Abstract: A winding for a power transformer comprises a wire at least partially covered with a bonding material. The wire comprises a first winding formed into a first winding layer comprising a first plurality of turns positioned adjacently to each other, wherein the first plurality of turns are bonded together. The wire also comprises a second winding formed into a second winding layer from a first continuous wire portion extending from the first winding layer, the second winding layer comprising a second plurality of turns positioned adjacently together.

Abstract: The present invention relates to a composite sandwich wall panel comprising: at least two fine sand gypsum or concrete panels (I) in each of which a glass fiber web (2) is disposed at center, and at least one polystyrene panel (3), which are bonded alternatively. The surface layer and the bottom layer are the fine sand gypsum or concrete panels, and according to the requirement, the wall panel can be produced to have three or more layers of composite panels. The wall panel of the present invention has advantages of light weight, easy installation, strong loading capacity, no seam crack, no plaster, and good performance of thermal insulation, sound insulation and fireproof as well as it is suitable for internal wall and external wall.