排序方式: 共有52条查询结果,搜索用时 31 毫秒
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庞丹阳 叶沿林 江栋兴 郑涛 王全进 李智焕 李湘庆 陈志强 胡青元 张高龙 王佳 A.Ozawa Y.Yamaguchi C.Wu R.Kanungo D.Fang I.Tanihata 《原子核物理评论》2005,22(1):6-10
分析了北京大学核物理实验小组在日本RIKEN实验室完成的25 MeV/u 6He和9Be的弹性散射实验数据,得到了弹性散射微分截面角分布. 利用双折叠模型,并通过拟合弹性散射微分截面得到了此弹靶体系在此能量下的弹性散射光学势. We analyzed the 6He elastic scattering from 9Be target at 25 MeV/u. A Center of Beam (CB) method was used to calibrate the particle tracking detectors and set the reference system of the detection system. The double folding model approach was used to calculate the real part of the optical model potential. The preliminary optical model potential parameters were extracted by fitting the experimental differential elastic scattering cross sections. 相似文献
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在回顾和总结强脉冲电子束表面改性实验的基础上, 利用有限元数值计算方法对强脉冲电子束辐照铝和304不锈钢产生的温度场进行模拟, 给出了靶的近表面区域流体状态存在的特征尺度和特征时间, 并对不同材料特性下熔坑的产生原因进行了讨论. 采用两相流模型, 通过水平集方法和有限元方法结合的计算流体力学模拟了熔坑和表面突起形貌在表面处于熔融状态下的运动特征, 通过和实验数据相对比, 验证了对于高黏度, 高表面张力的高熔点金属, 表面处于流体状态下的张力驱动效应是熔坑等表面形貌演化的重要原因. 相似文献
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重核大集团(14C-34Si)发射的半衰期在理论上用Wentzel-Kramers-Brillouin近似进行了计算.利用双折叠模型计算大集团和剩余子核间的核相互作用,在折叠积分中选取了密度依赖的、零力程交换项的核子-核子相互作用.计算得到的半衰期和液滴模型结果、系统公式的结果以及实验数据进行了比较,表明目前的计算能够很好地给出重核大集团(14C-34Si)发射的寿命.这可为重核其他大集团(15N, 46Ar,48Ca等)的发射提供可靠的预测.
关键词:
半衰期
双折叠模型
集团发射 相似文献
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Nucleus--nucleus potentials are determined in the framework of
double folding model for M3Y--Reid and M3Y--Paris effective
nucleon--nucleon (NN) interactions. Both zero-range and
finite-range exchange parts of NN interactions are considered in
the folding procedure. In this paper the spherical
projectile--spherical target system 16O+208Pb is selected
for calculating the barrier energies, fusion cross sections and
barrier distributions with the density-independent and
density-dependent NN interactions on the basis of M3Y--Reid and
M3Y--Paris NN interactions. The barrier energies become lower for
Paris NN interactions in comparison with Reid NN interactions,
and also for finite-range exchange part in comparison with
zero-range exchange part. The density-dependent NN interactions
give similar fusion cross sections and barrier distributions, and
the density-independent NN interaction causes the barrier
distribution moving to a higher position. However, the
density-independent Reid NN interaction with zero-range exchange
part gives the lowest fusion cross sections. We find that the
calculated fusion cross
sections and the barrier
distributions are in agreement with the experimental data after
renormalization of the nuclear potential due to coupled-channel
effect. 相似文献
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For the research of CCD neutron radiography,a neutron collimator was designed based on the exit of thermal neutron of the Boron Neutron Capture Therapy(BNCT)reactor.Based on the Geant4 simulations,the preliminary choice of the size of the collimator was determined.The materials were selected according to the literature data.Then,a collimator was constructed and tested on site.The results of experiment and simulation show that the thermal neutron flux at the end of the neutron collimator is greater than 1.0×106n/cm2/s,the maximum collimation ratio(L/D)is 58,the Cd-ratio(Mn)is 160 and the diameter of collimator end is 10 cm.This neutron collimator is considered to be applicable for neutron radiography. 相似文献