The angular correlation of gamma rays in 2–2–0 cascade transitions in Xe¹²⁶ and Te¹²⁶ is measured from the decay of I¹²⁶ in order to obtain the mixing ratio of competing E2 and M1 transitions in the 2–2 transition. The mixing ratio is found to have positive sign for both nuclei, as expected from the systematics of excited levels in even-even nuclei.

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The gamma and beta rays following the decay of I¹²⁴ which was produced by Sb (α, n) reaction have been studied with scintillation spectrometers both single and in coincidence, and with a beta-ray spectrometer. Three gamma rays at 2.74–MeV, 2.29–MeV and 1.50–MeV and probably 0.9–MeV which were not found in decay of Sb¹²⁴ were observed. The beta-gamma coincidence experiments revealed that the first positron group decays to the ground level of Te¹²⁴ so that the energy difference between I¹²⁴ and Te¹²⁴ becomes 3.22–MeV, being consistent with beta decay energy systematics. In addition this beta component was found to have an unique 1st forbidden type spectrum, showing the spin and parity of the ground state of I¹²⁴ is 2−. From these results we led to conclude the presence of two new levels at 2.88–MeV and 2.74–MeV which the spin value is probably 1 and the parity is negative. A doublet level at the second excited level previously reported was not confirmed in the present experiment. However a definite evidence of cross-over transition from the second level to the ground level was obtained which may indicate a presence of a 2+ level at the second excited level. The tentative decay scheme is proposed.

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A theory of the thermoelectric power of the NaCl crystal doped with CdCl₂ is developed, when we measure it by using the chlorine gas electrode. We derive also the expressions of it by taking into account the Coulomb interaction between defects in NaCl and AgBr, and estimate the correction terms to the simple theory. Next the relation between the thermoelectric power with the metallic electrodes and that with the halogen electrodes is derived, and the theoretical result is compared with experiments in silver halides and lead halides.

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The ionic conductivity, σ_i, of β-Ag₂Te and β-Ag₂Se is estimated from the time constant of the ionic polarization with the help of the galvanic cell Ag|AgI|specimen|Pt, showing that σ_i depends on the composition (deviation from the stoichiometric ratio) in contrast with the composition-independent σ_i in their α phase. The chemical potential of Ag ion, ζ_i, known from the e.m.f., E, of the cell is also dependent on the composition in the β phase, and accordingly E does not represent the relative position of the Fermi level as in the α phase. This composition dependence of ζ_i and σ_i is accounted for by a simple theory. In addition, the electronic properties measured as functions of E are also compared with the theory with a correction to E by ζ_i.

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Domain structures in ferroelectric glycine sulfate are studied by etching in various alcohols. Methyl alcohol etches the head of polarization more readily than the tail end, and gives, in a relatively short time, clear domain patterns. Moreover, this etchant etches the (001) surface very slowly and after a long time delineates the arranging manner of domains along the polarization axis. Domain boundaries have cylindrical surfaces parallel to b axis, but the sections perpendicular to the axis are quite indefinite in dimensition and direction. Domain terminated with a rounded tip in the antiparallell domain was observed. Crystal imperfection seems to have a considsrable effect on the domain structure of this crystal. Some preliminary studies of domain wall motion under the application of electric field are also reported.

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The electronic structure of the U₂ center is studied by using the so called “point ion lattice model”.
The wave function which is obtained for the ground state of the U₂ center by considering the effects of various kinds of interactions, is applied to analyze the observed data of E.S.R.
The 1s wave function of the free hydrogen orthogonalized to the core orbitals of the surrounding ions gives us the interpretation of E.S.R. in the order of magnitude, however, there still remain some discrepancies between the calculated and the observed values. The physical origins of these discrepancies are considered. The large zero point vibration of the U₂ center suggests to us that the width of the absorption curve of E.S.R. is broadened about 20% by the vibration. Discussions on the effect of polarization, of crystalline field and on the optical absorption are made briefly by assuming the point ion and dipole approximation.

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Cleavage surface of ferroelectric G.A.S.H. crystal was etched with a mixture of water and ethyl alcohol, followed by rinsing in benzene. Identical etch pits were observed on matching cleavage faces. Density of the pits is 10⁴/cm² in the order of magnitude. Mechanical shock produces etch pits. Successive etching causes growth of pits at the unchanged locations. These facts lead us to conclude that the pits must correspond to dislocations. Patterns of etch pits on the upper and the lower cleaved faces of the crystal indicated that dislocation penetrates the crystal several hundred micron thick. Pair arrangements and linear arrays of etch pits were observed. Etch pits, of which the deepest points differ from the centers of triangles, correspond to dislocations not perpendicular to cleavage surface.

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Pure quadrupole spectra of N¹⁴ in para-bromoaniline, para-chloroaniline, para-phenylenediamine, and urea were obtained. From the spectra quadrupole coupling constants and asymmetry parameters were determined. The apparent intensity of the high frequency line was always greater than that of the low frequency line when the method of Zeeman modulation was applied. This fact was interpreted from the second-order perturbation theory of Zeeman effect. By using the method of frequency modulation, the intensity difference between two lines became so small as it was interpreted with the population-difference between each state. The principal axis system of nitrogen in para-bromoaniline was determined with Zeeman studies. Discussions supported that the three bonds about nitrogen in these compounds are coplanar with the plane of benzen ring.

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Exact solutions of the Thomas-Fermi equation for positive ion have been obtained including their derivatives by the inward numerical integration. The whole range of the ionization degree of physical interest has been covered in sufficient detail to permit accurate interpolation for intermediate regions. Using these numerical solutions, several physical quantities of free positive ions have been investigated.

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Saito et al have observed anomalous behaviours in the double resonances in metal halides in the early stage of saturational narrowing. They have reported following observations, which remained unexplained.
(1) The resonance line of the traced nucleus (B) becomes asymmetric and simultaneously shows shift, when the frequency of the nucleus (A) irradiated by the strong r.f. field is slightly off-resonant.
(2) In the case of the exact resonance, the intensity of the B-resonance decreases and the line disappears from observation. They called this phenomenon “collapsing”.
(3) In some crystals (e.g. Li F) having short spin lattice relaxation time, anomalous effects (1) and (2) do not appear. Recently Bloembergen and Sorokin have observed a large dispersive polarization of the saturated Cs¹³³ in Cs¹³³ Br⁸¹ double resonance by applying a r.f. field precessing near the Br⁸¹ resonance. At first sight, above mentioned two phenomena appear to be very different, however, they are closely related to each other. It is the purpose of this paper to propose a general theory unifying the two different situations by taking into consideration the effect of the higher order transitions introduced by Bloembergen in discussing the “Overhauser Induction”.
By using a generalized Solomon equation derived from a density matrix, the behaviours of the coupled spin system is discussed.

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Complex Young’s modulus, rigidity and bulk modulus are measured at 33 kc/s, 66 kc/s and 1 Mc/s for polystyrene, polymethyl methacrylate, polyvinyl acetate and phenol resin. In each material, the storage modulus-temperature curve has a discontinuity in the slope, irrespective of frequency and type of modulus, at the glass transition temperature T_g determined from thermal expansion. This discontinuity takes place through a strong dependence of the modulus on the specific volume.
Besides, the first three materials exhibit secondary discontinuities at T_g′, about thirty degrees below T_g, both in thermal expansion and modulus-temperature curve. Some possible interpretations are given to this secondary discontinuity, resulting in the conclusion that the glass transition occurs over a rather wide range of temperature and is completed at T_g with increasing temperature.
The ratio of the temperature coefficients of the modulus, taken below and above T_g, agrees well with that of volume expansion curve. This is also the case about T_g′, being indicative of predominantly energetic nature of elasticity.
The loss factor begins to rise slightly at T_g′, then rapidly at T_g as the temperature is elevated, suggesting that local motions of molecular chains are first encountered at T_g′.
The real part of Poisson’s ratio seems nearly constant through the temperatures studied, including the glass transition temperature, whereas the imaginary part is found to vanish.

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Molecular rotation in cubic ammonium nitrate was studied by using a single crystal obtained by slow cooling from the melt. The observed X-ray scatterings of two different kinds were used: one is the Laue-Bragg scattering and another the diffuse scattering. The first and the second order diffuse scatterings of disk-like shape (sin(\varphi⁄2)⁄λ×10⁻⁸=0.1945, 0.3089) perpendicular to the direction a^* and its equivalents in the reciprocal lattice were observed in addition to the diffuse scattering due to ordinary thermal vibration. These diffuse scatterings were considered to be due to the rotation of nitrate groups.
By the study on the Laue-Bragg scattering two models of the hindered rotation were selected and it was found by the study on the diffuse scattering that one of these two models is most probable. Further, the correlation among the individual rotating nitrate groups was considered for interpreting the characteristic intensity distribution of the first order diffuse scattering as well as the existence of the second order diffuse scattering. One type of the correlations which is specified by a parameter P denoting the degree of the randomness in the distribution of the rotation-axes was taken into consideration for the analysis of the diffuse scattering. The model thus obtained is closely connected with the model of the rotation in the tetragonal ammonium nitrate and it seems that there still exists correlation not only between the neighbouring nitrate groups but also between remoter ones.

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Mechanisms proposed for the dielectric anomaly observed in the low temperature form of n-primary alcohols are re-examined, considering especially the influence of thermal history of a sample. The slowly cooled sample gives the longer relaxation time τ and wider distribution of τ than the rapidly cooled one. The activation energy for the dipole orientation depends upon the number of carbons in the alcohol molecule. Results obtained are different from those of previous investigators, but a reasonable model is obtained for this Debye-type abnormal dispersion.

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When a negative potential is given to the double probe usually used as floating condition for gaseous discharge, two ion sheaths formed around the two single probes may overlap. Application is made of this phenomenon in measuring the thickness of ion sheath in a dark plasma.

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Theory of excitation of standing waves in a uniform plasma layer by an injected electron beam is presented. Various characteristics of excited waves are investigated; in particular, discontinuous jumps of frequency and mode can be expected with the variation of electron density, layer thickness and beam voltage. The consequences of the theory are compared with experimental results. It is seen that observed phenomena concerning standing plasma waves are satisfactorily illustrated in a quite natural way.

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The two-dimensional high subsonic flow at the choked state past a symmetrical double-wedge profile placed midway between two parallel walls is investigated. The subsonic flow field over the front half of the profile is given by the relaxation solution for a Tricomi’s boundary value problem in the hodograph plane. The supersonic flow over the rear half is calculated by the method of characteristics. The results for the pressure distribution and the choking Mach number are found to agree well with Marschner’s analytical results over fairly wide range of the transonic parameter.

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In this paper, the well-known classical one-dimentional rheological equation of Voigtian material having a single retardation time is extended so as to be applicable to three-dimentional and large deformation, and Lagrange’s and Euler’s representations are explicitly used.
Our rheological equation in Euler’s representation is reduced to the most general stress-strain relation which was described by Rivlin and is derived by general procedure using the elastic theory of finite deformation, when its terms relating to viscosity are eliminated, and is reduced to the most general stress-strain rate relation which was derived by Reiner and Rivlin, when its terms relating to elasticity are omitted.
Then, the above equation is applied to simple elongation and simple shear, with satisfactory results.

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Observation was made on the surface cracks of soda-lime-silica sheet glass produced by sodium vapor treatment in vacuum at 350°C. It was suggested first by Andrade and Tsien and recently concluded by Gordon et al that these surface cracks are developed from latent Griffith cracks through some etching action (the so-called decoration by Gordon et al) of sodium vapor. According to the present experiment, there are several phenomena on the surface cracks which are difficult to explain by the latent crack theory. The correlations of surface cracks to the drawing mark or to the direction of the periphery of the specimen, for instance, can be more reasonably explained by the cracking mechanism due to the shrinkage of transmuted surface layers after the sodium vapor attack. In this connection, it should rather be prefered that the surface cracks are newly originated by the treatment.

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