[en] The superconducting magnet development work at the Institute of Electrical Engineering, Academia Sinica, is described. Progress with the main projects: high energy physics, fusion, MHD power generation, superconducting homopolar generator, magnets for scientific instruments, high field magnets and magnetic separation, is summarized. The near future programmes are outlined. (author)

[en] Using a superconducting foil, rolled up with a magnetically neutral layer in between, it is possible to homogenize the magnetic field of a simple coaxial solenoid. As the foil very effectively decouples the fields inside from those outside, it can be used even within closed superconducting shields without the need to calculate the influence of the shield on the homogeneity. (author)

No abstract available

[en] In terms of the microscopic theory of superconductivity it is shown that in layered superconductors with the Josephson interaction between the layers the dependence of supercurrent on the phase difference in the layers has the form of j(φ)=Σj_nsin(nφ). The amplitudes j_n are the growing functions of the tunnel integral relation between the layers and the order parameter σ/Δ and decreases with the growth of n. The contribution to supercurrent from the terms with n > 1 at σ/Δ ∼ 0.03 does not exceed 2%, while at σ/Δ ∼ 0.1 this is about 8%. The density of states N(ω is calculated. It is shown that the gap in the spectrum is less than |Δ| and the root at ≠ Δ is absent. The effect of nonsinusoidal supercurrent on the Josephson vortex atructure and the voltage-current characteristics is discussed

[en] The physical information derived from induction measurements of superconducting transitions in ceramic samples is analysed and possible parameters of rf squids at nitrogen temperatures are estimated. Intrinsic fluctuations of the magnetic flux in the superconducting ceramics are revealed, which lead to excess noise in quantum interferometers

[en] The motion of fluxons in long Josephson junctions with a spatially nonuniform distribution of the critical current density is investigated theoretically and experimentally. The possibility of resonances between the fluxon and plasma modes is predicted and the conditions for such resonances are formulated. Numerical simulation of the current-voltage characteristics show that there are steps on them which correspond to soliton-plasma resonances. The dependence of the position of the steps on the parameters of the junctions is elucidated. Some features predicted are observed experimentally in the current-voltage characteristics of Nb-NbO_x-Pb junctions with artificially formed inhomogeneities in the dielectric layer. The experimental results are compared with calculations carried out within the framework of perturbation theory and with numerical simulation

[en] Functional integral techniques are utilized in the study of the superconductivity in a system of electrons containing both, a large band and a narrow-one with large effective mass and an attractive coupling. After deducing the free energy functional, the equations for the order parameter and transition temperature are obtained and discussed. Finally the electronic specific heat and its jump at T_c are calculated. (author)

[en] The study on a new superconductor oxide Ba-Y-Cu with high critical temperature Tc is described. The experimental results show that positron lifetime reducing reflects variable curve of resistance with temperature. A peak of positron lifetime is appeared at critical temperature

[en] Temperature dependences of electric resistance and inductive diamagnetic response of samples of solid solution compounds in Y-Ba-Cu-O system, prepared by the method of solid phase synthesis are investigated in 4.2-290 K range. It is shown that large-sized crystals of YBa₂Cu₃O_6+δ, δ=0.9-1.1 composition should be grown in order to achieve abrupt superconducting transition in Y-Ba-Cu-O

[en] The influence of reactor radiation by fast neutrons at low temperatures and further annealing on temperature dependence and transition to the superconducting state of high-temperature superconductors (HTSC) Y_1.2Ba_0.8CuO_4-δ and Y₁Ba₂Cu₃O_7-δ is studied. Long annealing (120 days) of samples prepared by 1.6x10²² m^-2 neutron fluence is shown to lead to loss of superconductivity. The character of temperature dependence of resistance changes in this case from metallic (dR/dT>0) to nonmetallic (dR/dT<0). From the results obtained it follows that degradation of superconductivity in HTSC under irradiation at higher temperatures can occur in fluences ∼ 10²² m^-2