Abstract: A toner is provided. The toner includes a resin and a fluorine-containing component. The toner satisfies the following formula: 5.0?FXPS/FXRF?25.0 where FXPS (atomic %) represents a content rate of fluorine atom in the toner determined by X-ray photoelectron spectroscopy (XPS) and FXRF (weight %) represents another content rate of fluorine atom in the toner determined by X-ray fluorescence analysis (XRF).

Abstract: A toner is provided. The toner includes a resin and a fluorine-containing component. The toner satisfies the following formula: 5.0?FXPS/FXRF?25.0 where FXPS (atomic %) represents a content rate of fluorine atom in the toner determined by X-ray photoelectron spectroscopy (XPS) and FXRF (weight %) represents another content rate of fluorine atom in the toner determined by X-ray fluorescence analysis (XRF).

Abstract: A toner is provided. The toner includes an amorphous resin, a crystalline resin dispersed in the amorphous resin, and a release agent. The toner satisfies the following inequality: B/A<0.8 where A represents a perimeter of the crystalline resin and B represents a length of a part of the perimeter A of the crystalline resin at which the crystalline resin is in contact with the amorphous resin, A and B being measured from a cross-sectional image of the toner observed with transmission electron microscope.

Abstract: A toner is provided. The toner includes an amorphous resin, a crystalline resin dispersed in the amorphous resin, and a release agent. The toner satisfies the following inequality: B/A<0.8 where A represents a perimeter of the crystalline resin and B represents a length of a part of the perimeter A of the crystalline resin at which the crystalline resin is in contact with the amorphous resin, A and B being measured from a cross-sectional image of the toner observed with transmission electron microscope.

Abstract: A toner, wherein an amount of Al detected in the toner is 0.7% to 1.3%, where the amount of Al detected is determined based on quantitative analysis of Al by X-ray photoelectron spectroscopic analysis (XPS), and wherein [Tg2nd (THF insoluble matter)] is ?40° C. to 30° C., where the [Tg2nd (THF insoluble matter)] is a glass transition temperature measured in second heating of differential scanning calorimetry (DSC) of THF insoluble matter of the toner.

Abstract: A toner, including: base particles containing a polyester resin, a colorant, and a release agent, wherein the toner has a glass transition temperature (Tg1st) of 20° C. to 50° C. where the glass transition temperature (Tg1st) is measured in first heating of differential scanning calorimetry (DSC) of the toner, wherein tetrahydrofuran (THF) insoluble matter of the toner has a glass transition temperature [Tg2nd (THF insoluble matter)] of 30° C. or lower where the glass transition temperature [Tg2nd (THF insoluble to matter)] is measured in second heating of differential scanning calorimetry (DSC) of the THF insoluble matter, and wherein 50% or less of the colorant is present within a region of 1,000 nm from a surface of each of the base particles toward a center thereof.

Abstract: Provided is a toner including at least a polyester resin, wherein the polyester resin has a urethane bond and a urea bond, wherein a ratio (B)/(A) between a nitrogen content (A) in a compound that is contained in a pyrolysate of the toner produced when the toner is pyrolyzed from 50° C. to 700° C. and has two isocyanate groups and a nitrogen content (B) in a compound that is contained in the pyrolysate and has one isocyanate group and one amino group satisfies 0.6?(B)/(A)?1.3, and wherein a nitrogen content in the surface of the toner is from 0 atom % to 0.9 atom %.

Abstract: A toner, wherein an amount of Al detected in the toner is 0.7% to 1.3%, where the amount of Al detected is determined based on quantitative analysis of Al by X-ray photoelectron spectroscopic analysis (XPS), and wherein [Tg2nd (THF insoluble matter)] is ?40° C. to 30° C., where the [Tg2nd (THF insoluble matter)] is a glass transition temperature measured in second heating of differential scanning calorimetry (DSC) of THF insoluble matter of the toner.

Abstract: A toner, wherein the toner satisfies a ratio XPS (%)/CIC (ppm) of 1.40×10?2 or less, where CIC (ppm) denotes a fluorine content ratio (ppm) determined by combustion ion chromatography and XPS (%) denotes a fluorine content ratio (%) determined by X-ray photoelectron spectroscopic analysis.

Abstract: A toner, including: base particles containing a polyester resin, a colorant, and a release agent, wherein the toner has a glass transition temperature (Tg1st) of 20° C. to 50° C. where the glass transition temperature (Tg1st) is measured in first heating of differential scanning calorimetry (DSC) of the toner, wherein tetrahydrofuran (THF) insoluble matter of the toner has a glass transition temperature [Tg2nd (THF insoluble matter)] of 30° C. or lower where the glass transition temperature [Tg2nd (THF insoluble to matter)] is measured in second heating of differential scanning calorimetry (DSC) of the THF insoluble matter, and wherein 50% or less of the colorant is present within a region of 1,000 nm from a surface of each of the base particles toward a center thereof.

Abstract: An air-fuel ratio of respective (individual) cylinders of an engine is changed individually from a stoichiometric air-fuel ratio to a lean air-fuel ratio with the change timing of each of respective cylinders deviated and the intake air flow into an engine 11 is changed gradually by opening an air bypass valve in parallel to the changing of the air-fuel ratio. Concurrent change of ignition timing is also disclosed.