Vol. 12, No. 1 (1956)
1956-01-05
CONTENT
1956, 12 (1): 5-19.
doi: 10.7498/aps.12.5
Abstract +
In this paper it is shown that our volume visco-elastic theory of fluids is applicable not merely to the case of structural relaxation as apparently regarded by some authors, but is equallyapplicable to all three kinds of relaxations-thermal, structural and chemical. From our equationof irreversibility of volume change (4), is inferred the equation of thermal irreversibility (10) as originally assumed by Herzfeld and Rice for the case of thermal relaxation. Also, in the case of chemical relaxation, our equation of irreversibility of volume change is shown to imply the equation of chemical irreversibility (15) as obtained from kinetic considerations by Lieber-mann.Regarding application of this theory to sound absorption and dispersion phenomena, Bourgin-Kneser equations (29) and (33) for the case of thermal relaxation and Liebermann equation (43) for the case of chemical relaxation are shown to follow directly from the results of our theory of compressibilities when the appropriate thermodynamic considerations have been made. This derivation reveals that Liebermann equation of sound absorption can be a good approximation only for the case of liquids.It is pointed out in passing that the accuracy of certain existing sound absorption and dispersion measurements in the case of gases has already made it possible to determine from them the static and instantaneous compressibilities β0 and β∞ and hence the two ratios of heat capacities γ0 and γ∞ and the external and internal heat capacities C(e) and C(i), and thus to draw directly from them certain conclusions regarding the structure of the molecule and the processes of energy exchanges upon collisions.Finally, the appropriateness of our definition of volume viscosity is discussed.
1956, 12 (1): 20-28.
doi: 10.7498/aps.12.20
Abstract +
The conditions of stability of thermodynamical equilibrium are derived by the method of statistical mechanics based on the formula of fluctuations. In the case of a chemically pure substance, the formula of energy fluctuation based on canonical ensemble is used with the result This is the required condition of stability. In the case of a homogeneous system consisting of l independent components the formula of fluctuation of energy and of the number's of molecules of different kinds are used yielding the result These are the yield conditions of stability.Finally, the condition of stability is investigated from the homogeneity rela-tion of extensive quantities.
1956, 12 (1): 29-40.
doi: 10.7498/aps.12.29
Abstract +
It is shown that the modified Schr?dinger equation proposed by Janossy cannot describe the behavior of the electron correctly. However, it is further shown that the equation can be regarded as a model of a possible phenomenalogical theory of nuclei or as a model of a possible theory of elementary particles. The quantization of the equation is discussed.
1956, 12 (1): 41-49.
doi: 10.7498/aps.12.41
Abstract +
Frequently, it was thought that frictional slip would occur in the direction of least resistance, which was unfortunately taken as the direction of the shortest normal to the free boundary. In this paper, the condition of least resistance is accepted, but the direction of resistance is properly determined without assumption. The result is "the rule of gredient", that is, at a given point on the contact surface, the direction of least resistance is the direction of the gredient of unit friction τ, which is related to the unit pressure P and the coefficient of friction, f, by τ=fP, the gredient lines of τ and P coincide with each other. Consequently, the family of least resistance lines of friction is exactly the family of curves orthogonal to the pressure contours, and can be determined from the experimental surface distribution of pressure. One case of such friction-lines in rolling is presented, the curves bear remarkable resemblance to the under-evalu-ted "probable" lines of friction derived by siebel from deformation meassurements. The way to consider change in direction of τ in one-dimensional theory of rolling is to take an average friction line whose direction cosine, cos φ, vanishes at the neutral section according to the gredient rule. By doing so, f cos φ corresponds to the "coefficient of friction" which vanishes at the neutral section according to Brown's theory. The Karman's equation is written in the mean value form by taking τx=fP cos φ instead of τx=fP. The modified equation yields solutions smoothly continuous at the neutral section, and two such continuous solution to Karman's equation for the case of solid friction are presented, detailed investigation is left to another paper. By simple arguement, it is thought that the boundary of no-slip region should be a crossed curve given by a pressure contour which is a roop according to experimental results.The rule of gradient has already led to three concequences, and is expected to be a very useful relation for plasticity under compression, because up to this paper the differential equation for slip direction remains unknown.
1956, 12 (1): 50-57.
doi: 10.7498/aps.12.50
Abstract +
For the purpose of supplying useful information to manufacturing organizations, and of systematically examining the effects of temperature and time of annealing on the domestically produced low silicon steel electrical sheets, a series of experiments has been performed. The results show that the lowest obtainable values of core loss of samples box-annealed in its own atmosphere are approximately P10=2.3 watt kg, P15= 5.2 watt/kg, 30% lower than the permissible values set in ГOCT 802-41 for э1A.
1956, 12 (1): 66-79.
doi: 10.7498/aps.12.66
Abstract +
The electron voltaic effect of semiconductor was first studied by Becker and Kruppke (see ref. 1) and later by Ehrenberg, Lang and West (see ref. 2 & 3). They found that the e.m.f. developed on the photo element under the bombardment of electron beam increases at first rapidly with accelerating voltage, reaches a maximum and then decreases. The accelerating voltage corresponding to the maximum e.m.f. developed on the cell was found to be various from cell to cell. In this paper a detailed theory of electron voltaic effect was developed under the assumption that the primary current of the electron beam is so small that a linear appoximation may be used. The Thomson-Whiddington law is used for getting the energy dissipation of the electron beam in semiconductor. The results of the present theory show that the e.m.f. developed on the cell appears a maximum, when the depth for which the incident electrons penetrate into the semiconductor is of the same order of the diffusion length of the excited electrons, rather than the thickness of the barrier layer. The numerical calculation is carried out for some typical examples and the results are discussed and compared with the experimental data.
