Vol. 27, No. 3 (1978)
1978-02-05
CONTENT
1978, 27 (3): 237-246.
doi: 10.7498/aps.27.237
Abstract +
The expansion coefficients of the SU(3)?SO(3) and SU(4)?SU(2)×SU(2) wave functions in the Gelfand bases are given for particle number f = 1-6 and f = 1-4 respectively.
1978, 27 (3): 247-259.
doi: 10.7498/aps.27.247
Abstract +
In this paper, a combined system consists of electrostatic round lens and magnetic deflector with additional superimposed fields is studied. The general power-series expression for magnetic deflection fields, the electron trajectories described in vector form and the Gaussian optical characters of the system are obtained and discussed. Formulae for calculating the third order aberration in such a combined system are given in a compact matrix form, they are appropriate for numerical computational purpose. This paper and the previous work [1] are all concerned with the general theory of a combined electrostatic-magnetic system of electron optics, hence they may be useful for designers of cathode ray tubes and electron optical instruments.
1978, 27 (3): 260-268.
doi: 10.7498/aps.27.260
Abstract +
The magnetic properties of two kinds of alloys (Ni-Pe-Nb and Ni-Pe-Nb-Al) after various heat-treatments are studied. The initial and maximum permeabilities are high and can be compared with those of the technical Mo-permalloys. Some of the physical parameters of Ni-Pe-Nb and 4Mo-permalloy are tabulated here for comparison.The quaternary Ni-Pe-Nb-Al alloy possesses higher Vickers hardness and electrical resistivity. Curves of a. c. magnetic permeabilities of the Ni-Pe-Nb-Al alloy specimens are presented.In the specimens of Ni-Pe-Nb-Al after slow cooling from high temperature, modulated structures are developed with a wave-length of about 160?. Eapid cooling from 970℃ suppresses the formation of the modulated structure. The material with a modulated structure possesses higher hardness as well as higher coercive force.
1978, 27 (3): 269-275.
doi: 10.7498/aps.27.269
Abstract +
After a careful study of the article by Hull and Rimmer, we found that there existed some contradictions between the facts and theory put forward. Basing on the experimental data from related references and those obtained in our own laboratory, and retaining the rational basis of the above mentioned work, we suggest a new mechanism of creep rupture and derive a formula for the rupture time. The theoretical values agree fairly well with those measured. From these results, it seems that our treatment has improved some what the theory of Hull and Rimmer.
1978, 27 (3): 276-283.
doi: 10.7498/aps.27.276
Abstract +
This paper deals with the properties of films used as entrance window of a gas-flow type ultrasoft X-ray counter. The effects of the base material and conductive coatings of the films on performance characteristics of the counter are investigated. Experimental results show that, among the material under study, Formvar exhibits more satisfactory gas-sealing property and has higher transmissivity for X-rays. In addition, it is found that the conductive coating on the film has a significant effect on the stability of the measured intensity. An interpretation on these effects by taking into acounts of the feature of electron multiplication process in the counter caused by ultra-soft X-rays is proposed.
1978, 27 (3): 284-290.
doi: 10.7498/aps.27.284
Abstract +
In this paper, the possibility of realization of a dye laser with double pumping source is discussed. The introduction of an auxilary T1 → S1 pumping is shown to be beneficial in lowering the laser threshold, increasing the gain and flourescence quantum yield, and further extending the types of laser dyes and the frequency tunning range.
1978, 27 (3): 291-302.
doi: 10.7498/aps.27.291
Abstract +
In this paper, the impurity profile of the 4 mm band silicon avalanche diode is studied by means of the characteristics of the Schottky barrier. The characteristics of the impurity profile of the epitaxial layers, the impurity profile of the device and its effects on device performance are measured and discussed.
1978, 27 (3): 303-313.
doi: 10.7498/aps.27.303
Abstract +
In this paper, we report the design and performance of a rotational type lumious intensity distribution measuring device and an integration sphere. They can be used to measure the angular distribution of luminons intensity and total light flux of LED's. Geometry of the experimental arrangement is described in detail. Measure-ments have been carried out on red emitting GaAsxPx-1, yellow and green emitting GaP and up-conversion GaAs diodes.
1978, 27 (3): 314-321.
doi: 10.7498/aps.27.314
Abstract +
The irregular variation of lattice constants of the α-LiIO3 single crystal originated in the growth process and the fluctuation phenomena of lattice constants under the action of an electrostatic field were investigated by an X-ray double-crystal spectro-meter in the (n, -n) arrangement.The results obtained support the view point that the enhancement of neutron diffraction intensity of the l≠0 reflection under the action of an electrostatic field along z-axis is due to the existence of a gradient of lattice constant c.
1978, 27 (3): 322-330.
doi: 10.7498/aps.27.322
Abstract +
In this article, dynamical features of non - equilibrium phase transitions are dis-cussed, taking the physical problems of OPO and laser processes as two examples. The phase transition point is found to be the point of sudden change from a stable nodal point to a saddle point. The role of fluctuations and dissipations in such phase transi-tions is elucidated, and critical exponents analogous to those in the second order phase transition are found (β = 1/2, γ = 1).
