Arch-shaped microelectromechanical systems (MEMS) have been used as mechanical memories, micro-relays, micro-valves, optical switches and digital micro-mirrors. A bi-stable structure, such as an arch, is characterized by a multivalued load deflection curve. Here we study the symmetry breaking, the snap-through instability and the pull-in instability of a bi-stable arch-shaped MEMS under static ...

the osteology of the hyoid and branchial arches in several representatives of eurypterygian fishes were examined. the hyoid arches consist of a single basihyal and urohyal, and the arch on each side consists of a dorsal and a ventral hypohyal, an anterior and posterior ceratohyal, an interhyal, and branchiostegal rays that are borne on the ceratohyals. the branchial arches consist of three sing...

We present the catalog of X-ray sources detected in a shallow Chandra survey of the inner 2×0.8 of the Galaxy, and in two deeper observations of the Radio Arches and Sgr B2. The catalog contains 1352 objects that are highly-absorbed (NH&4 × 10 cm) and are therefore likely to lie near the Galactic center (D≈8 kpc), and 549 less-absorbed sources that lie within .6 kc of Earth. Based on the inferr...