Disclosed is a composition having nanoparticles or particles of a refractory metal, a refractory metal hydride, a refractory metal carbide, a refractory metal nitride, or a refractory metal boride, an organic compound consisting of carbon and hydrogen, and a nitrogenous compound consisting of carbon, nitrogen, and hydrogen. The composition, optionally containing the nitrogenous compound, is milled, cured to form a thermoset, compacted into a geometric shape, and heated in a nitrogen atmosphere at a temperature that forms a nanoparticle composition comprising nanoparticles of metal nitride and optionally metal carbide. The nanoparticles have a uniform distribution of the nitride or carbide.

Disclosed is a composition having nanoparticles or particles of a refractory metal, a refractory metal hydride, a refractory metal carbide, a refractory metal nitride, or a refractory metal boride, an organic compound consisting of carbon and hydrogen, and a nitrogenous compound consisting of carbon, nitrogen, and hydrogen. The composition, optionally containing the nitrogenous compound, is milled, cured to form a thermoset, compacted into a geometric shape, and heated in a nitrogen atmosphere at a temperature that forms a nanoparticle composition comprising nanoparticles of metal nitride and optionally metal carbide. The nanoparticles have a uniform distribution of the nitride or carbide.

A porous honeycomb heat storage structure including: a honeycomb structure which has a porous partition wall which defines a plurality of cells extending one end face to the other end face and allows a reaction medium to flow into the cells; and a heat storage portion which is configured by filling a heat storage material performing heat storage and heat dissipation by a reversible chemical reaction with the reaction medium or physical adsorption/desorption in at least a portion of each cells, wherein the heat storage portion has an area ratio in a range from 60% to 90% with respect to a cross sectional area of a honeycomb cross section orthogonal to an axial direction of the honeycomb structure.

A structure according to the embodiment includes a first crystal grain, a second crystal grain, and a first region. The first crystal grain includes silicon nitride. The second crystal grain includes a first element selected from a first group consisting of scandium, yttrium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, aluminum, chromium, zirconium, magnesium, zinc, titanium, gallium, beryllium, calcium, strontium, barium, hafnium, vanadium, niobium, tantalum, tungsten, iron, cobalt, nickel, and copper, and oxygen. The first region includes an oxide of the first element.

According to one embodiment, a structure according to the embodiment includes a β type silicon nitride type crystal phase and a Y.sub.2Si.sub.3O.sub.3N.sub.4 type crystal phase. In an X-ray diffraction pattern according to a θ-2θ method of the structure, a ratio of a second peak intensity being maximum and appearing at 2θ=31.93±0.1° with respect to a first peak intensity being maximum and appearing at 2θ=27.03±0.1° is 0.005 or more and 0.20 or less.

A probe card board in the present disclosure includes a plurality of through holes designed to receive a probe brought into contact with a measurement object. The probe card board is composed of silicon nitride based ceramics. The probe card board includes a first surface opposed to the measurement object and a second surface located opposite to the first surface. The probe card board contains a plurality of crystal phases of metal silicide. Metal constituting the metal silicide is at least one kind selected from among molybdenum, chrome, iron, nickel, manganese, vanadium, niobium, tantalum, cobalt and tungsten.

Disclosed is a composition having nanoparticles or particles of a refractory metal, a refractory metal hydride, a refractory metal carbide, a refractory metal nitride, or a refractory metal boride, an organic compound consisting of carbon and hydrogen, and a nitrogenous compound consisting of carbon, nitrogen, and hydrogen. The composition, optionally containing the nitrogenous compound, is milled, cured to form a thermoset, compacted into a geometric shape, and heated in a nitrogen atmosphere at a temperature that forms a nanoparticle composition comprising nanoparticles of metal nitride and optionally metal carbide. The nanoparticles have a uniform distribution of the nitride or carbide.

Disclosed is a composition having nanoparticles or particles of a refractory metal, a refractory metal hydride, a refractory metal carbide, a refractory metal nitride, or a refractory metal boride, an organic compound consisting of carbon and hydrogen, and a nitrogenous compound consisting of carbon, nitrogen, and hydrogen. The composition, optionally containing the nitrogenous compound, is milled, cured to form a thermoset, compacted into a geometric shape, and heated in a nitrogen atmosphere at a temperature that forms a nanoparticle composition comprising nanoparticles of metal nitride and optionally metal carbide. The nanoparticles have a uniform distribution of the nitride or carbide.

A turbine assembly includes an axial turbine with an axially arranged series of rotor sections and an external sheath providing structural support for the axial turbine, wherein the sheath is made from dense silicon nitride. Each rotor section includes an outer ring and rotor blades and the outer rings of the rotor sections connect to form a rotating outer casing, wherein the rotor sections are made from reaction bonded silicon nitride.

An apparatus and a method for producing fine particles includes a vacuum chamber, a material feeding device connected to the vacuum chamber and feeding material particles into the vacuum chamber from material feeing ports, and a plurality of electrodes connected to the vacuum chamber. Tip ends of the electrodes protrude into the vacuum chamber to generate plasma, and a collecting device is connected to the vacuum chamber and collects fine particles. The electrodes generate discharge inside the vacuum chamber and produce the fine particles from the material. The material feeding ports of the material feeding device are arranged in a lower side than (below) the plural electrodes in the vertical direction in the vacuum chamber.