RECURRENCE RELATIONS OF GREEN FUNCTIONS FOR THREE PARTICLE POTENTIAL

The recurrence relations between Green functions are derived for the two and three particle potentials. The time variation of the field operator is used for the derivation of these recurrence relatiions.     

关于超纲链方法中无规相近似的讨论

应用超纲链方法讨论均匀费密子系统的多体效应时常用无规相近似和选取原始波函数为费密球分布的波函数。本文讨论这种做法的适用性,给出其适用范围与势的性质和密度的关系。 关键词：     

高功率振荡器锁相的粒子模拟

用粒子(PIC,Particle-in-Cell)模拟方法研究了当前颇感兴趣的高功率振荡器的锁相问题。给出了模拟计算结果。讨论了锁相(Phase Locking)、Priming和InjectionSeeding等概念的区别。     

多元无序合金相干势近似的图形分析

本文将处理二元无序合金电子性质的平均单粒子和双粒子格林函数的图形分析推广到多元无序合金。在单格点近似下,如果我们自洽地处理累积量中的多次占有修正,则从图形分析得到的平均单粒子和双粒子格林函数与相干势近似的结果相一致。 关键词：     

QUASI-ADIABATIC APPROXIMATION FOR THE SLOWLY-CHANGING QUANTUM PROCCESS AND BERRY PHASE FACTOR

By using group representation theory,the quasi-adiabatic approximation solution of the schrodinger equation of a quantum system with slowly-changing Hamiltonian are presented in this paper.We not only obtained the Berry phase factor and strictly proved the quantum adiabatic theorem as the zeroth-order approximation,but also studied the universal Berry phase factor and its geometrical interpretation when the adiabatic condition is violated.It is pointed out that this universal Berry phase factor has observable effects.     

NUCLEAR PAIRING PHASE TRANSITION

The intrinsic structure of the eigenfunctions of Cranking Shell Model hamiltonian and the pairing phase transition at high rotational frequency are investigated with the particle-number-conserving approach.Pair-transfer matrix elements and the K-structure of the wave functions display similar behaviour under the Coriolis interaction and hence both of them may be used to indicate the pairing phase transition.The blocking effects on pairing parameter,,are much more important than the Coriolis anti-pairing effects.     

2024Al的三相物态方程

 给出了铝基合金2024Al的包括固、液、气三相的物态方程。考虑了熔化熵的影响，通过标定，选取了合理的汽化与熔化温度的比值。为了更好地描述稀疏区的状态，将冷压作了分段处理。对低于正常密度的区域，提出了一个新的冷压形式。     

实际射频阱中多极势分量的计算和消除

采用边界元方法,计算了当实际射频阱出现帽极开孔、环极开环带以及轴向存在装配误差时阱内电势的多极分量,并给出其随孔径大小变化的规律。结果表明在一定条件下,某些非线性因素可以部分抵消从而产生较为理想的四极势     

一维势阱中被噪声驱动的粒子的逃逸问题

通过计算机数值模拟直接解朗之万方程，得到一维势阱中被高斯白噪声驱动的粒子的逃逸率，并与理论结果进行了对照。     

原子核力场之研究

本篇应用王淦昌所建议之两个核子间之相互位能即V=V(r)=-Ae^klr在r≥α时;及V=V(α)在r<α时。以求下列数点:(1)重子在正常情形时之波函数,(2)中子与质子间之扩散断面值,及(3)重子被γ射线击破之断面值。本篇所计算得之各断面值之结果与实验所得者,颇相近似。     

ENERGY LEVELS OF NUCLEI USING BOGOLIUBOV-VALATIN:TRANSFORMATIONS FOR THREE PARTICLE: INTERACTION

The calculation of energy Levels of nuclei in the presence of three-particle interaction is very involved.But using the Bogoliubov-Valatin transformations this calculation is considerably simplified.     

THE INTERPLAY OF NUCLEAR DEFORMATION AND PAIR CORRELATION NUCLEAR PHASE DIAGRAM

Bringing together the gauge space into consideration,the sudden transition ofnuclear shape can be analyzed in association with that of pair correlation.Thus,notonly the dramatic retardation of the E2 transition rate at the backbending can be reasona-bly used as a criterion for establishing the shape transition,but also the interplay ofnuclear deformation and pair correlation can be clearly shown.     

核破裂中的粒子发射和临界涨落

用晶格气体模型系统地研究了 ¹²⁹Xe热发射体的轻粒子、带电粒子和中间质量碎片的发射特性,发现了在温度5—5.5MeV区间,以上物理量的平均多重性和发射源的最大碎片余核及源的热激发能随温度变化的斜率存在着各自的峰值,同时它们的分布宽度（即涨落）也存在着最大值.进一步研究发现在5—5.5MeV区间,这些宽度随温度的变化的斜率显示了明显的不连续性.所有这些特征说明了在5—5.5MeV的拐点温度处,最大的临界涨落是自发地伴随着相变和临界现象. 关键词：     

ON THE PHASE EQUILIBRIUM OF NUCLEAR MATTER

The phase equilibrium of nuclear matter is studied thermodynamicallylat zero temperature. The equation of state obtained from the Thomas-Fermi model of Seyler-Blanchard shows that there are two kinds of states of the nuclear matter: gas and liquid. pure neutron matter is always in a gas phase.For the nuclear matter with two semi-infinite half spaces in contact at a plane boundary,the phase equilibrium is studied in three cases.Our calculation gives the neutron drip point δ_ND=0.305 and the proton drip point δ_PD=0.678.The phase equilibrium is possible between two nuclear matter systems up to δ_C~0.89 where the system becomes homogeneous.     

THE ESCAPE OF BROWNIAN PARTICLE OVER POTENTIAL BARRIERS

A convenient method is introduced to calculate the rate of escape of Brownian particle over potential barriers by exact solution of Smoluchowskian equation. This method is applied to calculate the nuclear fission probabilities. The results for four different cases are compared with the results of other theories.     

双球近似和速度空间的非平衡相变

本文在双球近似下,用边界层近似解法求解了磁化等离子体中的反应——扩散方程。结果表明,由扩散项的非线性正反馈同样能导致非平衡相变,而且环流器中的磁面可以不是等电位面。     

无反射势的Schr?dinger方程严格解的三维推广

文献[1]给出无反射势V(x)=-N(N+1)sech²x当N为任意正整数时Schr?dinger方程束缚态和散射态的严格解。本文推广文献[1]的工作,继续给出三维情况下无反射势Schr?dinger方程束缚态和散射态的严格解,并得到了与一维情况不同的一些物理结果。 关键词：     

A STUDY OF THE NUCLEAR POTENTIAL BETWEEN TWO NUCLEI

According to the physical picture of dinucleus molecule and considering the particle-hole interaction between two nuclei, the exchange of valence nucleons and nuclear potential between two nuclei were studied.     

PRINCIPLE OF MAXIMUM OVERLAP AND OPTIMAL SINGLE PARTICLE POTENTIAL

The principle of maximum overlap is applied to the derivation of optimal single particle (sp) wave functions for a many-fermion system under the proposition that the ground state correlation should be taken into account rigorously. If the sp potential U_αβ is defined in terms of the mass operator M_αβ^(u) by u_αβ=M_αβ(εβ), it is shown that the eigenfunctions of the sp Hamiltonian h_αβ=t_αβ+u_αβ automatically fulfill the requirements of the above principle.     

WKB波函数连接公式的初等推导与一维势阱势垒的WKB近似解

本文用初等方法导出ＷＫＢ波函数的连接公式，其要点是在转折点邻近，用阶跃型势能曲线代替真实的势能曲线。给出了求一维势阱能级及一维势垒穿透因子的方法与结果。方法简便，可供初等量子力学与普通物理教学参考。