Optical reflectivity in A15 compounds

Optical reflectivity at normal incidence for a series of A15 compounds shows an absorption peak at 0.7 eV for V₃Si and V₃Ge and is attributed to a critical point in the joint density of states. No such peak was found in Ti₃Sb and V₃Pt.     

SiFe0.5Co0.5 - a weak itinerant ferromagnet

The high field and high pressure magnetic properties of SiFe_0.5Co_0.5 alloy are characteristic of weak itinerant ferromagnets.     

Effect of spatial alignment transformations in PCA and ICA of functional neuroimages

It has been previously observed that independent component analysis (ICA), if applied to data pooled in a particular way, may lessen the need for spatial alignment of scans in a functional neuroimaging study. In this paper, we seek to determine analytically the conditions under which this observation is true, not only for spatial ICA, but also for temporal ICA and for principal component analysis (PCA). In each case, we find conditions that the spatial alignment operator must satisfy to ensure invariance of the results. We illustrate our findings using functional magnetic-resonance imaging (fMRI) data. Our analysis is applicable to both intersubject and intrasubject spatial normalization.