By an exact renormalization method the trail problem on a regular fractal for the diffusion-limited aggregation is considered, and the mean square end-toend distance critical exponent v is obtained. It is indicated that self-avoiding trails and self-avoiding walks are in different universality classes on this irreversible kinetic growth fractal.

Both the similarities existing between diffusion-limited aggregation (DLA) cluster border and Brownian motion and the perimeter-area relation have revealed that the fractal dimension of DLA cluster border is about 2.0.

By borrowed operators, the heat kernel regularization method is applicable in supersymmetry. The anomalies of supersymmetry Yang-Mills current and spinor current are derived by this method.

The behavior of logarithmic moments of particle distributions in different rapidity windows is discussed for pp and PA collisions at high energies. The special role of those events, having no-particle in the rapidity window, is stressed.

A two-level convolution formula for the nuclear structure function is derived in considering the nucleus as a composite system of baryon-mesons which are also composite systems of quark-gluons again. The results show that the European Muon Colaboration effect can not be explained by the nuclear effects as nucleon Fermi motion and nuclear binding contributions.

There is a peak in the excitation function of total cross section of low energy α-particles in the reaction ¹²C+¹⁶O at E_c.m≈33.5MeV. The experimental distribution of α-particle emitted event has been obtained. The result of theoretical calculation roughly agrees with experimental data, gives an orientation where three-body resonances can be expected, and the information on internal structure of three-body linear chain molecule.

Allowed Δn = 0 transitions of highly ionized metal atoms, which may appear in the solar spectra as well as in spectra from the high-temperature tokamak plasmas, lie in the extreme vacuum UV (XUV) region, 100Å≤ λ ≤ 200Å . Here we report our theoretical calculation of the Δn = 0 transitions of C-like cobalt ions; it is in good agreement with the experimental measurement. Such theoretical calculations of the transition wave lengths and their oscillator strengths should be very helpful to identify the XUV spectra.

In this letter, a new derivation of Keldysh's formula is presented and a brief discussion about the comparison between the new derivation and the original one is given.

On the basis of hydrodynamic equations, an exact theory of non-linear standing sound waves is proposed, avoiding the unaccountable results of earlier theories.

The allotropic effect on the electronic topping power of protons in solids was systematically determined by the nuclear resonance reaction ²⁷Al (p ,γ) ²⁸Si at E_p =774 and 992ke V in an silicon on sapphire (SOS) sample of epitaxial Si on sapphire. Details of the experimental technique are described. The experimental error is less than3 %.

Lattice dynamics of strained (Si)₄/(Ge)₄ superlattice grown pseudomorphically on (001)-oriented Si_1-xGe_x (0 ≤ x ≤ 1) substrate is investigated. In the present calculations, the effects of strain and substrate are discussed.

Relations of phase boundaries and phase region for site-bond percolation are given. It can be seen from the simulation of Monte Carlo that the relations describe the site-bond percolation process much better than others practically.

The sample with nominal composition Bi_1.8Pb_0.35Sr₂Ca₂Cu₃O_y was prepared by solid state reaction method. Through the measurements of resistivity, dc. susceptibility, and the analysis of X-ray diffraction and Energy Dispersive X-ray (EDX) microanalysis, we found that: (1) there is only one superconducting transition with transition temperature near 110K, its zero-resistance temperature (Tce) is as high as 106.5K, the diffraction pattern is similar to that of 2223 single phase (110K), but the cation ratio of Bi:Pb:Sr:Ca:Cu is near 25.8:5.74:18.43:19.53:30.50, i.e., Bi_2.5Pb_0.5Sr₂Ca₂Cu₃.We suppose that the 3223 phase is caused by intergrowth in the sample; (2) like the 1-2-3 phase material, the superconductivity of Bi-system is sensitive to oxygen content. We suppose that different oxygen content in the same crystal structure leads to the change of electronic structure, and so to great difference in the superconductivity.