Production of direct single electrons in proton-nucleus collisions at 13 GeV/c

Direct production of single electrons in proton-nucleus collisions at 13 GeV/c has been measured. A rising $\text{e}\text{π}$ ratio with decreasing p_T above the 10^?4 level is observed for low p_T single electrons. The source of the rising $\text{e}\text{π}$ ratio at low $\text{e}\text{π}$ ratio at low p_T is discussed in connection with the low mass dielectron continuum below the ? mass region.     

Carbon-13 NMR chemical shift and electronic structure of polypeptide as studied by tight-binding MO theory: poly (β-benzyl L-aspartate) with the right-handle α-helix and left-handed α-helix forms

An attempt was made to calculate ¹³C NMR chemical shifts of poly(β-benzyl L-aspartate) having the right-handed α-helix (α_R-helix) and left-handed α-helix (α_L-helix) forms by a tight-binding MO sum-over-states theory within the extended Hückel framework, in order to examine whether or not the conformation-dependent ¹³C chemical shifts previously determined by the cross polarization-magic angle spinning technique are reproduced by a change of electronic structure of the polymer. It is found that the relative displacements of the observed C_α, C_β and carbonyl ¹³C chemical shifts between the α_R- and α_L-helices are reproduced qualitatively by the calculation.     

A light-scattering study of deformation of liquid-crystalline spherulites of poly(γ-benzyl-L-glutamate) in an electric field

The deformation of liquid-crystalline spherulites of poly(γ-benzyl-L -glutamate) (PBLG) in an electric field was investigated by light scattering, polarized-light microscopy, and birefringence measurements. Under the polarizing microscope, the deformation was found to be dependent upon the field strength. The spherulites deformed perpendicular to the field. Above 75 V/cm in N,N-dimethylformamide or 120 V/cm in 1,1,2-trichloroethane, the deformed spherulites were transformed to rodlike textures. With increasing voltage, the rods gradually oriented parallel to the electric field. On the basis of the experimental results, models for affine deformation are proposed. With these models, light-scattering patterns are calculated. The calculated and experimental patterns agree semiquantitatively.