Heat capacity of the solid solution of alpha-titanium with 8∼28 at% oxygen has been measured to investigate calorimetric effects associated with the interstitial order-disorder transformation of oxygen atoms. Anomalous heat absorption is observed in the temperature range from 300 to 600°C varying with oxygen contents. The transformation at oxygen contents higher than about 15 at% is characterized by the appearance of double peaks in the specific heat curve. In the light of the results of diffraction studies, the peaks are interpreted to be due to the two successive processes from the ordered phase α″ to the disordered solid solution α through the intermediate phase α′. The transformation energy and entropy as well as the critical temperature are determined as functions of composition. It is found that two maxima appear in the transition energy-composition curve around 15 and 24 at% O with nearly the same value of about 390 cal/mol, and that a similar behavior is also observed in the transition entropy-composition curve with the maximum values of about 0.3 R at these compositions.

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A theory of the interstitial order-disorder transformation in the h.c.p. lattice has been developed on the basis of the Bragg-Williams approximation. The calculated results are compared with the experiments on the Ti–O system reported in Part I and Part II. Oxygen atoms situated on the octahedral interstices are considered to repel each other. As the interstitial disordering proceeds in the two successive steps of the intra- and inter-plane disordering, analytical calculations are made by treating the two processes independently. Then numerical computations are carried out taking account of mutual correlations of these processes. It is revealed that the intra-plane disordering is considerably modified by simultaneous occurrence of the inter-plane disordering. The transformation energy and entropy are deduced as a function of oxygen contents. A tentative phase diagram is constructed by evaluating the repulsive energies for three pairs of the oxygen atoms. These results are consistent with the characteristic features observed experimentally, but some discrepancies are noted on the inter-plane disordering.

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One-dimensional anharmonic lattices with quadratic as well as quartic potentials between nearest neighbors are treated on computer to see the long-time behaviors of the vibration. As is the case of two-dimensional lattice, the induction period is found to exist and its length increases on decreasing the anharmonic coupling constant. The possible existence of the critical value of the anharmonic coupling constant is surmised, below which the system is almost periodic. Above this critical value, the system tends to reach a thermal equilibrium, which is confirmed by the long-time averages of the squares of the velocities and by the products of velocities of different particles. The significance of the errors introduced during computation for the ergodic property of the system is pointed out.

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A relation for the photon-magnon conversion efficiency in axially magnetized garnet delay line has been developed which is independent of the saturation magnetization and depends on the position of the turning point. Calculations have been made for the various positions of the turning point. The calculated result agrees with the experimental value.

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Pressure dependence of the magnetization of fcc Fe–Ni alloys including Invar alloy is calculated on the basis of a simple band model. This quantity is closely related to the pressure dependence of the critical composition which bounds the strong ferromagnetic state in Ni-rich region and the paramagnetic state in Fe-rich region. In the calculation, we use a step-type density of states curve and assume that there is fluctuation in the local composition characterized by a Gaussian distribution function. Calculated result is about a fifteenth in magnitude of the observed ones, but the variation with composition is exactly similar to each other.

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By the measurement of AC magnetic susceptibility, the field induced reorientation transition in Mn(HCOO)₂·2H₂O was observed over the temperature range from 1.3°K to 3.7°K(T_N). The transition could be verified by the change of the angular pattern of proton resonance. The threshold field, H_th, was found to be proportional to |T−T_R|^1⁄2 near the spontaneous reorientation transition temperature, T_R(1.7°K). The temperature dependence of H_th could be accounted for by the relation H_th=\sqrt2H_E|H_A| considering the competing two sorts of anisotropy energies which have different temperature dependences. The angular dependence of H_th on the external field direction was given by a hyperbolic relation in the b–d plane and by an elliptic one in the a–c plane. This dependence is discussed phenomenologically.

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Electron spin resonance (ESR) of manganese in copper and silver metals was investigated with a special interest to an anomalous line shift observed in the so called antiferromagnetic region. The shift was found to be nearly inversely proportional to temperature. This fact gives rise to a possibility that the effective anisotropy may come from the nuclear spin polarization as was first observed in antiferromagnetic KMnF₃. To check this possibility, and ENDOR study of the Ag–Mn dilute alloys was done and the effect of the nuclear anisotropy was verified by the result that the ESR signal shows a slight shift when the nuclear spin system is under saturation with the frequency between 240 and 340 MHz. The hyperfine constant |A| was determined as 40×10⁻⁴ cm⁻¹ which agrees with the data given by the γ-ray polarization experiment below 1°K. It is also found that the shift is much enhanced under the presence of the third element, such as Fe, Co, Ni, and Pd atoms.

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In pseudobinary system (Zr_1−xNb_x)Fe₂, the crystal structure is MgCu₂ type for x≤0.3, MgZn₂ type for x>0.5 and six layers structure for 0.35<x<0.5. The compounds show ferromagnetism for x≤0.4, antiferromagnetism for 0.4<x≤0.5 and (Pauli) paramagnetism for x>0.5. It is concluded with reference of the Mössbauer experiment that the magnetic moment of iron is far larger in MgCu₂ structure than in MgZn₂ structure. Dominant factors to affect the magnetic polarization of iron are the arrangement of the surrounding atoms as well as the magnetic polarization of the surrounding iron atoms.

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Superconducting tunneling effects in the mixed states of Nb, whose H_c2(0)=4450 Oe, were observed using the usual oxidization technics. Results are rather well explained by the theory of Brandt et al with the assumption of diffuse boundary scattering, if we substitute Δ·Λ⁄h·v_f by Δ·Λ⁄h·v_f·α, where α is an arbitrary parameter.

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The giant quantum attenuation of longitudinal sound waves in bismuth was investigated in pulsed magnetic fields up to 170 kG, at a temperature of 1.65°K and at sound wave frequencies of 60 and 100 Mc/s. The angle between the sound wave vector q and the magnetic field vector H was varied by rotating a sample. By combining data in a previous paper with the present ones the anisotropy of the spin splitting factor for electrons in the principal pocket is completely determined for two cases H||XY-plane and H||YZ-plane, where X-, Y- and Z-axis refer to a binary, a bisectrix and the trigonal axis, respectively. The Baraff theory is successfully applied to interpret the anisotropy, and values of some parameters in the theory are determined. The hole spin splitting factor for the case H||Z-axis is found conclusively to be (1.86±0.02).

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Superconducting tunneling effects were observed for Pb_0.7In_0.3–GaAs junctions in the magnetic field which was varied from zero to upper critical fields. Results are explained well with de Gennes′ theory above 0.7H_c2 and 0.56_c3, if we take τ, the correlation time, a parameter. Gap parameters are also explained well with usual theories of the second kind superconductivity.

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A series of solid solutions between Sr₂(FeMo)O₆ and Sr₂(FeW)O₆ were synthesized and their electrical properties were studied by the measurements of both the temperature dependence of the electrical conductivity and the Seebeck coefficient. The valence states of iron ions were studied by the Mössbauer effect measurements. The compounds in the range (0.5≤x≤1) have high conductivity (ρ\simeq10⁻³ ohm·cm) with the metallic type. The valence distribution between the B sublattice ions is considered to be Sr₂(Fe³⁺Mo_x⁵⁺W_1−x⁵⁺)O₆. The compounds in the range (0.3≤x≤0.4) is considered to be a semiconductor with a very small energy gap or a degenerate semiconductor. And the compound in the range (0≤x≤0.2) may be called semiconducting. A mixed valence compound Sr₂(Fe_1−x²⁺Fe_x³⁺Mo_x⁵⁺W_1−x⁶⁺)O₆ will be formed in the range (0≤x≤0.1). The rapid change in valence in the range (0.1≤x≤0.4) is evidenced by a rapid replacement of the Fe³⁺ ions for the Fe²⁺ ions.

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The photoconductivity of palladium 8-hydroxy-quinolinate has been measured by the method of illuminating a specimen with two different wavelength lights. Palladium 8-hydroxy-quinolinate shows a main-response of photoconductivity at the wavelength 600∼700 mμ and a sub-response at 900∼950 mμ. The sub-response is affected by another illumination: the sub-response is increased by the illumination of 500∼700 mμ and decreased by the illumination of 700∼1200 mμ. It seems that this photoconduction behavior is caused by the trapping of exciton.

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The absorption and luminescence spectra were observed below 77°K by using a high resolution spectrograph. The crystal field spectra show that the structures of some Tm³⁺ centers are common to both of ZnSe:Tm, Cu and ZnSe:Tm, Li crystals. One of the common centers has a cubic symmetry and the crystal field parameters A₄⁰⟨r⁴⟩=15.1 cm⁻¹ and A₆⁰⟨r⁶⟩=−2.5 cm⁻¹. The Tm³⁺ ion in this center shows strong emission. Discussions on the model of this center and on the excitation mechanism are given.

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Explicit expression for the mixing interaction due to the lattice anharmonicity between the upper and the lower branch of polaritons is derived, using the generalized Langevin equation. Treating the mixing in a rough approximation, the calculated dispersion of the damped polariton qualitatively coincides with the phenomenological one used by Rimai et al. [Phys. Rev. 168 (1968) 623] in explaining their observed data in BaTiO₃. Their observed data, however, does not call for the concept of polariton and the frequency shift considered by them is concluded to come from nothing but the coupling between the annihilation and the creation operater for the same Fourier component of the displacement of the ions.

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A theory of two-dimensional lattice scattering for electrons or holes in a semiconductor inversion layer is described. The theory can explain the electron mobility in Si inversion layers at room temperature taking the two-dimensional deformation potential constant as 23±1 eV.

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The theory of two-phonon absorption is given for the ultrasonic donorspin resonance in Ge. The result of calculations predicts that the dependence of two-phonon absorption on the direction of magnetic fields is different from that of one-phonon absorption. It is shown that the observation of two-phonon absorption can be expected in Sb-doped Ge at low temperatures.

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Acoustoelectric-after-effect followed by the abrupt termination of the externally applied voltage was studied in semiconducting CdS with Brillouin scattering measurements. Damping behaviors of the generated acoustic flux was first revealed experimentally. The acoustic loss is separated into electronic and nonelectronic contribution via linear and nonlinear process. The nonelectronic linear loss of the acoustic shear waves obeys ω^1.5-law rather than Akhieser’s prediction: ∝ω². White’s gain curve reduced by this nonelectronic loss agrees well with our experimental results. Nonlinear acoustic loss via second harmonic generation was also estimated. The nonlinear loss is mainly ascribed to the nonlinear acoustoelectric interactions, but not to the lattice anharmonicity. Finally, the relationship between the acoustic flux φ and the acoustoelectric-after-current I was found to be I∝φ². This means that our observed after-current is mainly caused by the nonlinear acoustoelectric interactions.

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Dielectric constants of KH₂PO₄ below and above the transition temperature were precisely measured with and without dc biasing field. Phenomenological theoretical consideration on experimental results suggests that KH₂PO₄ undergoes a first-order phase transition.

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In iron-doped gallium phosphide two sorts of EPR spectra (denoted A and B spectrum here) have been observed: g=2.020±0.001, and g=2.131±0.002, for the A and the B spectrum, respectively. The A spectrum is attributed to the (3d)⁵ configuration of substitutional Fe. The B spectrum seems to be attributed to the (3d)⁷ configuration of Fe. The center corresponding to the B spectrum (B center) is not the center corresponding to the A spectrum (A center) which have trapped electrons, but an Fe impurity at a certain site of the lattice which have trapped a hole. Both spectra are photosensitive. Measurements of their photoresponse and temperature dependence have been made. They show that the activation energies of electrons and of holes for the A center are 0.5 eV and 1.7 eV, respectively.

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To elucidate the mechanism of the substitutional solid-solution strengthening of iron, evaluation of the modulus parameter and the direct observation of dislocation configuration were made for six alloy systems; Fe–Be, Fe–Al, Fe–Si, Fe–V, Fe–Ge and Fe–Mo.
The rate of the solid-solution strengthening at 300°K was best described as a function of the combined mismatch parameters by the equation d(τ⁄μ)⁄dc=0.04(ε_μ′+1.5ε_a)², where ε_a and ε_μ′ are the size and the modulus mismatch parameter, respectively. The dislocations observed at the lower yield point were almost of screw type in all the alloys but their densities were extensively different from alloy to alloy.
It was concluded that the elastic interaction of screw dislocations with the solute atoms was the dominant cause of the solid-solution strengthening of iron at 300°K. The wide variety of dislocation density was well-explained by a proposed model that it is determined by the condition for the applied stress to be minimum in a constant strain-rate.

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A theory is developed which allows one to discuss the stability of multiply-twinned particles and to calculate critical sizes for stable and quasi-stable states.
An icosahedral particle is essentially stable for r≤r_iw^*, quasi-stable for r_iw^*<r≤r_it⁰ and unstable for r>r_it⁰ where r is an edge length of the particle, while a decahedral particle is not essentially stable but quasi-stable for r≤r_dt⁰ and unstable for r>r_dt⁰. The critical sizes r_iw^*, r_it⁰ and r_dt⁰ are formulated as functions of the specific surface energy γ_hkl, the twin boundary energy γ_t, the elastic strain energy W and the adhesive energy γ_a to the substrate. Calculated critical diameters 2r_iw^*,2r_it⁰ and 2r_dt⁰ for the particles grown in free space for several elements range between 15.5Å and 106.8Å, between 109.8Å and 486.1Å and between 725Å and 3961Å, respectively. These values are in good agreement with experimental results.

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The corrections of the mean inner potential, or the scattering factor of 0-th order V₀ due to plasmon excitation and phonon excitation are calculated on the basis of the 2nd order perturbation theory. It is shown that the contribution of the plasmon excitation becomes large in low energy electron diffraction. Numerical calculations are performed for Si and Al.

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The energy loss spectra of electrons at the accelerating voltage 100∼500 kV are measured. The most probable energy loss depends on the orientation of the crystal to the incident beam. The most probable energy loss at the Bragg reflecting position is less than that at other diffraction conditions. The energy loss in thin crystal about 5 μm thick is less than that expected by the Landau theory (J. Phys. USSR 8 (1944) 201).

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A general theory for the intensities of X-rays scattered by molecular crystals was under harmonic approximation given by taking account of the molecular translational and librational lattice vibrations as well as their mutual coupling. The molecules were taken as rigid bodies. The relationship of this theory to the other ones hitherto given for the diffuse scattering by molecular crystals was discussed.

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The Ochkur approximation method was used to calculate the excitation cross section for the 1s→3s, p, d transitions of H in electron-hydrogen collisions. The results of this calculation are compared with those of other approximation methods and with experimental results.

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Absorption cross sections and photoionization efficiencies of I₂ have been measured in the 600 to 1000Å region by the double and single ion-chamber methods, using a He continuum light source, with a resolution of about 2Å. The absolute photon intensity was determined by calibrating the chamber with Ar and Xe gases. In this wavelength region, the absorption spectrum of I₂ consisted only of a smooth ionization continuum, and no band structure was found. The absorption cross section decreases monotonically with respect to photon energy from the value of 100 Mb at 1000Å to the value of 25 Mb at 600Å. There is, however, some undulation superposed on the downward sloping curve, with a kind of shoulder at about 740Å. This observation may be explained by the interference effect in the photoionization of molecules which was first suggested by Cohen and Fano. Ionization efficiencies of less than 1.0 were observed in the range of about 820Å and above, and at shorter wavelengths they were observed to be equal to or slightly larger than 1.0.

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Photoionization efficiency curves have been determined for parent and fragment ions of methanol and methanol-d₁ in the photon energy range from 1150 Å to 950 Å. Vibrational and autoionization levels of the parent ions were observed in a region near the threshold of the photoionization efficiency curves. The vibrational structure observed in this work was analyzed using both the isotope effect and infrared spectroscopic data. Above the threshold of photoionization were observed two vibrational structures; the stretching and the twisting vibrations.

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Rodlike macromolecules in solution undergo translational and rotatory Brownian motions. These motions are not independent, since the translational mobility is anisotropic, and the components are orientation-dependent. By taking this fact into consideration, the space-time correlation function of density is calculated to obtain the spectral intensity of the Rayleigh scattered light. Extra terms are found to exist in the expression of spectral intensity in addition to the main term which comes from the translational and rotatory diffusions assumed independent of each other. This may provide a method to measure separately the principal values of the mobility tensor of rodlike macromolecule.

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A series of experiments has been performed using drift tube technique, in which both the primary and secondary ions are mass identified. Design of the apparatus is described briefly. Drift velocities of ions in the drift tube are measured with gate pulse technique. Cross sections of reactions ²²Ne⁺+²⁰Ne→²²Ne+²⁰Ne⁺ and Ar⁺+N₂→Ar+N₂⁺ are determined as functions of mean energies of the ions in the range from 0.04 to 4 eV. Cross section of the former reaction decreases from 5.2±0.2×10⁻¹⁵ cm² at 0.045 eV to 3.7±0.2×10⁻¹⁵ cm² at 2.5 eV. Comparisons of measured cross section with the theory of Rapp-Francis and the previous experiments show that the technique and apparatus used are quite reliable. Cross section of the latter reaction increases from 3.0±0.3×10⁻¹⁶ cm² at 0.43 eV to 2.2±0.2×10⁻¹⁵ cm² at 4.4 eV, and it does not agree with the previous experiments using beam technique at higher energy.

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A valence bond calculation for the four electrons involved in the straight hydrogen bond O–H···O without excess charges is performed nonempirically. Five valence bond structures proposed by Tsubomura are adopted, i. e., (I) O–H O, (II) O⁻H⁺ O, (III) O⁺H⁻ O, (IV) O⁻H—O⁺ and (V) OH⁻ O⁺. The calculations are done for both trigonal and tetrahedral hybrid atomic orbitals of oxygen atoms. The adiabatic potential of the proton is calculated as a function of the O···O and the O–H distances. The shifts of the equilibrium O–H distance and of the O–H frequency with the formation of the hydrogen bond are studied. When different orbital exponents are used in the atomic orbitals of O, O⁻ and O⁺, and H and H⁻, according to Slater’s rule, the obtained shifts agree qualitatively with experiment, although the absolute values deviate from experimental ones in the short hydrogen bond.

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The differential and total cross sections for the elastic scattering of slow electrons by the hydrogen molecule are calculated by solving the scattering equation in two-center prolate spheroidal coordinates. The two nuclei are fixed in the calculation and the average over the molecular orientation is taken afterwards. The exchange effect is taken into account by properly antisymmetrizing the wave function with respect to three electrons in the system and the polarization effect is approximately represented by the adiabatic dipole polarization potential. The results of the calculation agree well with experimental data when the exchange and the polarization effects are taken into account. The change of the magnitude in the forward scattering as a function of the incident energy is explained by the polarization effect.

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Studies of ultrasonic attenuation in the mixtures of dioxane and benzene at 25 MHz show that α⁄f² varies with concentration in a way similar to that found in mixtures of unassociated liquids. The results are in full agreement with the earlier findings in similar systems.

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The response time (τ) of hydrogen ion beam is investigated with a modified PIG ion source by appling the radio frequency. The control electrode is biased at 70 volts negative with respect to the source plasma and modulated by the radio frequency in the interval of 0.05–15 MHz. The response time is proportional to the square root of the gas pressure (P) and to the reciprocal ion density (n). Moreover the time depends on the amplitude of the radio frequency. These effects on the response time can be explained from the recovery time of the perturbed ion density written as τ=250(PE)^1⁄2⁄n where E is the mean field strength.

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When an incompressible liquid flows under the action of a constant pressure gradient through a channel of arbitrary cross section rotating with a uniform angular velocity about an axis perpendicular to the channel, secondary flow is set up. The secondary flow is examined, assuming the channel to be the annulus between two concentric circles. It is shown that the secondary motion may be regarded as screw motion in opposite directions about two pairs of straight lines passing through four degenerate points lying on the axis of rotation. The stream lines in the central plane are discussed and an expression for the rate of flow is obtained .The results of Barua are recovered as a particular case for a single channel of circular cross section.

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A Fourier expansion method is applied to obtain a solution of the hydrodynamic stability problem. As an example the stability of a plane jet is investigated. Three different boundary conditions are tested. Good overall agreement with the exact result is obtained even with simple approximate boundary conditions and with a few-term truncation of the expansion. The result becomes less accurate at small values of the wave number of the disturbance.

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The magnetohydrodynamic laminar flow between two parallel porous disks is examined for large suction Reynolds number and arbitrary Hartmann number. The equations of motion are solved using the singular perturbation technique and the expressions for the velocity, pressure and shear stress distributions are obtained. The results of this analysis are compared with the case of large injection Reynolds number.

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In order to examine the separation of a magnetohydrodynamic boundary layer, the development of the flow started from rest near the rear stagnation point in the presence of an applied magnetic field normal to a wall is considered by a usual unsteady approach as in the non-magnetic case on the assumption of small magnetic Reynolds number. The equations governing the flow are attempted to solve by series expansion in an unsteady parameter and series solutions are obtained in a form of integral. The skin friction up to the sixth order approximation calculated by numerical quadratures indicates that separation delays as N increases from zero (N=SRm, S: the pressure number, Rm: the magnetic Reynolds number) and when about N=1.2, separation is seen to be completely inhibited.

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This paper concerns with the numerical investigation of the effect of Hall currents on the steady boundary layer flow of an incompressible, viscous and electrically conducting fluid past a semi-infinite flat plate in the presence of a transverse magnetic field on the assumption of small magnetic Reynolds number. The numerical solutions of boundary layer equations are obtained by the difference-differential method originated by Hartree and Womersley with an iterative method in solving resulting differential equations. The velocity profiles and the skin friction on the flat plate are computed for various values of the Hall parameter. Hall currents induce the flow and the skin friction in the cross direction. The effect of Hall currents especially on the skin friction is examined in detail.

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The present paper deals with the propagation of waves of small but finite amplitude in slightly inhomogeneous media. The system of equations considered is that of quasi-linear hyperbolic partial differential equations, in which the inhomogeneity is characterized by a slowly varying function of a space coordinate. The original system is reduced, in the lowest step of a perturbation, to a single non-linear equation, which can be integrated by the method of characteristics in case of smooth solutions.

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One model to the mechanism of electro-spraying is proposed as the following; a droplet with constant radius falls out from a capillary by electric repulsion against surface tension, and the droplet breaks up into many small particles in accordance with the transition from the excited level to the ground level. To make sure of this model electro-spraying of several dielectric solutions was done by using simple experimental equipment. Especially the spread of the small particles and their density distribution were examined newly. These results and a few results obtained before by other experimentalists agree fairly good with the approximate values to be calculated by this model.

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