Deformed tensor interactions in deuteron elastic and inelastic scattering

The various forms of tensor potentials present in deuteron elastic and inelastic scattering on a deformed target nucleus are derived using a folding model for the deuteron-nucleus interaction. Approximate expressions for the radial dependence of the deformed tensor interactions parametrized with the derivatives of Woods-Saxon potentials are obtained and discussed for the case of a rotational nucleus.     

Negative resistance and local charge-density-wave dynamics

Charge-density-wave (CDW) dynamics is studied on a submicron length scale in NbSe(3) and o-TaS(3). Regions of negative absolute resistance are observed in the CDW sliding regime at sufficiently low temperatures. The origin of the negative resistance is attributed to the different forces that the deformed CDW and quasiparticles feel: the force on the CDW is merely caused by a difference of the electric potentials, while the quasiparticle current is governed by a difference of the electrochemical potentials.     

Identity for the Exponential-Type Molecule Potentials and the Supersymmetry Shape Invariance

The identity and the supersymmetry shape invariance for a class of exponential-type molecule potentials are studied by introducing a deformed five-parameter exponential-type potential (DFPEP) and via the multi-parameter deformations. It has been shown that the DFPEP is a shape-invariant potential with a translation of parameters. By making use of the shape invariance approach, the exact energy levels are determined for the bound states with zero angular momentum. A class of molecule potentials and their exact energy spectra for the zero angular momentum states are reduced from the DFPEP and a general energy spectrum formula, respectively. The interrelations for some molecule potentials are also discussed.     

Resonant and weakly-bound one-particle levels in quadrupole-deformed potentials

Both positive-energy and weakly-bound one-particle levels for neutrons in Y₂₀ deformed Woods-Saxon potentials are examined in comparison with those in spherical Woods-Saxon potentials. While s_1/2 levels play a unique role in spherical drip-line nuclei, the Ω^π = 1/2⁺ levels in Y₂₀ deformed potentials, which always contain some amount of s_1/2 component, exhibit an important role in deformed drip-line nuclei. As the potential strength becomes weaker, some weakly-bound Ω^π = 1/2⁺ levels continue to the positive-energy region as one-particle resonant levels, while others have no such continuation. Among an infinite number of one-particle levels at a given positive-energy and in a given deformed potential, only some selected levels expressed in terms of eigenphase are found to be important in the pair-correlated ground state of neutron-drip-line nuclei.     

Quantum Deformation of the Two-Dimensional Hydrogen Atom in a Magnetic Field

The deformed Schrodinger equation for thetwo-dimensional hydrogen atom in a homogeneous magneticfield is obtained. It is found that the deformedpotential belongs to a new set of quasi-exactly solvable potentials.     

Heavy-ion inelastic scattering from deformed nuclei

Theoretical and experimental methods for studying heavy-ion inelastic scattering from deformed nuclei are described. The theoretical methods involve classical-limit approximations, while particle- γ-spectroseopy techniques are employed experimentally. With these approaches, heavy-ion excitation in the Coulomb-nuclear interference region acquires a transparent interpretation, despite the apparent complexity of the multistep excitation processes involved. The examples discussed provide a good illustration of the relationship between classical and quantum physics. The sensitivity of the inelastic scattering to details of the surface ion-ion potential due to radial and angular localization is exploited to provide a method of determining the equipotential contours in a direct manner which bypasses particular model-dependent parametrizations. The method is used to construct ion-ion potentials from inelastic scattering data for the systems ⁴⁰Ar + ¹⁶⁰Gd, ¹⁵⁶Gd, ¹⁶²Dy, ¹⁶⁴Dy, and¹⁸⁰Hf. The contribution of adiabatic giant resonance polarization to this potential is discussed. The relation between the deformed ion-ion potential and nuclear shapes is illustrated by comparing the experimental potentials to deformed double-folding and deformed proximity-potential calculations.     

Studies on the analytical potential energy function of diatomic molecular ion XY~+ using variational method

It is well-known that the accurate behavior of potential energy function of molecular ion plays an important role in the studies such as solution chemistry, atmosphere chemistry, nebular medium, plasma physics, and gun powder, etc.[1, 2]. The values of potential energy function of diatomic molecular ion could significantly influence the optical efficiency of laser pump using ion vapors as working substrate[3]. The ionic potential is very important for the studies on low-energy ion-atom collisi…     

形变重离子光学势的自洽半经典计算

利用由自洽半经典方法确定的形变核基态核子密度分布P_q(r)(q=n,p)和突然近似,计算了两碰撞核之间的光学势,分析了它的取向依赖性及产生袋结构的可能性。 关键词：     

Corrections to Schwarzschild solution in noncommutative gauge theory of gravity

A deformed Schwarzschild solution in noncommutative gauge theory of gravitation is obtained. The gauge potentials (tetrad fields) are determined up to the second order in the noncommutativity parameters Θμν${\Theta }^{\mu \nu }$. A deformed real metric is defined and its components are obtained. The noncommutativity correction to the red shift test of general relativity is calculated and it is concluded that the correction is too small to have observable effects. Implications of such a deformed Schwarzschild metric are also mentioned.     

Pockets in heavy ion potentials for the deformed systems Th + Ta,U + Th and Th + Th

Using a realistic nucleon-nucleon interaction the optical potentials for the strongly deformed systems Th + Ta, U + Th and Th + Th are calculated at E_lab/A ≅ 6 MeV and for different orientations. Pockets exist in the total real potentials (nuclear plus Coulomb potentials) at surface contact. It has been found that the deepest pockets for the U + Th and Th + Th systems exist when the two colliding nuclei are touching with orientation angle β ≅ 45° while for the Th + Ta system the deepest pocket occurs at β = 90° (equator touching).     

On the Theory of the Optical Potential for Even-Even Deformed Nuclei

Optical-model potentials are constructed for nucleon-nucleus scattering. The contribution of collective states to the imaginary part of the optical potential is investigated; the interaction between the incident nucleon and an even-even deformed target nucleus is considered in the weak coupling scheme of the Semiphenomenological Model of the Nucleus. The potentials constructed are in good agreement with the phenomenological ones. Numerical estimates are given for the target nucleus ¹⁵⁶Gd at the incident energy 16 Mev.     

Consequences of weak absorption in light heavy-ion reactions: Molecular resonances and nuclear rainbows

In the elastic angular distributions of the systems composed of tightly bound α-nuclei, ¹²C+¹²C, ¹⁶O+¹⁶O and ¹⁶O+¹²C, the higher-order Airy minima are observed in the energy region between 5 and 10 MeV per nucleon. The obtained optical potentials are deeply attractive and with incomplete absorption. The same potentials successfully describe the lower-energy (molecular resonances) and the higher-energy (first Airy minimum) data.     

变形核强阻尼碰撞中巨复合体系的形成和衰变

利用改进的量子分子动力学（ImQMD）模型研究了质心系入射能量为980 MeV时变形核238U+238U体系的3种不同碰撞模式（腹对腹、 尖对腹和尖对尖）下强阻尼反应过程中初级超重碎块的产生几率和复合体系的寿命、 形状和拉长取向等性质, 发现尖对腹碰撞模式有利于初级超重碎块的产生, 还发现这种碰撞模式产生的复合体系有最长的寿命。Three different collision modes ( Belly belly, Belly tip and Tip tip) of the deformed uranium nucleus 238U bombarding the deformed 238U in strongly damped reaction at the incident energy 980 MeV has been investigated based on the improved quantum molecular dynamics (ImQMD) model. The formation and properties of the formed composite system during the reaction process were carefully studied including the lifetime, the shape configuration and the angular distribution of primary fragment. It was found that the Belly tip mode is suitable for producing the super heavy fragments, and the composite system has the longest lifetime in this mode.     

Relation between nuclear matter and nuclear potential in inelastic alpha—nucleus scattering

Inelastic transition form factors for alpha—nucleus collective excitations are derived from deformed matter distributions by averaging an effective alpha nucleus interaction over the nucleons in the nucleus. The method is an extension of the procedure of calculating the real part of elastic alpha—nucleus potentials from nuclear matter distributions. Numerical examples for the nuclei of ⁴²Ca and ¹⁴²Nd are given. The resulting inelastic form factors depend on the multipolarity of the inelastic excitation and differ from those conventionally derived from a deformed optical potential.     

Bound state solutions of d-dimensional Schrödinger equation with Eckart potential plus modified deformed Hylleraas potential

We study the d-dimensional Schrödinger equation for Eckart plus modified deformed Hylleraas potentials using the generalized parametric form of Nikiforov-Uvarov method. We obtain energy eigenvalues and the corresponding wave function expressed in terms of Jacobi polynomial. We also discuss two special cases of this potential comprised of the Hulthen potential and the Rosen-Morse potential in three dimensions. Numerical results are also computed for the energy spectrum and the potentials.     

Cu-Au体系非对称异质外延行为的分子动力学研究

利用分子动力学模拟方法研究了Cu/Au(001)和Au/Cu(001)异质外延岛的演化行为. 研究结果显示：Cu-Au体系的相互外延行为呈现出明显的非对称性. Cu在Au(001)基体表面可以形成完整的外延结构，而Au在Cu(001)基体表面外延将导致失配位错的出现. 导致非对称外延生长行为的根本原因是外延岛的应变状态的差异和外延岛自身性质的不同. 随着外延岛的长大，Cu外延岛与Au(001)基体的微观失配度由最初的接近宏观失配度的9%左右迅速单调下降，并最终趋于晶格匹配；而Au在Cu(001)基体表面外延的微观失配度则呈现出振荡增加趋势. Cu/Au(001)体系的基体形变主要发生在外延岛的边缘，而Au/Cu(001)体系的基体形变主要发生在外延岛内部所对应的区域.     

Molecular dynamics simulation of processing using AFM pin tool

A three-dimensional molecular dynamics (MD) model is utilized to investigate the effect of tool geometry on the deformation process of the workpiece and the nature of deformation process at the atomic-scale. Results show that different states exist between the atomic force microscope (AFM) pin tool and the workpiece surface, i.e. the non-wear state, the ploughing state, the state in which ploughing is dominant and the state in which cutting plays a key role. A relationship between the deformation process of the workpiece and the potential energy variation is presented. The potential energy variation of atoms in different deformed regions in the workpiece such as plastically deformed region, elastically deformed region and the mixed deformation region is different. The features of variations of potential energy are discussed.     

Nuclear molecular resonances in α+12C and α+16O systems

The nuclear molecular resonances observed in α+¹²C and α+¹⁶O systems are described in a diatomic-like molecular picture using a Morse-type bonding potential. The depths of the bonding potentials are found to be 11.5 MeV and 11 MeV respectively, with long range of about 15 fm. Both the bound and resonance states of these potentials are calculated which compare quite well with the observed states. The diatomic-like rotational and vibrational picture of the quasi-molecular states proposed earlier for¹²C+¹²C system system is found to be quite valid for α+¹²C and α+¹⁶O systems. In these two systems, the rotational vibrational characteristics are equally well pronounced as in the¹²C+¹²C system.