300 research outputs found
Patterns of Stranger and Serial Rape Offending: Factors Distinguishing Apprehended and at Large Offenders
Patterns of Stranger and Serial Rape Offending: Factors Distinguishing Apprehended and at Large Offenders
Sampling metrics for robust reconstructions in multislice ptychography: Theory and experiment
While multislice electron ptychography can provide thermal-vibration limited
resolution and 3D information, it relies on the proper selection of many
intertwined experimental and computational parameters. Here, we outline a
theoretical basis for selecting experimental parameters to enable robust
ptychographic reconstructions. We develop a series of physically informed
metrics to describe the selection of experimental parameters in multislice
ptychography. Image simulations are used to comprehensively evaluate the
validity of these metrics over a broad range of experimental conditions. We
develop two metrics, areal oversampling and Ronchigram magnification, which
predict reconstruction success with high accuracy. Lastly, we validate these
conclusions with experimental ptychographic data, and demonstrate close
agreement between trends in simulated and experimental data. Using these
metrics, we achieve experimental multislice reconstructions at a scan step of
1.0 \unit{\AA/px}, enabling large field-of-view (>\!18\unit{nm}),
data-efficient reconstructions. These experimental design principles enable the
routine and reliable use of multislice ptychography for materials
characterization.Comment: 9 pages, 5 figure
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