Photoneutron cross sections of Cl³⁵ and S³² have been studied with a 30 Mev betatron by measuring the induced activity yields of Cl³⁴ and S³¹ respectively. Yields were measured by flow method to suppress activities from other types of reactions. The cross sections of the two reactions attain maxima at 19.8 and 20.5 Mev, their values being 13.5 and 13.6 mb respectively. The widths of the giant resonance curves are 6.5 and 6.3 Mev and the integrated cross sections are 93 and 86 Mev-mb respectively. In the yield curve of Cl, breaks were observed at 13.8, 14.1, 15.1, 16.2, 17.6 and 18.2 Mev, and in the case of S at 16.2 and 17.0 Mev.

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The time dependent perturbation series for the density matrix is shown to be equivalent to an integral equation. This integral equation is given in the form of a series in the coupling parameter λ, which is allways convergent when t→∞. The terms of this series can be represented by time retarded operators.

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Theory of degradation previously reported is generalized. In this paper rate constants are not restricted to two kinds. Fundamental equations which determine the distribution of molecules are formulated. Their solution is obtained and time dependence of number, weight and viscosity averages of degree of polymerization are studied. Results are closely analogous to those given in the previous paper.

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Relaxation time of a Richter type after-effect in nickel-zinc ferrites was determined as a function of ferrous ion content. It was expressed as τ=τ_∞exp(E⁄kT), where both τ_∞ and E were functions of ferrous ion content.
Analysis of τ_∞ in terms of a wall relaxation model showed that τ does not directly mean relaxation time of electron diffusion τ_e, though they have a close connection.

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Exciton states in alkali halides are analysed on the basis of a “transfer” model. Numerical calculation is made for the exciton state in KCl. The Hartree-Fock solutions of the 4s electron in a free potassium atom and of the 3p electron in a free chlorine atom are used for the wave functions of the transferred electron and the hole, respectively. The result obtained for KCl is employed to discuss exciton structures in KBr and KI qualitatively. The qualitative behaviors of exciton structures obtained for alkali halide crystals with fcc structure are similar to the conjectures of Eby, Teegarden and Dutton based on the analysis of their experiments.

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Kinetics of the resoftening of quench-hardened copper was investigated, and the activation energy for the resoftening was found to be about 5 eV. Two possible mechanisms of quench hardening in copper, i. e. stacking fault tetrahedra and extended prismatic loops, were discussed based upon this observation with reference to the transmission electron microscopy of quenched copper.

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Current-controlled negative resistances have been observed in a variety of point-contact Ge diodes. Experiments were done at 300°K and 243°K, using both dc and pulsed currents. In these experiments both contacts are of the ohmic, non-injecting type. The effect has been seen in both n and p-type Ge single crystals having resistivities that range from 0.1 to 50 ohm-cm. The frequency of the relaxation oscillations resulting from the negative resistance has ranged from 1 KC to 10 MC depending on the cathode-anode spacing and the external capacitance used. Analysis shows that thermal effects can not explain these results. The negative resistance is believed to be due to the two carrier current flow (double injection) in the bulk material after avalanche injection has been produced at the point contact. This explanation for the negative resistance differs from those previously proposed and allows predictions of the I-V curve as well as frequency limitations. Experiments with different sized points, varying pulse widths and magnetic fields are described and analyzed in terms of the above model.

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The proton resonance in borax agrees with the structure proposed by Morimoto. The lineshape in Na₂B₄O₇. 5H₂O can be accounted for by writing the molecular formula as Na₂B₄O₆(OH)₂·4H₂O. In lower hydrates, protons do not exist as in water molecules and an amorphous structure is proposed. Na²³ resonance confirms this view. B¹¹ resonance suggests that there exist two types of boron atoms in these borates—one with trigonal and other with tetrahedral co-ordination.

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Electronic specific heats for various transition metals at higher temperature are deduced from experimental results. It is pointed out that the transition metals with small values of paramagnetic susceptibility and coefficient of low temperature specific heat, γ₀, have larger values of the electronic specific heat than the extrapolation of γ₀T, and the metals with large values of these have smaller values of the electronic specific heat than the extrapolation of γ₀T, at higher temperatures. With use of electronic state density determined from the data of γ₀, for Cr–Fe and Cr–V alloys, the temperature variations of electronic specific heat and spin susceptibility of Cr are calculated at arbitrary temperatures. The calculated electronic specific heats satisfactorily agree with the experimental results, whereas the calculated spin susceptibilities are smaller than the experimental results. It is pointed out that the main difference is attributable to the orbital paramagnetic susceptibility.

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The Mössbauer absorption of Fe⁵⁷ in ordered Fe₃Al has been studied in order to examine the magnetic structure. Two different internal magnetic fields are found to exist in the crystal, corresponding to the fields at iron nuclei on two crystallographically different sites. The internal field values at room temperature are 299 kOe and 229 kOe, approximately proportional to the sublattice magnetic moments determined by polarized neutron diffraction. The temperature dependence of the internal field on each site is consistent with that of the saturation magnetization of the crystal. The extrapolated values at 0°K are 246 kOe and 336 kOe. The isomer shift of the Fe⁵⁷ with low magnetic moment is determined to be 0.28 mm/sec. This indicates that the 3d electron configuration of this iron atom is different from that of an iron atom in pure iron.

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Effects of the electron-electron interaction on the distribution function of warm electrons in semiconductors are investigated by the Born approximation with a screened Coulomb potential. The theory shows that the effect of the e-e interaction is remarkable, unless the density of the electrons is quite small. We compare the theoretical results to Gunn’s experiment. He observed the behaviors of the warm electrons n-type germanium doped with Sb at 77°K by changing the impurity concentration from 6.6×10¹³ to 2.9×10¹⁶ cm⁻³. We find that the theory does not give a good agreement with the experiment, when we do not consider the e-e interaction. The theory with the e-e interaction, however, agrees quite well with the experiment all through the impurity concentrations.

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A correct perturbational approach to the calculation of the magnetic anisotropy energy is presented. The theory is applicable even to the case of extreme anisotropy. The anisotropy energy is to be evaluated from the total (free) energy in a given direction of the magnetization vector. It is emphasized that one has to take into account, particularly in the higher order perturbation calculation, the presence of a thermo-dynamic magnetic field which fixes the magnetization vector in the given direction, because otherwise the magnetization vector deviates from the assumed direction, producing a false energy change. As an application the anisotropy energy in FeF₂ is calculated. The present theory yields a consistent explanation of both the magnitude and the temperature dependence of the observed anisotropy energy in FeF₂.

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The elastic constants of no crystal belonging to the crystal class 4, \bar4, 4/m have yet been determined. Pentaerythritol belongs to the \bar4 crystal class. All seven elastic constants of it have been determined by the study of (200), (202) and (004) diffuse reflections with [010] axis and, (200) and (220) diffuse reflections with [001] axis perpendicular to the direction of incidence of the X-rays. The value of the elastic constants thus determined is given below in units of 10¹⁰ dynes/cm².
C₁₁=6.1, C₃₃=8.0, C₄₄=3.5; C₆₆=4.6, C₁₆=−0.39, C₁₃=0.50, C₁₂=−2.5

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Crystal structures, electrical and magnetic properties of Sr(NiW)_0.5O₃-Ba(NiW)_0.5O₃ system were studied in the temperature range from room temperature to about 400°C. The compound of strontium undergoes a phase transition at about 260°C, where the crystal structure which is perovskite-like changes from tetragonal to cubic. The anomaly was also observed at the transition temperature in the measurements of electrical and magnetic properties. Sr(NiW)_0.5O₃ shows a rather small value of dielectric constant of about 17 and the magnetic susceptibility of 6.2×10⁻⁶ e.m.u. at room temperature. Ba(NiW)_0.5O₃ which is cubic in the whole range shows the similar values. Both substances behave as paramagnetic, though a small anomaly is observed in Sr(NiW)_0.5O₃ at the tetragonal-cubic transition. The effective Bohr magneton numbers of Ni²⁺ are estimated as 2.92 in the tetragonal and 3.06 in the cubic for Sr(NiW)_0.5O₃ and 3.02 for Ba(NiW)_0.5O₃. The lattice distortion observed in the compound of strontium is considered to be due to the slight variation of the electronic configuration of the transition metal ions surrounded by oxygen octahedra in the crystal.

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To investigate the correlation of electrons in the same shell due to the exchange correlation with the other unpaired electron, and so-called in-out effect, several approximate methods (Hartree-Fock, unrestricted Hartree-Fock, projected unrestricted Hartree-Fock, split shell and spin degenerate state configuration interaction) are developed. As the simplest example, the ground state ²S and first excited state ²P of the Li atom are considered. Slater type 1s, 2s, and 2p orbitals are adopted and the wave functions and total energies are determined by the variational method. The electron spin density at the nucleus (ψ²(0)) is given for the respective cases. Discussions on the results are given.

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The “Boundary-Perturbation Method” i.e. a general method for estimating the effect caused by a small change in the shape of the boundary (or, of the hypersurface in the many-dimensional space, the time-coordinate being included) upon the solutions or eigenvalues of linear partial differential equations, which was presented for the case of scalar fields earlier (J. Phys. Soc. Japan 15(1960) 2069), is developed to the case of tensor fields and formulated so as to permit their immediate use. Some examples are given to illustrate the method.

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A theoretical relation between molecular weight and temperature coefficient of ultrasonic velocity and boiling temperature has been derived following the theoretical treatment given by Kishimoto and Nomoto. This theoretical relation has been tested from the available data in organic liquids, liquified gases and molten metals and also the data obtained by the authors. It has been shown that Lagemann’s empirical relation is an approximation of this new relation. The deviations in some cases like alcohols, molten metals and liquified gases is attributed to molecular association in liquids and it is shown that better agreement will be obtained after applying a correction by using the association factor determined by Ramsay and Shield’s equation. A new relation between ultrasonic velocity and latent heat of vaporisation has also been obtained and confirmed by the experimental data for organic liquids, liquified gases and molten metals. This relation has also been obtained theoretically from thermodynamics.

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The expression (9) on page 1248 should be read as
n(p,k,t)=n(p,k,0)exp{−kr₁−(p−1−k)r₂}t+exp{−kr₁−(p−1−k)r₂}tUφ+Bψ)n(q,l,0).

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