Partial stacking faults (PSFs) have been frequently observed inside {101-1} and {101-2} twins in hexagonal close-packed (HCP) metals. Formation of PSFs, first described by Song Gray, only displaces atoms on every other basal plane, stark contrast to conventional SFs created Shockley partial dislocations which a global displacement vector can be defined. To experimentally verify this process is ...

Mesostructured porous materials possess unique surface, structural, and bulk properties that lead to important practical applications. By retaining structure-directing species in the product material, mesostructured organic-inorganic composites are obtained which are of broad interest for fundamental studies of confinement effects and surface interaction on structural and dynamic properties of ...

Possible transformation paths that involve no long range diffusion and their corresponding microstructural details were predicted by Bendersky, Roytburd, and Boettinger [J. Res. Natl. Inst. Stand. Technol. 98, 561 (1993)] for Ti-Al-Nb alloys cooled from the high temperature BCC/B2 phase field into close-packed orthorhombic or hexagonal phase fields. These predictions were based on structural an...

Hexagonal packing geometry is a hallmark of close-packed epithelial cells in metazoans. Here, we used fiber cells of the vertebrate eye lens as a model system to determine how the membrane skeleton controls hexagonal packing of post-mitotic cells. The membrane skeleton consists of spectrin tetramers linked to actin filaments (F-actin), which are capped by tropomodulin1 (Tmod1) and stabilized by...

It is known that if a 2-universal hash function H is applied to elements of a block source (X1, . . . , XT ), where each item Xi has enough min-entropy conditioned on the previous items, then the output distribution (H,H(X1), . . . , H(XT )) will be “close” to the uniform distribution. We provide improved bounds on how much min-entropy per item is required for this to hold, both when we ask tha...

We report the in situ microscopy observation of an unnatural phase of Ni, a highly strained hexagonal close-packed shcpd form which we believe is stabilized by heteroepitaxial growth on the s001d face of MgO. We find that the nanosized hcp nickel islands transform into the normal face-centered cubic structure when the size of the islands exceeds a critical value sabout 2.5 nm thick with a later...