Abstract: A solid oxide fuel cell, a method of producing the same, a fuel cell stack, and a solid oxide fuel battery. The fuel cell including a solid electrolyte layer, a cathode layer formed on one surface thereof and which contains at least Sr, an anode layer which is formed on the other surface of the solid electrolyte layer, and an intermediate layer formed between the solid electrolyte layer and the cathode layer. At least a part of the intermediate layer is an element diffusion prevention layer; the element diffusion prevention layer being formed of a complex oxide containing at least one rare earth element and Zr; and after having been subjected to accelerated heating in air at 1,000° C. for 100 hr, the element diffusion prevention layer has a thickness of 600 nm or more to 2,000 nm or less and a percent Sr coverage of 90% or lower.

Abstract: A gas detector for use in, for example, measuring the concentration of flammable gas or detecting leakage of flammable gas. The gas detector has a gas detection element in which at least a heat-generating resistor and an insulation layer are laminated on a semiconductor substrate made of silicon while the insulation layer encloses the heat-generating resistor. The gas detector detects flammable gas on the basis of temperature and resistance of the heat-generating resistor which vary according to flammable gas. In the gas detection element, a protection layer in the form of a gas impermeable oxide film is provided on its outermost surface which comes into contact with an environmental atmosphere that contains flammable gas. Thus, alkali resistance is ensured. Since the protection layer is impermeable to gas, entry of impurities (organic silicon) contained in the environmental atmosphere into the protection layer is restrained, whereby output is stabilized and becomes accurate.

Abstract: A gas detector for use in, for example, measuring the concentration of flammable gas or detecting leakage of flammable gas. The gas detector has a gas detection element in which at least a heat-generating resistor and an insulation layer are laminated on a semiconductor substrate made of silicon while the insulation layer encloses the heat-generating resistor. The gas detector detects flammable gas on the basis of temperature and resistance of the heat-generating resistor which vary according to flammable gas. In the gas detection element, a protection layer in the form of a gas impermeable oxide film is provided on its outermost surface which comes into contact with an environmental atmosphere that contains flammable gas. Thus, alkali resistance is ensured. Since the protection layer is impermeable to gas, entry of impurities (organic silicon) contained in the environmental atmosphere into the protection layer is restrained, whereby output is stabilized and becomes accurate.

Abstract: A document processing apparatus comprises: a storing portion for storing document data; an instruction generation portion for generating a first set of instructions and second sets of instructions with regard to the document data in response to a first user, each of the second sets of instructions assigned to each of second users; and an automatic processing control portion for sequentially changing a parson who can access to the document data from one of second users to another of the second users and for controlling of execution of the second sets of instructions for the parson. The first set of instructions and second sets of instructions are transmitted together with the document data through a mail box system. A user having or treating the document data is supervised by providing a management table. When the document is transmitted to another user, the name of the user is stored in the management table.