Abstract: A structural element with a controllable heat transfer coefficient comprises a frame. A first sheet and a second sheet opposite one another are arranged in the frame. The sheets and the frame have the effect of defining a closed-off volume which is filled with at least one gas. At least one two-dimensional element is arranged between the sheets. An upper intermediate space is formed between the two-dimensional element and the frame vertically upwardly and a lower intermediate space is formed between the two-dimensional element in the frame vertically downwardly. A first cavity is between the first sheet and the two-dimensional element. A second cavity is between the two-dimensional element and the second sheet. The cavities are connected via the upper intermediate space and the lower intermediate space such that a convection flows between the cavities via the intermediate spaces. At least one means arranged in the intermediate spaces controls the convection flow.

Abstract: The present invention relates to a curtain which is suitable as shatter protection and has optical and thermal functionality. Curtains of this type are required in particular in order to protect buildings for example during terrorist attacks. This fundamentally relates to any type of building, in particular however, office buildings with large areas of glass. The fundamental concept of the present invention is to provide curtains which absorb the huge amount of energy, for example of an explosion, however also irreversible damage of the curtain being able to be accepted. It is thereby essential that the curtain absorbs the acting energy and inter alia prevents any possibly occurring fragments of a glass façade being thrown into the room and being able to injure people there. The curtain is configured for this purpose as an internally situated or externally situated curtain, advantageously as a slatted curtain/shutter or even as a roller blind.