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D A Shirley

Publications and source records attributed to D A Shirley.

7 recordsLinked to original sources
PubMed1981

Fourier-transform analysis of normal photoelectron diffraction data for surface-structure determination.

A direct method for surface-structure determination from normal emission photoelectron diffraction (NPD) data is presented. Fourier transforms of the calculated NPD intensities yield peaks at adsorbate-substrate normal interlayer distances. Applications are demonstrated, using theoretical NPD curves for the Se/Ni system calculated by dynamical theory. These results show that interplanar spacings between the overlayer and as many as four substrate layers can be determined with an accuracy of better than 3%.

Journal Article↗
PubMed1969

Study of carbonic anhydrase using perturbed angular correlations of gamma radiation.

The angular correlation of the 150-247 kev gamma-ray cascade of (111m)Cd is strongly perturbed when this nucleus is bound to the enzyme carbonic anhydrase. A comparison of the perturbed angular correlation for the apoenzyme with that for native carbonic anhydrase confirms that the (111m)Cd binds at the active region of the enzyme. These results provide good evidence that the perturbed angular correlation reflects the effective molecular rotational correlation time at the metal binding site, and that this radioactive nucleus can be used as a rotational tracer to label biological macromolecules. The qualitative dependence of the perturbed angular correlation of the (111m)Cd cascade on the molecular rotational correlation time at the metal binding site is illustrated using a cadmium-complex solution at various temperatures.

Binding Sites↗
PubMed1967

Chemical bonding information from photoelectron spectroscopy.

High-resolution measurements of photoelectrons produced by x-rays in compounds of iodine and europium have revealed chemical shifts in the core-level energies, from which chemical bonding information can be obtained. The observed shifts, 0.8 electron volt per unit change in oxidation number in iodine and 9.6 electron volts in europium, are discussed in terms of two theoretical models.

Chemical Phenomena↗