Abstract: A mattress and a laid bedding for a bed are disclosed. The laid bedding is configured such that a mattress in which split cores are freely combined is laid and filled in a box-like closed bottom frame composed of a bottom and an edge erected on a peripheral portion of the bottom. In the mattress, there are three types: a mattress composed of a latex layer, a urethane layer and a low-resilience urethane layer; a mattress composed of an extremely fine fibrous resin layer in which extremely fine fibrous resin is three-dimensionally intertwined and welded together, a urethane layer and a latex layer; and a mattress composed of an extremely fine fibrous resin layer in which extremely fine fibrous resin is three-dimensionally intertwined and welded together, a urethane layer and a low-resilience urethane layer. Each of the mattresses is composed of three or six cores according to size.

Abstract: A current collector for an electrochemical element including an aluminum foil showing a peak in the range between 945 cm?1 and 962 cm?1 in measurement of a surface layer of the aluminum foil by Fourier transform infrared spectroscopy. The current collector can be obtained by a manufacturing method which includes the steps of: preparing an aluminum foil material; washing a surface of the aluminum foil material with a chemical solution capable of dissolving aluminum such as hydrochloric acid, aqueous nitric acid, aqueous sulfuric acid, aqueous solutions of alkali metal hydroxides and aqueous solutions of alkaline earth metal hydroxides; and optionally heat treating the aluminum foil at 70 to 200° C. and/or forming a coated layer including an electrically conducive material, on one or both surfaces of the aluminum foil.