The energy spectra of neutrons emitted in the reaction F¹⁹(d, n)Ne²⁰, produced by the 2.17 MeV deuteron, were measured with nuclear plates disposed at angles of 0 to 165 degrees, with respect to the incident deuteron, at intervals of 15 degrees. The general features of the spectra were consistent with the evaporation model. From these spectra, the energy levels of Ne²⁰ were found at excitation energies of 1.74±0.03, 4.20±0.04, 4.96±0.05, 5.62±0.04, 6.80±0.01, 7.16±0.09, 7.41±0.05, 7.90±0.04, 9.15±0.04 and 10.01±0.03 MeV. Some evidences for the existence of new levels at 0.65±0.04, 2.53±0.07, 8.32±0.03, 8.71±0.01 and 9.50±0.04 MeV were also obtained. The Q-value for the ground state transition was determined to be 10.81±0.03 MeV. The angular distributions of the neutrons leading to the ground state and the lowest four excited states, with exception of the uncertain states, were obtained and compared with the stripping theory. The agreement is not very good. The relative values of total cross sections for each neutron group were estimated.

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The absolute differential cross sections for the elastic scattering of 14 MeV neutrons in Al, Fe, Pb and Bi have been measured for large angles up to 170°. The neutrons generated by ³T(d, n)⁴He reactions were scattered by the disk-shaped scatterer, and counted by the n−α coincidence circuit with the resolving time of 4 ns. An anticoincidence method was used to reduce the accidental coincidences between the α-particles and the neutrons which run directly to the detector from the target.
Except for the lighter nucleus, the angular distributions obtained fit fairly well with distributions based on the optical model theory employing a surface imaginary part and a real spin-orbit coupling term.

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It was proposed in a previous paper that the multiplicity n_± of charged mesons produced in the high energy nucleon-nucleon interaction can be empirically expressed as a function of the inelasticity K and the Lorentz factor γ_c in the center-of-mass system: n_±≅3.5 K(γ_c−1) for γ_c\lesssim7, n_±≅9 K(γ_c−1)^1⁄2 for γ_c\gtrsim7. It is shown here that further experimental results published in recent years are also consistent with this dependence. It is also suggested, with the support of experimental material, that the peripheral collision of high energy α-particles with nuclei can be explained in terms of a superposition of a few nucleon-nucleon collisions so that the meson multiplicity in the interaction can also be represented by the above equations. The results of observation of a jet (3+33_α) initiated by a high energy α-particle (∼1.2×10¹³ eV/nucleon) are described.

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The Brownian motion of an oscillator in a thermostat is considered assuming simple forms of interaction between them. No further assumption is made except that the thermostat is always in thermal equilibrium in itself. Solving the Liouville equation or its counterpart in quantum mechanics the long time evolution of the system is clarified. Thus the theory connects automatically the irreversible and the equilibrium behaviors of the system without any ad hoc assumption as in conventional theories. The results include, as a special case, the equation derived by Kramers and Chandrasekhar using the theory of stochastic processes. It is shown that the oscillating part of the distribution function or the density matrix plays an important role to which the peculiar way of damping of the oscillator is to be attributed.

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Excess noise has been studied on narrow alloyed p-n junctions fabricated on heavily doped p-type and n-type germanium with less than 200 Å junction width, which exhibit inverted rectification and negative resistance in the forward direction. Considerable 1⁄f noise has been observed in a forward range, the character of which is stable and surface insensitive. Moreover, the noise was found to be mainly associated with the excess forward current that is peculiar to narrow p-n junctions. Measurements were made also at low temperatures down to 77°k on both noise and static characteristics. The origins of the excess forward current and the associated excess noise were discussed in connection with the crystal imperfection.

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The impurity band conduction was treated where the resonance energy (or the translational energy) is much smaller than the fluctuation of local potential energy. By the interaction with phonon, electron can hop from one localized state to another, exchanging the difference of the local potential energies for a phonon. The agreement between theoretical and experimental results is fairly satisfactory.

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Magnetic properties of synthesized solid solutions of ilmenite (MgTiO₃, MnTiO₃, FeTiO₃, CoTiO₃ and NiTiO₃) and hematite (αFe₂O₃) are investigated and it was confirmed that those of any ilmenite-hematite series can be divided into three parts: i) pure ilmenite, ii) solid solutions with R\bar3 crystal symmetry and iii) those with R\bar3c crystal symmetry. Pure ilmenites are antiferromagnetics having their Néel temperature below 80°K except MgTiO₃, the Néel temperature of MnTiO₃ being determined to be 41°K. The solid solutions with R\bar3 symmetry are ferrimagnetic except MgTiO₃ series which is paramagnetic. Ferrimagnetism in FeTiO₃, CoTiO₃ and NiTiO₃ series is due to the same mechanism, while that in MnTiO₃ series to the different one. The solid solutions with R\bar3c symmetry are again antiferromagnetics on which feeble ferromagnetism is superimposed.
Through the analysis of magnetic properties of ferrimagnetic specimens, the sign of superexchange interaction with the coupling angle (∠Me–O–Me) of 90° in the rhombohedral structure was determined.

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The forced magnetostriction above technical saturation was measured on some ferromagnetic materials at various temperatures, from the boiling point of oxygen to about 250°C. As expected theoretically, large forced magnetostrictions were observed either as the temperature approached up to the Curie point, or in the sample which has a considerable anomaly of thermal dilatation, such as alloys of invar system. The results obtained were discussed from the standpoint of thermodynamics. We also observed the magnetostriction at the temperature above the Curie point.

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When the PVA film is irradiated in CCl₄, PVA is swollen and crosslinked. A Phenomenological theory is proposed for this experiment. The processes are considered that with the change of diffusion constant CCl₄ enters into PVA as the radiation dose increases, and the radicals from CCl₄ react upon PVA and cause crosslinking. The results of calculation agree reasonably with experiments, that is, the weight changes of swollen polymers against the total dose, the gel fraction changes and the viscosity average molecular weight changes in sol fractions against the total dose. Other various mechanisms that can be considered are discussed .

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In the present work, it is reported that the glass transition phenomena of chain polymers can be studied by observing the temperature dependency of the photoelasticity of the materials, and the transition temperature determined using this method agrees with the second order transition point by the specific volume method for P.V.C., but for polystyrene it is a little higher and rather near to the softening point by the dynamical elastic method.

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The spin-lattice relaxation time of Cu-Tutton salt is calculated basing on the Van Vleck theory. At liquid helium temperatures, calculated relaxation time shows a remarkable anisotropy, which arises from the nature of orbital states of Cu²⁺ in the crystalline field. Its order of magnitude is too large compared with the value 2×10⁻⁴ sec. measured by Townes et al.. At liquid air temperatures, however, it is in fairly good agreement with experimental data if a reasonable value is assumed for the separation of the first excited orbital state from the ground state.

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The effect of the magnetic ions of those paramagnetic salts whose spin degeneracy is completely lifted by the combined action of the spin-orbit coupling and the crystalline electric field, on the magnetic resonance of nuclear spins and electronic spins of other kind of ions such as Cu²⁺, Co²⁺, Mn²⁺ substituted for the host ions are studied theoretically. General formulas for the resonance field shift, line width and the thermal relaxation time in nuclear (or electron) spin resonance in magnetic substances are given. T₁ and T₂ are here related to the difference between isothermal and isolated susceptibilities. Temperature dependence of T₁ and T₂ as well as magnetic field dependence of them are studied. At low temperatures they become longer rapidly (exponentially) as temperature is lowered while at high temperatures they are independent of temperature. Field dependence of the line width is of the type of H₀²+H_i² when the line is narrowed by spin-spin interaction among the host ion spins, or \sqrtH₀²+H_i² when the line is not narrowed, where H_i denotes the local magnetic field. Field dependence of 1⁄T₁ is always like H₀²+H_i². The theoretical results are compared with some available experimental data on electron spin resonance. The agreement between theory and experiment seems to be not unreasonable as far as order of magnitude and qualitative characters of the line width are concerned, though experimental data are now rather scanty.

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Nuclear magnetic resonance of transition elements in paramagnetic salts under two situations is studied theoretically. One is the case where the magnetic ions have no Kramers degeneracy and their spin degeneracy is completely lifted by the combined action of the spin-orbit coupling and the crystalline electric field. Another is the case of the ideal paramagnetic substances under a strong magnetic field and at low temperatures. The resonance field (or frequency) shift, the relaxation times T₁ and T₂ due to hyperfine interaction and the indirect nuclear spin coupling via electron spins are calculated. The results show that the nuclear resonance of transition elements in paramagnetic salts is expected to be observable under favorable conditions.

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The origin of the local high electric field in the electroluminescence of insulated phosphor particles is considered and attributed to the disturbance of the applied field due to the conductive substance in the insulative phosphor. The distributions of local field are calculated and the dependence of brightness on the applied voltage is discussed. However, the comparison with experiments is impossible because of the complicated structure of the phosphor. Finally, the luminous efficiency of electroluminescent cell is estimated and an agreement is obtained with the observed value.

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The flow past a normal plate is discussed phenomenologically by the free streamline theory. The pressure distribution on the normal plate is determined by the pressure distribution on a free streamline which is obtained as a function of the distance from the separation point. In case when the latter is obtained only in the “free streamline range” (e.g., the range from the separation point to a distance equal to about one and a half of the breadth of the plate), the pressure distribution and other quantities on the normal plate are estimated with their probable deviations. The shape of the free streamline is also examined.

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Two-dimensional rigorous solutions are presented for the acoustic field in the air caused by the vibrating source arbitrarily distributed on an infinitely thin and infinitely long ribbon. Using rectangular coordinates, the unique solution satisfying the boundary condition is obtained by the method of expansion in the hypergeometric polynomials. The expression of the velocity potential at large distance, pressure on the ribbon plate and power of radiation are obtained as a function of k=2πa⁄λ, where a is the half-breadth of the plate and λ is the wave length.

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It is shown that the equation of perturbation given to a known two-dimensional or axisymmetric flow of compressible fluid can be written in a simple form by choosing appropriate coordinates.
From an approximate solution of this equation in the case of a slender body, we can deduce a velocity transformation formula
∫_U^q\frac\sqrt1−q²⁄c²qdq=log\left(\fracqU\ ight)_i,
where q, c and U are the velocity of fluid at an arbitrary point on the surface of the body, the local velocity of sound and the velocity of free stream (the critical speed of sound being taken as the unit of velocity), and (q⁄U)_i is the velocity of incompressible flow at the same point taking the velocity of free stream as unit.
Though this result has been given earlier by Imai in two-dimensional case and by Kusukawa in axisymmetric case, our deduction gives it as a first approximate solution which could be refined by a procedure of successive approximations. It is also expected that the perturbation equation will play some important role in mathematical discussion on mixed flow problems.

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The attenuation of ultrasonic waves for suspensions of polymethyl methacrylate particles (mean radius a=ca. 40μ) in ethyl alcohol, carbon tetrachloride and their mixtures are measured in the range of frequency 1–6 Mc/s. For ka>0.5 (k=2π/wave length) the scattering and reflection losses are found to be predominant origins of the attenuation. But when ka approaches unity, the observed attenuation lies markedly below the prediction from Rayleigh’s formula which is established under the condition of ka<<1. For ka<0.5, the viscous loss predicted by Lamb and Urick and the loss due to the internal viscosity of suspended particles become appreciable. A simple theory for the latter loss is developed under some assumptions. The sum of the theoretical values of these three kinds of losses is in satisfactory agreement with the experimental one. In the frequency range where the internal loss predominates, the method employed in this research can be used to measure the volume viscosity of a solid material.

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A new method of observing the limit of superheat was devised, in which small drops of a sample liquid are heated as they rise up in the non-soluble heating liquid with a suitable temperature gradient upward. Using the method, the limit of superheat was determined, mainly for some saturated hydrocarbons and polymethylenes. The result was compared with Döring’s theory of spontaneous bubble formation in superheated liquids. The agreement between the theory and experiment was satisfactory, which seems to throw some light upon the problem of surface free energy on the nuclear bubble.

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P. 319   left column, line 4 to 5
0 1/8 1/8 \curvearrowleft, 0 7/8 7/8 \curvearrowleft;
0 1/8 7/8 \curvearrowleft, 0 7/8 1/8 \curvearrowleft.
should be read
1/2 1/8 1/8 \curvearrowleft, 1/2 7/8 7/8 \curvearrowleft;
1/2 1/8 7/8 \curvearrowleft, 1/2 7/8 1/8 \curvearrowleft.
P. 321   left column, in the equation (4), Δf_s·Δf_s′
should be read ⟨Δf_s·Δf_s′⟩
in the equation (6), (Δf_s)² and Δf_s·Δf_s′
should be read ⟨(Δf_s)²⟩ and ⟨Δf_s·Δf_s′⟩

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Eq. (11), page 652, ∫₀^t\fracNaxKc₁dx   should read ∫₀^l\fracNaxKc₁dx.

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Caption of Fig. 7, page 964, should read: “Rate of adsoption versus amount of H₂O adsorbed.”

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