Abstract: Provided is an electrosilver plating bath yielding a semiglossy to glossy appearance across a wide current density range without the use of a cyan compound, and a plating method using the electrosilver plating bath. An electrosilver plating fluid that is an aqueous solution containing (A) at least one soluble silver compound, (B) at least one benzoic acid derivative or a salt of the derivative, and (C) at least one acid and/or complexing agent, wherein the benzoic acid derivative is expressed by the following general formula (m is 1, 2, 3, 4 or 5; Ra is a carboxyl group; individual instances of Rb are selected independently from an aldehyde group, a carboxyl group, an amino group, a hydroxyl group, or a sulfonic acid group; individual instances of Rc are independently oxygen or any substituent; and one or more oxygen or CH2 may be introduced into the bond between Ra or Rb and a benzene ring.

Abstract: A multifuel internal combustion engine in which single low boiling point component fuel and at least one kind of fuel having properties different from those of the single low boiling point component fuel are introduced into a combustion chamber CC separately or together thereby operating the multifuel internal combustion engine, includes lubricant-oil temperature detecting unit means (temperature sensor 91) that detects a temperature of lubricant oil, or lubricant-oil temperature estimating unit means that estimates the temperature, and purge control unit means (electronic control unit 1) that prohibits purge control by an evaporation gas purge apparatus (evaporation gas passage 42, check valve 43, canister 44, on-off valve 45) or reduces a purge flow rate of evaporation gas in the purge control, when the detected or estimated temperature of the lubricant oil is near a boiling point temperature of the single low boiling point component fuel at which it is necessary to reduce a fuel injection amount from a fue

Abstract: A multifuel internal combustion engine in which single low boiling point component fuel and at least one kind of fuel having properties different from those of the single low boiling point component fuel are introduced into a combustion chamber CC separately or together thereby operating the multifuel internal combustion engine, includes lubricant-oil temperature detecting unit means (temperature sensor 91) that detects a temperature of lubricant oil, or lubricant-oil temperature estimating unit means that estimates the temperature, and purge control unit means (electronic control unit 1) that prohibits purge control by an evaporation gas purge apparatus (evaporation gas passage 42, check valve 43, canister 44, on-off valve 45) or reduces a purge flow rate of evaporation gas in the purge control, when the detected or estimated temperature of the lubricant oil is near a boiling point temperature of the single low boiling point component fuel at which it is necessary to reduce a fuel injection amount from a fue