[en] With the Landau adiabatic theory, an analytical expression of the photoionization probability of atoms by strong laser fields is given. Then it is shown that this analytical expression is reduced to the well-known Keldysh's formula in some conditions and is an approximate result of the model-theory. At last, two possible improvements to the present result is discussed briefly

[en] The resonating valence bond transition temperature T_RVB as a function of doping δ is calculated by going beyond the mean-field approximation. The results show that the higher order corrections are unimportant for discussing the change of T_RVB with doping δ

[en] A new kind of ion source, the matal vapor vacuum arc (MEVVA) ion source is developed to meet the needs in research and practice in material modification by ion implantation. The source makes use of vacuum arc discharge between cathode and anode to create high dense metal plasma from which an intense beam of metal ions is then extracted with a three grid multiaperture extractor. The MEVVA source operates in a pulsed mode. A beam current about 0.6 ∼ 1.26 A per pulse is extracted for Al, Ti, Fe, Cu, Mo and W. The time-average beam current is about 10 mA for Ti. The extracted beam current depends on operating parameter of source, extraction voltage and cathode material. This sorce neither requires nor produces a gaseous ambient in its operation. The operating presure is about 3 x 10^-4 pa

[en] The ground state pattern and the single-particle potentials of asymmetric nuclear matter are investigated with relativistic Hartree-Fock approximation. The phase transition from a Fermi sphere pattern to a Fermi shell are found at high densities. The inner boundary momentum of the Fermi shell and external one are also investigated. The effects of the Fermi shell pattern on the single-particle potential are calculated and it is important

[en] Problems are proposed which would have to be investigated in order to clarify the relation between the macroscopic thermodynamic theory of kinetics of phase transitions and the microscopic process of aggregation. In the process of aggregation, how to introduce the interaction between particles? how to define the free energy, the entropy, the surface and surface energy for the aggregate? how to introduce the effect of temperature and thermal agitation? how to calculate the change of fractal dimension caused by these effects? and so on are discussed

[en] Experimental results show that spontaneous emission coefficients of argon ion Ar⁺ vary in instense light field. They are not constant parameters that do not depend on outside conditions. It is also found that their variance is related to change of total angular momentum ΔJ and orbital angular momentum ΔL of ion during transition

[en] Because of high flux, ion implantation using a MEVVA (metal vapor vacuum arc) source can modify a thicker surface layer with metallic ions of rather low energies. Beam heating helps to retain a higher concentration of implants and to induce intermetallic compounds as fine precipitates. These make MEVVA a valuable high current ion source in industrial applications. The behaviour and state of the implanted atoms are characterized and the potential prospects of MEVVA are predicted

[en] At slightly less half filling case, there are one kind of Bose excitations which is spinless, charged 2e, and mass 2m. This excitation describe the propagation behaivour of the pair of electrons in the valence bonds. The onset of superconductivity can be explained in terms of the Bose condensation of those bosons. The theoretical value of superconducting transition temperature T_c is in agreement with the values of the experiments