An apparatus and method for manufacturing solid particles based on inert gas evaporation. The method includes forming a continuous gaseous feed flow, and injecting the continuous gaseous feed flow through an inlet into a free-space region of a reactor chamber in the form of a feed jet flow, and forming at least one continuous jet flow of a cooling fluid and injecting the at least one jet flow of cooling fluid into the reaction chamber. The feed jet flow is made by passing the feed flow at a pressure above the reactor chamber pressure in the range from 0.01.Math.10.sup.5 to 20.Math.10.sup.5 Pa through an injection nozzle. The jet flow of cooling fluid is made by passing the cooling fluid through an injection nozzle which directs the jet flow of cooling fluid such that it intersects the feed jet flow with an intersection angle between 30 and 150°.

The present disclosure discloses a preparation method of pressed Scandia-doped dispenser cathode using microwave sintering. Embodiments of the present disclosure include dissolving some nitrates and ammonium metatungstate with deionized water to prepare a homogeneous solution. Precursor powder with uniform size is obtained by spray drying, the precursor powder is decomposed, and two-step reduction may be proceeded to form doped tungsten powder with uniform element distribution. The cathode is prepared by one-time microwave sintering. One-time forming of cathode sintering is realized, and sintering shrinkage and sintering time are reduced significantly. The method has excellent repeatability, and the cathode has a homogeneous structure and excellent emission performance at 950° C.

The present disclosure discloses a preparation method of pressed Scandia-doped dispenser cathode using microwave sintering. Embodiments of the present disclosure include dissolving some nitrates and ammonium metatungstate with deionized water to prepare a homogeneous solution. Precursor powder with uniform size is obtained by spray drying, the precursor powder is decomposed, and two-step reduction may be proceeded to form doped tungsten powder with uniform element distribution. The cathode is prepared by one-time microwave sintering. One-time forming of cathode sintering is realized, and sintering shrinkage and sintering time are reduced significantly. The method has excellent repeatability, and the cathode has a homogeneous structure and excellent emission performance at 950° C.

Provided herein are methods of preparing tetrahexahedra nanoparticles and methods of using the tetrahexahedra nanoparticles as an oxidative catalyst.

Provided herein are methods of preparing tetrahexahedra nanoparticles and methods of using the tetrahexahedra nanoparticles as an oxidative catalyst.

[Object] To provide fine particles 2 having good printing characteristics, good thermal conductivity, and good electrical conductivity.

[Solution] The fine particles 2 are flake-like. A main component of the fine particles 2 is an electrically conductive metal. A typical metal is silver. A particle diameter D50 of particles including a large number of the fine particles 2 is equal to or greater than 0.10 μm but equal to or less than 0.50 μm, a particle diameter D95 of the particles is equal to or less than 1.00 μm, and a maximum particle diameter Dmax of the particles is equal to or less than 3.00 μm. A particle diameter D10 of the particles is equal to or greater than 0.05 μm. A BET specific surface area of the particles is equal to or greater than 2.0 m.sup.2/g. A tap density TD of the particles is equal to or greater than 2.0 g/cm.sup.3. An average Tave of thicknesses of the fine particles 2 is equal to or less than 0.05 μm.

[Object] To provide fine particles 2 having good printing characteristics, good thermal conductivity, and good electrical conductivity.

[Solution] The fine particles 2 are flake-like. A main component of the fine particles 2 is an electrically conductive metal. A typical metal is silver. A particle diameter D50 of particles including a large number of the fine particles 2 is equal to or greater than 0.10 μm but equal to or less than 0.50 μm, a particle diameter D95 of the particles is equal to or less than 1.00 μm, and a maximum particle diameter Dmax of the particles is equal to or less than 3.00 μm. A particle diameter D10 of the particles is equal to or greater than 0.05 μm. A BET specific surface area of the particles is equal to or greater than 2.0 m.sup.2/g. A tap density TD of the particles is equal to or greater than 2.0 g/cm.sup.3. An average Tave of thicknesses of the fine particles 2 is equal to or less than 0.05 μm.

The present invention provides a silver coating composition that develops excellent conductivity (low resistance value) by low-temperature and short-time calcining, and that is excellent in fine-line drawing performance and suitable for intaglio offset printing. A silver particle coating composition comprising: silver nano-particles (N) whose surfaces are coated with a protective agent containing an aliphatic hydrocarbon amine; a surface energy modifier; and a dispersion solvent. The surface energy modifier may be selected from the group consisting of a silicon-based surface energy modifier and an acrylic surface energy modifier. The coating composition preferably further comprises silver microparticles (M). The silver coating composition is suitable for intaglio offset printing.

The present invention provides a silver coating composition that develops excellent conductivity (low resistance value) by low-temperature and short-time calcining, and that is excellent in fine-line drawing performance and suitable for intaglio offset printing. A silver particle coating composition comprising: silver nano-particles (N) whose surfaces are coated with a protective agent containing an aliphatic hydrocarbon amine; a surface energy modifier; and a dispersion solvent. The surface energy modifier may be selected from the group consisting of a silicon-based surface energy modifier and an acrylic surface energy modifier. The coating composition preferably further comprises silver microparticles (M). The silver coating composition is suitable for intaglio offset printing.

The present invention provides a silver coating composition that develops excellent conductivity (low resistance value) by low-temperature and short-time calcining and that has excellent printability. A silver particle coating composition including: silver nano-particles whose surfaces are coated with a protective agent including an aliphatic hydrocarbon amine; and a dispersion solvent, wherein the dispersion solvent includes a solvent selected from the group consisting of a glycol ether-based solvent and a glycol ester-based solvent. The silver particle coating composition is suitable for various printing methods such as intaglio offset printing and screen printing.