ELASTIC SCATTERING OF K± MESONS BY 40—48Ca AND THE ANALYSIS OF NEUTRON DISTRIBUTIONS

The differential cross sections of the elastic scattering of K^±on ^40—48Ca are calculated in the framework of eikonal approximation. The theoretical values obtained by using different parameters are compared. Through adjusting the parameters of the neutron distribution, the improvement of the coincidence between the theoretical values and the experimental data is arrived. The result shows that the r.m.s radius of the neutron distribution of ⁴⁰Ca is smaller than that of the proton. (about 0.15fm smaller) and the surface thickness of the neutron distribution of ⁴⁰Ca is thinner than that of proton. This is consistent with the results of computation made by H.F. method and agrees with the analysis of elastic scaatering of protons in the mediate energy on ⁴⁰Ca by other authors.     

A MEASUREMENT OF THE ELASTIC SCATTERING FOR REACTION 12C+28Si AT ENERGIES 56MeV—69MeV

The angular distributions of the elastic scattering for reaction ¹²C+²⁸Si have been measured at the energies 69.5MeV, 66MeV, 59MeV, 56MeV using the large area position sensitive ionization chamber. The experimental data are fitted by use of the optical model. The probable reasons of the enhancement and oscillation of the elastic scattering angular distribution are discussed.     

n+6Li散射态中6Li的集团结构和交换效应

本文有略去α集团外核子与α内核子交换的共振群方法计算了n+⁶Li系统的弹性散射相移和微分截面, 并通过这些计算研究了⁶Li的d+α集团结构和反对称交换效应. 所得的结果表明, ⁶Li的d+α集团结构显著, 因此合理地选取⁶Li的d+α集团波函数, 特别是d与α的相对运动波函数是很重要的; 由于⁶Li的d+α集团结构显著, 且α束缚得委紧, 所以略去了α与n和d之间的反对称交换能得到与冗长的标准共振群方法相一致的结果.     

d+6Li散射态的QRGM分析

本文利用工作[1]中得到的结果, 即⁶Li集团结构显著和可以略去与α集团的反对称交换效应, 计算了d+⁶Li的弹性散射相移和微分截面. 这个工作表明, 在d+⁶Li弹性散射中, 也可以忽略与α集团的反对称交换效应, 而得到与严格的共振群方法基本一致的结果.     

MONTE CARLO RENORMALIZATION GROUP STUDY OF φ4 MODEL

The Monte Carlo renormalization group method proposed by Callaway is applied to φ⁴ model on two dimensional triangle lattice.The flow diagram,fixed point and critical exponent are determined,There is no fixed point in the range of 0.1<λ<10⁹.The large λ limit,as expected,is consistent with the Ising model.     

THE DOUBLE SPECTRAL FUNCTIONS OF PHOTON-NUCLEON SCATTERING AND INELASTIC CROSS-SECTIONS OF γ+p→p+π++π-

Using elastic unitary condition of t channel, the double spectral function of photon-nucleon scattering and absorbtive parts of scattering amplitude (s channel) are given. Using date of low energy πN(3,3) resonance ρ resonance, the photo-production cross-sections of γ+q+q+π⁺+π- are calculated. The results are compared with the recent experimental data.     

STUDY OF QUASI-MOLECULE RESONANCE OF CHAIN CONFIGURATION INDUCED BY 6Li(d,dd) α REACTION AT LOW ENERGY

⁶Li(d,dd) α reaction induced by 7.3—10.6MeV deuterons was studied under collinear condition.An enhancement in differential cross section beyond the well known QFS and FSI contribution was observed at incident energy of 9MeV.It is the state of quasi-molecule resonance of chain configuration.     

STUDY OF ANGULAR DISTRIBUTION OF THE SCATTERING OF 31.2 MeV α PARTICLE BY THE NUCLEUS 10.11B

Angular distribution of the scattering of 31.2 MeV-α-particle by the nucleus ^10,11B is measured. Our results show that there is anomalous phenomenon in the case of ¹⁰B but there is not in ¹¹B. Calculations and analysis are made with the optical model adding the Regge-Pole model. The results show that for the nucleus of 1p-shell, such as α+¹⁶O, the result of the calculation agrees very well with the experimental measurements but it fails in α+¹⁰B. As to the analysis with the double v-power optieal model for α+¹⁶O, the agreement is somewhat a little worse than the former's and the result for α+¹⁰B agrees only qualitatively with the experimental measurement. It is well known that the analysis with these models for α+⁴⁰Ca agrees very well with the experimental data. Thus we may come to the conclusion that the mechanism of ALAS of the nucleus of 2s-1d shell is different from that of 1p-shell, and the mechanisms of ALAS of the nuclei of 1p-shell are also different.     

6Li基态中氘的压缩和变形

本文用双位阱壳模型投影交分方法对⁶Li基态进行计算.计算说明,⁶Li基态中氘的方均根半径比自由氘核的方均根半径小;随着氘核集团同a集团的平均间距的减小,氘核集团表现出先压缩而后稍膨胀的压缩效应和先呈扁形而后呈拉长形的变形效应.计算初步地说明了,核力的奇宇称态排斥分量和集团间核子的包利交换效应,无论在⁶Li基态的集团结构中和氘核集团的压缩和变形效应中都起着重要作用.     

6Li的集团结构态间的跃迁

本文用含有p态激发的双阱集团壳模型波函数,计算了⁶Li的集团结构态间的约化跃迁几率B（E2）和均方根半径2>^1/2,得到与LCCO相近的结果。     

STUDY OF THE MECHANISM OF 12C（d,d）12C AND 12C（d,p）13C* REACTIONS

A formalism for studying the interference between the direct reaction and the compound resonance processes is presented by the S-matrix theory; The mechanism of ¹²C（d, d） ¹²C, ¹²C（d, p₁） ¹³C* and ¹²C（d, p₂） ¹³C* reactions in the energy range E_d=1.63 MeV to 2.05 MeV is analysed.Te results show that: the interference between these two processes exists; and the quantitative relation between them is given. While the parameters of direct reactions and compound resonance processes, particularly for four resonance states with E_d=1.726, 1.767, 1.792 and 1.86 MeV are determined.     

程函波函数对准自由散射6Li（p,pd）α的应用

近似地用程函波函数作为粒子在原子核作用下的扭曲波函数,分析了入射能量为156MeV、590MeV与670MeV的质子对原子核⁶Li引起的准自由散射⁶Li（p,pd）α。从156MeV的情况可看到,用程函波函数来研究准自由散射所得的结果和用分波法得到的结果同样使人满意。对590MeV与670MeV的情况,所得结果与平面波冲量近似相比有所改进。     

ANALYSIS OF SURFACE EXCITATION OF ELASTIC WAVE FIELD IN A HALF SPACE OF PIEZOELECTRIC CRYSTAL——GENERAL FORMULAE OF SURFACE EXCITATION OF ELASTIC WAVE FIELD

This paper developes the general theory of the surface excitation of elastic wave field in a halfspace of piezoelectric crystal for both free and metallized surfaces.It is shown that the general elas-tic wave field U is equal to the convolution of the generalized Green's functions G and the general-ized forces T, U = G Twhere symbol,expresses dot-product-convolution. The generalized Green's functions are independent of excitation conditions and only dependenton material parameters and orientation. For the piezoelectric crystal,not only a mechanical source distribution at the surface,but anelectrical source distribution can also excite the elastic wave fields.Complete expressions of thegeneralized forces representing mechanical and electrical source distribution respectively are given.Especially for the free surface,the surface electrical sources can be composed of the discontinuityof normal electric displacement at the surface,and of the discontinuity of the tangential electric fieldas well.     

THE ANALYSIS OF RADIOACTIVE DECAY CURVES (Ⅰ) TWO-COMPONENT DECAY CURVES——INTRODUCTION OF A NON-CLASSICAL METHOD OF ANALYSIS

In present paper, a non-classical method ("λ" method) of analyzing the two-component radioactive decay curve was developed. The use of the relationship between the apparent decay constant λ(t) and the time t in fitting is to be distinguished from the use of the relationship between the total activity A(t) and t in fitting by the classical method ("A" method). In "λ" method, there are three unknowns while in "A" method there are four, thus the former is simpler than the latter.     

SCATTERING OF SOUND FROM A PAIR OF FINITE CYLINDERS——A PRELIMINARY STUDY APPLICABLE TO SOUND INTENSITY TECHNIQUE

In this paper,it is studied that the scattering effect is caused by microphones itself,on both wavemagnitude and phase.The experimental method was found difficult to do this.We will apply the Bound-ary Element Method(BEM)to the problem and explain the results obtained.The numerical methodseems to be a powerful tool in this situation.     

THE STUDY OF α-EMISSION INDUCED BY 16O ON 27Al

The α-particles induced by 84.5MeV and 62 MeV ¹⁶O on ²⁷Al are measured using ΔE-E semiconductor telescope. The energy spectra, the angular distributions, the contour plot of d²σ/dE﹒dΩ in the E-θ plane of the emitted α particles and the variation of the nuclear temperature with the emission angles are obtained. The mechanism of the direct α particles is discussed.     

ON THE RELATIVE WAVE FUNCTION OF α-AND d-CLUSTERS IN 6Li

In this paper,we have analyzed the experimental results of the quasifree scattering⁶Li（p,pd）a with E_p=156 MeV.Both PWIA and DWIA are performed.UsingDWIA and the relative wave function proposed by Sakamoto et al.,the results of ourcalculation agree better with the experiment.     

MEASUREMENT AND ANALYSIS OF EMITTED α PARTICLES IN REACTIONS OF 12C BOMBARDING 12C,27Al AND natCa

The energy spectra and angular distributions of the emitted α particles in the reactions of the 69.5MeV ¹²C bombarding ¹²C,²⁷Al and ^natCa have been measured and analysed using the fast particle exciton model. The contribution from the equilibrium and preequilibrium α-emissions is calculated to be 89%, 81% and 83% of the total α yields for the three reactions respectively, where the preequilibrium α emissions are 11%, 14% and 16% respectively. A small contribution comes from the other reaction mechanism.     

6.8MeV/A—5.1MeV/A 14N+59Co, 51V发射α粒子的研究

用ΔE-E半导体望远镜测量了6.8MeV/A—5.1MeV/A的¹⁴N轰击⁵⁹Co和⁵¹V产生的α粒子, 得到了发射α粒子, 得到了发射α粒子的能谱、角分布和E-θ平面上的d²σ/dΩdE等高图, 区分了直接机制α及复合核蒸发α粒子, 并对直接机制α粒子的来源作了讨论.