推广的Thomas–Fermi方法中适用的新式核密度

给出一种适用于推广的Thomas-Fermi方法(ETF)的密度形式.取SkM势参量,对几个球形核的基态性质进行了计算,结果优于通常采用的多参数密度形式.用期望值方法(EVM)给出的基态能量能重现H—F的计算结果.     

热核表面能的Thomas－Fermi统计模型理论

用Ｓｅｙｌｅｒ－Ｂｌａｎｃｈａｒｄ动量相关非定域相互作用的含温Ｔｈｏｍａｓ－Ｆｅｒｍｉ统计理论，对半无穷大核物质模型计算了核物质表面能系数σ（Ｔ，δ）随温度Ｔ和不对称度δ的变化，发现在低温Ｔ≤５ＭｅＶ和不对称度δ≤０．２时，可以近似写成σ（Ｔ，δ）＝σ０（Ｔ）［１＋Ｋ（Ｔ）δ２］，其中σ０（Ｔ）和Ｋ（Ｔ）可以拟合成温度Ｔ的二次函数．     

超重核的球形和变形壳结构

应用宏观 微观模型系统研究了超重核的形状和结构性质.其中,宏观能是由基于核子密度泛函的连续介质模型计算得到.计算结果很好地再现了超重核的结合能、α衰变能和寿命的实验数据.对单粒子能级的计算和分析表明超重核的壳结构是形变和同位旋相关的.位能曲面的计算结果显示,与其它区域的核相比,超重核的形状不易变化. The structure of superheavy nuclei has been studied by using the macroscopic-microscopic model. The macroscopic energy was calculated with the continuous medium model in which the energy is expressed as a functional of nucleon densities. The deformations and structures of superheavy nuclei were investigated systematically. Calculations reproduce well the available data of experimental α decay energies and half-lifes. The investigation of single-particle levels shows that the shell structure is deformed a...     

超重核的基态性质

用Skyrme Hartree Fock+BCS方法计算了超重核的基态性质,讨论了结合能、α衰变、形变、壳结构和自发裂变等问题.计算得到的结合能较好地反映了实验测量值,α衰变能与实验值符合很好.发现基本上有两种类型的超重核形变:在270108核附近的β2≈0.2的长椭球形变和在298114核附近的近球形形变.单粒子能级分布计算表明:在质子Z=108和中子N=162存在变形壳,在质子Z=114和中子N=184存在球形壳.用得到的α衰变能和Viola Seaborg公式估算了α衰变半寿命,能合理地符合实验测量值. The ground state properties of superheavy nuclei are investigated using the Skyrme Hartree Fock model. The pairing correlation is treated by the BCS method with the pairing δ force. Binding energies, α decays, spontaneous fissions, shell structures and deformations are discussed. Our calculations reproduce experimential binding energies and α decay energies.It is found that superheavy nuclei can be grouped with two kinds of deformations: i) well deformed prolate shapes (β2≈0.2) around 270108...     

改进的核密度模型与强子-核Drell-Yan过程中的核效应

提出了改进的核密度模型，用唯象的方法找到了束缚核子内价夸克和海夸克的核效应的参数公式，其中利用了核密度与原子核的平均结合能之间的联系. 利用该模型所得到的束缚核子内部分子分布函数，对强子与核的Drell-Yan过程的核效应给出了满意的解释, 深化了对原子核内夸克分布受核效应影响的认识. 关键词： 核密度模型 核效应 强子-核Drell-Yan过程     

超重核密度的计算

用Skyrme Hartree Fock模型计算了超重核的密度分布,并讨论了其形状和同位旋相关性。 以292120核为例,计算表明形变对密度分布有相当大的影响。     

改进的核密度模型与轻子-核DIS过程中的核效应

提出了改进的核密度模型, 用唯象的方法找到了束缚核子内价夸克和海夸克的 核效应的参数公式, 其中利用了我们已经建立的核密度与原子核的平均结合能 之间的联系. 利用该模型所得到的束缚核子内部分子分布函数, 对轻子与核 的DIS(深度非弹性散射)过程的核效应给出了满意的解释, 深化了对原子核内夸克分布受核效应影响的认识.     

应用原子核的宏观－微观模型研究远离稳定线核的性质

应用原子核的宏观－微观模型研究远离稳定线核的性质，得到了一些结果，例如质子和中子滴线，质子和中子密度分布及其均方根半径和中子皮厚度随同位素位移的变化．对一些奇异核性质的计算结果同相对论平均场方法计算的结果作了比较，对质子滴线附近核的质子放射性也作了简要讨论．     

原子核的核密度经验公式与核子结构函数的核效应

文中给出了原子核的核密度经验公式,建立了核密度与原子核的平均结合能之间的联系,由公式可以得出A≥12的所有核的核密度值.利用公式给出的C,Al,Ca,Fe,Sn和Pb核的核密度值及核子结构函数核效应的核密度模型,计算了核效应函数R^A1/A2(x,Q²),所得结果与μ子实验合作组测得的实验结果符合甚好.     

原子核密度经验公式与轻子-核DIS过程的核效应

在核密度模型基础之上利用原子核密度经验公式得到的核密度和利用电磁半径平方平均值得到的核密度分别计算了轻子 核深度非弹性散射过程中的核效应函数RHe/D(x, Q2), RLi/D(x, Q2), RC/Li(x, Q2), RCa/Li(x, Q2), 发现利用由原子核密度经验公式得到的核密度计算核效应函数所得结果与NMC实验数据符合得较好, 并且优于用后者方法计算核效应函数的理论结果, 从而说明利用原子核密度经验公式研究核子结构函数核效应的合理性。 The nuclear effect functions in l A DIS process RHe/D(x, Q2), RLi/D(x, Q2), RC/Li(x, Q2) and RCa/Li(x, Q2) are calculated on the basis of the nuclear density model by using nuclear densities obtained from an empirical formula or the experimental values of the electromagnetic mean of radius square 〈r2〉, respectively．It is shown that the nuclear effect functions obtained from the empirical formula are in good agreement with the NMC experimental data, and better than the later ones．The empirical formula of the nuclear density can be used to study the nuclear effect of nucleon structure functions reasonably.     

Looking for an Optimal Ground State Within Quasiparticle Random Phase Approximation

A new ansatz for the correlated ground state of the many-nucleon system is proposed which results in obtaining a modified Quasiparticle Random Phase Approximation (QRPA). An additional degree of freedom is introduced which allows to determine variationally the ground state simultaneously with solving the QRPA equations. This new approach, QRPA with an optimal ground state, is studied within the proton-neutron Lipkin model. New solutions have been found, in the range of the interaction strength where the standard QRPA formalism does not work. A relation between one of them and the solution obtained within a semi-classical approach is established. A detailed study of the expectation value of the quasiparticle number operator in the ground state and the transition amplitude for the two-neutrino double beta Fermi decay, is also presented.     

同位旋非对称核物质性质与扩展的BHF方法(Ⅰ)同位旋相关的扩展的BHF方法

通过引进基态关联和同位旋自由度的区分,推广了Brueckner Hartree Fock理论方法,并应用于同位旋非对称核物质,系统地研究了在整个同位旋自由度范围内核物质的状态方程和单粒子特性及其同位旋效应.还研究了微观三体核力对同位旋非对称核物质性质及其同位旋效应的影响,定量讨论了三体力效应与相对论性平均场理论及Dirac Brueckner方法的联系.主要给出了同位旋相关的Brueckner Hartree Fock方法的基本理论和计算公式.     

核反应截面测量中扣除激发态对基态影响的计算公式

根据人工放射性的生长与衰变规律，推导出了一个扣除激发态对基态影响的普遍计算公式，解决了在实际的核反应截面测量中激发态对基态的影响问题.     

A New Expression for Nuclear Rotational Spectra

A new formula, which is derived from a deformed rotor model for describing nuclear rotational spectra, is analyzed. The ground band of most even-even rare-earth and actinide nuclei are accurately reproduced using a damped nonlinear least-square fitting procedure for determining parameters of the theory. The results show that energy spectra obtained from a deformed rotor model are more accurate than those from a three-parameter formula based on perturbation theory.     

Magnetic Properties of One-Dimensional Ferromagnetic Mixed-Spin Model within Tyablikov Decoupling Approximation

In this paper, we apply the two-time Green's function method, and provide a simple way to study the magnetic properties of one-dimensional spin-(S,s) Heisenberg ferromagnets. The magnetic susceptibility and correlation functions are obtained by using the Tyablikov decoupling approximation. Our results show that the magnetic susceptibility and correlation length are amonotonically decreasing function of temperature regardless of the mixed spins. It is found that in the case of S=s, our results of one-dimensional mixed-spin model is reduced to be those of the isotropic ferromagnetic Heisenberg chain in the whole temperature region. Our results for the susceptibility are in agreement with those obtained by other theoretical approaches.     

Magnetic Properties of One-Dimensional Ferromagnetic Mixed-Spin Model within Tyablikov Decoupling Approximation

In this paper, we apply the two-time Green＇s function method, and provide a simple way to study the magnetic properties of one-dimensional spin-（S, s） Heisenberg ferromagnets. The magnetic susceptibility and correlation functions are obtained by using the Tyablikov decoupling approximation. Our results show that the magnetic susceptibility and correlation length are a monotonically decreasing function of temperature regardless of the mixed spins. It is found that in the case of S = s, our results of one-dimensional mixed-spin model is reduced to be those of the isotropic ferromagnetic Heisenberg chain in the whole temperature region. Our results for the susceptibility are in agreement with those obtained by other theoretical approaches.     

核探测器中混合气配制新方法

以质量流敏感器件和系统控制器为主要部件,建立起一套新的混合气配制系统,其配比误差小于满量程的1%,动态响应时间小于3s,有很好的长期稳定性,能满足核探测器对混合气体的多种需要.     

A New Effect in the QCD Fusion of Nuclear Partons

The parton fusion in nucleus at the leading order of recombination is investigated based on perturbative QCD. We compute various cut diagrams including the nuclear parton fusion, and find that the parton-fusion effects depend on the nuclear QCD structure.     

A New Scheme for Probabilistic Teleportation and Its Potential Applications

We propose a novel scheme to probabilistically teleport an unknown two-level quantum state when the information of the partially entangled state is only available for the sender. This is in contrast with the fact that the receiver must know the non-maximally entangled state in previous typical schemes for the teleportation. Additionally, we illustrate two potential applications of the novel scheme for probabilistic teleportation from a sender to a receiver with the help of an assistant, who plays distinct roles under different communication conditions, and our results show that the novel proposal could enlarge the applied range of probabilistic teleportation.     

A New Scheme for Probabilistic Teleportation and Its Potential Applications

We propose a novel scheme to probabilistically teleport an unknown two-level quantum state when the information of the partially entangled state is only available for the sender. This is in contrast with the fact that the receiver must know the non-maximally entangled state in previous typical schemes for the teleportation. Additionally, we illustrate two potential applications of the novel scheme for probabilistic teleportation from a sender to a receiver with the help of an assistant, who plays distinct roles under different communication conditions, and our results show that the novel proposal could enlarge the applied range of probabilistic teleportation.