[en] Using the mass differences K⁺ - K⁰ and D⁺ - D⁰ as constraints, the mass splitting between B⁺ and B⁰ mesons has been calculated as -1.3+-1.22 MeV in the nonrelativistic quark model and -1.6+-0.72 MeV in the chiral symmetry breaking theory. (author)

[en] We have examined in the unified gauge theory with the integrally-charged quark model the Bjorken-Paschos relation within the impulse approximation of the parton picture. We find that the relation is valid for the forward scattering region and provides a reliable way to test the charge assignment of the quarks and the gluons. (author)

[en] The dispersion integrals for the meson-baryon sigma term may be classified according to where they are evaluated: the Dashen point of the Weinberg point. Some of the dispersion integrals appearing in the literature for the kaon-nucleon sigma term are discussed in this context, and new ones introduced. (Author)

[en] Within the standard six-quark model with the Kobayashi-Maskawa parametrisation the mass of the top quark is estimated using both the Ksub(L)-Ksub(s) mass difference and the CP non-conservation parameter epsilon of the neutral-kaon system as two independent constraints. (author)

[en] The generalized Langevin equation theory is used to obtain two different spin diffusion constants of Kubo, namely, the local spin diffusion constant and the external spin diffusion constant of the spin van der Waals model. The local spin diffusion constant has an interesting temperature dependence near the critical point, whereas the external spin diffusion constant is always zero. (Author)

[en] Friction welds are formed by the mechanisms of diffusion as well as mechanical inter-locking. The severe plastic flow at the interface by the forge action of the process brings the subsurface so close together that detection of any unbonded area becomes very difficult. No reliable method is available so far to determine the weld quality nondestructively. This paper presents an attempt to determine weld strength quantitatively using the ultrasonic pulse-echo method. The new approach calculates the coefficient of reflection based on measured amplitudes of the echoes. This coefficient provides a single quantitative measurement which involves both acoustic energy reflected at the welded interface as well as transmitted across the interface. As a result, it was known that the quantitative relationship between the coefficient and the weld strength(torsional strength) could be drawn. (Author)

[en] We have investigated magnetic phase transitions for the dilute semiconductors Zn_1-xMn_2+xAs₂ (x=0, 0.23, 0.33), by estimating the spin-spin relaxation times T₂ in the temperature range 113-360 K. From ZnMn₂As₂, a critical anomaly in T₂ was found around T_AF=175 K, consistent with anomalous behavior in magnetization observed previously. In Zn_1-xMn_2+xAs₂ with x=0, 0.23 and 0.33, such an anomaly in T₂ was found at 225 and 235 K, respectively

[en] To relate the Cabibbo angle and the quark mass ratios, one has to impose additional symmetries. It is shown that Usub(A)(1) may be the group theoretical structure for the discrete symmetries. (Auth.)

[en] The in-depth concentration of Ar atoms in Si surface after Ar⁺ ion sputtering was investigated using medium-energy ion spectroscopy (MEIS) and dynamic Monte Carlo simulation. The primary Ar⁺ ion energy was 0.5, 1 and 3 keV, and the primary Ar⁺ ion beam direction was varied from surface normal to glancing angle. In the case of the surface normal incidence, the MEIS result shows that the maximum atomic concentration of Ar atoms increases from 6% at the depth of 2 nm to 16% at the depth of 3 nm as the primary ion energy increases from 0.5 to 3 keV. However, in the case of the incident angle of 80 deg., that is 2.5% at the depth of 1.5 nm when the primary energy is 3 keV, in-depth Ar distribution cannot be observable when the primary ion energy is 0.5 keV. Dynamic Monte Carlo simulation reproduced the in-depth concentration distribution of Ar atoms quantitatively

[en] The quasistatic approximation is incorporated in HEXKIN, a 2-group, 2-dimensional reactor kinetics code specially developed for a hexagonal lattice-type reactor. The code allows maximum 15 delayed neutron groups, 279 lattice points, and 500 different driving functions to be able to initiate perturbation at each lattice point. Reactivity feedback due to power-dependent fuel temperature change is also involved. To check the accuracy of the code, a result of numerical experiment is compared with the measurement at the Savannah River Laboratory. The experiment was specifically designed to emphasize delayed neutron holdback. The calculated flux tilts agree with the measured flux tilts within the small uncertainty of the measurements. (author)