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1.
We investigate the alpha-decay half-lives of non-spherical nuclei with the Yukawa potential as the prox- imity potential and an angle-dependent term that accounts for the deformation effects and apply the results to Ho, Tb, Lu, Tin, Ta, Hf, Yb, Re, Ir, Pt, Au, Po, etc. as examples. The comparison with the existing data is encouraging. 相似文献
2.
The surface diffuseness of deformed and rotating nuclei has been studied using the energy density formalism. It is shown that
the surface diffuseness exhibits an anisotropy. This anisotropy in surface diffuseness can result in an anisotropic charged
particle emission from highly spinning nuclei as has been seen in some recent experiments. 相似文献
3.
Systematic study of α decay half-lives for even–even nuclei within a deformed two-potential approach
In this work, we systematically study the α decay half-lives of 196 even–even nuclei using a two-potential approach improved by considering nuclear deformation. The results show that the accuracy of this model has been improved after considering nuclear deformation. In addition, we extend this model to predict the α decay half-lives of Z = 118 and 120 isotopes by inputting the α decay energies extracted from the Weizsacker–Skyrme-type (WS-type) mass model, a simple nuclear mass formula, relativistic continuum Hartree–Bogoliubov theory and Duflo-Zuker-19 (DZ19) mass model. It is useful for identifying the new superheavy elements or isotopes for future experiments. Finally, the predicted α decay energies and half-lives of Z = 118 and 120 isotopes are analyzed, and the shell structure of superheavy nuclei is discussed. It shows that the shell effect is obvious at N = 184, while the shell effect at N = 178 depends on the nuclear mass model. 相似文献
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5.
In this work,β~+/EC decays of some medium-mass nuclei are investigated within the extended quasiparticle random-phase approximation(QRPA),where neutron-neutron,proton-proton and neutron-proton(np) pairing correlations are taken into consideration in the specialized Hartree-Fock-Bogoliubov(HFB) transformation.In addition to the pairing interaction,the Br¨uckner G-matrix obtained with the charge-dependent Bonn nucleon-nucleon force is used for the residual particle-particle and particle-hole interactions.Calculations are performed for even-even proton-rich isotopes ranging from Z =24 to Z =34.It is found that the np pairing interaction plays a significant role inβ-decay for some nuclei far from stability.Compared with other theoretical calculations,our calculations show good agreement with the available experimental data.Predictions of β-decay half-lives for some very neutron-deficient nuclei are made for reference. 相似文献
6.
The odd-proton nucleus155Tb and odd-neutron nucleus155Dy are studied along with doubly-even nucleus156Dy using microscopic method of variation after projection of angular momentum and conservation of nucleon number in each projected
state. The calculated energies of the ground band in156Dy and the ground and excited bands in155Dy and155Tb are in good agreement with the corresponding experimental data. The role played by thei
13/2 neutron pair in these nuclei is discussed. 相似文献
7.
8.
We consider a finite chain of particles in one dimension, interacting through the Lennard-Jones potential. We prove the ground state is unique, and approaches uniform spacing in the infinite-particle limit.Research supported in part by NSF grant MCS 78-01520. 相似文献
9.
This paper investigates the effect of basis sets through the potential energy curves(PECs) of six rare gas complexes He 2,Ne 2,Ar 2,He-Ne,He-Ar,and Ne-Ar.The coupled cluster singles and doubles method with perturbative treatment of triple excitations,doubly augmented basis sets of d-aug-cc-pVQZ,bond functions,and basis set superposition errors are employed.The diffuse function is more effective than the polarization function on describing the dissociation energy.The PECs are fitted into analytical potential energy functions(APEFs) using three expressions.It is found that all the expressions are suitable for describing the complexes of rare gases.Based on these APEFs,the spectroscopic parameters are calculated and the results are compared with the theoretical and experimental data available in the literature. 相似文献
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11.
Structure and analytical potential energy function for the ground state of the BCx (x=0, -1) 下载免费PDF全文
In this paper, the electronic states of the ground states and dissociation limits of BC and BC- are correctly determined based on group theory and atomic and molecular reaction statics. The equilibrium geometries, harmonic frequencies and dissociation energies of the ground state of BC and BC- are calculated by using density function theory and quadratic CI method including single and double substitutions. The analytical potential energy functions of these states have been fitted with Murrell-Sorbie potential energy function from our ab initio calculation results. The spectroscopic data (αe, ωe and ωeχe) of each state is calculated via the relation between analytical potential energy function and spectroscopic data. All the calculations are in good agreement with the experimental data. 相似文献
12.
The neutron rich nucleus 193Os was produced in the 192Os(7Li, 6Li)193Os reaction. An isomeric state based on the 9/2-[505] Nilsson orbital was identified in the present work. The half-life of the isomeric state was extracted and discussed in terms of the K quantum number. A level scheme built on the isomeric state was proposed based on the experimental data. 相似文献
13.
运用群论及原子分子反应静力学方法,推导了XY(H,Li,Na)分子基态的电子态及相应的离解极限.并采用密度泛函方法(B3LYP)和二次组态相互作用方法(QCISD)优化计算了XY(H,Li,Na)分子基态的平衡结构、振动频率和离解能.使用QCISD/6-311++G(3df,3pd)方法,对XY(H,Li,Na)分子基态进行了单点能扫描计算,采用最小二乘法拟合Murrell-Sorbie函数得到了相应的势能函数和与该基态相对应的光谱常数(Be,αe,ωe和ωeχe),计算结果与实验数据符合得相当好.
关键词:
组态相关方法
基态
势能函数 相似文献
14.
Yun-Guang Zhang 《中国物理 B》2022,31(5):53101-053101
Potential energy curves of the X$^{1}\Sigma ^{+}$ and A$^{1}\Pi $ states of the AlF molecule are studied through the combination of the multi-reference configuration interaction (MRCI) approach and Davidson corrections (MRCI$+$Q). The AWCV5Z basis set is employed in the calculations. The transition dipole moments (TDMs) of the A$^{1}\Pi \leftrightarrow {\rm X}^{1}\Sigma^{+}$ transition are explored based on the AWCV5Z basis set and (4, 2, 2, 0) active space. The Schrödinger equation is solved via the LEVEL 8.2 program, and the vibrational levels and rotational constants of the X$^{1}\Sigma^{+}$ and A$^{1}\Pi $ states are calculated. It is shown that the AlF molecule has high diagonal Franck-Condon factors ($f_{00}=0.9949$ and $f_{11}=0.9854$) and large Einstein coefficients for the transition of A$^{1}\Pi {(\nu }'=0)\leftrightarrow {\rm X}^{1}\Sigma^{+}{\rm (\nu }'=0)$. In addition, the radiative lifetimes of the vibrational levels are close to 10$^{-9}$ s for the A$^{1}\Pi $ state. The line intensities of the A$^{1}\Pi {\rm (\nu }'=4-15)\leftrightarrow {\rm X}^{1}\Sigma^{+}{\rm (\nu }'=0)$ transitions are also calculated. The calculated TDMs and transition probabilities in this work are credible and provide some guidance for the study of similar transitions, particularly for exploring interstellar space. 相似文献
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Luoxin Wang Changhai Yi Hantao Zou Jie Xu Weilin Xu 《Journal of Physical Organic Chemistry》2009,22(9):888-896
In this work, some important structures tied closely to the isomerization of 2‐(phenylazo)pyridine (2‐PAPy) and 4‐(phenylazo)pyridine (4‐PAPy) on the S0 and S1 states were characterized in detail by using the complete active space SCF (CASSCF) theory. The isomerization mechanism was discussed on the basis of the mapped potential energy surfaces (PESs) and conical intersections (CIs). A comparison of PAPy with azobenzene was carried out to stress the effect of molecular structure on the photoisomerization details. The results indicate that the thermal isomerization for both 2‐PAPy and 4‐PAPy are mainly attributed to the inversion of CNN angle on the side of the pyridine ring. In view of the energy, an optimized CIrot with a twisting structure supports the rotation mechanism in the photoisomerization of PAPy on the S1 state. However, it was found that another conical intersection (CIinv) with a planar structure is higher in energy than the corresponding trans‐FC structure, via which only the PAPy excited on S2 state or vibrationally hot S1 state can relax their excitation energy. Minimum energy paths (MEPs) showed that the relaxation process of cis‐PAPy being excited on the S1 state is characterized by a smoothly falling curve, which is very similar to that of azobenzene. Furthermore, a S1 minimum and a transition state (TS1) were found to exist on the MEP starting from the trans‐FC point to the CIrot for 4‐PAPy, but these two typical structures were not found on the MEP of 2‐PAPy. Compared with azobenzene, 4‐PAPy exhibits a very similar photoisomerization PES, but a subtly different one can be predicted in the case of 2‐PAPy. The present results are expected to provide useful information for the design of photoresponsive materials based on the PAPy units. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
17.
利用有效液滴模型计算了超铅区结团放射半衰期.在计算Gamow势垒穿透因子时采用了碎块体积不守恒以及有效惯性系数因子,并用有效的核半径常数公式代替原来的经验公式.理论计算得到的结团放射半衰期和实验值符合得很好,其半衰期对数值的均方差只有0.895.理论结果表明,有效液滴模型能充分反映N=126和Z=82的壳效应,并且在奇数结团25Ne,29Mg中出现了明显的奇偶质量摆动现象.另外,理论计算得到的结团半衰期基本符合盖革-努塔尔定律,并基于理论结果得到了一些关于盖革-努塔尔定律的有意义的结论. 相似文献
18.
E. Roeckl 《Hyperfine Interactions》2001,132(1-4):153-161
By using heavy-ion induced fusion-evaporation reactions at the on-line mass separator of GSI, decay properties of neutron-deficient
isotopes between 56Ni and 100Sn were investigated. Recent experimental results will be presented and discussed, with particular emphasis on the role of
masses, Q values and separation energies.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
19.
基于CUO分子(X3A″)的多体展式分析势能函数,用准经典的MonteCarlo轨迹法研究了U+CO(0,0)的分子反应动力学过程.结果表明:在碰撞能低时(<215kJ.mol-1),可以生成长寿命络合物CUO(X3A″),并且该络合反应是无阈能反应,这一结论与前文用多体项展式理论计算的CUO分子势能曲线结果一致.碰撞能大于4184kJ.mol-1后,逐渐出现置换产物UO和UC,随碰撞能进一步增大,分子将被完全碰散成U,C,O原子,而且反应U+CO(0,0)→UO+C,U+CO(0,0)→UC+O和U+CO(0,0)→U+O+C是有阈能反应基于CUO分子(X3A″)的多体展式分析势能函数,用准经典的MonteCarlo轨迹法研究了U+CO(0,0)的分子反应动力学过程.结果表明:在碰撞能低时(<215kJ.mol-1),可以生成长寿命络合物CUO(X3A″),并且该络合反应是无阈能反应,这一结论与前文用多体项展式理论计算的CUO分子势能曲线结果一致.碰撞能大于4184kJ.mol-1后,逐渐出现置换产物UO和UC,随碰撞能进一步增大,分子将被完全碰散成U,C,O原子,而且反应U+CO(0,0)→UO+C,U+CO(0,0)→UC+O和U+CO(0,0)→U+O+C是有阈能反应
关键词:
玻色-爱因斯坦凝聚体
V型三能级原子
双模压缩态光场
光场正交压缩 相似文献
20.
Yin-Wen Sun Ye Liu Shou-Wan Chen Quan Liu Jian-You Guo 《The European Physical Journal A - Hadrons and Nuclei》2012,48(2):18
Influences from different fields of mesons on the pseudospin symmetry are investigated for deformed nuclei. The energy splitting
between pseudospin partners are extracted from the relativistic mean field calculations. The results show that the σ-field contribution to the pseudospin energy splitting has nearly the same magnitude as the one obtained by the ω-field, but with opposite signs. The pseudospin energy splittings either for neutron or for protons are almost the same if
the σ-field (V
σ
) and the ω-field (V
ω
) change at the same scale. The pseudospin energy splitting depends in the same way as the nucleus binding energy of the cancellation
of these two potentials, and is controlled by the same nuclear physics scale as the potential sum V
ω
+ V
σ
In comparison with the σ- and ω-fields, it is seen that the ρ meson field produces a minor influence on the pseudospin symmetry. 相似文献