Abstract: The filtering membranes of the present invention are made from a pair of polymer films stretched in a liquid surface-active medium for the formation of crazes filled with the aforementioned medium. The crazed films are perforated and then stack together in a stretched or released state and are welded together into a sealed structure with a plurality of parallel welding seams arranged, e.g., in mutually perpendicular directions, so that a plurality of sealed cells is formed. The cells have on one side of the membrane input openings and on the other side output openings. If an input opening is in one cell, then an output opening is in the adjacent cell. Adjacent cells are interconnected only through the welding seams. Welding can be carried out by contact heating or with the use of a laser beam, or the like. The material of the welding seam has an amorphous structure.

Abstract: A method for amplifying optical signals without dependence of output signal intensity on an input-signal phase is provided. This method is based on nonlinear interaction of three phase-synchronized modes in one core of a waveguide. The method may be realized by passing the above-mentioned signals through an optical element with a waveguide (200) having pulse interaction and propagation portions (205 and 207) which receive impulses in first and second coherent waveguide modes which cause a nonlinear interaction between the first and second waveguide modes and generate a third waveguide mode. This third mode is phase-synchronized with the first and second waveguide modes. The method may be realized in optical amplifiers, switches, as well as logical optical AND gates, OR gates, etc.

Abstract: A foldable earthquake protective bed comprises a support frame (10) and two moveable members (20 and 22) pivotally attached to the support frame (10) and capable of being pivoted between a folded position in which the moveable members are arranged as conventional parts of the bed and an unfolded position in which they form a rigid protective cover above the bed's occupant(s). The bed may have a power drive in the form of a pneumatic cylinder (42) with a piston (43) sliding inside the cylinder (42). A piston rod (44) of the piston (43) is pivotally attached by a link (46) to a bracket (30) of the pivotable member (20) and by a link (48) to a bracket (32) of the pivotable member (22). Compressed air can be admitted to the cylinder (42) from a pressure vessel (50) via a control valve (52). This valve can be activated either manually by pushing a pushbutton (62) built into the bed frame, or automatically from a seismic sensor (58) attached to the wall of the building.