The Ar⁴⁰(p,γ)K⁴¹ reaction has been studied in the range of proton energies from 750 Kev to 1450 Kev using a thin Ar⁴⁰ target prepared by a method of electromagnetic mass separation. 66 excited levels in K⁴¹ were observed. Gamma-rays from the reaction Ar⁴⁰(p,γ)K⁴¹ have been studied at the six resonances occurring at E_p=1091, 1106, 1112, 1123, 1311 and 1391 Kev by the use of a NaI crystal scintillation spectrometer. In the nucleus K⁴¹, levels at 0.98, 1.29, 1.58 and 8.5∼9.2 Mev were observed. Spins of 1.58, 8.864 and 8.879 Mev levels were assigned to be 3/2, 5/2 and 3/2, respectively from the angular distributions of gamma-rays.

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Direct observation of 180° walls in an a-domain crystal of BaTiO₃ with circular electrode is reported. They are only visible during and a short time after switching.
Wedge-shaped antiparallel domains are detectable owing to the formation of the bright regions of 10⁻⁴ cm thickness at the domain boundaries. It is concluded that the optic elasticity axes of this boundary region are rotated about 1° from those in the inner part of the domain.

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The optical absorption spectrum of the interstitial Co⁺⁺ ion in KCl observed by Nasu and Kuwabara is studied theoretically in the framework of the crystalline field theory. The crystalline field parameters D_q and B are determined (D_q=325 cm⁻¹, B=734 cm⁻¹). The absolute value of the oscillator strength of the visible absorption peak is calculated, by using Van Vleck molecular orbital model. The calculated f value by using the 3d and 4p orbitals of the Co⁺⁺ ion and the σ orbitals of the ligands is in good agreement with the experiment. In this case, the Co⁺⁺ 4p orbitals which are admixed with the 3d orbitals play an important role in the intensity. The mixing ratio of the 4p orbitals determined from the observed f value is about 0.35. If K⁺ vacancies are present near the Co⁺⁺ ion, this value can be obtained by the perturbation due to the crystalline field of lower symmetry, but if the symmetry of the crystalline field is tetrahedral, such a large value cannot be obtained.

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The internal field or Knight shift and T₂ of Cu nucleus were measured in Cu-Ni alloys by spin-echo method in the whole concentration range. Ni resonance was measured for alloys containing less than 10 atomic percent of Cu. The internal field at the site of Cu nucleus in dilute Cu alloy is about −45 kOe and decreases with increasing concentration of Cu, c. The internal field at Ni nucleus decreases more slowly. The following model is proposed; the screening around Cu atoms is incomplete and only 0.4 part of one excess Cu electron goes into 3d holes of neighbouring Ni atoms. Cu has no d hole and the average moment of Ni decreases as (0.6−c)⁄(1−c). The internal field at Cu nucleus is mainly caused by the negative polarization of the 4s electron at Cu nucleus induced by the magnetization of the nearest neighbouring Ni atoms.

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Knight shift and some other properties of Cu nuclear magnetic resonance in Cu-Pd alloys were measured. It was observed that the shift is negative, and its magnitude is almost proportional to the susceptibility, having the value of −0.9% at 1 atomic percent of Cu. A deviation from the proportionality was observed in Cu dilute region and it is suggested that the charge screening radius is of short range. The transverse relaxation time increases with the concentration of Pd, and the resonance line width takes a maximum value at 25% Pd. The longitudinal relaxation time keeps a constant value, about 1/3 of that of pure Cu metal, through all the concentration measured.

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Indium-activated zinc sulphide single crystals were investigated on their luminescent, photoconductive and optical properties. Fairly bright yellow and green emissions were observed under ultraviolet excitation. Besides, additive coloration was found in ultraviolet and visible regions. The relative intensities of yellow and green emissions were strongly dependent on the stoichiometric composition of the crystals. The yellow emission was found to be closely correlated with the additive coloration and the photoconductivity. On the other hand the green emission was found to have less relation with the additive coloration and the photoconduction. Models were proposed for both emission centers based on the dual character of the indium ion: a trivalent indium ion in zinc site is the yellow emission center and a monovalent indium ion is the green emission centre.

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Magnetic susceptibility and nuclear magnetic resonance measurements have been made in Nb-Tc alloys. Calculations on the temperature variations of electronic specific heats and magnetic susceptibilities are performed for Nb and Mo metals and Nb-Mo alloys by making use of the density of states determined from low temperature specific heat data for 4d transition metals and their alloys. Temperature variations of the electronic specific heats for Nb and Mo metals are well explained by the present numerical calculations. Temperature variations of the magnetic susceptibilities of these metals and their alloys are explained by taking account of the effect of the temperature independent orbital paramagnetism and the effects of the negative (for Nb metal) and the positive (for Nb_0.75Mo_0.25 alloy) molecular fields. The Knight shifts of Nb⁹³ and Tc⁹⁹ in Nb-Tc and Nb-Mo alloys are discussed. It is shown that the main contribution to these Knight shifts appear to arise from the orbital paramagnetism of the d electrons.

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Quadratic deviation of mobility μ due to higher electric fields (E) (μ=μ₀(1−βE²)) in germanium and silicon has been measured in the temperature range between 150°K and room temperature by a microwave (9.6 kMc) absorption method. To heat the carriers, 0.5 μ sec. and 1.0 μ sec. pulse electric fields were applied and the induced mobility change was determined from the microwave absorption.
The measured values of “warm electron coefficient” β is compared with the theories of Stratton and Adawi. It is found that the experimental results for n-type germanium agree with the theory and that no difference between high and low resistivity n-type germanium exists.
The large discrepancy between the experimental and the theoretical values in the case of p-type germanium and silicon is considered to be due to the effect of the light holes.

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Mosaic structures in iron single crystal plates and their bodily changes in early stages of tensile deformation are investigated from the appearances of the X-ray spectral lines and the ground figures of the Laue-spots appearing on the X-ray radiograph taken by means of the Divergent X-ray Method.
The iron single crystal plates have such a mosaic structure that it consists of many narrow grains which are arranged almost along the direction of rolling by which the plate was made before conversion into single crystal and the mutual disorientation among them is the order of one minute of arc. Deformation pattern of ground figures of Laue-spots indicates that the virgin slip already occurs at about 0.1% of stretching.

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Magnetic field dependence of resistivity ρ and Hall coefficient R_H of antimony-doped germanium samples containing between 2×10¹⁶ and 1×10¹⁷ cm⁻³ excess donors have been measured below 4.2°K. These samples belong to the hopping or the intermediate region of the impurity conduction and the temperature dependence of ρ obeys an exponential law ρ_∞ exp(ε⁄kT). The main effect of the magnetic field is an increase of pre-exponential factor ρ_∞ for the hopping samples while it is an increase of activation energy ε for the intermediate ones. The increase of ε is proportional to H² and the proportionality coefficient depends on donor concentration, compensation ratio and it also depends slightly on temperature. A model which can qualitatively explain these features of intermediate impurity conduction is proposed.

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A wave-optical foundation is given for a geometrical optics for electrons and X-rays in distorted crystalline media. A “modified Bloch-wave” and the associated Eikonal function are introduced for this purpose. The modified Bloch-wave behaves like the usual Bloch-wave within local small regions. The trajectory of the wave can be given by a variational principle as to the phase integral along a path with fixed end points A and B, namely
δ∫_A^B(k₀·dr)=0
k₀ being the wave-vector associated with the modified Bloch-wave. This is nothing more than the Fermat’s principle. The Euler’s equation of the variational equation gives the change in k₀ along the trajectory.

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A theory of inelastic scattering of fast electrons by thin crystals is developed. The inelastic scattering exciting plasma oscillation, exciting or quenching thermal vibration, or causing band transition is an object of application of the theory.
Results of the theory are applied to interpretations of subsidiary maxima of Kikuchi pattern (R. Uyeda, Y. Fukano and T. Ichinokawa: Acta Cryst. 7 (1954) 217) and extinction fringes of electron micrograph produced by inelastically scattered electrons (Y. Kamiya and R. Uyeda: J. Phys. Soc. Japan 16 (1961) 1361, 17 (1962) Suppl. B-II, 191).

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The temperature dependence of the nuclear quadrupole resonance of N¹⁴ in C₂H₄(NH₂)₂ was studied between 77°K and 280°K. The resonance lines were measured with a Pound-Watkins’ type recording spectrometer by applying frequency modulation.
The curve of resonance frequency vs. temperature exhibited a break around 180°K. It could be attributed to a phase transition of the crystal structure. Another break suggesting the phase transition was also observed around the liquid nitrogen temperature.
The quadrupole coupling constant eQq and the asymmetry parameter η were 3.9965 Mc and 0.313 at the liquid nitrogen temperature. By assuming hybridized atomic orbitals of sp³ type for the nitrogen bonds, two alternative models were employed. In one model three nitrogen bonds have equal s-hybridization, and in the other model s-hybridization of the N-C bond is different from that of the N-H bonds. It was shown that the latter model was suitable.

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An anomalous microwave radiation from a dc discharge plasma in a magnetic field was observed. The intensity was extremely large compared with that of black body (about 1×10⁴°K) and amounted to the power radiated from the plasma in the thermal equilibrium equivalent to 5.5×10⁶°K in the case of Kr and 1.5×10⁶°K in the case of Xe. This radiation occurred very sharply at cyclotron resonance field, the width being by one order smaller than that of normal cyclotron radiation. The radiation was observed in Xe, Kr and Ar plasmas in the pressure range of 1×10⁻¹∼5 mmHg, but not in Ne and He plasmas at any pressure. Further, the radiation was observed when the whole tube was placed in a longitudinal magnetic field, but not when only a part of the positive column was immersed in the field.
It is discussed whether this anomalous radiation can be interpreted as a phenomenon of the negative radiation temperature at cyclotron resonance in partially ionized plasmas.

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In order to examine the validity of the power law for multiple ionization by electron impact, the probability curves of single and double ionization of Ca are studied in succession to the previous study on Na, K and Mg.
The formation of Ca⁺⁺ is not a simple square function of electron energy, but it increases gradually above the threshold and has two or three maxima between 25 eV and 30 eV, then increasing again steeply. The steep increase at 31 eV agrees well with the curve obtained by Fayard et al..
It is suggested that three different kinds of processes contribute to the formation of Ca⁺⁺. That is, process (I) which follows the square law corresponds to the direct ionization process, and process (II) which has some maxima is attributed to some autoionization processes, and process (III) which is linear to the energy is attributed to Auger ionization process caused from ionization of 3p electron.
Also brief discussion on formation of Ca⁺ is given.

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In a hot cathode discharge tube dipole oscillations having the frequency of f_p⁄\sqrt2 were observed without applying external oscillating electric fields, where f_p is the frequency of the plasma electron oscillation. In the presence of a weak magnetic field the dipole oscillation splitted into two oscillations whose frequencies were given by
f_±=\sqrt\fracf_p²2+\left(\fracf_c2\ ight)²±\fracf_c2,
where f_c is the cyclotron frequency of electron.

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A study is made of unsteady free convection flow from a vertical flat plate. Using similarity concept the Navier Stokes equations and energy equation are reduced to a set of ordinary non-linear differential equations and are then integrated using an integral method. Effect of the unsteady characteristic parameter ‘A’ on the temperature and the velocity profiles is studied. It is found that there exist for each Prandtl number, a value of ‘A’ for which there is no heat transfer at the plate. For A=0, the results reduce to the steady state case of Ref. 7.

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The unsteady, axially symmetric stagnation-point flow problem for an incompressible fluid past a body of revolution, with velocity outside the boundary layer fluctuating with time as U₀(x){1+εe^iwt} is investigated. By assuming U₀(x)=u₁x+u₃x³+···, and using Howarth’s corresponding power series solution for steady flow, a power series for the fluctuating velocity component is obtained, the coefficients of which are universal functions of η=y(2u₁⁄ν)^1⁄2, with ω as a parameter. Numerical calculations performed show that the variation of skin friction from the steady-state value becomes insignificant as the point of separation is approached.

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