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Isospin dependence of nucleon effective masses in neutron-rich matter

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Nuclear Science and Techniques 2016年第6期27卷 25-32页

作者： bao-An Li bao-jun Cai Lie-Wen Chen Xiao-Hua Li Department of Physics and Astronomy Texas A&MUniversity-Commerce Department of Physics and Astronomy and Shanghai Key Laboratory for Particle Physics and Cosmology Shanghai Jiao Tong University School of Nuclear Science and Technology University of South China

In this talk,we first briefly review the isospin dependence of the total nucleon effective mass M Jinferred from analyzing nucleon-nucleus scattering data within an isospin-dependent non-relativistic optical potential model,and the isospin dependence of the nucleon E-mass M;E J obtained from applying the Migdal–Luttinger theorem to a phenomenological single-nucleon momentum distribution in nuclei constrained by recent electron-nucleus *** information about the isospin dependence of both the nucleon total effective mass and E-mass,we then infer the isospin dependence of nucleon k-mass using the well-known relation M_J~*=M_ J^(*1E).Implications of the results on the nucleon mean free path in neutron-rich matter are discussed.

关键词：同位旋相关有效质量单核子核物质丰中子平均自由程非相对论分析数据

How tightly is the nuclear symmetry energy constrained by a unitary Fermi gas?

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Nuclear Science and Techniques 2017年第12期28卷 248-254页

作者： Nai-Bo Zhang bao-jun Cai bao-An Li William G.Newton jun Xu Department of Physics and Astronomy Texas A&M University-Commerce Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment Institute of Space Sciences Shandong University Department of Physics Shanghai University Department of Physics and Astronomy Shanghai Key Laboratory for Particle Physics and Cosmology Shanghai Jiao Tong University Shanghai Institute of Applied Physics Chinese Academy of Sciences

We examine critically how tightly the density dependence of nuclear symmetry energy E_(sym)(q) is constrained by the universal equation of state of the unitary Fermi gas EUG(q) considering currently known uncertainties of higher order parameters describing the density dependence of the equation of state of isospin asymmetric nuclear matter. We found that E_(UG)(q) does provide a useful lower boundary for the E_(sym)(q). However, it doesnot tightly constrain the correlation between the magnitude E_(sym)(q_0) and slope L unless the curvature K_(sym)of the symmetry energy at saturation density q_0 is more precisely known. The large uncertainty in the skewness parameters affects the E_(sym)(q_0) versus L correlation by the same almost as significantly as the uncertainty in K_(sym).

关键词： Symmetry energy Unitary gas Equation of state Nuclear matter

Constraints on the skewness coefficient of symmetric nuclear matter within the nonlinear relativistic mean field model

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Nuclear Science and Techniques 2017年第12期28卷 279-287页

作者： bao-jun Cai Lie-Wen Chen School of Physics and Astronomy and Shanghai Key Laboratory for Particle Physics and Cosmology Shanghai Jiao Tong UniversityShanghai 200240China

Within the nonlinear relativistic mean field(NLRMF) model, we show that both the pressure of symmetric nuclear matter at supra-saturation densities and the maximum mass of neutron stars are sensitive to the skewness coefficient, J_0, of symmetric nuclear matter. Using experimental constraints on the pressure of symmetric nuclear matter at supra-saturation densities from flow data in heavy-ion collisions and the astrophysical observation of a large mass neutron star PSR J0348+0432, with the former favoring a smaller J_0 while the latter favors a larger J_0, we extract a constraint of -494 MeV≤J_0≤-10 MeV based on the NL-RMF model. This constraint is compared with the results obtained in other analyses.

关键词： Equation of state of nuclear matter Heavy-ion collisions Neutron stars

Systematic study of the synthesis of heavy and superheavy nuclei in 48Ca-induced fusion-evaporation reactions

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Nuclear Science and Techniques 2024年第7期35卷 157-172页

作者： Shi-Hao Zhu Tian-Liang Zhao Xiao-jun bao Department of Physics Collaborative Innovation Center for Quantum EffectsKey Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of EducationHunan Normal UniversityChangsha410081China School of Nuclear Science and Technology Lanzhou UniversityLanzhou730000China School of Physics Xi’an Jiaotong UniversityXi’an710049China

We systematically studied the evaporation residue cross sections of ^(48)Ca-induced reactions on lanthanide and actinide target nuclei under the Dinuclear System(DNS)model framework to check the reliability and applicability of the *** produce new proton-rich Fl and Lv isotopes through hot fusion reactions in the superheavy element region with Z≥104,we utilized the reactions ^(48)Ca+^(236,238,239) Pu and ^(48)Ca+^(242,243,244,250) ***,owing to the detection limit of available equipment(0.1 pb),only 283Fl and 287−289Lv,which have the maximum evaporation residue cross section values of 0.149,0.130,9.522,and 0.309 pb,respectively,can be ***,to produce neutron-deficient isotopes of actinides near the proton drip line with Z=93−100,we attempted to generate the new isotopes(224−227Pu,228−232,237Cm)using the reactions ^(48)Ca+180,182,183 W and ^(48)Ca+^(184,186,187,192) *** maximum evaporation residue cross section values are 0.07,0.06,0.26,and 0.30 nb for the former set of reactions,and 1.96 pb,5.73 pb,12.16 pb,19.39 pb,54.79 pb,and 6.45 nb for the latter,*** results are expected to provide new information for the future synthesis of unknown neutron-deficient isotopes.

关键词： Dinuclear system(DNS)model Evaporation residue cross section Neutron-deficient isotopes

Cachazo-Svrcek-Witten rules for tree-level gluonic amplitudes revisited

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Science China(Physics,Mechanics & Astronomy) 2022年第4期65卷 20-31页

作者： Wen-Jie Zhang jun-bao Wu Chuan-Jie Zhu Center for Joint Quantum Studies and Department of Physics School of ScienceTianjin UniversityTianjin 300350China Peng Huanwu Center for Fundamental Theory Hefei 230026China College of Mathematics and Physics Science Hunan University of Arts and ScienceChangde 415000China

We provide a new proof of Cachazo-Svrcek-Witten rules for tree-level gluonic *** a key step,we explicitly demonstrate the cancellation of spurious poles originating from the maximally helicity violating vertices in these *** achieve this,we introduce specially-defined two-off-shell-line sub-amplitudes and examine their residues at spurious poles.

关键词： general properties of perturbation theory perturbative calculations dualities in gauge field theories

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Prediction of dissolved oxygen content changes based on two-dimensional behavior features of fish school and T-S fuzzy neural network

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Water Science and Engineering 2022年第3期15卷 210-217页

作者： Yu-jun bao Chang-ying Ji Bing Zhang College of Engineering Nanjing Agricultural UniversityNanjing 210031China School of Electrical and Information Engineering Changzhou Institute of TechnologyChangzhou 213032China

Dissolved oxygen(DO)content is an important index of river water *** quality sensors have been used in China for urban river water monitoring and DO content ***,water quality sensors are expensive and difficult to maintain,and have a short operation period and difficult to *** study developed a scientific and accurate method for prediction of DO content changes using fish school *** behavioral features of the Carassius auratus fish school were described using two-dimensional fish school *** degree of DO content decline was graded into five levels,and the corresponding numerical ranges of cluster characteristic parameters were determined by considering the opinions of ***,the variation of DO content was predicted using the characteristic parameters of the fish school and the multiple-input single-output Takagi-Sugeno fuzzy neural *** prediction results were basically consistent with the actual variations of DO ***,it is feasible to use the behavioral features of the fish school to dynamically predict the level of DO content in water,and this method is especially suitable for prediction of sharp decline of DO content in a relatively short time.

关键词： Fish behavior Cluster feature DO Fuzzy neural network Water quality monitoring

Predicting buckling of carbon fiber composite cylindrical shells based on backpropagation neural network improved by sparrow search algorithm

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Journal of Iron and Steel Research International 2023年第12期30卷 2459-2470页

作者： Wei Guan Yong-mei Zhu jun-jie bao Jian Zhang School of Mechanical Engineering Jiangsu University of Science and TechnologyZhenjiang212003JiangsuChina

The buckling load of carbon fiber composite cylindrical shells(CF-CCSs)was predicted using a backpropagation neural network improved by the sparrow search algorithm(SSA-BPNN).Firstly,two CF-CCSs,each with an inner diameter of 100 mm,were manufactured and *** buckling behavior of CF-CCSs was analyzed by finite element and ***,the effects of ply angle and length–diameter ratio on buckling load of CF-CCSs were analyzed,and the dataset of the neural network was generated using the finite element *** this basis,the SSA-BPNN model for predicting buckling load of CF-CCS was *** results show that the maximum and average errors of the SSA-BPNN to the test data are 6.88%and 2.24%,*** buckling load prediction for CF-CCSs based on SSA-BPNN has satisfactory generalizability and can be used to analyze buckling loads on cylindrical shells of carbon fiber composites.

关键词： Composite cylindrical shell:Carbon fiber Backpropagation neural network Sparrow search algorithm Buckling

F+ Ion Implantation for Enhancing Surface Hydrophobicity of Medical Polymethylmethacrylate

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Chinese Physics Letters 1998年第9期15卷 662-664页

作者： LIU bao-jun LI De-jun GU Han-qing Department of Physics Tianjin Normal UniversityTianjin 300074 Department of Materials Science and Engineering Tsinghua UniversityBeijing 100084 Institute of Uretic Surgery Tianjin 300211

The surface of medical polymethylmethacrylate intraocular lens was treated by F^(+) ion implantation at 80 keV with various *** test showed that contact angle was increased from 68.5ºto 83.5ºwith increasing *** appreciable changes in optical transparency and tensile strength were observed.X-ray photoelectron spectroscopy and electron spin resonance analysis indicated that F+ion implantation broke some original O-containing groups to form some new C-F bond and radicals on the surface.

关键词： implantation strength transparency

Dynamic Mechanical Behavior and Hypervelocity Impact Performance of an Al-Based Nanocrystalline Alloy

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Acta Metallurgica Sinica(English Letters) 2017年第12期30卷 1169-1176页

作者： Shan-Shan Deng Gang Wang Run-Qing Chi bao-jun Pang Dong-jun Wang jun Shen School of Materials Science and Engineering Harbin Institute of Technology Harbin China Laboratory for Microstructures Institute of MaterialsShanghai University Shanghai China National Key Laboratory for Precision Hot Processing of Metals Harbin Institute of Technology Harbin China Key Laboratory of Micro-Systems and Microstructures Manufacturing Ministry of Education Harbin China School of Materials Science and Engineering Tongji University Shanghai China

In a wide strain rate range from 10^-5 to 10^3s^-1, the deformation behavior of an Al-based nanocrystalline alloy was investigated. After fracture, the debris collected was used for statistical analysis, which is expected to reflect the profile of the fracture behavior of the alloy. The energy absorption of alloy at different strain rates was elucidated on account of mass distribution of debris. Based on the parameters obtained by the compression experiment at different strain rates, the numerical simulation experiment was carried out to evaluate the performance of Al-based nanocrystalline alloy as spacecraft shielding. The results suggest that Al-based nanocrystalline alloys have better shield performance than alu- minum alloy under the identical areal density at velocity of 1-7 km/s. The better shield performance is attributed to high fracture strength, high hardness and low toughness of Al-based nanocrystalline alloy as compared with those of aluminum alloy.

关键词： Nanostructure material Sintering Mechanical properties Computer simulation Spacecraft shielding