A material that facilitates dissipation of heat is provided and includes hexagonal boron nitride and alumina.

A system for converting fuel is provided and includes a first reactor comprising a plurality of ceramic composite particles, the ceramic composite particles comprising at least one metal oxide disposed on a support, wherein the first reactor is configured to reduce the at least one metal oxide with a fuel to produce a reduced metal or a reduced metal oxide; a second and reactor configured to oxidize at least a portion of the reduced metal or reduced metal oxide from the said first reactor to produce a metal oxide intermediate; a source of air; and a third reactor communicating with said source of air and configured to regenerate the at least one metal oxide from the remaining portion of the solids discharged from the said first reactor and the solids discharged from the said second reactor for by oxidizing the metal oxide intermediate.

A piezoelectric composition comprises a plurality of crystal particles, wherein the piezoelectric composition includes bismuth, iron, barium, titanium, and oxygen; the crystal particle include a core and a shell having a contents of bismuth higher than that in the core and covering the core; and the total area of the cross sections of the cores exposed to the cross section of the piezoelectric composition is expressed as S.sub.CORE, the total area of the cross sections of the shells exposed to the cross section of the piezoelectric composition is expressed as S.sub.SHELL, and 100.Math.S.sub.CORE/(S.sub.CORE+S.sub.SHELL) is 50 to 90.

A piezoelectric composition comprises a plurality of crystal particles, wherein the piezoelectric composition includes bismuth, iron, barium, titanium, and oxygen; the crystal particles include a core and a shell covering the core; the average value of the contents of bismuth in the cores is expressed as C.sub.CORE % by mass, the average value of the contents of bismuth in the shells is expressed as C.sub.SHELL % by mass, and the C.sub.CORE is lower than the C.sub.SHELL; and the number of all the particles comprised in the piezoelectric composition is expressed as N, the number of the crystal particles including the core and the shell is expressed as n, and n/N is 0.10 to 1.00.

Disclosed are a grain boundary and surface-doped rare earth zirconium-based ceramic material and a preparation method and application thereof, and part of doped elements are positioned at the grain boundary and surface of the rare earth zirconium-based ceramic material by a step-by-step doping method. The sintering activity of the rare earth zirconium-based ceramic material can be changed by adjusting the type and content of doping elements at the grain boundary and the surface, thereby enabling the control of the grain size and the grain boundary number and characteristics of the rare earth zirconium-based ceramic material, and finally optimizing the properties, such as electrical and mechanical properties, of the material. The doping method has the advantages of simple process, low cost and high universality, and can meet the requirements of different rare earth zirconium-based ceramics on doping elements, and thus is suitable for large-scale application.

A material that facilitates dissipation of heat is provided and includes hexagonal boron nitride and alumina.

Provided is a method of making a composite ceramic material for a fuel cell. The composite ceramic material for the fuel cell forms a cored structure where perovskite ceramic particles having a small particle diameter surround lanthanum cobaltite particles having a large particle diameter. Lanthanum cobaltite is added as a starting material in a process of synthesizing the perovskite ceramic particles. The composite ceramic material for the fuel cell made according to this method improves an electric connection characteristic between a separation plate and a polar plate of the fuel cell, and is chemically and mechanically stable.

The present disclosure relates to the formation of polycrystalline diamond materials with fine diamond grains and nano-sized particles of a grain growth inhibitor. In one embodiment, a method of fabricating a polycrystalline diamond material is provided. The method includes providing a mixture of diamond particles with an average particle size of about 1 micron or less, distributing a plurality of nano-sized titanium-containing particles with the diamond mixture, to act as a grain growth inhibitor, and sintering the mixture of diamond particles and titanium-containing particles at high pressure and high temperature to create a polycrystalline structure of sintered diamond grains. The sintered diamond grains have an average size of about 1 micron or less.

Disclosed is a composite abrasive with hard core and soft shell, comprising hard abrasive core with grain diameter in a range of 0.11 m and a soft oxide shell with thickness in a range of 5100 nm, the grain size of the oxide of the soft oxide shell is in a range of 520 nm, the composite abrasive is obtained from aqueous solution of oxide inorganic salt precursor and the hard abrasive by dispersing, constant temperature reflux hydrolyzing, solid-liquid separating, washing and drying. The component abrasive with hard core and soft shell of the present invention can improve the manufacturing efficiency and the surface quality during the ultraprecise manufacturing of the sapphire substrate.

An epsilon-type iron oxide having an Fe-site that is substituted with a platinum group element, provided that Fe of a D-site of the epsilon-type iron oxide is not substituted with the platinum group element.