Abstract: Strain waves of THz frequencies can coherently generate radiation when they propagate past an interface between materials with different piezoelectric coefficients. Such radiation is of detectable amplitude and contains sufficient information to determine the time-dependence of the strain wave with unprecedented subpicosecond, nearly atomic time and space resolution.

Abstract: Strain waves of THz frequencies can coherently generate radiation when they propagate past an interface between materials with different piezoelectric coefficients. Such radiation is of detectable amplitude and contains sufficient information to determine the time-dependence of the strain wave with unprecedented subpicosecond, nearly atomic time and space resolution.

Abstract: A header is received within an interior of a vehicle and secured against the roof portion thereof to extend transversely with respect to the front to back directions of the vehicle. The header supports a roller which in turn supports a flexible transparent or clear curtain which may be drawn downwardly to provide a portion of the vehicle air barrier to divide one portion of a vehicle interior from the other. A pair of side curtains are provided along each edge of the center curtain and are extendable outwardly to provide a further barrier to air circulation or air flow past the barrier. In one embodiment, the side curtains are formed of a flexible material and are hingedly secured to the vertical edges of the center curtain. In an alternate embodiment, a pair of side rollers are pivotally secured to the header and support respective side curtains which may be extended downwardly and drawn outwardly to complete the air barrier.