Abstract: An organic light-emitting device includes a first light-emitting layer and a second light-emitting layer. The first light-emitting layer contains a first organic compound, a first light-emitting material, and a second light-emitting material. The second light-emitting layer contains a second organic compound and a third light-emitting material. Each of the light-emitting materials is a fluorescent material. The following relationships or inequalities (a) to (c) are satisfied, S1D2>S1D1 ??(a), S1D3?S1D2 ??(b), and S1D2?S1D1>S1D3?S1D2 ??(c) where S1D1 is a singlet energy of the first light-emitting material, S1D2 is a singlet energy of the second light-emitting material, and S1D3 is a singlet energy of the third light-emitting material.

Abstract: An organic compound represented by formula [1]. In the formula rings Q represented by formula [1-1] are each independently present at positions *1 and *2 such that positions * of the rings Q correspond to the positions *1 and *2. The rings Q may be the same or different. R4 and R5 represent groups each independently selected from the group consisting of a hydrogen atom and a substituted or unsubstituted aryl group. The rings Q are aromatic hydrocarbons. R1 to R3 represent groups each independently selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, and a cyano group. At least one of R1 to R3 represents a cyano group.

Abstract: The present disclosure provides an organic light-emitting element including: a first electrode; a light-emitting layer; and a second electrode, wherein the light-emitting layer contains at least a first compound in which a naphthalene ring and a tricyclic or higher cyclic fused ring are bonded together by a single bond and a second compound in which the naphthalene ring and the fused polycyclic ring of the first compound are further cyclized.

Abstract: An organic light-emitting element including a positive electrode, a negative electrode; and a light-emitting layer between the positive electrode and the negative electrode, wherein the light-emitting layer contains a first compound represented by the following formula [1] and a second compound represented by the following formula [2]. In the following formula [1], L denotes a bidentate ligand with a main backbone of naphtho[2,1-f]isoquinoline or phenanthro[2,1-f]isoquinoline.

Abstract: An organic compound represented by the following formula [1]: Ar is selected from the group consisting of a substituted or unsubstituted aryl group and a substituted or unsubstituted heteroaryl group. R1 and R2 are independently selected from the group consisting of a hydrogen atom and a substituent. m and n are selected from integers of 1 or more and 3 or less.

Abstract: An organic compound is represented by general formula [1-1]. In general formula [1-1], X is an oxygen atom, a sulfur atom, a selenium atom, or a tellurium atom, and R1 to R18 are each independently selected from the group consisting of a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted amino group, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted silyl group, and a cyano group.

Abstract: A cBN sintered compact has cubic boron nitride particles and a ceramic binder phase, and in the sintered compact, WSi2 having an average particle diameter of 10 nm to 200 nm is dispersed such that a content thereof is 1 vol % to 20 vol %. A cutting tool has the cBN sintered compact as a tool body.

Abstract: A cBN sintered material cutting tool includes a cutting tool body that is made of a sintered material including cubic boron nitride particles and a binder phase, in which: an average particle size of the cBN particles is 0.5 ?m or less and a content ratio of the cBN particles in the sintered material is 35 vol % to 80 vol %; and the binder phase includes 1.0 vol % to 20 vol % of an Al compound, an average particle size of the Al compound present in the binder phase is 300 nm or less, and a value of a ratio (a value of SN/SO; area ratio) of a content SN of nitrogen (N) included in the Al compound to a content SO of oxygen (O) included in the Al compound is 1.1 to 5.

Abstract: A cBN sintered compact has cubic boron nitride particles and a ceramic binder phase, and in the sintered compact, WSi2 having an average particle diameter of 10 nm to 200 nm is dispersed such that a content thereof is 1 vol % to 20 vol %. A cutting tool has the cBN sintered compact as a tool body.

Abstract: A cBN sintered material cutting tool includes a cutting tool body that is made of a sintered material including cubic boron nitride particles and a binder phase, in which: an average particle size of the cBN particles is 0.5 ?m or less and a content ratio of the cBN particles in the sintered material is 35 vol % to 80 vol %; and the binder phase includes 1.0 vol % to 20 vol % of an Al compound, an average particle size of the Al compound present in the binder phase is 300 nm or less, and a value of a ratio (a value of SN/SO; area ratio) of a content SN of nitrogen (N) included in the Al compound to a content SO of oxygen (O) included in the Al compound is 1.1 to 5.

Abstract: Provided is a cBN sintered material for a tool body in which a ratio (PNTB/PNBN) of the number (PNTB) of cBN particles in contact with a Ti boride having a long axis of 150 nm or more to the total number (PNBN) of cBN particles is 0.05 or less.

Abstract: A cubic boron nitride-based sintered material includes cubic boron nitride particles of 70 to 95 vol %, in which in a structure of a cross-section of the sintered material, a binder phase with a width of 1 nm to 30 nm is present between the adjacent cubic boron nitride particles, the binder phase being made of a compound containing at least Al, B, and N and having a ratio of an oxygen content to an Al content of 0.1 or less in terms of atomic ratio.

Abstract: A cBN sintered material cutting tool is provided. The cBN cutting tool includes a cutting tool body, which is a sintered material including cBN grains and a binder phase, wherein the sintered material comprises: the cubic boron nitride grains in a range of 40 volume % or more and less than 60 volume %; and Al in a range from a lower limit of 2 mass % to an upper limit Y, satisfying a relationship, Y=?0.1X+10, Y and X being an Al content in mass % and a content of the cubic boron nitride grains in volume %, respectively, the binder phase comprises: at least a Ti compound; Al2O3; and inevitable impurities, the Al2O3 includes fine Al2O3 grains with a diameter of 10 nm to 100 nm dispersedly formed in the binder phase, and there are 30 or more of the fine Al2O3 grains generated in an area of 1 ?m×1 ?m in a cross section of the binder phase.

Abstract: Provided is a cBN sintered material for a tool body in which a ratio (PNTB/PNBN) of the number (PNTB) of cBN particles in contact with a Ti boride having a long axis of 150 nm or more to the total number (PNBN) of cBN particles is 0.05 or less.

Abstract: A cubic boron nitride-based sintered material includes cubic boron nitride particles of 70 to 95 vol %, in which in a structure of a cross-section of the sintered material, a binder phase with a width of 1 nm to 30 nm is present between the adjacent cubic boron nitride particles, the binder phase being made of a compound containing at least Al, B, and N and having a ratio of an oxygen content to an Al content of 0.1 or less in terms of atomic ratio.

Abstract: A cBN tool that exhibits: excellent chipping resistance and wear resistance; and excellent cutting performance, for a long term use even in intermittent cutting work on high hardened steel is provided. The cutting tool includes a cutting tool body that is a cubic boron nitride-based material containing cubic boron nitride particles as a hard phase component. In the cutting tool, the cubic boron nitride particles includes an Al2O3 layer with an average layer thickness of 1.0-10 nm on a surface of the cubic boron nitride particles, a rift with an average rift formation ratio of 0.02-0.20 being formed in the Al2O3 layer, and the cubic boron nitride-based sintered material includes a binding phase containing at least one selected from a group consisting of: titanium nitride; titanium carbide; titanium carbonitride; titanium boride; aluminum nitride; aluminum oxide; inevitable products; and mutual solid solution thereof, around the cubic boron nitride particles.

Abstract: A cBN sintered material cutting tool is provided. The cBN cutting tool includes a cutting tool body, which is a sintered material including cBN grains and a binder phase, wherein the sintered material comprises: the cubic boron nitride grains in a range of 40 volume % or more and less than 60 volume %; and Al in a range from a lower limit of 2 mass % to an upper limit Y, satisfying a relationship, Y=?0.1X+10, Y and X being an Al content in mass % and a content of the cubic boron nitride grains in volume %, respectively, the binder phase comprises: at least a Ti compound; Al2O3; and inevitable impurities, the Al2O3 includes fine Al2O3 grains with a diameter of 10 nm to 100 nm dispersedly formed in the binder phase, and there are 30 or more of the fine Al2O3 grains generated in an area of 1 ?m×1 ?m in a cross section of the binder phase.

Abstract: A cutting tool made of cubic boron nitride-based sintered material that exhibits excellent chipping resistance and fracturing resistance in the intermittent cutting work on high hardness steel is provided. In the cutting tool, the average size of the cubic boron nitride particles is 0.5 to 8 ?m. A portion of the cubic boron nitride particles are coated with aluminum oxide films having an average thickness of 10 to 90 nm on surfaces thereof, and a rift is partially formed in the aluminum oxide film. The average rift formation ratio satisfies the formula 0.02?h/H?0.08, wherein h is a breadth of the rift of the aluminum oxide film and H is a girth of the particle of cubic boron nitride.

Abstract: A cBN tool that exhibits: excellent chipping resistance and wear resistance; and excellent cutting performance, for a long term use even in intermittent cutting work on high hardened steel is provided. The cutting tool includes a cutting tool body that is a cubic boron nitride-based material containing cubic boron nitride particles as a hard phase component. In the cutting tool, the cubic boron nitride particles includes an Al2O3 layer with an average layer thickness of 1.0-10 nm on a surface of the cubic boron nitride particles, a rift with an average rift formation ratio of 0.02-0.20 being formed in the Al2O3 layer, and the cubic boron nitride-based sintered material includes a binding phase containing at least one selected from a group consisting of: titanium nitride; titanium carbide; titanium carbonitride; titanium boride; aluminum nitride; aluminum oxide; inevitable products; and mutual solid solution thereof, around the cubic boron nitride particles.

Abstract: A cutting tool made of cubic boron nitride-based sintered material that exhibits excellent chipping resistance and fracturing resistance in the intermittent cutting work on high hardness steel is provided. In the cutting tool, the average size of the cubic boron nitride particles is 0.5 to 8 ?m. A portion of the cubic boron nitride particles are coated with aluminum oxide films having an average thickness of 10 to 90 nm on surfaces thereof, and a rift is partially formed in the aluminum oxide film. The average rift formation ratio satisfies the formula 0.02?h/H?0.08, wherein h is a breadth of the rift of the aluminum oxide film and H is a girth of the particle of cubic boron nitride.