Quasielastic Scattering of the Halo Nucleus ^6He at 25 MeV／u from a ^9Be Target

The differential cross sections of quasielastic scattering of a 25 MeV/u ^6He from ^9Be target have been measured.The double-folding model approach is applied to generate the real part of the optical potential. The imaginary potential parameters as well as some of the real potential parameters are studied in comparison with the experimental data. The effect of the unstable nucleus is discussed.     

Optical Potential Parameters for Halo Nucleus System ^6He＋^12C from Transfer Reaction ^11B（^7Li, ^6He）^12C

The optical potential parameters for the halo nucleus system ^6He＋^12C are extracted from fits to the measured angular distributions of ^11B（^7Li, ^6He）12C reaction at energies of 18.3 and 28.3MeV with distorted-wave Born approximation analysis. The characters of the obtained optical potentiM parameters are basically consistent with the results extracted from the fits to the elastic-scattering angular distributions in the literature.     

An Approach to Extract the Spin Transfer to ∧in Polarized Proton--Proton Collision

We introduce an approach to extract the spin transfer to A in polarized proton-proton collision, based on the relation between single spin asymmetry and the polarization of A production. With 4 × 10^6 ∧ events simulated for a PHENIX detector system, DLL = 0.1598 ± 0.0343 is retrieved by the approach and it agrees very well with the input value of 0.1429. The approach is further tested and confirmed with ‘bunch shuffling＇ method for the simulated events as well as experimental events collected at PHENIX in 2003. It is concluded that one can correctly extract the spin transfer without detailed understanding of acceptance correction even if the correction is significantly large in PHENIX experiment by using the approach described here. The method can be generally used for spin transfer study.     

Near-Field Optical Transfer Function for Far-Field Super-Resolution Imaging

The far-field superlens based on surface plasmon polaritons （SPP） has shown great application potential, but it is difficult and time-consuming to reconstruct the far-field image. We derive a near-field optical transfer function （NOTF） of a silver slab and analyse its validity so that accurate information of nano-seale object in the near-field can be computed rapidly. The NOTF is helpful not only for analysing the super-resolution imaging process in far-field, but also for providing a track to describe the transmission of optical information from near-field to far-field by using the optical transfer functions theorv only.     

Analytical Potential Energy Function for Doubly Charged Ions O2+2, Be2+2 and He2+2

A new analytical potential function is proposed in our preceding paper as which can be used to describe the potential curves for doubly charged diatomic ions with both potential minimum and maximum where ρ=R-Rmin, if R=Rmin, ρ=0, if R=Rmax, ρ=Rmax-Rmin. The parameters a1～a4 are obtained by a least-squares fit based on the ab initio calculations, the values of parameters Rmin and Rmax are fixed from the same calculations. The application of this function is quite flexibly, for it can be also used to describe the potential curves without any potential minimum and maximum, i.e., no stationary point, where ρ=R. The present paper is to examine the proposed potential function form further by describing potential curves of O2+2, Be2+2 and He2+2. The calculations using the theoretical method CID with basis set 6-311++G* have showed the Rmin() and Rmax() to be 1.045 and 1.60, 2.141 and 3.50, and 0.736 and 1.05 for the ground state X1Σ+g of O2+2, Be2+2 and He2+2, respectively, which are in good agreement with reference data. The analytical potential function for the ground state of these doubly charged diatomic ions have been successfully derived for the first time     

Optical Potential Parameters of Weakly Bound Nuclear System 17F+13C

Elastic scattering angular distributions of the 14^N＋16^O system and the angular distributions of transfer reaction 16^O（14^N,13^C）17^F at ELab=76.2 MeV and 57 MeV have been measured and calculated by means of the exact finiterange distorted-wave Born approximation with the PTOLEMY code. The optical potential parameters for the weakly bound nuclear system 17^F＋13^C have been deduced and applied to analyse the elastic scattering angular distributions of the similar systems 17^F＋12^C and 17^F＋14^N which are taken from literature. The result shows that the transfer reaction with stable projectile and target combination can be used as an alternative method to extract the optical potential parameters for the weakly bound nuclear system.     

Unusual Threshold Anomaly in the ^6Li＋^208Pb System

The angular distributions of elastic scattering for the ^6Li ＋^208Pb system have been measured at several energies around the Coulomb barrier. The parameters of optical potential are extracted by means of a phenomenological optical model analysis. It is found that the real and imaginal potentials show a pronounced energy dependence. The behaviour of the potential at the nearly especially sub-barrier energies in the ^6Li＋^208Pb system is quite different from the results of some previous reports observed in other systems, such as ^19F＋^208Pb and ^16O＋^208Pb. This unusual threshold phenomenon indicates that breakup channel is strongly coupled with the elastic channel and has obvious effects on optical potential.     

The Formation Mechanism and Binding Energy for the Octahedral Central Structure of the He7^＋ Cluster

The formation mechanism for the octahedral central structure of the He7^ cluster is proposed and its total energy curve is calculated by the method of a modified arrangement channel quantum mechanics (MACQM). The energy is a function of separation R between two nuclei at the center and an apex of the octahedral central structure. The result of the calculation shows that the curve has a minimM energy -19.7296 a.u. at R = 2.40α0. The binding energy of He7^ with respect to He^ 6He was calculated to be 0.6437 a.u. This means that the duster of He7^ may be formed in the stable octahedral central structure with R=2.40 α0.     

An efficient Jacobian scaling method for time-domain optical mammography

<正>Time-domain diffuse optical tomography can efficiently reconstruct optical parameters which can be further applied in diagnosing early breast cancer.Nevertheless,the performances of reconstructed imaging are badly influenced by different Jacobian magnitudes of absorption coefficient and reduced scattering coefficient.With the introudction of a relative data type based on generalized pulse spectrum technique, an efficient Jacobian scaling method is proposed.The interrelated simulated validation is also revealed for the enhancing performances.     

Energy eigenvalues from an analytical transfer matrix method

A detailed procedure based on an analytical transfer matrix method is presented to solve bound-state problems. The derivation is strict and complete. The energy eigenvalues for an arbitrary one-dimensional potential can be obtained by the method. The anharmonic oscillator potential and the rational potential are two important examples. Checked by numerical techniques, the results for the two potentials by the present method are proven to be exact and reliable.     

Nucleonic ~1S_0 Superfluidity Induced by a Soft Pion in Neutron Star Matter with Antikaon Condensations

The nucleonic ~1S_0 superfluidity is investigated by solving the gap equation for the Reid soft-core potential as the nucleon-nucleon interaction in neutron star(NS) matter which is considered to be made up of p, e, μ and condensed antikaon matter. We mainly study the influence of the soft pion-induced potential on the nucleonic~1S_0 pairing gaps in the above NS matter. It is found that the intensities of the nucleonic ~1S_0 pairing gaps including the soft pion-induced potential are smaller than those calculated in the case of not including the soft pion-induced potential. Furthermore, the nucleonic ~1S_0 pairing gaps with the soft pion-induced potential fall into decline with the deepening of the optical potential of antikaons in the above NS matter, whereas they increase with the parameter η for the fixed optical potential of antikaons. Due to the appearance of the soft pion-induced potential, the maximum values of nucleonic ~1S_0 pairing gaps at parameter η = 0.20,0.55 are suppressed by1.7%-6.8% with respect to the case without soft pion-induced potential in the above NS matter.     

Lattice plasmon mode excitation via near-field coupling

The optical response of metal nanoparticles can be modified through near-field or far-field interaction,yet the lattice plasmon modes(LPMs)considered can only be excited from the latter.Here instead,we present a theoretical evaluation for LPM excitation via the near-field coupling process.The sample is an arrayed structure with specific units composed of upper metal disks,a lower metal hole and a sandwiched dielectric post.The excitation process and underlying mechanism of the LPM and the influence of the structure parameters on the optical properties have been investigated in detail by using a finite-difference time-domain(FDTD)numerical method.Our investigation presented here should advance the understanding of near-field interaction of plasmon modes for LPM excitation,and LPMs could find some potential applications,such as in near-field optical microscopes,biosensors,optical filters and plasmonic lasers.     

Influence of D-state in 4He on S Factor for the 2H（d, γ）^4He Reaction

We employ a direct capture method to study the influence of D-state in ^4He on S factor for the ^2H（d,γ）^4He reaction, in which the D-state component of the colliding deuterons and D-state component in ^4He ground state are considered. The parameters of Woods-Saxon （WS） potentials are obtained by reproducing the binding energy of d-d （i.e. ^2H-^2H） system, and d-d elastic scattering phase shifts calculated by the resonating group method. The theoretical results are in good agreement with the experimental data at Ec.m〈 3 MeV. The impact of the D state probability in ^4He on the extrapolated value of the astrophysical S factor for ^2H（d, γ）^4He reaction is discussed.     

A feedback-controlled Brownian ratchet operated by a temperature switch

In this paper, we present a model of the Brownian motor in a feedback controlled ratchet, in which the application of the flashing potential depends on the state of the particle to be controlled. We derive an analytical expression for the velocity induced by the feedback ratchet, which is a function of several parameters, including the ratio of the two switching temperatures and the asymmetry parameter of the potential field. The motor shows a current inversion when either parameter is varied.     

A numerical Hartree self-consistent field calculation of an autoionization resonance parameters for a doubly excited 2s~2, 3s~2, and 4s~2 states of He atom with a complex absorbing potential

The self-consistent Hartree-Fock equation for the He atom is solved using the pseudospectral method. The Feshbachtype autoionization resonance parameters for doubly excited 2s~2, 3s~2, and 4s~2 ~1S states of He have been determined by adding a complex absorbing potential to the Hamiltonian. The Riss–Meyer iterative and Pad′e extrapolation methods are applied to obtain reliable values for the autoionization resonance parameters, which are compared to previous results in the literature.     

The Hugoniot equation of state of the fluid He+D2 mixtures

The fluid variational theory and effective one-component model have been used to calculate the Hugoniot equation of state (EOS) of fluid He, D2, and He+D2 mixtures with different He:D2 compositions under high pressures and temperatures. An examination of the confidence of above computation is performed by comparing experiment and calculation, in which the similar calculation procedure used for He+D2 is adopted, of He and D2 each, since no experimental data are available to conduct this kind of comparison. Good agreement in both comparisons is found. This fact may be looked as if an indirect positive verification of calculation procedure used here at least in the pressure and temperature domain covered by the experimental data of He and D2 used for comparison, numerically nearly up to 35 GPa and 105K.     

Size transition of spiral waves using the pulse array method

The domain size of spiral waves is an important issue in studies of two-dimensional (2D) spatiotemporal patterns. In this work, we use the 2D complex Ginzburg--Landau equation (CGLE) as our model and find that an initially big spiral can successfully transfer to several small spirals by applying a pulse array method. The impacts of several important factors, such as array density, controlling intensity and pulsing time, are investigated. This control approach may be useful for the control of 2D spatiotemporal patterns and has potential applications in the control of some realistic systems, such as meteorological and cardiac systems.     

Theoretical study of the trapping efficiency of an optical tweezers array system

Optical tweezers have been a valuable research tool since their invention in the 1980s. One of the most important developments in optical tweezers in recent years is the creation of two-dimensional arrays of optical traps. In this paper, a method based on interference is discussed to form gradient laser fields, which may cause the spatial modulation of particle concentration. The parameters related to the optical tweezers array are discussed in detail and simulated by the Matlab software to show the influence of important parameters on the distribution of particle concentration. The spatial redistribution of particles in a laser interference field can also be predicted according to the theoretical analysis.     

Microscopic study of ~7Li-nucleus potential

A microscopic approach is employed to study the optical potential for the 7Li-nucleus interaction system without any free parameters.It is obtained by folding the microscopic optical potentials of the constituent nucleons of 7Li over their density distributions.We employ an isospin-dependent nucleon microscopic optical potential,which is based on the Skyrme nucleon-nucleon effective interaction and derived using the Green's function method,as the nucleon optical potential.The harmonic oscillator shell model is used to describe the internal wave function of 7Li and obtain the nucleon density distribution.The 7Li microscopic optical potential is used to predict the reaction cross-sections and elastic scattering angular distributions for the target range from 27Al to 208Pb and energy range below 450 MeV.Generally,the results can reproduce the measured data reasonably well.In addition,the microscopic optical potential is comparable to a global phenomenological optical potential by fitting the presently existing measured data.