Vol. 17, No. 3 (1961)
1961, 71 (3): 117-132. doi: 10.7498/aps.17.117
In this article the parametrically coupling of oscillations in a small ellipsoid of ferrite under the excitation of an uhf pumping of any spatial distribution is discussed. It is pointed out that the coupled oscillations may be induced through the two types of driving, field driving and magnetization driving. A special case of the former was recently discovered by Denton, who used a longitudinal pumping field uniform in space. A special example of the latter is found in Suhl's theoretical analysis and a number of experimental works after him. The pumping field transverse in direction and spatially uniform does not induce the coupled oscillations directly, but the rf magnetization of the Kittel precession excited by the pumping becomes the driving force of the oscillations. For each type of a uniform pumping we obtain from a set of differential equations the magnetostatic potential functions (the first order approximation) as linear combinations of Walker's functions. These solutions are different from those given by MOHOCOB. Making. use of the boundary conditions at the ferrire surface we find that for the Walker modes involved in the oscillations to be coupled, thtir indices must satisfy certain condi'ions. For the case of magnetostatic operations the dc magnetic field is tuned to a pair of the Walker modes, the potential functions may be reduced greatly. By studying the power drawn by the coupled oscillations from the pumping, we obtain the selection rules of a pair of magnetostatic modes excited by a pumping field of any given spatial distribution. We point out that for the determination of the amplitudes of the oscillations the equations derived from the conservation of energy and from the equality of the number of quanta emitted must be used. Finally, the threshold intensity of Denton's pumping field is derived using Suhl's method. We indicate that this method is based on a perturbation calculation.
1961, 71 (3): 133-134. doi: 10.7498/aps.17.133
An Experiment designed the p-resonance in π-π scattering process is suggested.
1961, 71 (3): 135-142. doi: 10.7498/aps.17.135
Up to now, the energy, spin and parity of the energy levels of Mg24 below 5.24 Mev. have been precisely measured, but those above it are far less accurate. Though the rotational Characteristic of Mg24 levels is well established, yet the discrepancy between the experimental value 4.12 Mev. and the value 4.6 Mev. calculated from the simple rotation energy formula is beyond the limit of experimental uncertainty. There are two kinds of corrections, the rotation-viberation interaction and the rotational perturbation. In this paper, we show that the levels of Mg24 can not be explained satisfactorily by taking into consideration either one of the above mentioned corrections singly. When both of them are taken up simultaneously, the experimental values of the energy levels and spin of Mg24 can be well accounted for and the recently measured γ-transition branching ratio and E(2)/M(1) ratio can also be explained.
As an attempt in the research of nonlinear networks, the application of the polyterminal network theory is suggested in the present paper.The fundamental character of the nonlinear polyterminal networks with constant flux is considered. Two theorems about N-terminal nonlinear network are established as follows:Theorem I: The nonlinear X-terminal network is determined by a function system of N-1 independent functions, each of which contains N-1 independent variables.Theorem II: The equivalent network of the nonlinear N-terminal (N>2) networks can not be realized by the nonlinear elements, whose potentialdifference-flux characteristic is a function of a single variable; the potentialdifference-flux characteristic of the nonlinear elements in the equivalent network of the nonlinear N-terminal network is a function of many variables.
As an important aspect of the application of nonlinear polyterminal network theory suggested in the accompanied paper, the problem of finding the flux distribution in the nonlinear networks with constant flux is disscussed in this paper.This polyterminal network method breaks the restriction of the previous methods for solving the nonlinear networks with constant flux. The procedure of this method with an example of solving the flux distribution in bridge circuit is given.