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Synthesis of superheavy nuclei with ^(238)U target

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Science china(Physics,Mechanics & Astronomy) 2009年第10期52卷 1482-1488页

作者： liu zuhua1,3 & bao jingdong2,4 1 key laboratory of beam technology and material modification of ministry of education,beijing normal university,beijing 100875,china 2 Department of Physics,beijing normal university,beijing 100875,china 3 china Institute of Atomic Energy,beijing 102413,china 4 Center of Theoretical Nuclear Physics,National laboratory of Heavy Ion Accelerator of Lanzhou,Lanzhou 730000,china key {1. of beam technology and material modification of ministry of education Beijing Normal University Beijing 100875 China Department of Physics Beijing Normal University Beijing 100875 China china Institute of Atomic Energy Beijing 102413 China Center of Theoretical Nuclear Physics National Laboratory of Heavy Ion Accelerator of Lanzhou Lanzhou 730000 China

The production of superheavy nuclei with Z=1.8-1.6 via hot fusion reactions of the neutron-rich projectiles with 238U target is systematically *** results show that the production cross sections of superheavy nuclei do not decrease monotonously as the atomic number Z *** cross sections of the superheavy nuclei at Z = 1.2 and 1.5 are enhanced as compared with the whole Z-trend in synthesis of the superheavy nuclei,which clearly illustrates that the reactions with large negative Q-value and shell correction are more favorable to synthesize superheavy nuclei.

关键词： superheavy nuclei fusion reaction cross section 238U target

First-principles calculations on implanted TiO_2 by 3d transition metal ions

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Science china(Physics,Mechanics & Astronomy) 2009年第6期52卷 838-842页

作者： HOU XingGang1,2, HUANG MeiDong1, WU XiaoLing2 & liu AnDong2 1 Department of Physics, Tianjin normal university, Tianjin 300387, china 2 key laboratory of beam technology and material modification of ministry of education, beijing normal university, beijing 100875, china Department of Physics Tianjin Normal University Tianjin 300387 China key {1. of beam technology and material modification of ministry of education Beijing Normal University Beijing 100875 China

3d transition metal (V, Cr and Fe) ions are implanted into TiO2 by the method of metal ion implantation. The electronic band structures of TiO2 films doped 3d transition metal ions have been analyzed by ab initio band calculations based on a self-consistent full-potential linearized augmented plane-wave method within the first-principle formalism. Influence of implantation on TiO2 films is examined by the method of UV-visible spectrometry. The results of experiment and calculation show that the optical band gap of TiO2 films is narrowed by ion implantation. The calculation shows that the 3d state of V, Cr and Fe ions plays a significant role in red shift of UV-Vis absorbance spectrum.

关键词： 3d transition metal ions implantation TiO2 FP-LAPW electronic structure

Exotic structure of the third excited state in^(21.Na

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Chinese Science Bulletin 2005年第23期50卷 2677-2680页

作者： LI Xihan1,2,3, LIANG Yujie1,2,3, DENG Fuguo1,2,3, liu zuhua1,4 & ZHOU Hongyu1,2,3 1. key laboratory of beam technology and material modification of Minister of education, beijing normal university, beijing 100875, china 2. Institute of Low Energy Nuclear Physics, and Department of material Science and Engineering, beijing normal university, beijing 100875, china 3. beijing Radiation Center, beijing 100875, china 4. china Institute of Atomic Energy, beijing 102413, china key {1. of beam technology and material modification of Minister of education Beijing Normal University Beijing 100875 China Institute of Low Energy Nuclear Physics and Department of Material Science and Engineering Beijing Normal University Beijing 100875 China beijing Radiation Center Beijing 100875 China china Institute of Atomic Energy Beijing 102413 China

The probability of the last proton being out of the binding potential, P and the root-mean-square (rms) ra- dius (1.2= of the third excited state in 21.a are calcu- lated by means of asymptotic normalization coefficient (ANC) method with the experimental date existing. The results are P=54.73% and 1.2=5.28 fm respectively. The P value and the contribution of the asymptotic part to the 1.2 are compared with those of several other low energy states in 21.a. It is found that the valence particle in the third excited state has an obvious larger P than those of other states. The density distribution of the valence proton in this state is also compared with the nucleons in the nuclear core 20Ne, and a far extended tail can be seen clearly. These results show that the third ex- cited state in 21.a is a proton halo state.

关键词：钠第三激发态外部结构有效半径密度分布渐近标准化系数

Shell effect and capture cross sections in the synthesis of superheavy nuclei

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Science china(Physics,Mechanics & Astronomy) 2009年第10期52卷 1489-1493页

作者： DU SaiSai1,2,BIAN baoAn1,2,3,liu Min1,2,4,FENG ZhaoQing5,6 & ZHANG FengShou1,2,6 1 key laboratory of beam technology and material modification of ministry of education,College of Nuclear Science and technology,beijing normal university,beijing 100875,china 2 beijing Radiation Center,beijing 100875,china 3 School of Science,Jiangnan university,Wuxi 214122,china 4 College of Physics and technology,Guangxi normal university,Guilin 541004,china 5 Institute of Modern Physics,Chinese Academy of Sciences,Lanzhou 730000,china 6 Center of Theoretical Nuclear Physics,National laboratory of Heavy Ion Accelerator of Lanzhou,Lanzhou 730000,china key {1. of beam technology and material modification of ministry of education College of Nuclear Science and Technology Beijing Normal University Beijing 100875 China beijing Radiation Center Beijing 100875 China School of Science Jiangnan University Wuxi 214122 China College of Physics and technology Guangxi Normal University Guilin 541004 China Institute of Modern Physics Chinese Academy of Sciences Lanzhou 730000 China Center of Theoretical Nuclear Physics National Laboratory of Heavy Ion Accelerator of Lanzhou Lanzhou 730000 China

The shell effect is included in the improved isospin dependent quantum molecular dynamics model in which the shell correction energy of the system is calculated by using the deformed two-center shell model. A switch function is introduced to connect the shell correction energy of the projectile and the target with that of the compound nucleus during the dynamical fusion process. It is found that the calculated capture cross sections reproduce the experimental data quantitatively at the energy near the Coulomb barrier. The capture cross sections for reaction 35 80 Br + 82 208 Pb → 1.7 288 X are also calculated and discussed.

关键词： superheavy nuclei transport theory shell effect cross sections

Direct measurement of the break-out ^(1.)F(p,γ)^(20)Ne reaction in the china Jinping underground {1.(CJPL)

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Nuclear Science and Techniques 2024年第8期35卷 142-152页

作者： Yin‑Ji Chen Hao Zhang Li‑Yong Zhang Jian‑Jun He Richard James deBoer Michael Wiescher Alexander Heger David Kahl Jun Su Daniel Odell Xin‑Yue Li Jian‑Guo Wang Long Zhang Fu‑Qiang Cao Zhi‑Cheng Zhang Xin‑Zhi Jiang Luo‑Huan Wang Zi‑Ming Li Lu‑Yang Song Liang‑Ting Sun Qi Wu Jia‑Qing Li bao‑Qun Cui Li‑Hua Chen Rui‑Gang Ma Er‑Tao Li Gang Lian Yao‑De Sheng Zhi‑Hong Li Bing Guo Wei‑Ping {1. key {1. of beam technology of the ministry of education College of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China Department of Physics and Astronomy The Joint Institute for Nuclear AstrophysicsUniversity of Notre DameNotre DameIN 46556USA School of Physics and Astronomy Monash UniversityClaytonVIC 3800Australia Facility for Rare Isotope beams Michigan State UniversityEast LansingMI 48824USA Institute of Nuclear and Particle Physics and Department of Physics and Astronomy Ohio UniversityAthensOH 45701USA Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China china Institute of Atomic Energy Beijing 102413China College of Physics and Optoelectronic Engineering Shenzhen UniversityShenzhen 518060China School of Nuclear Science and technology University of Chinese Academy of SciencesBeijing 100049China College of Science Southern University of Science and TechnologyShenzhen 518055China Institute of Radiation technology Beijing Academy of Science and TechnologyBeijing 100875China key {1. of Nuclear Physics and Ion‑beam Application(MOE) Institute of Modern PhysicsFudan UniversityShanghai 200433China School of Mathematics and Physics Handan UniversityHandan 056005China

Calcium production and the stellar evolution of first-generation stars remain fascinating mysteries in *** one possible nucleosynthesis scenario,break-out from the hot carbon–nitrogen–oxygen(HCNO)cycle was thought to be the source of the calcium observed in these oldest ***,according to the stellar modeling,a nearly tenfold increase in the thermonuclear rate ratio of the break-out ^(1.)F(p,γ)^(20) Ne reaction with respect to the competing ^(1.)F(p,α)^(1.) O back-processing reaction is required to reproduce the observed calcium *** performed a direct measurement of this break-out reaction at the china Jinping underground *** measurement was performed down to the low-energy limit of E_(c.m.)=1.6 keV in the center-of-mass *** {1. resonance was observed at 225.2 keV for the first *** a temperature of approximately 0.1.GK,this new resonance enhanced the thermonuclear ^(1.)F(p,γ)^(20) Ne rate by up to a factor of≈7.4,compared with the previously recommended NACRE *** is of particular interest to the study of the evolution of the first stars and implies a stronger breakdown in their“warm”CNO cycle through the ^(1.)F(p,γ)^(20) Ne reaction than previously *** break-out resulted in the production of the calcium observed in the oldest stars,enhancing our understanding of the evolution of the first stars.

关键词： Nuclear astrophysics First stars Abundance of calcium Reaction cross section Reaction rate china Jinping underground {1.(CJPL) JUNA

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真空烧结泡沫304不锈钢吸声性能

中国有色金属学报 2017年第12期27卷 2560-2566页

作者：刘培生徐新邦孙进兴崔光北京师范大学核科学与技术学院射线束技术教育部重点实验室北京100875 北京市辐射中心北京100875

利用挂浆工艺,在1.50℃下真空烧结3 h,成功制备三维网状的泡沫304不锈钢,制品烧结良好。样品平均孔径约1.8 mm,孔隙率约93.7%。测试该泡沫金属在200~6300 Hz及其加入背腔后在2500~4000 Hz时的吸声系数,探讨背腔对样品吸声性能的影响。... 详细信息

利用挂浆工艺,在1.50℃下真空烧结3 h,成功制备三维网状的泡沫304不锈钢,制品烧结良好。样品平均孔径约1.8 mm,孔隙率约93.7%。测试该泡沫金属在200~6300 Hz及其加入背腔后在2500~4000 Hz时的吸声系数,探讨背腔对样品吸声性能的影响。结果表明:本制品在测试范围的中高频段表现出较好的吸声效果,其第一共振频率为4000 Hz,此时最大吸声系数约0.7;在1.50~31.0 Hz之间,增加样品厚度可明显提高吸声效果;加入背腔可大幅度提高样品的整体吸声效果。

关键词：多孔材料泡沫金属泡沫不锈钢吸声性能

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 {1.-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

Quantum Dissipative Threshold and Its Effect on Decay of Metastable State

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Communications in Theoretical Physics 2005年第4X期44卷 697-700页

作者： bao Jing-Dong The key {1. of beam technology and material modification of ministry of education Beijing Normal UniversityBeijing 100875 ChinaThe Key Laboratory of Beam Technology and Material Modification of Ministry of Education Beijing Normal UniversityBeijing 100875 China Department of Physics Beijing Normal University Beijing 100875 China

The coupling between system and reservoir is considered to be linear in the coordinates of the bath but nonlinear in the system's coordinate. A dissipative threshold is observed at finite temperatures due to nonlinear dissipation. The quantum decay rate of a metastable state including higher-order expanded terms of the coupling form function is proposed, which can be strongly decreased at finite temperatures when the quantum dissipative threshold is added to the saddle point of the potential.

关键词： threshold decay rate nonlinear dissipation quantum correction factor

Direct imaging and determination of the crystal structure of six-layered graphdiyne

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Nano Research 2018年第3期11卷 1714-1721页

作者： Chao Li Xiuli Lu Yingying Han Shangfeng Tang Yi Ding Ruirui liu Haihong {1. Yuliang Li Jun Luo Tongbu Lu Center for Electron Microscopy TUT-FEI Joint Laboratory Tianjin Key Laboratory of Advanced Porous Functional Materials Institute for New Energy Materials & Low-Carbon Technologies School of Materials Science and Engineering Tianjin University of Technology Tianjin 300384 China key {1. of Organic Solids Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China

Since its discovery, the direct imaging and determination of the crystal structure of few-layer graphdiyne has proven difficult because it is too delicate under irradiation by an electron beam. In this work, the crystal structure of a six-layered graphdiyne nanosheet was directly observed by low-voltage transmission electron microscopy （TEM） using low current density. The combined use of high-resolution TEM （HRTEM） simulation, electron energy-loss spectroscopy, and electron diffraction revealed that the as-synthesized nanosheet was crystalline graphdiyne with a thickness of 2.1. nm （corresponding to a thickness of six layers） and showed ABC stacking. Thus, this work provides direct evidence for the existence and crystal structure of few-layer graphdiyne, which is a new type of two-dimensional carbon {1. complementary to graphene.

关键词： few-layer graphdiyne crystal structure low-voltage transmissionelectron microscopy