The highest superconducting transition temperature of 8.42 and 5.16K has been observed in the alloy system PdH and PdCuH, where the atomic ratio n=H/Pd(Cu) are 1 and 0.6, respectively. The effect of lattice disorder induced by 220keV Ar ion beam bombardment at liquid helium-temperature is detrimental to the superconductivity.

Using a new technique we have observed the correlation between the angular distribution and Doppler broadening of the positron annihilation in silica aerogel and synthetic quartz crystal, for which the relative intensities of the central peaks of the angular correlation with fine selection of gamma ray energy are 1.7 and 1.4 times those without energy selection, respectively.

The hydrogen depth profiling in solids has been done by elastic recoil detection (ERD) technique with multicharged ¹⁹F ion beam from a small Tandem Accelerator of 2x1.7MV. Details of the experimental technique are described. The depth resolution of about 230Å in the near-surface regions (~5000Å)is much better than that of ERD technique with 2.5MeV He beam and heavy ion beam of 30MeV.

The electronic states, especially the deep levels of the defects in GaSb/AlSb (001) superlattices have been calculated. The band gap becomes larger and the donor binding energy becomes deeper with the decrease of the quantum well width. The impurity deep levels exhibit a position dependent relation.

The solution of Anderson model is got by using the Bogoliubov-type transformation. The calculated Wilson ratio for the heavy-fermion systems is in qualitative agreement with the experimental results.

The pressure coefficients between Γ conduction subbands, heavy( h) and light (1) hole subbands are determined. It is found that the pressure coefficient decrease with increasing subband energy or decreasing well width(Lz), from 10.3meV/kbar for the 130Å well to 9.6meV/kbar for the 29Å well. This result shows that the Γ valley of GaAs is not a rigid sphere with same pressure coefficient. Pressure dependence of photoluminescence intensity has been also measured for both the 130Å and 29Å wells. It is markedly different from that of the bulk GaAs.

A quantum gravity version is given to the Brans-Dicke theory. We find that the matter field quantum fluctuation induces the conformal quantum fluctuation of space-time, and that the latter backreacts to the classical space-time and transforms it from Einstein space-time into the Brans-Dicke one.

We have established a relation between the parameters of periodic Anderson model Hamiltonian and the Landau's phenomenological paramerters, and applied it to heavy-fermion superconducting systems. The calculated results of specific heat coefficients and superconducting critical temperatures are in agreement with the experimental ones. The conclusion is that heavy-fermion superconducting systems induced by Fermi liquid interaction are P-wave type.

The analytical expressions of the second moments for a dissipative quantum system are derived by using path integral method with a solvable model. The quantum and non-Markovian effects on the quantum Brownian motion are studied quantitatively.

The carbon-ion radioactivity of ²²³Ra has been measured with solid state track detectors. A branching ratio of the emission of ¹⁴c nuclei to that of alpha-particles of (8.7±1.7)x10^-10 is obtained. The preformation probability of ¹⁴c in ²²³Ra and the odd-even effect are discussed.

High Tc Ba-Y-Cu-O thin films have been successfully prepared by the RF magnetron sputtering method. The highest Tc onset is determined to be 89.5K and the Tc midpoint is about 55K. Inductive measurement showed that the samples are diamagnetic and the Meissner effect appeared around 10K.

Room temperature photoreflectance were made on a selectively doped GaAs/n-Al_XGa_1-XAs two-dimensional electron gas grown by molecular beam epitaxy (MBE). The lineshapes can be made fit by Aspnes' theory, and the results explained with a simple model.

The oxide compounds of Ba_xY_1-xCuO_3-y(x=0.3-0.5) have been successfully prepared. The zero resistance temperature of the samples is at 91.5K. with Tc onesets higher than 100K. The ac magnetic susceptibility measurements show that the superconducting phase at 82K is not less than 85% in volume.