Effects of the symmetry energy slope on the axial oscillations of neutron stars

The impact of symmetry energy slope L on the axial w-mode oscillations is explored, where the range of the con- strained slope L of symmetry energy at saturation density is adopted from 25 MeV to 115 MeV while keeping the equation of state （EOS） of symmetric nuclear matter fixed. Based on the range of the symmetry energy slope, a constraint on the frequency and damping time of the wi-mode of the neutron star is given. It is found that there is a perfect linear relation between the frequency and the stellar mass for a fixed slope L, and the softer symmetry energy corresponds to a higher frequency. Moreover, it is confirmed that both the frequencies and damping times have a perfect universal scaling behavior for the EOSs with different symmetry energy slopes at saturation density.     

Impact of neutron star crust on gravitational waves from the axial w-modes

The imprints of the neutron star crust on the gravitational waves emitted from the axial w-modes are investigated by adopting two typical equations of state (EOSs) of the crust matter and two representative EOSs of the core matter. It is shown that there is a significant effect of the crust EOSs on the gravitational waves from the axial w-mode oscillation for a stiff core EOS.     

Neutrino energy loss by electron capture in magnetic field at the crusts of neutron stars

Based on the p-f shell model, the effect of strong magnetic field on neutrino energy loss rates by electron capture is investigated. The calculations show that the magnetic field has only a slight effect on the neutrino energy loss rates in the range of 10⁸—10¹³G on the surfaces of most neutron stars. But for some magnetars, the range of the magnetic field is 10¹³—10¹⁸G, and the neutrino energy loss rates are greatly reduced, even by more than four orders of magnitude due to the strong magnetic field.     

Neutrino energy loss by electron capture in magnetic field at the crusts of neutron stars

Based on the p-f shell model,the effect of strong magnetic field on neutrino energy loss rates by electron capture is investigated.The calculations show that the magnetic field has only a slight effect on the neutrino energy loss rates in the range of 108-1013 G on the surfaces of most neutron stars.But for some magnetars,the range of the magnetic field is 1013-1018 G,and the neutrino energy loss rates are greatly reduced,even by more than four orders of magnitude due to the strong magnetic field.     

Constraints on the symmetry energy from observational probes of the neutron star crust

A number of observed phenomena associated with individual neutron star systems or neutron star populations find explanations in models in which the neutron star crust plays an important role. We review recent work examining the sensitivity to the slope of the symmetry energy L of such models, and constraints extracted on L from confronting them with observations. We focus on six sets of observations and proposed explanations: i) The cooling rate of the neutron star in Cassiopeia A, confronting cooling models which include enhanced cooling in the nuclear pasta regions of the inner crust; ii) the upper limit of the observed periods of young X-ray pulsars, confronting models of magnetic field decay in the crust caused by the high resistivity of the nuclear pasta layer; iii) glitches from the Vela pulsar, confronting the paradigm that they arise due to a sudden recoupling of the crustal neutron superfluid to the crustal lattice after a period during which they were decoupled due to vortex pinning; iv) the frequencies of quasi-periodic oscillations in the X-ray tail of light curves from giant flares from soft gamma-ray repeaters, confronting models of torsional crust oscillations; v) the upper limit on the frequency to which millisecond pulsars can be spun-up due to accretion from a binary companion, confronting models of the r-mode instability arising above a threshold frequency determined in part by the viscous dissipation timescale at the crust-core boundary; and vi) the observations of precursor electromagnetic flares a few seconds before short gamma-ray bursts, confronting a model of crust shattering caused by resonant excitation of a crustal oscillation mode by the tidal gravitational field of a companion neutron star just before merger.     

Cross-section measurements for (n, 2n) reactions on stannum isotopes in the neutron energy range of 13.5 to 14.6 MeV

Cross-sections for (n, 2n) reactions have been measured on stannum isotopes at the neutron energies of 13.5 to 14.6 MeV using the activation technique. Data are reported for the following reactions:112Sn(n, 2n)111Sn, 118Sn(n, 2n)117Sn and 124Sn(n, 2n)123mSn. The neutron fluences were determined using the monitor reaction 93Nb(n, 2n)92mNb or 27Al(n, α)24Na. The results of present work were compared with data published previously.     

13.5－14.6MeV中子能区锡的同位素的(n,2n)反应截面的测量

报道了在13.5－14.6MeV中子能区用活化法测得的112Sn(n,2n)111Sn,118Sn(n,2n)117Sn 和 124Sn(n,2n)123mSn的反应截面值. 中子注量用93Nb(n, 2n)92mNb或27Al(n,α)24Na反应截面得到.单能中子由T(d, n)4He反应获得. 同时还列举了已收集到的文献值以作比较.     

重离子碰撞中同位旋分馏对碰撞系统同位旋的依赖性

利用同位旋相关的量子分子动力学模型，研究了中能重离子碰撞过程中同位旋分馏现象及其对于碰撞系统同位旋的依赖性.计算结果表明:在碰撞系统膨胀的低密度区, 气相(发射核子)与液相(碎片)的中子-质子比出现不均等分配现象,即同位旋分馏. 同位旋分馏的强弱明显地依赖于碰撞系统的中子-质子比,其强度随着系统中子-质子比的增大而增大. 丰中子碰撞系统产生丰中子的气相和缺中子的液相,而缺中子碰撞系统产生缺中子的气相和丰中子的液相.在丰中子的碰撞系统中同位旋分馏强度敏感地依赖于对称势,而对于两体碰撞的同位旋效应并不敏感，但对于缺中子的碰撞系统,同位旋分馏强度对于对称势不敏感， 同时发现动量相关作用对于同位旋分馏过程的作用不明显. 关键词： 中能重离子碰撞 同位旋分馏 同位旋效应 对称势     

Electric and magnetic field effects on the binding energy of a hydrogenic impurity in quantum well wires with different shapes

In this work, we directly calculate the ground state energies for an electron in quantum well wires (QWWs) with different shapes in the presence of applied electric and magnetic fields using the finite difference method. Then, we study the ground state binding energy of a hydrogenic impurity with a variational approach. We obtain the binding energy for QWWs consisting of the combinations of square and parabolic well potential. Our results indicate that the impurity binding energy depends strongly on the structural confinement and also, on the applied electric and magnetic field.