The authors demonstrate the generation of multicycle narrow-bandwidth terahertz pulses in periodically inverted GaAs structures using optical rectification of 2 μm, 100 fs pump pulses. Three different types of orientation-inverted samples are employed: optically contacted multilayer, orientation-patterned, and diffusion-bonded GaAs. The terahertz pulses are characterized by two-color (pump at 2...
The authors demonstrate an efficient room temperature source of terahertz radiation using femtosecond laser pulses as a pump and GaAs structures with periodically inverted crystalline orientation, such as diffusion-bonded stacked GaAs and epitaxially grown orientation-patterned GaAs, as a nonlinear optical medium. By changing the GaAs orientation-reversal period (504–1277 μm), or...
Field collections in the Southern Gulf of Oman and the Northwestern Arabian Sea, and
examination of museum collections from this study area, yielded 7 genera and 33 species
of apogonid fishes. Twenty one species of Apogon, one Archamia, four Cheilodipterus,
three Fowleria, one Rhabdamia, two Siphamia, and one Holapogon are...
Recent work has shown that AdaBoost can be viewed as an algorithm that maximizes the margin on the training data via functional gradient descent. Under this interpretation, the weight computed by AdaBoost, for each hypothesis generated, can be viewed as a step size parameter in a gradient descent search. Friedman...
In 1981, illegal processing of rapeseed oil by a Spanish oil refinery resulted in the mass foodborne illness epidemic known as Toxic Oil Syndrome (TOS). The toxic oil associated with this epidemic was sold in neighborhood markets and by itinerant salesmen as inexpensive olive oil. Ingestion of the toxic oil...
The floating ice shelf of Petermann glacier interacts directly with the ocean and is thought to lose at least 80% of its mass through basal melting. Based on three opportunistic ocean surveys in Petermann Fjord we describe the basic oceanography: the circulation at the fjord mouth, the hydrographic structure beneath...