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Influence of coalescence parameters on the production of protons and Helium-3 fragments

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Science China(Physics,Mechanics & Astronomy) 2016年第7期59卷 40-45页

作者： QingFeng Li YongJia wang xiaobao wang CaiWan Shen School of Science Huzhou University

The time evolution of protons and 3He fragments from Au＋Au/Pb＋Pb reactions at 0.25, 2, and 20 GeV/nucleon is investigated with the potential version of the Ultrarelativistic Quantum Molecular Dynamics （UrQMD） model combined with the traditional coalescence afterburner. In the coalescence process, the relative distance R0 and relative momentum P0 are surveyed in the range of 3-4 fm and 0.25-0.35 GeV/c, respectively. For both clusters, a strong reversed correlation between R0 and Po is seen and it is time-dependent as well. For protons, the accepted （R0, P0） bands lie in the time interval 30-60 fm/c, while for 3He, a longer time evolution （at about 60-90 fm/c） is needed. Otherwise, much smaller R0 and P0 values should be chosen. If we further look at the rapidity distributions from both central and semi-central collisions, it is found that the accepted [tout, （R0, P0）] assemble can provide consistent results for proton yield and collective flows especially at mid-rapdities, while for 3He, the consistency is destroyed at both middle and projectile-target rapidities.

关键词： coalescence afterburner UrQMD model light clusters dynamical process

Triaxiality and shape coexistence in the A ～ 30 “island of inversion”nuclei

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Science China(Physics,Mechanics & Astronomy) 2015年第11期58卷 99-106页

作者： DONG GuoXiang wang xiaobao YU ShaoYing School of Science Huzhou University

Understanding the properties of nuclei inside "island of inversion" is still an interesting issue. Based on a simple Nilsson model with a new set of isospin-dependent parameters, and with non-axial deformations considered, we have performed three-dimensional potential-energy-surface calculations for Ne, Na, Mg and Al isotopes that are claimed to be in or nearby the A～30 island of inversion". It is found that shape coexistence and triaxial deformation(or softness) exist in these nuclei. Large deformations are obtained by the improved Nilsson parameters, which explains the observed large electric quadrupole transition probabilities. The large deformations happening in30 Ne,31Na,32 Mg and33Al indicate the quenching of the spherical N = 20 neutron shell gap. The calculations of nuclear binding and two-neutron separation energies have been also improved with the isospin-dependent parameters and the inclusion of the non-axial deformation degree of freedom.

关键词： island of inversion shell evolution triaxial deformation shape coexistence

An investigation of ab initio shell-model interactions derived by no-core shell model

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Science China(Physics,Mechanics & Astronomy) 2016年第9期59卷 52-58页

作者： xiaobao wang GuoXiang Dong QingFeng Li CaiWan Shen ShaoYing Yu School of Science Huzhou University

The microscopic shell-model effective interactions are mainly based on the many-body perturbation theory （MBPT）, the first work of which can be traced to Brown and Kuo＇s first attempt in 1966, derived from the Hamada-Johnstou nucleon-nucleon potential. However, the convergence of the MBPT is still unclear. On the other hand, ab initio theories, such as Green＇s function Monte Carlo （GFMC）, no-core shell model （NCSM）, and coupled-cluster theory with single and double excitations （CCSD）, have made many progress in recent years. However, due to the increasing demanding of computing resources, these ab initio applications are usually limited to nuclei with mass up to A = 16. Recently, people have realized the ab initio construction of valence-space effective interactions, which is obtained through a second-time renormalization, or to be more exactly, projecting the full-many- body Hamiltonian into core, one-body, and two-body cluster parts. In this paper, we present the investigation of such ab initio shell-model interactions, by the recent derived sd-shell effective interactions based on effective J-matrix Inverse Scattering Potential （JISP） and chiral effective-field theory （EFT） through NCSM. In this work, we have seen the similarity between the ab initio shell- model interactions and the interactions obtained by MBPT or by empirical fitting. Without the inclusion of three-body （3-bd） force, the ab initio shell-model interactions still share similar defects with the microscopic interactions by MBPT, i.e., T = 1 channel is more attractive while T = 0 channel is more repulsive than empirical interactions. The progress to include more many-body correlations and 3-bd force is still badly needed, to see whether such efforts of ab initio shell-model interactions can reach similar precision as the interactions fitted to experimental data.

关键词： shell model effective interactions ab initio methods

基于能量密度泛函理论研究对关联对原子核裂变过程的影响

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原子核物理评论 2024年第1期41卷 127-134页

作者：宿阳李泽宇刘丽乐陈永静王小保中国原子能科学研究院核数据重点实验室中国核数据中心北京102413 湖州师范学院理学院浙江湖州313000

以^(239)Pu的中子诱发裂变为例,系统研究了对力形式的不确定性以及对关联强度的不确定性对裂变可观测量的影响,从而揭示了对关联在裂变过程所起的作用。首先使用基于Skyrme有效核力的能量密度泛函理论(DFT)计算了^(240)Pu二维形变空间... 详细信息

以^(239)Pu的中子诱发裂变为例,系统研究了对力形式的不确定性以及对关联强度的不确定性对裂变可观测量的影响,从而揭示了对关联在裂变过程所起的作用。首先使用基于Skyrme有效核力的能量密度泛函理论(DFT)计算了^(240)Pu二维形变空间中的静态裂变位能曲面,在Hartree-Fock-Bogoliubov (HFB)近似中分别使用了体积型、表面型及混合型对力,并测试了不同对力强度的影响;然后基于密度泛函的计算结果,进一步采用含时生成坐标(TDGCM)和高斯重叠近似(GOA)方法开展了^(240)Pu裂变动力学计算。通过分析讨论了对力类型和对力强度变化对裂变过程中相关物理量的影响,发现对力强度的改变在原子核小形变、大形变区域均有明显影响,然而对力类型的改变主要在大形变区域会产生明显差异。原子核的大形变组态会对裂变动力学过程产生比较重要的影响。计算结果表明,不同的对力类型得到的大形变组态会有较为显著的差别,因而合适的对力类型的选取对裂变描述是比较重要的,混合对力在裂变计算中效果最佳。

关键词：核裂变密度泛函理论对关联裂变位能曲面

Collective properties of neon isotopes investigated by projected shell model

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Chinese Science Bulletin 2014年第29期59卷 3847-3852页

作者： Guoxiang Dong xiaobao wang Furong Xu Shaoying Yu State Key Laboratory of Nuclear Physics and Technology School of PhysicsPeking University Department of Physics University of Jyvskyl40014 JyvskylFinland School of Science Huzhou Teachers College

Collective phenomenon in neon isotopes is an interesting ***,even the ground-state deformations cannot be well described by ***,QJ Zhi and ZZ Ren[Phys Lett B 638:166(2006)]have suggested an improved Nilsson potential,which can give a suitable description of ground-state properties in magnesium *** order to test the description of neon isotopes located around the‘‘island of inversion’’,we have used this potential to provide the deformed basis for the projectedshell-model *** low-lying spectra and transition properties of neon isotopes can be reproduced *** gyromagnetic factors of neon isotopes have also been *** structures of excited states along the yrast line are studied in the language of band diagrams.

关键词：氖同位素投影壳模型基态性质集体霓虹灯物理学尼尔森激发态

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多情景下喀斯特山区土地利用对碳储量的影响

环境科学与技术 2024年第8期47卷 205-216页

作者：周玉琴赵筱青冉玉菊徐逸飞普军伟叶显民汪小宝王越男瞿国寻云南大学地球科学学院云南昆明650500 云南大学国际河流与生态安全研究院云南昆明650500 西南联合研究生院云南昆明650092 云南省国土资源规划设计研究院云南昆明650500

喀斯特地区生态系统脆弱,对气候变化响应敏感,碳汇潜力巨大。其生态治理对土地利用格局的改变,使生态系统碳储量的变化显著,对陆地生态系统碳循环和区域生态安全具有深远影响。该研究以滇东南典型喀斯特地区文山壮族苗族自治州为例,运用... 详细信息

喀斯特地区生态系统脆弱,对气候变化响应敏感,碳汇潜力巨大。其生态治理对土地利用格局的改变,使生态系统碳储量的变化显著,对陆地生态系统碳循环和区域生态安全具有深远影响。该研究以滇东南典型喀斯特地区文山壮族苗族自治州为例,运用InVEST模型和混合元胞自动机(MCCA)模型,预测了自然发展、耕地保护以及生态保护3种情景下2035年碳储量的分布状况,并采用全局Moran’s I指数以及敏感性指数,分别研究碳储量的时空演变规律和土地利用变化对碳储量的影响。结果表明:(1)文山州土地利用以耕地、林地、草地为主,占研究区总面积的90%以上。地类转换集中在林地、草地、耕地以及建设用地之间。(2)研究区整体碳储量较高,但随着土地利用方式变化,造成固碳效果和潜力均出现一定程度的降低。2000-2020年,碳储量共减少了0.66 Tg。Moran’s I指数均通过90%的置信度,表明碳储量在空间上呈现出空间集聚效应。(3)2035年,在自然发展、耕地保护以及生态保护3种情景下的碳储量分别为192.40、192.00、193.13 Tg。3种情景下,碳储量分别变化了0.11、-0.29、0.84 Tg。根据敏感性指数发现碳储量对土地利用变化敏感,林地变化是造成碳储量变化的主要原因。相比可知在生态保护的情景下,区域碳汇能力较强。建议研究区科学提高林地面积和优化现有用地的空间格局,控制建设用地等措施提升碳储量。

关键词：土地利用变化碳储量 MCCA模型情景模拟滇东南喀斯特地区

Analysis of the Fungal Community in Apple Replanted Soil Around Bohai Gulf

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Horticultural Plant Journal 2018年第5期4卷 175-181页

作者： wang Gongshuai YIN Chengmiao PAN Fengbing wang xiaobao XIANG Li wang Yanfang wang Jinzheng TIAN Changping CHEN Jie MAO Zhiquan State Key Laboratory of Crop Biology/College of Horticultural Science and Engineering Shandong Agricultural University College of Chemistry and Material Science Shandong Agricultural University Shandong Instiute of Pomology Yantai Academy of Agricultural & Science Garden Office of Linyi Lanshan

Apple replant disease(ARD) is a frequently occurring plant disease in replanted orchards around Bohai Gulf, which causes growth inhibition and even death of plants. The aim of this study was to investigate the etiology of ARD around Bohai Gulf. In this study, the primary growth inhibition of apple seedlings was evaluated in ten replanted soils, sampled around Bohai Gulf. A fungal clone library was used to identify changes in the structure and composition of the soil fungal community. The results revealed that the Simpson diversity indices of Laizhou and Pulandian orchards were higher than others, presenting severe ARD. Ascomycota dominated around Bohai Gulf at the phyla level. Fusarium and Saccharomyces were abundant in all replanted soils. In addition, correlations between the relative abundance of fungal genera in soils and the severity of ARD were analyzed. The results showed that Fusarium was correlated positively with the severity of ARD, but Mortierella was negatively correlated. Furthermore, the quantitative PCR of Fusarium oxysporum, which was regarded as a factor of ARD, was performed. Overall, this study demonstrated that ARD was strongly associated with an unbalanced microbial ecosystem with more pathogenic fungi, while Fusarium in the apple replanted soil was the key factor for ARD around Bohai Gulf.

关键词： apple replanted disease Fungi clone library fusarium fungal community

Dealuminated Hβ zeolite for selective conversion of fructose to furfural and formic acid

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Green Energy & Environment 2024年第2期9卷 311-320页

作者： Rui Li Qixuan Lin Junli Ren xiaobao Yang Yingxiong wang Lingzhao Kong State Key Laboratory of Pulp and Paper Engineering School of Light Industry and EngineeringSouth China University of TechnologyGuangzhou510640China Institute of Coal Chemistry Chinese Academy of Sciences27 South Taoyuan RoadTaiyuan030001China CAS Key Laboratory of Low-Carbon Conversion Science and Engineering Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai201210China School of Environmental Science and Technology Suzhou University of Science and Technology Suzhou Jiangsu215009China

The fructose-to-furfural transformation is facing major challenges in the selectivity and high efficiency. Herein, we have developed a simple and effective approach for the selective conversion of fructose to furfural using Hβ zeolite modified by organic acids for dealuminization to regulate its textural and acidic properties. It was found that citric acid-dealuminized Hβ zeolite possessed high specific surface areas, wide channels and high Brønsted acid amount, which facilitated the selective conversion of fructose to furfural with a maximum yield of 76.2% at433 K for 1 h in the γ-butyrolactone(GBL)-H_(2)O system, as well as the concomitant formation of 83.0% formic acid. The^(13)C-isotope labelling experiments and the mechanism revealed that the selective cleavage of C1–C2 or C5–C6 bond on fructose was firstly occurred to form pentose or C5 intermediate by weak Brønsted acid, which was then dehydrated to furfural by strong Brønsted acid. Also this dealuminized Hβ catalyst showed the great recycling performance and was active for the conversion of glucose and mannose.

关键词： Fructose Dealuminated-Hb zeolite Selective conversion Furfural

Molecular Dynamics Simulations of Displacement Cascade in Ni-Based Concentrated Solid Solution Alloys

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Acta Mechanica Solida Sinica 2024年第1期37卷 82-89页

作者： Chaoquan Zhao Rongxuan Xie Chuanlong Xu xiaobao Tian Qingyuan wang Wentao Jiang Haidong Fan Department of Mechanics Sichuan UniversityChengdu 610065China

Single-phase concentrated solid solution alloys(SP-CSAs),including high-entropy alloys,have received extensive attention due to their excellent irradiation *** this work,displacement cascade simulations are conducted using the molecular dynamics method to study the evolution of defects in Ni-based *** with pure Ni,the NiCr,NiCo,and NiCu alloys exhibit a larger number of Frankel pairs(FPs)in the thermal peak stage,but a smaller number of surviving ***,the NiFe alloy displays the opposite *** explain these different observations for NiFe and other alloys,the formation energy and migration energy of interstitials/vacancies are *** the NiFe alloy,both the formation energy and migration energy barrier are *** the other hand,in NiCr and other alloys,the formation energy of interstitials/vacancies is lower,as is the migration energy barrier of *** energy analysis agrees well with previous *** present work provides new insights into the mechanism behind the irradiation resistance of binary Ni-based SP-CSAs.

关键词： Molecular dynamics simulation Displacement cascade Point defect Ni-based concentrated solid solution alloys