Rotational Deformation of Neutron Stars

The rotational deformations of two kinds of neutron stars are calculated by using Hartle‘s slow-rotation formulism. The results show that only the faster rotating neutron star gives an obvious deformation. For the slow rotating neutron star with a period larger than hundreds of millisecond, the rotating deformation is very weak.     

An Impact Model of the Imbrium Basin for Distribution of Thorium on Lunar Surface

We consider the thorium distributions that are coincident with the distribution of ejecta after the Mare Imbrium impact occurs on the lunar surface and derive a simple model on the spherical target to predict the thickness of Imbrium ejecta deposits as a function of distance from the centre of the Imbrium basin. Then we use the result of Lunar Prospector＇s gamma ray experiment to test the hypothesis that the distribution of thorium on the lunar surface has an origin from the Mare Imbrium.     

核物质中核子能量密度的单圈图重整化手征σ模型

本文详细地给出了手征σ模型在单圈图真空起伏近似下,动量在质量壳上的重整化,计算了核物质中单个核子的能量密度,并与零动量重正化所得到的结果进行了比较.     

核物质中核子能量密度的单圈图重整化手征σ模型

本文详细地给出了手征σ模型在单圈图真空起伏近似下,动量在质量壳上的重整化,计算了核物质中单个核子的能量密度,并与零动量重正化所得到的结果进行了比较.     

Current Inversion in a Temperature Ratchet with Asymmetric Unbiased External Forces

Transport of a Brownian particle moving in a symmetric potential is investigated in the presence of an asymmetric unbiased external force. The viscous medium is alternately in contact with the two heat reservoirs. We present the analytical expression of the net current at the quasi-steady state limit. It is found that the competition of the temporal asymmetric parameter of the driving force with the temperature difference leads to current reversals. The competition between the two opposite driving factors is a necessary but not a sufficient condition for current reversals.     

核物质中π分子引起的粒子－空穴和△－空穴激发

以π介子为例给出了正确计算核物质中粒子－空穴激发的相对论方法，指出了它与通常计算方法的区别及通常计算方法中所作近似的不合理性．并与非相对论的粒子－空穴激发的色散关系进行了比较．我们还用这一方法计算并给出了△－空穴激发的表达式．     

Properties of Neutron Stars Rotating at Kepler Frequency with Uniform Strong Magnetic Field

A uniform strong magnetic field is considered in calculating the properties of neutron star rotating at the Kepler frequency. The results show that the effect of the magnetic field on the properties of neutron star is evident, and the properties of the neutron stars rotating at the Kepler frequency can be used as a criterion to the equations of states of the neutron star matters.     

Particle Transport with Asymmetric Unbiased Forces and Entropic Barrier

Transport of a Brownian particle moving along the axis of a three-dimensional （313） symmetric and periodic tube is investigated in the presence of asymmetric unbiased forces. It is found that in the presence of entropic barrier, the asymmetry of the unbiased forces is a way of inducing a net particle current. The particle current is a peaked function of temperature, which indicates that the thermal noise may facilitate the transport even in the presence of entropic barrier. There exists an optimized radius at the bottleneck at which the particle current takes its maximum value. The current can be influenced by the slope of tube walls and there exists an optimized slope for which the particle current takes its maximum value.     

Least square fitting of low resolution gamma ray spectra with cubic B-spline basis functions

In this paper, the least square fitting method with the cubic B-spline basis lunctions is derived to reduce the influence of statistical fluctuations in the gamma ray spectra. The derived procedure is simple and automatic. The results show that this method is better than the convolution method with a sufficient reduction of statistical fluctuation.     

狭窄程度对锥缩血管中脉动流的影响

建立了一个轴对称的狭窄锥缩刚性动脉模型.利用不可压缩的N-S方程作为计算的理论基础,采用有限差分方案进行数值分析.提供了3种狭窄程度下的管壁切应力分布曲线并进行了分析和比较,同时给出了模型M3(h/R₀=1/3)在一个流动周期内的流线图.结果显示狭窄附近的流场受到了干扰,特别是狭窄的喉部及其下游区域的流场,并且狭窄程度越严重,狭窄对流场的影响就越大.