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Poon, H. C.

Publications and source records attributed to Poon, H. C..

3 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2011

New Light on Disordered Ensembles: Ab Initio Structure Determination of One Particle from Scattering Fluctuations of One Particular from Scattering Fluctuatins of Many Copies

We report on the first experimental ab initio reconstruction of an image of a single particle from fluctuations in the scattering from an ensemble of copies, randomly oriented about an axis. The method is applicable to identical particles frozen in space or time (as by snapshot diffraction from an x-ray free electron laser). These fluctuations enhance information obtainable from an experiment such as conventional small angle x-ray scattering.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2011

Beyond the crystallization paradigm: Structure determination from diffraction patterns from ensembles of randomly oriented particles

We amplify on the priciples of the method we have recently proposed for recovering an oversampled diffraction pattern of a single particle from measured diffraction patterns from multiple particles in orientations related by rotation about an axis parallel to the incident radiation. We propose an alternative method of phasing a reference resolution ring by means of a non-negativity constraint on the diffraction intensities, point out the need for caution about enantiomeric ambiguities in the reconstruction of a diffraction pattern from its angular correlations, and show that converged correlations may be deduced by appropriate averaging of even very noisy data.

59 BASIC BIOLOGICAL SCIENCES↗