spin−orbit splittings ofΛby a factor of 5 but has a negligible effect on the wave functions ofΛ.Similar conclusions are observed in otherΛ−nuclei,including ^(16)O+Λ,^(40)Ca+Λand ^(208)Pb+Λ.It is indicated that the spin symmetry in anti-lambda-nucleus systems is still a good approximation irrespective of the tensor coupling.

关键词： theory tensor symmetry

research on the feature extraction of DC space charge behavior of oil-paper insulation

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2011年第5期54卷 1315-1324页

作者： TANG Chao LIAO RuiJin CHEN George YANG LiJun College of Engineering and Technology Southwest University Chongqing 400715 China The State Key Laboratory of Power Transmission Equipment & System Security and New Technology Chongqing University Chongqing 400044 China School of Electronics and Computer Science University of Southampton Southampton SO17 3B J UK

As the ultra high DC voltage grid comes into an important stage in the ‘Twelfth Five-year Plan’ of China, the requirement on the operation safety of power equipment needs to be improved. Oil-paper insulation plays a significant role as the main insulation material of many key power equipments. The space charge behaviors of oil-paper insulation not only affect the dielectric strength, but also relate to the stability and security of power transmission facilities. Until now, the research on the space charge behaviors of oil-paper insulation remains on the stage of objective description and phenomenon explanation, thus it is very urgent to make some feature extractions on the test results in order to further investigate the DC space charge behaviors of oil-paper insulation. In this paper, based on the large numbers of test data in the first stage, data mining and feature extractions were performed on the DC space charge behavior of oil-paper insulation. The variation laws of some key characteristic parameters obtained in different experiment conditions such as the total charge injection amount, apparent charge mobility, and trap energy distribution were analyzed. In addition, the distribution of trapping level inside oil-paper was calculated by using the PEA test results based on the mechanism of the isothermal decay current, which realized the approximate calculation of trap depth by charge decay characteristics. What’s more, the exponential injection and decay equations of DC space charge changing with time were acquired for the first time, and the physical meanings of related parameters were defined. This has laid a foundation for the prediction and simulation of space charge in the oil-paper insulation.

关键词： oil-paper insulation space charge DC feature extraction

Effect of helium concentration on irradiation damage of Fe-ion irradiated SIMP steel at 300℃and 450℃

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2021年第5期30卷 81-86页

作者： Zhen Yang Junyuan Yang Qing Liao Shuai Xu Bingsheng Li Sino-French Institute of Nuclear Engineering and Technology Sun Yat-sen UniversityZhuhai 519082China State Key Laboratory for Environment-Friendly Energy Materials Southwest University of Science and TechnologyMianyang 621010China

SIMP steel is newly developed fully martensitic steel for lead-cooled fast reactors and accelerator-driven *** is important to evaluate its radiation resistance via high flux neutron irradiation,where dense He atoms can be formed via(n,α)transmutation ***-irradiation with Fe and He ions,instead of neutron,was *** were irradiated with 6.4-MeV Fe ions to the damage dose of 5 dpa at a depth of 600 *** different helium injection ratios of 60-appm He/dpa(dpa:displacements per atom),200-appm He/dpa and 600-appm He/dpa at a depth of 600 nm,were *** different irradiation temperatures of 300℃and 450℃were carried *** effect of helium concentration on the microstructure of Fe-irradiated SIMP steel was *** damage was observed using transmission electron *** formed dislocation loops and bubbles depended on the helium injection ratio and irradiation *** of dislocation loops and helium bubbles were homogeneously distributed at 300℃,but not at 450℃.The causes of observed effects are discussed.

关键词： martensitic steels Fe and He co-irradiation microstructure transmission electron microscopy