Measurement of the photoproduced two neutral pions from hydrogen was performed up to 730 MeV by detecting the both pions by means of thier decay gamma rays in coincidence. The differential cross section, we obtained, around 600 MeV is close to zero within our statistics and is consistent with the static model calculation. The cross section around 700 MeV, however, is about 0.25 μb/(sterad)² at θ_π1=θ_π2=55° in the laboratory system.

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The (p, t) reactions on ¹⁵⁸Gd, ¹⁶⁴Dy, ¹⁷²Yb, ¹⁷⁶Hf and ¹⁸⁴W have been studied with 51.7 MeV protons. Triton spectra have been measured with a broad-range magnetic spectrometer with a 200 proportional-counter array. The cross sections for the states of the ground state rotational band which have been found to depend on mass number, have been analyzed by the distorted-wave Born-approximation. Especially Y₄-diformation parameter β₄ for each nucleus has been obtained from the cross section for the 4⁺ state of the ground state rotational band. The cross sections for the first excited 0⁺ states have been found to have a mass number dependence and this dependence was compared with the prediction based on the pairing vibrational mode.

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The ionization cross sections of Al–K, Ti–K, Cu–L, Mo–L, Ag–L and W–M shells have been presented for the incident protons and deuterons in the energy range from 90 to 180 keV/amu. The cross sections are derived from the thick target yields of the respective characteristic X-rays. In contrast with the prediction by Born approximation, isotope dependence is clearly found in the ionization of each target atom. The cross section ratios for K and L shells against the projectile energy per nucleon line up systematically according to the shell binding energies of target atoms. The magnitudes of the K shell ionization cross sections are in good agreement with “binding theory” of Brandt et al.. This means that, in the present energy range, the ionization cross sections depend strongly on the Coulomb deflection of the incident particle and the transient additional binding energy of the K shell electron with the incident particle during the collision.

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Analysis of correlations between spacings of arbitrary pairs of neutron resonance levels for intermediate and heavy nuclei is described. It is found that pairs of levels separated at particular spacings appear very frequently and the observed levels are also preferentially distributed at periodical positions with particular periods. These correlations are found in the observed resonances of ⁷⁵As, ¹²¹Sb, ¹²³Sb, ¹⁴⁶Nd, ¹⁶⁶Er, ¹⁷⁴Yb, ¹⁷⁷Hf, ²³⁴U, ²⁴⁰Pu, etc.. It is shown that these regular level distributions are rarely expected for statistically distributed levels.

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The dielectric function in a disordered system is discussed in the RPA and using the Klauder-Yonezawa model. It is shown that the “vertex correction” is essential for satisfying general requirements of the dielectric function. The high frequency tail of the optical absorption spectrum is shown to be proportional to ω^−3⁄2, contrary to the simple Drude theory ω⁻², by virtue of allowance of direct transitions. This conclusion seems to be a natural result for the case that impurity band splits from the conduction band. It should be noted, however, that it is also true for the case that impurity potential is weak and it has no bound state, where the perturbational approach can be thought of as good. Several exact properties of the dielectric function are also investigated and it is shown that the static screening constant is given by the same formula as that of uniform electron gas, which is also true for the case that the Fermi level lies in the impurity band.

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By using the method of projection operators introduced by Zwanzig, steady-state solutions of the master equation of the density matrix of the spin system in the rotating reference frame have been obtained in the limit of weak spin-lattice interaction and high temperature. With the aid of these solutions, the saturation behaviors of the spin system in solids have been investigated in the two limiting cases, weak-H₁ and strong-H₁, where the spin system is not uniform and some sorts of cross relaxation take place. Furthermore, the remaining terms of the steady-state solution obtained under Redfield’s assumption of a single spin temperature have been derived directly starting from the master equation.

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A markoffian stochastic model of interacting Ising spins is discussed near its critical point. The long time behavior of relaxation of its magnetization and energy is investigated near T_c by the use of high-temperature series expansion and the ratio method. The numerical estimate of the critical exponent Δ_MM of slowing down of magnetization is made, the results of which show Δ_MM\simeq2 for the simple square and triangular lattices, and Δ_MM\simeq1.4 for the simple cubic lattice. The exponent Δ_EE of slowing down of energy is also estimated, which gives the result Δ_EE\simeq2 for the simple square and triangular lattices. The method to derive high-temperature expansion of an n-spin correlation function ⟨σ₁σ₂…σ_n⟩ for an Ising model of spin 1/2 by the use of an equation of detailed balance is presented and applied to these estimates.

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The self-consistent equation of the band calculation, which can be used for both metals and ionic crystals, is derived in the limit of the statistical exchange approximation and the muffin tin approximation. By G.F.M. the self-consistent calculations of energy bands for Cu and Al have been carried out and they are compared with the former results by self-consistent APW method. The excellent agreement is obtained. For vanadium metal the results by another self-consistent procedure, which was proposed by Wakoh, are compared with those by this Hartree-Fock-Slater self-consistent one. When the original Slater exchange is reduced about 0.8 times the two results coincide fairly well. Some practical remarks on the self-consistent band calculation are also given.

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The excluded volume effect of linear chain polymer is investigated with the aid of the method of cluster expansion theory which has been developed in the theory of imperfect gases. Three prototypes of simple clusters, their generalizations and their complex combinations are considered. The linear expansion factor α of the effect is obtained in a double series with respect to the number of segments N in a chain polymer. The series are summed with the help of Hankel’s integral representation of the Gamma function. Using the method of the steepest descent, the factor is evaluted for large N. It approaches monotonically to a finite value with increasing N, and does not show the behaviors given by ordinary two parameter theories.

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Temperature dependences of the paramagnetic resonance line-widths ΔH of ferrimagnetic (very nearly ferromagnetic) RbNiF₃ and antiferromagnetic RbMnF₃ have been observed in order to investigated the dynamics of the spin fluctuation near the critical points. Reflecting the importance of the anisotropy energy, by which the damping of K=0 transverse mode is influenced, no anomalous increase in widths occurs in isotropic antiferromagnet RbMnF₃ on passing through the critical point. But in the case of uniaxial ferrimagnet RbNiF₃, great narrowing of the width occurs with decreasing temperatures. The width is minimum at (1.025∼1.035)T_c and increases slightly with further decreasing temperatures. The product ΔH·x_⊥, where x_⊥ is the perpendicular susceptibilty, shows almost exactly the same temperature variation as that of MnF₂ with the critical exponent −2⁄3, supporting the theory of Mori and Kawasaki pretty well.

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Mean power losses produced in a cylindrical specimen, when an external magnetic field along the cylindrical axis is increased with a constant rate, are calculated under an assumption that the temperature inside the specimen is uniform. With the aid of this result, a simplified heat equation to describe the variation of the temperature of the specimen with time is derived. Then, calculations are carried out for several qualities vitally concerned with flux jumps, e.q., the relation between the flux jump field and the sweeping rate, the minimum field for the flux jump, and the jump intervals. In addition, an analysis of temperature fluctuations is worked out under the condition of small heat leakage, and the results are compared qualitatively with the experimental data on Nb–Ti rods.

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Magnetic resonance of a ZnCr₂Se₄ single crystal with screw spin structure was observed in the frequency range of 38∼83 GHz at above 4.2K, mainly at 5.5K. Frequency and angular dependences of the resonance field were successfully explained by a theory of first order perturbation due to uniaxial anisotropy.
Data of the resonance, together with the results of static magnetization measurements, give two isotropic molecular field constants in k space: E(0)−E(k₀)=2.15 and E(0)−E(2k₀)=−0.01 (mole) and three anisotropy constants: K(0)=0.01₅, K(k₀)=0.10 and K(2k₀)=−0.06 (mole). It is demonstrated conclusively that superexchange interaction through more than two Se ions is important in this substance.

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Magnetic measurements under hydrostatic pressure up to 8 k bar were made on f.c.c. Fe₆₅(Ni_1−xMn_x)₃₅ alloys in magnetic fields up to 12 kOe and at temperatures down to 4.2°K. The results indicate that in the ferromagnetic alloys (x<0.3) the spontaneous magnetization and the Curie temperature decrease appreciably by compression and the fractional change of the spontaneous magnetization with pressure at low temperatures −σ⁻¹dσ⁄dP is nearly equal to the fractional change of the Curie temperature with pressure −T_c⁻¹dT_c⁄dP and both values are approximately proportional to the high field susceptibility at low temperatures. These ferromagnetic volume effects can be understood in terms of weak itinerant electron ferromagnetism. On the other hand, the Néel temperature and the magnetic susceptibility of the antiferromagnetic alloys (0.3<x) decrease by compression. These antiferromagnetic volume effects can qualitatively be explained by using a band theory of antiferromagnetism.

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Thermal expansion measurements were made on f. c. c. Fe₆₅ (Ni_1−xMn_x)₃₅ alloys at temperatures down to 4.2°K and the spontaneous volume magnetostriction of these alloys was evaluated from their thermal expansion curves. The results indicate that the spontaneous volume magnetostriction at 0°K is positive and decreases with increasing x in the ferromagnetic alloys (x<0.3), and is positive and increases with increasing x in the antiferromagnetic alloys (0.3<x). The spontaneous volume magnetostriction varies with temperature as T² in the temperature range below about half of the magnetic transition temperature. If a simple and reasonable density of states curve is assumed, these experimental results can be understood on the basis of the weak itinerant electron ferromagnetism or of the weak itinerant electron antiferromagnetism.

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Linear thermal expansion α of Au₄V in the ordered and disordered states has been measured from 4.2°K to 100°K. An anomaly, which corresponds to the magnetic ordering, has been found in the ordered state. The magnetic entropy estimated from the magnetic contribution α_m is (0.55±0.16)R, which suggests a magnetic moment of approximately 1μ_B per V atom. The Curie temperature of the ordered Au₄V is 52±1°K. The electronic contribution to α, α_e, and the lattice contribution α_L in units of °K⁻¹ are; α_e=(0.95±0.05)×10⁻⁸T and α_L=(9.6±0.2)×10⁻¹¹T³ (T≤20°K) in the disordered state and α_e=(3.65±0.05)×10⁻⁸T and α_L=(9.1±0.3)×10⁻⁶C_Debye(θ_D=245)⁄3R (T≥60°K) in the ordered state.
The pressure dependence of Curie temperature ∂T_c⁄∂P in the ordered Au₄V is estimated to be +0.2°K/kbar. The Grüneisen constants in both states are estimated.

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Magnetic susceptibility and NMR measurement on dilute Ag–Mn alloys have been made at temperatures between 1.5 K and 300 K. The manganese concentrations are 25, 42, 81 and 470 ppm. The impurity contribution to the observed line widths is proportional to the impurity concentration and the averaged impurity spin which is determined from the susceptibility data. The effective J value is derived from the proportionality constant as |J|=1.1±0.1 eV. For the derivation of the J value the local field distribution caused by the impurity due to the RKKY interaction and the direct dipolar interaction has been calculated. This magnitude of J is different by a factor of 5.0±0.5 from the value obtained from T_K=40 mK.

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The heat capacity was measured between 1.5 and 280 K. At liquid helium temperatures a heat capacity anomaly was observed and a new phase transition was found at 211.4 K with a secondary C_p maximum at 215.5 K. The entropy and the enthalpy changes for the overall transition are ΔS_t=13.778 J K⁻¹ mol⁻¹ and ΔH_t=3322 J mol⁻¹, respectively.
The infrared spectra were measured at 120, 225 and 295 K. Many new absorption peaks appeared below the transition point. A mechanism for the phase transition is suggested in terms of ordering processes of crystalline water.
A new model is proposed for explaining the heat capacity anomaly at liquid helium temperature: The cluster ions with equilateral triangle symmetry at room temperature are slightly distorted through the phase transition processes resulting two kinds of cluster ions forming isosceles triangles with different exchange parameters. The closest agreement with the experimental data was obtained by assuming J₀=30 k and J₁=4.5 k for half moles of the cluster ions and J₀=30 k and J₁=−1.5 k for the remaining half moles.

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Change of the Kapitza resistance as a metal goes from the normal state to the superconducting state is estimated in the dielectric-metal junction by extending Little’s theory that the interaction between surface waves and conduction electrons contributes to heart transfer in the liquid-solid junction. According to this estimate, no change is expected in the case that sound velocities of the dielectric are larger than those of the metal. The sapphire-indium junction is such a case. The Kapitza resistance of this junction measured by the authors from 0.6°K to 2.2°K shows, however, a small difference between the nornal and the superconducting states of indium contrary to the above estimation.

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The faulting in stacking sequence of close-packed layers of the martensite in Cu-38.6 at. %Zn alloy has been studied by electron diffraction, utilizing the selected area diffraction technique of electron microscopy. Observed diffraction spots were shifted and diffused owing to the stacking faults. The shifts of sports were analyzed by the Kakinoki-Komura theory with Reichweite s=3, and the stacking fault probabilities α were found to be between 0.13 and 0.43, α being a fault parameter representing the cubic type stacking faults. The result is compared with the case of the Cu–Al martensite: the predominant type of stacking faults is cubic type for the Cu–Zn martensite while hexagonal type for the Cu–Al martensite. This difference is explained by the phenomenological theory of martensitic transformation.

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Acoustomagnetoelectric (AME) and acoustoelectric (AE) effects were investigated in n-InSb on applying longitudinal acoustic waves of 8.7 GHz at liquid helium temperatures in magnetic fields up to 12 KOe. The temperature dependences and the magnetic field dependences of the AME and the AE effects were measured. The AME effect in the weak magnetic field region was compared with Épshtein and Gulyaev’s theory. In high magnetic field region above 3 KOe, the quantum limit condition is valid, and so the theory of the AME effect in the quantum limit condition was newly developed. The broadening of the lowest Landau level could be estimated by comparing the experimental results with the theory. The broadening is about 0.17 meV at 4 KOe at 4.2°K and it decreased with increasing the magnetic field. Thus the long range impurity scattering process could be expected in the high magnetic field region.

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The heat capacity of the clathrate compound of quinol with hydrogen cyanide was measured from 12 to 300 K. It exhibited a well defined anomaly at 177.8+0.1 K. The entropy change associated with it was estimated to be 5.71±0.3 J/mol K. This value is close to Rln2, implying that the anomalous heat capacity is due to the order-disorder phase transition concerned with the orientation of the trapped molecules. Dielectric study supported this view. Far infrared spectra of the crystal was recorded from 38 to 500 cm⁻¹ over a range of temperature. Two bands at 46 and 95 cm⁻¹ were found to be characteristic of this substance. A possible assignment of the former band was proposed. Finally, the lattice sum calculation showed that the dipole interaction energy between the guest molecules corresponds to 318 K of temperature compared with the observed transition temperature.

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Low temperature heat capacities of the nonstoichiometric clathrate compounds with methanol were measured on four specimens of different occupation fractions. Heat capacity anomalies were found at 65.7, 61.0, 54.4 and 44.4 K, corresponding to the occupation fractions 0.974, 0.897, 0.837 and 0.728, respectively. Magnitude of the entropy change of transition is consistent with the view that the transition is due to randomization of direction of the methanol molecules along the c-axis. Single crystal dielectric data support this interpretation. Variation of the transition temperature with the occupation fraction was compared with data on analogous systems. The lattice energy calculation showed that the dipole interaction between methanol molecules corresponds to 27 or 67 K of temperature depending on the component of the moment taken into account.

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Collimation effects on the coherent bremsstrahlung produced in a thin silicon crystal have been studied by using 1 BeV electrons whose angular divergence is suppressed by scrapers in synchrotron orbit. The energy spectra of the bremsstrahlung exhibited narrow spikes and large enhancement ratios.
The full width at half-maximum of the enhanced spike of 15% has been obtained at the photon energy of 435 MeV.
The observed spectra were fitted to the theoretical ones calculated by the least square method. The fit gives the effective collimation angle Θ_eff of 0.54 reduced angles. The continuous part was 1.85 times as large as the theoretical prediction. Considering that the mechanical collimation angle Θ_c is 0.32 reduced angles, Θ_eff is mainly ascribed to the calculated multiple scattering angle Θ_ms of 0.65 reduced angles as well as Θ_c.

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Optical absorption spectra of poly-L-leucine, poly-DL-leucine, poly-L-alanine, poly-DL-alanine, poly-L-methionine, poly-L-valine, poly-L-serine, poly-L-tyrosine, poly-L-phenylalanine, Nylon 3, Nylon 4, Nylon 6 and polyglycine were measured with special regard to their conformations in the wavelength region from 2500Å to 1200Å.
On the assumption that the absorption spectra of polypeptides at random conformation could be approximated by that of Nylons, the dependence of the absorption spectra of polypeptides on the conformation was estimated by comparing them with that of Nylons.
It is noticed that α-helical polypeptides in general have a significant absorption peak near 1650Å and this band shows the dominant hyperchromism. The origin of this 1650Å absorption band may be the same as that observed between NV₁ and NV₂ transition bands for peptide monomers, and it is plausible that σ orbitals are related to this absorption band.
The sum of the oscillator strength up to 10 eV was ca. 1 for polyglycine. Since the total sum of the oscillator strength is expected to be 33, the dominant part of the absorption of polypeptides will appear in the energy range higher than 10 eV.

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Effective cross section for the rotational excitation of the HD molecule by low energy electron (incident energy of the electron ranges from 1.0 eV to 13.6 eV) is calculated for the transitions of the rotational state from J=0 to 1, 2 and from J=1 to 2. The adiabatic approximation is used to obtain these cross sections. It is found that the rotational excitation cross section with ΔJ=2 is almost the same as the e–H₂ result and that the cross sections with ΔJ=1 are about 10% of those with ΔJ=2 in the above mentioned energy region.

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Algebraic expressions are obtained for the generalized oscillator strengths of hydrogen-like atoms for the transitions involving s-, p-, and d-states with the principal quantum number n of 2, 3, and 4. Zero minima are found for all the transitions involving s-states, and their positions are shown to be proportional to the effective charge, the coefficients being tabulated. The Transitions from the 1s-state sometimes show zero minima if different effective charges are used for the initial and the final states. Even nodeless wave functions can produce zeros owing to the nodes of the spherical Bessel function. Some excitation processes of Ne, Na, Mg, and Ar caused by high-energy charged particles are investigated in the first Born hydrogen-like approximation, and the possibility of finding zero minima in the differential cross sections is discussed; the 3s→4p transitions of Na and Mg have the most conspicuous zeros of all that are studied.

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A cross section formula for the rotational transition in a symmetric-top molecule by electron collisions is derived in the Born approximation, with adopting a general form of electron-molecule interaction. Then, the result is applied to the electron-NH₃ collision. The cross section for the transitions ΔK≠0 (K being the quantum number representing the angular momentum around the symmetry axis) is calculated for the first time and its magnitude is found to be much less than the dipole excitation cross section (for which ΔK=0). In a large-angle scattering, however, the differential cross section for ΔK≠0 has a non-negligible effect.

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The viscosity of PNT melts (m.p. 51.6°C) in the temperature interval 47°–75°C have been determined. The results follow an Arrhenius behaviour above the melting point. In the supercooled region also the viscosity data fit an Arrhenius equation with different values of the E_vis and pre-exponential factor. The results indicate hindered rotation of the PNT molecules in the supercooled region.

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The mechanism of the end loss and the axial behaviors of a mirror θ-pinch plasma are studied. For this purpose, both the mirror and the straight field configurations are used at the first half cycle controlling the reverse bias field. The end loss in the mirror field is found to be decided by the axial motion, which is caused by the axial pressure gradient of the plasma due to the axially inhomogeneous magnetic field. The e-folding time of the decaying plasma at the midplane agrees well with the result of the numerical calculations on the basis of non-steady M.H.D. equations. The relation between the confinement time and the initial conditions of produced plasma is discussed.

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Electron plasma waves are excited by grids in an argon plasma. The comparison between the experimental results and the theory for an infinite collisionless plasma is made. With increasing wave amplitudes under the condition of 1<v_ph⁄v_e<3, where v_ph and v_e are the phase velocity and the thermal velocity, respectively, the enhancement of damping is observed and is found to depend strongly on the phase velocity of the waves. These results are compared with those by Dawson and Shanny.

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The stability of transient natural convection generated in a vertical slab of a fluid confined between two parallel plates held at different temperatures is investigated. The flow is found to be always unstable, but the critical Reynolds number decreases monotonically in time so that the final state is more unstable than all preceding states.

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Experimental studies on thermal convection flow of water between two vertical parallel plates held at different temperatures were carried out. The flow pattern between the plates and the type of distributions of the velocity and the temperature depend almost only on the Rayleigh number A. (A=γΔTgd³⁄(κν), ΔT being the temperature difference, d the distance between the plates, γ the thermal expansion coefficient, κ the thermal diffusivity, ν the kinematic viscosity, and g the acceleration of gravity.) As the Rayleigh number becomes larger, the flow tends to the type of boundary layer flow. There has been found a critical value of the Rayleigh number, such that, below it the flow is always laminar and above it the flow becomes unstable. Beyond the critical value (A_crit.\fallingdotseq12×10⁶) wavy motions of streamlines appear, then they develop to rows of periodic vortices and eventually burst into turbulent flow.

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