We use a LaCoste-Romberg model D gravimeter to measure the gravitational forces at fixed positions when a large cylindrical reservoir is full and when it is empty. The differences determine the intermediate-range force at various separations around 50m to about 0.5 % accuracy.

Theoretical and experimental results of laser cooling and laser heating of an atomic beam in a standing-wave field and in a misaligned standing-wave field are reported. The results show that in strong fields, laser heating in a standing-wave field become laser cooling in a misaligned standing-wave field and in weak fields, laser cooling become more efficient in a standing-wave field than in a misaligned standing-wave field.

The electron densities in a short space-charge lens are measured with the radiofrequency method under different applied magnetic inductions and voltages, and relations between the focusing power of the lens and the external electromagnetic fields are investigated.

The evolution of an initially squeezed electromagnetic field was studied by using two-photon interaction Dicke model and pertubation approach. It was found that under certain condition in two-photon Dicke model squeezing will be enhanced. The physical insight of this phenomenon is discussed.

A simplified model of gas multiplication in the proportional region is proposed. A linear relationship between In A and V is derived. The formulae relating the macroscopic parameters of proportional region with the microscopic parameters of gas multiplication are obtained. By analyzing the experimental data the values of these parameters under different conditions are determined.

Diamond thin films were produced by microwave plasma chemical vapor deposition. The deposit is identified by X-ray diffraction, Raman spectroscopy and Scanning electron microscopy. During the course of diamond growth, the characteristics of the plasma have been measured by means of the Langmuir double probe and emission spectrometer.

A nonlocal theory for trapped ion absorption in ion cyclotron radiofrequency heating is developed. The gyrokinetic equation is adopted and a full partied orbit and wave coupling is kept.

Bragg's law with refractive correction of low-angle X-ray diffraction for periodic multilayers is deduced according to the optical refractive law and interference rules. Variant forms of this law, which accorded with experiments quite well, are given.

The polar films of liquid crystal(8CB) with large dipole moment have been fabricated by the Langmuir-Blodgett technique. The pyroelectric effects in the polar structure have been observed by the static method. The static pyro-electric coefficients depend on the temperature of the sample and the surface pressure of aqueous subphase during the deposition of monolayers.

By using electroabsorption method, we find that the built-in field (~10⁵ V.cm^-1) in the a-Si sublayers of a-Si:H/a-SiN_x:H multilayers points towards the sample surfaces. We ascribe the internal field to the asymmetric distribution of defect states which exist primarily in the silicon side of the silicon-on-nitride interfaces, owing to the large repellent lattice stress there. We also find that the built-in potential depends strongly on x, with a maximum value near x = 1.0. We intend to explain it as a result of structural softening as more N atoms are introduced into Si networks in the range of x > 1.0.

The specimens of YBa₂Cu₃O_7-δ are irradiated by 35 MeV proton at 70K, the sero-resistance temperature TC0 is increased with the proton fluence within the range (2.21 x 10¹³-1.77 x 10¹⁴p/cm²). T_c0 is increased from 91 to 97K at the fluence 1.77 x 10¹⁴p/cm² and critical current is also enhanced.

The structural and magnetic properties of NdTiFe₁₁N_0.5 and YTiFe₁₁N_0.5 have been studied. The nitrides retain the tetragonal ThMn₁₂ structure and their unit cell volumes slightly increase. The interstitial nitrogen atoms are found to increase the Curie temperature and saturation magnetization of the compounds, and especially have a strong effect on the magnetocrystalline anisotropy.

The transformation horn stage-2 to stage-1 in HC1O₄-graphite intercalation compounds is studied by in-situ Raman scattering. The results show the coexistence of well-ordered regions of both stages during the stage transition. The resonant enhancement of Raman scattering has been found in stage1 and stage-2 HC1O₄-GICs.

Deep level defects in undoped semi-insulating GaAs were investigated by photo-luminescence technique at room temperature. The 0.69eV band is associated with the main mid-gap level EL2, and the 0.76eV band is suggested to be caused by some native point defects related to excess As, such as As anti-site defect. Two-dimensional and pseudo three-dimensional plots of the EL2 related band have been observed for as grown and annealed wafers.