This paper is concerned with the general conditions of the existence of a stable period-N orbit for the Hénon map. The critical parameter values of Its "window" and destabilizing location are determined exactly by an analytical method. Our theoretical results agree with Hamouly and Mira's numerical calculations very well. We find that the mutual relations between the two window curves of the period-5 orbit and their corresponding destabilizing curves are changed.

It is shown that the observed dependence of multiplicity distribution on the size of the "rapidity window" and the existence of spike events are natural consequences of a previously proposed statistical model.

The generation of UV radiation at 285.4nm by four-wave mixing in magnesium vapor is reported. A dye-laser radiation is focused into magnesium vapor and tuned to the resonance wavelength of the two-photon transition 3s^{2 1}S₀ -3s4s ¹S₀. The dependence of the signal intensity at 285.4nm on Mg vapor density and incident laser power has been measured and the spectral behaviour has been studied.

The contribution of Nd³⁺ ions to the magnetocrystalline anisotropy of intermetallic compound Nd₂Fe₁₄B was calculated by single ion theory. The results explained the high anisotropy of Nd-Fe-B alloy. By adjusting the shielding factors the calculated K₁-T and K₂-T relations agree with the experimental curves.

The coordination number and distances around a Ge atom in binary oxide glasses BiO_1.5-GeO₂ and PO _2.5-GeO₂ have been measured by EXAFS. The results show that Ge-O tetrahedron network in GeO₂ rich BiO_1.5-GeO₂ glass is much like that in amorphous GeO₂ but that in PO_2.5-GeO₂ glass it is more disordered.

We point out that rneasurements on the ratios of R_D=(D→τv_τ) /(D→μv) and R_F =(F → τv) /(F → μv) can provide information on g_τ/g_μ and m_vτ.

The differential cross section data for high energy K^-p elastic scattering showing a break near - t = 4 (Gev)/c )² have been fitted for p_L=20, 100 and 200GeV/c with -t extended up to 14 (Gev/c ))² by using a dipole pomeron mode.

For ²⁰Ne + ¹²C scattering, the rising oscillatory structure in the differential cross section is explained by a two α transfer process between the nuclei.

A new type of self-pulsing oscillation with a period t_R has been observed in liquid crystal hybrid optical bistable devices. Theoretical analysis indicates that, a square wave Self-pulsing oscillation with a period t_R exists in bistable regions, and when suitable parameter values are chosen, bifurcation will appear in the upper branch of optical bistable regions and overlay the peak part of the square wave self-pulsing. This new type of oscillation and the concomitant bifurcation predicted by theory are in agreement with the experimental results.

SCF-SW-Xα method has been used to calculate the electronic structure of Ni₄P and Pd₂Ni₂P clusters, to simulate the local electronic structure of Ni₈₀P₂₀ and Pd₄₀Ni₄₀P₂₀ glasses respectively. It can be concluded that the rigid band-charge transfer model is not suitable for these systems.

We have used optical and photoconductivity measurements on a-Si:H to acquire information about the band tail and gap states. The experimental results show that annealing and exposure do not change the slope of the absorption edge at certain temperatures but change the sub-gap excitation.

Two different kinds of Peierls transitions can exist depending on the anisotropic ratio y of intrachain and interchain coupling. γ has a critical value γ_o; if γ > γ_o, the Peierls transition will exhibit a CDW accompanied by a metal-semiconductor transition (kind I); if γγ_o, only CDW and superlattice occur at Peierls transition (kind II). Some experimental evidences are discussed.