The generating functional for truncated Green functions which is lacking in the field theories, is introduced for the spinor electrodynamics. Such generating functional is shown to be excellent in expressing the scattering matrix and used to construct a formula for the latter. The method is also applicable in principle to other field theories.

Excited nucleus ¹⁹⁸Bi was produced via the ¹⁸⁷Re(¹⁶O, 5n) ¹⁹⁸Bi reaction. The γ-rays following the β+/EC (electron capture) decay of ¹⁹⁸Bi were measured in beam by using a powerful multidetector system. Based on coincidences with the known γ-rays of ¹⁹⁸Pb, five new transitions were identified and eight new energy levels were established for ¹⁹⁸Pb.

The fine structure of lithium-like ls²4d states in the literature behaves irregularly as a function of Z. The fine structures of the B III and Ne VIII fall well below the isoelectronic curve. The term energies of these two systems in the data tables also give worse agreement with the theoretical prediction. In this work, we show that the reason for this unusual situation is caused by a misidentification in the original spectra. When the correct identifications are made, the fine structures of both systems fall on the isoelectronic curve and the agreement between theory and experiment is excellent .

The lattice inversion method is used to construct ab initio pair potentials in the noble-metal alloy systems Cu-Ag, Cu-Au and Ag-Au from the elemental crystals and a L1₂ binary superstructure as references. Also, we present an alternative method for the determination of the three-dimensional Möbius functions by using the Kronecker expansion.

The single-electron capture cross sections for the impact of rare-earth ions Ce⁺, Ho⁺ on H₂ are measured in the energy range 3-8keV by 'growth rate' method. The measurement also reveals that the incident ions are predominantly in ground state.

The hole-burning in the excitonic spectra of polydiacetylene toluene sulfonate under subresonant optical excitation is investigated. Through calculating the nonlinear absorption spectra, the position and depth of the hole are determined based on the phonon-mediated optical Stark effect. The comparison between measured data and theoretical results is made.

Peak and recovery heat flux densities (q_p, q_R) in the bath of subcooled superfluid helium (HeIIp, from 1.81 to 2.1 K at 0.1 MPa). Have been measured, in which a programmed voltage method with a triangle waveform of 20s is applied, and a RhFe wire (d = 51μm, L = 34.8mm) is horizontally immersed in a HeIIp cryostat, which served as sample, heater and temperature sensor.

Potasium sodium lead barium niobate KNPBN crystals have been grown successfully by flux method. The dielectric constant along the polar axis was measured at 50 kHz as a function of temperature in the range of 0 to 400°C. The flux system, diffuse phase transition and optical absorption were also discussed.

The generalized phonon density of states (PDOS) and the valence electron density of states (EDOS) of the amorphous Fe_90-xCo_xZr₁₀ (x=4, 10 and 40) alloys were measured at the room temperature by inelastic neutron-scattering and x-ray photoemission spectroscopy, respectively. Preliminary results show that the stronger the Invar effect, the softer is the PDOS in the low-energy region and the larger is the EDOS at the Fermi energy level. The enhancement of electron-phonon interaction was suggested to explain the low-energy phonon softening observed in Invar alloys.

We report the observation of photocurrent spectrum involving both the fundamental interband, extrinsic defect transitions β-FeSi₂ and the intrinsic transitions of Si substrate and demonstrate the sensitivity and reliability of the photocurrent measurement for revealing the energy band structure of β-FeSi₂. The transition energies are in good agreement with the results of absorption measurement and the theoretical calculation based on a simple recombination model.

The electron-hole interaction in conjugated polymers is considered for both a short chain and an infinite-long polyene. The attraction and repulsion between the electron and hole for different interactions are andysed. Excitonic states should exist in the attractive region.

The (Bi_0.9 Pb_0.13)₂Sr₂(Ca_0.98R_0.02)₂Cu₃O_10+δ superconductors (R = Sm, Eu, Gd, Dy, Ca) were prepared and the flux pinning effects of all samples were studied using vibrating sample magnetometer. We found that the pinning potential energy U increases but the flux pinning force F_p decreases when the magnetic moment of the rare earth element increases. We believe that this effect may come from the area of normal state resulting from the magnetic moment of the rare earth element which was particularly substituted for the Ca²⁺ ion of our samples.

A novel compound Fe-Ta-S crystal has been obtained using iodine vapor transport technology. At low temperature this compound is in a strong diamagnetic state, which is similar to a superconductor. The dependence of the diamagnetic phase transition temperature on the magnetic field could be expressed as T_c = T_c0 + γH^2/5 due to a strong coupling between electrons and the magnetic field.

Boron ions have been implanted into silicon at an incident energy of 3 MeV to a dose of 5 x 10¹⁵ cm^-2. Buried conductive layers have been formed in the silicon substrate after annealing at 1050°C for 20s. Infrared (IR) reflection spectrain the wavenumber range of 500-4000cm^-1 have been measured and interference fringes related to free-carrier plasma effects observed. By detailed theoretical analysis and computer simulation of the IR reflection spectra, the depth profile of the carrier concentration, the carrier mobility near maximum carrier concentration, and the carrier activation efficiency have been obtained. The physical interpretation of the results was given.

Blue emitting electroluminescent diode using PVCz doped with perylene and BBOT as electron transport has been constructed. The emission spectrum is a mixture of spectra of BBOT and perylene. A luminance of as high as 680cd/m² with lumen efficiency more then 0.0281m/W have been obtained.

Cubic boron nitride films have been synthesized using thermally assisted rf plasma chemical vapour deposition (CVD) with a tungsten filament in the reactive gasses of B₂H₆ and NH₃. The films obtained are of good quality and are characterized by transmission electron microscope, infrared absorption measurement and electron energy loss spectrometry. Experimental results showed that the structure and quality of cubic boron nitride films closely depend on the growth conditions of the films.

The Beijng Huairou extensive air shower (EAS) array has been operating since March 1988. Using data observed during the period from April 1991 through January 1993, a burst of 12 EAS events were observed within 2-minute interval beginning at 4:41’54’’ ante meridiem on December 30 1991 universal time, while only 2 EAS events on average would have been expected during such time interval.