A mooring system for a floating vessel such as a drilling unit is provided. The image forming apparatus can reduce impairment of settling rate of the developer images at the second half of the recording paper during the fixing process. The core includes at least one lithiated compound and the surface-treatment layer includes at least one coating material selected from the group consisting of coating element included-hydroxides, oxyhydroxides, oxycarbonates, hydroxycarbonates and any mixture thereof.