The present invention relates to a fluorescent nanodiamond preparing method including a first operation of preparing nanodiamonds having an average particle diameter of 10 nm or less, a second operation of implanting plasma ions into the nanodiamonds, a third operation of heat-treating the nanodiamonds implanted with the plasma ions under a vacuum or inert gas atmosphere, a fourth operation of oxygen treatment of the heat-treated nanodiamonds under a gas atmosphere including oxygen to oxidize the surfaces of the nanodiamonds, a fifth operation of acid-treating the oxygen-treated nanodiamonds, a sixth operation of centrifuging and cleaning the acid-treated nanodiamonds, and a seventh operation of drying the cleaned nanodiamonds, wherein, in the second operation, the plasma ions are implanted at an incident ion dose of 10.sup.13 ions/cm.sup.2 or more and 10.sup.20 ions/cm.sup.2 or less.

One variation of a method includes: ingesting an air sample captured during an air capture period at a target location for collection of a first mixture including carbon dioxide and a first concentration of impurities; conveying the first mixture through a liquefaction unit to generate a second mixture including carbon dioxide and a second concentration of impurities less than the first concentration of impurities; in a methanation reactor, mixing the second mixture with hydrogen to generate a first hydrocarbon mixture comprising a third concentration of impurities comprising nitrogen, carbon dioxide, and hydrogen; conveying the first hydrocarbon mixture through a separation unit configured to remove impurities from the first hydrocarbon mixture to generate a second hydrocarbon a fourth concentration of impurities less than the third concentration of impurities; and depositing the second hydrocarbon mixture in a diamond reactor containing a set of diamond seeds to generate a first set of diamonds.

The present invention is to provide a heteroatom-doped nanodiamond, the heteroatom-doped nanodiamond being doped with at least one heteroatom, the heteroatom-doped nanodiamond satisfying criteria (i) and/or (ii) below: (i) a BET specific surface area being from 20 to 900 m.sup.2/g, and (ii) an average size of primary particles being from 2 to 70 nm.

The present invention is to provide a heteroatom-doped nanodiamond, the heteroatom-doped nanodiamond being doped with at least one heteroatom, the heteroatom-doped nanodiamond satisfying criteria (i) and/or (ii) below: (i) a BET specific surface area being from 20 to 900 m.sup.2/g, and (ii) an average size of primary particles being from 2 to 70 nm.

A method of manufacturing a diamond substrate includes: forming an ion implantation layer at a side of a main surface of a diamond seed substrate by implanting ions into the main surface of the diamond seed substrate; producing a diamond structure by growing a diamond growth layer by a vapor phase synthesis method on the main surface of the diamond seed substrate, after implanting the ions; and performing heat treatment on the diamond structure. The performed heat treatment causes the diamond structure to be separated along the ion implantation layer into a first structure including the diamond seed substrate and failing to include the diamond growth layer, and a diamond substrate including the diamond growth layer. Thus, the method of manufacturing a diamond substrate is provided that enables a diamond substrate with a large area to be manufactured in a short time and at a low cost.

A method of manufacturing a diamond substrate includes: forming an ion implantation layer at a side of a main surface of a diamond seed substrate by implanting ions into the main surface of the diamond seed substrate; producing a diamond structure by growing a diamond growth layer by a vapor phase synthesis method on the main surface of the diamond seed substrate, after implanting the ions; and performing heat treatment on the diamond structure. The performed heat treatment causes the diamond structure to be separated along the ion implantation layer into a first structure including the diamond seed substrate and failing to include the diamond growth layer, and a diamond substrate including the diamond growth layer. Thus, the method of manufacturing a diamond substrate is provided that enables a diamond substrate with a large area to be manufactured in a short time and at a low cost.

The present invention is to provide an explosive composition comprising at least one explosive and at least one heteroatom compound, the heteroatom compound comprising at least one heteroatom selected from the group consisting of B, P, Si, S, Cr, Sn, Al, Ge, Li, Na, K, Cs, Mg, Ca, Sr, Ba, Ti, Zr, V, Nb, Ta, Mo, W, Mn, Ni, Cu, Ag, Cd, Hg, Ga, In, Tl, As, Sb, Bi, Se, Te, Co, Xe, F, Y, and lanthanoids.

The present invention is to provide an explosive composition comprising at least one explosive and at least one heteroatom compound, the heteroatom compound comprising at least one heteroatom selected from the group consisting of B, P, Si, S, Cr, Sn, Al, Ge, Li, Na, K, Cs, Mg, Ca, Sr, Ba, Ti, Zr, V, Nb, Ta, Mo, W, Mn, Ni, Cu, Ag, Cd, Hg, Ga, In, Tl, As, Sb, Bi, Se, Te, Co, Xe, F, Y, and lanthanoids.

The present invention provides a nanocluster in which a carbon nanomaterial modified with a higher alkyl group or a higher alkenyl group is self-assembled.

The present invention provides a nanocluster in which a carbon nanomaterial modified with a higher alkyl group or a higher alkenyl group is self-assembled.