The angular distribution of the neutrons from the N¹⁴(d, n) O¹⁵ reaction leading to O¹⁵ ground state was investigated in the angular range from 0 to 165 degrees (lab. system) by the photographic method. The energy of the bombarding deuterons was 1.96 MeV, and the Q-value was found to be Q₀=(5.13±0.05) Mev.
The angular distribution shows a maximum at about 30 degrees (c. m. s.) and decreases considerably beyond this maximum, in accordance with what is characteristic to the stripping process corresponding to l_p=1. In the backward direction, the intensity of neutrons increases remarkably and reaches the value almost three times as large as that of the forward maximum. The absolute cross section of this reaction was estimated to be σ(0°)=(2.4±0.7) mb/sterad. and σ=(38±7) mb.

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The natural rate of occurence of nuclear interactions of cosmic ray N-component in which more than 5 Mev are given to charged secondary particles have been measured in the nitrogen filled high pressure cloud chamber at Mt. Norikura (2840 m above sea level and 25°N geomagnetic latitude). From the rate of occurence of number interactions, the vertical intensity of N-component was estimated at (2.4±4%)·10⁻³· E^−1.4cm⁻²s⁻¹sr⁻¹Mev⁻¹ for the energy range from 10 Mev to 100 Mev by assuming the geometrical cross section. These events may be considered to be the source of the cosmic ray N-component with an energy less than that sufficient to produce nuclear interactions in the atmosphere, and it was shown that the spectrum of secondary particles was in accord with that of the latter. The absolute intensity of N-component was also consistent with that expected from the data of other energy regions in our previous paper. A possible scheme of the nuclear cascade was discussed in relation to the size distribution of the observed stars.

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Differential intensities of μ-mesons at sea-level at 24°N have been measured for the residual range equivalent to from 44 to 430 g/cm² of the air using a delayed coincidence method. It was found that the obtained range spectrum was nearly flat for present ranges and was 20 percent lower than Rossi’s curve which should be valid at geomagnetic latitude greater than 45°. The effect of the lateral displacement as well as the angular deflection of particles in the absorber was taken into account for the scattering correction. Mesons locally produced in the absorber was found to be at most a few per cent of all mesons that stop and decay in the apparatus. This fact suggests that the discrepancy between μ-meson spectra by the absorption method and by the magnetic cloud chamber method can not be accounted for only by the local π-meson production.

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It is shown that the radial distribution function of fluid can be derived from the expression for the free energy in the form of a “functional derivative” with respect to the pair interaction potential. Three examples are treated on the line of the theory: (1) the simple chain approximation of classical fluid, (2) the second quantization and (3) the lowest state of the spinless bosons derived by Bogolyubov and Zubarev. A procedure, which differs from the usual one, is given in the derivation of the expressions by which the pressure and the internal energy are expressed in terms of the radial distribution function.

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Submicroscopic topographies of oxidized stibnite and of etched zincblende were examined by electron microscopes. Crystallites of antimony oxide formed on stibnite have a roof-like shape bounded by two well-developed and four less developed {111} faces. This is in agreement with the conclusion drawn previously from electron diffraction study (Miyake, Sc. Pap. I. P. C. R. 34 (1938), 565). The direct observation by electron microscope gives some further information on the growth of the oxide. Zincblende surfaces etched by hydrochloric acid has a shape which is slightly different from the negative triakis tetrahedron inferred from electron diffraction study (Uyeda et al., Proc. Phys. Math. Soc. Japan 24 (1941) 1049). In the diffraction patterns from this surface, structures of reflexion spots finer than those previously reported were observed and analysed by the theory of the dynamical refraction effect.

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The impedance of bulk semiconductor in a junction diode, as defined as the “imref drop” for majority carrier divided by the total current through the junction, is calculated by using the low-level solution of minority carrier and is shown to have an inductive reactance, which becomes more and more dominant over the capacitive reactance of the impedance of the junction proper so that the impedance of the whole diode turns inductive as the injection level rises.

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Under the assumption that the anionic radical may be regarded as a rigid symmetric rotor, both the translational and the rotational lattice vibrations in the optical branches, which may be excited in isotropic complex crysta’s, are described on a macroscopic basis. By using the results obtained on it, the relative magnitudes of the mechanical and the radiative energy densities in the crystal are discussed for transverse vibrational modes. In addition, the interaction of a conduction electron with the rotational lattice vibration is investigated on the standpoint that the radiation field serves as a medium of the interaction.

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The frequencies of the translational and rotational vibrations (in optical branches) in the cubic NaClO₄ crystal, which is one of the complex crystals with simplest structure, are expressed in terms of the force constants of the interionic forces. The expression obtained with respect to the translational vibration is quite similar to that in the case of isotropic simple crystals, which is already known. Furthermore, by assuming reasonable values for these force constants, the orders of magnitudes of the both frequencies are estimated and compared with one another. The comparison shows that the both frequencies are nearly of the same order of magnitude.

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The electronic states of the F-center in LiF are theoretically investigated taking account of the detailed atomic structure of the crystal. The Hamiltonian of an F-center including polarization effects is presented. The polarizabilities of the ions in the crystal are determined from the static and high-frequency dielectric constants and the reststrahl frequency. Approximate eigenfunctions and energy levels are calculated with the use of variational wave functions comprising linear combinations of the 2s and 2p atomic functions on the six lithium ions adjacent to the missing negative-ion site. For both the ground and excited states, the resulting wave functions have larger coeffcients of the 2p functions than those of the 2s functions. The first optical excitation energy is obtained to be somewhat smaller than the experimental value; possible sources of this discrepancy are discussed. The g-factor of the F-center is also computed. A more satisfactory theory will be given in the next paper.

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The electronic structure of the F-center in LiF is investigated by making use of a variational wave function for the trapped electron which is orthogonal to all the ion-core functions. The variational parameters are so determined as to minimize the total energy of the whole crystal, including exchange interactions, polarization effects and van der Waals interactions. The equilibrium positions of the surrounding ions and the ion-core dipoles are determined in a self-consistent manner with the F-center wave functions. The resulting wave function shows correct oscillatory behaviors around each nucleus. The calculated first optical excitation energy is in excellent agreement with experiment. The associated oscillator strength is also evaluated. The line-width of the electron spin resonance is computed, yielding a value twice as large as the experimental value. A source of this discrepancy and other sources of errors which might have affected the energy levels are examined.

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Large single crystals of Fe₇Se₈ and Fe₃Se₄ were prepared, and their magnetic properties below the Curie point were investigated by a torque magnetometer. The results obtained on Fe₇Se₈ at room temperature show similar characterics to that of natural pyrrhotite (Fe₇S₈), i.e. the crystals can be magnetized only in the c-plane. As the temperature is lowered, however, the c-axis becomes the direction of easy magnetization. This change in direction seems to occur gradually. In the case of Fe₃Se₄, such a change in direction of easy magnetization does not take place. The obtained saturation magnetizations for Fe₇Se₈ and Fe₃Se₄ are respectively 68 and 80 gauss at the liquid air temperature.

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A nonempirical calculation of the electronic structure of the BH molecule based on a simple Heitler-London method is attempted. It is found that the results are in rather poor agreement with experiment and configuration interaction (CI) must be invoked. In the CI calculation we take into account all the configurations in which two electrons are retained in the 1s orbital of the boron atom. Thus we get 13 ¹∑⁺, 12 ³∏, 11 ¹∏, 9 ³∑⁻, 6 ³∑⁺, 6 ¹Δ, 3 ⁵∑⁻, 3 ³Δ, 3 ¹∑⁻ and 1 ⁵∏ configurations. In constructing the energy matrices, the orthogonalized atomic orbitals are used and we get the eigenvalue and eigenfunction of the lowest energy state of each symmetry by solving the secular equation. The results show marked improvements on those of the single configuration calculation.
A new nonempirical modification, in which intra-atomic energies are evaluated with atomic orbitals whose orbital exponents are adjusted according to an ionicity of the atom, is tried and leads to satisfactory results.

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In order to obtain an information about the configurational state of molecule in an aqueous solution of P.V.A., the measurements of the specific volume, the ultrasonic velocity and the dielectric constant were carried out over a certain range of the concentration and the temperature, and the experimental result was discussed from a view point of transition phenomena.
The result seems to show that in a region of concentration higher than a certain critical value (C_m) the configurational state of molecule in the solution is similar to that in solid P.V.A. plasticized by a solvent type plasticizer possessing no transition point, while in the region of concentration lower than C_m, only above a certain critical temperature T_β, a model of spherical coiled molecule is applicable. The heat of cross-linking estimated experimentally by making use of Eldridge and Ferry’s formula with respect to an apparent melting temperature of gel is about 12 k.cal./mol.

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The origin of magnetic aging in commercial pure iron is clarified by means of magnetic initial susceptibility and internal friction. It is due to very small amounts of carbon and nitrogen in iron, and the effect of nitrogen is more remarkable than that of carbon and it is dominant especially in the period of formation of intermediate nitride. Some possiblities that the different effect of nitrogen and carbon can be interpreted are suggested.

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The formulae for the velocity distribution over the surface of an obstacle of arbitrary shape are given to the transonic third approximation by the use of Imai’s thin-wing-expansion method. These formulae are applied to the flow past an elliptic cylinder and it has been found that the results are in accord with the other authors’s results within the order of the approximation used. Further, these formulae, together with the Ψ- and the ΦΨ-procedures, are applied to the flow past Tomotika-Tamada’s profiles. Calculated velocity distributions are compared with Tomotika-Tamada’s exact solutions as well as with Takami’s numerical results obtained by various approximate methods.
These formulae seem to be very useful, because their convergency and accuracy are very good up to considerably high Mach numbers.

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This paper presents detailed numerical evaluation of the Hermans-Fujita’s general equation for the electrophoretic mobility of a coiled polvelectrolyte molecule in salt solution. Values of the electrophoretic mobility u_p are obtained as functions of values of two basic parameters σ and β; here σ is Debye’s “shielding ratio,” and β is the radius of the polymer coil relative to the thickness of the diffuse double layer. It is shown that the criticism offered recently by Overbeek and Stigter for the validity of Hermans-Fujita’s u_p equation is doubtlessly incorrect. A procedure is demonstrated by means of which u_p vs. β curves for different fixed values of σ can be reduced approximately to a single curve. The approximate solution for the same problem obtained by Overbeek and Stigter is discussed and compared with the rigorous treatment in relation to this reduction procedure.

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Left column line 17 4∼7×10⁻¹⁴/cm³ should be read 4∼7×10¹⁴/cm³

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