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The effect of the Fermi motion on nuclear structure function at large Q2 (the EMC effect) is discussed in detail. We especially study its dependences on the kinematics of interaction, the 4-momentum transfer Q2, the nucleon momentum distribution inside nucleus and the nuclear mass number. Moreover the structure function of 12C at very large x such as x>l is evaluated by only the nuclear Fermi motion, and related problems are discussed. We also point out a new dynamical mechanism expected to produce the depletion of valence quark inside nucleus for intermediate x, which does not encroach upon the conventional nuclear physics, and discuss it along the line of scaling hypothesis proposed by Dat6 et al.

Although El-transition between levels below giant dipole resonance are almost always strongly hindered, there are several exceptions as observed in i~Be and ~3C. These fast El-transitions are studied by adopting a simple "cutoff" model, in which the behavior of single particle wave functions only outside of the nucleus contribute. The results are compared with the particle-GDR coupling model. The reason why the El-hindrance disappears is explained. We also investigate the direct capture of thermal neutron by 4~and N= 82 nuclei, where similar situation is observed. Further, the implication of the direct capture in multiple neutron capture is discussed.

Neutron capture gamma rays from the 84-keV p3/2 wave resonance, 266-keV p&/2-wave resonance, and 431-keV p3/2 wave resonance in ' Mg that have large reduced neutron width have been measured with an anti-Compton NaI(T1) detector, using a time-of-flight technique. Successful extraction of gamma-ray intensities for transitions to low-lying states in 'Mg was performed by an iterative unfolding method, in order to deduce partial radiative widths. Also, we have made an experimental contrivance separating the kernel of the 266-keV broad resonance from that of the 257-keV overlapping narrow resonance. Radiative widths were obtained for the E1 transitions to the ground ( -, '+), 585-keV ( -, '+), 975-keV ( -, ' ), 1965-keV ( -, '+), 2564-keV z and 2801-keV ( -, '+) states, and were compared with theoretical calculations based on the valence capture model that was developed by Lane and Mughabghab. Consequently, we found that in the p3/p wave resonance capture the observed and calculated widths for the transitions to the -, '+ states are in excellent agreement; however, the experimental widths for the transitions to the 2+ states are 20-50% of the theoretical ones. These noteworthy features in the retardation of E1 transition are explained in terms of the renormalized effective charge, which depends on the orbital angular momentum for the single-particle component of final bound states, as a result of the coupling of the single-particle transition with the isovector field generated by the giant dipole resonance. Moreover, the nonadiabatic coupled-channel calculation using a particle-rotator coupling model was carried out for partial radiative widths of the 266-keV p, /, -wave resonance. The calculations reproduced the observed values satisfactorily.

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