The present invention discloses a method for decomposing medium-/low-grade scheelite, specifically comprising steps of: grinding medium-/low-grade scheelite, decomposing in an autoclave by using sodium phosphate and activated magnesium fluoride as leaching agents, and treating by solid-liquid separation to obtain crude sodium tungstate solution and residue. In this way, the medium-/low-grade scheelite is decomposed. Magnesium chloride is added in a sodium fluoride solution to prepare activated magnesium fluoride as a leaching agent. The present invention has the advantage that the high-efficiency decomposition of medium-/low-grade scheelite can be realized with low consumption of leaching agents, and the leaching cost can be greatly reduced in comparison to the existing decomposition processes using sodium hydroxide and sodium carbonate. This process is short in route, simple in operation, readily available and reliable in production equipment, and easy for industrialization.

An infrared-absorbing fine particle-containing composition, including: infrared absorbing fine particles, a dispersant, and a solvent, wherein the dispersant has a polyether structure, has a glass transition temperature of −150° C. or higher and 0° C. or lower, and is contained in an amount of 10 parts by mass or more with respect to 100 parts by mass of the infrared absorbing fine particles, and a solvent content is 10 mass % or less.

An infrared reflective material, a method for producing the same, and an infrared reflective structure are provided. The method includes a preparation step implemented by mixing antimony and zirconium tungstate through a sol-gel manner to form zirconium tungstate composite powders doped with the antimony; a sintering step implemented by sintering the antimony and the zirconium tungstate in the zirconium tungstate composite powders doped with the antimony in a temperature gradient within a range from 500° C. to 1,100° C. for a predetermined time period, so that the antimony and the zirconium tungstate in the zirconium tungstate composite powders doped with the antimony bond together to form into composite tungsten oxide powders; a grinding step implemented by grinding the composite tungsten oxide powders; and a mixing step implemented by mixing the composite tungsten oxide powders that are grinded into an acrylic resin to form the infrared reflective material.

An infrared reflective material, a method for producing the same, and an infrared reflective structure are provided. The method includes a preparation step implemented by mixing antimony and zirconium tungstate through a sol-gel manner to form zirconium tungstate composite powders doped with the antimony; a sintering step implemented by sintering the antimony and the zirconium tungstate in the zirconium tungstate composite powders doped with the antimony in a temperature gradient within a range from 500° C. to 1,100° C. for a predetermined time period, so that the antimony and the zirconium tungstate in the zirconium tungstate composite powders doped with the antimony bond together to form into composite tungsten oxide powders; a grinding step implemented by grinding the composite tungsten oxide powders; and a mixing step implemented by mixing the composite tungsten oxide powders that are grinded into an acrylic resin to form the infrared reflective material.

The present invention relates to a composite of a cobalt-based perovskite material with a negative thermal expansion material, and a preparation method of the same, and a solid oxide fuel cell (SOFC) comprising the same, and belongs to the technical field of fuel cells. In the present invention, a negative thermal expansion material is introduced into a cobalt-based perovskite oxide to successfully prepare an SOFC cathode material with excellent electrochemical performance and low thermal expansivity. The composite electrode achieves prominent mechanical tolerance in SOFC, which can moderate a volume change during the whole calcination process and enable a smooth transition to a high-temperature stage. The composite electrode has a thermal expansion coefficient (TEC) only of 12.9×10.sup.−6 K.sup.−1, which is perfectly matched with that of an SDC electrolyte. In addition, the composite shows excellent oxygen reduction reaction (ORR) activity, high TEC, and extremely-excellent anti-CO.sub.2 poisoning performance.

Disclosed are embodiments of making a high Q ceramic material. The method includes providing Ba.sub.3CoTa.sub.2O.sub.9 and incorporating one of Ba.sub.2MgWO.sub.6, Ba.sub.8LiTa.sub.5WO.sub.24, Ba.sub.8LiTa.sub.5WO.sub.24, Ba.sub.2MgWO.sub.6, Ba.sub.3LaTa.sub.3O.sub.12, Ba.sub.8LiTa.sub.5WO.sub.24, BaLaLiWO.sub.6, Ba.sub.4Ta.sub.2WO.sub.12, Ba.sub.2La.sub.2MgW.sub.2O.sub.12, BaLaLiWO.sub.6, Sr.sub.3LaTa.sub.3O.sub.12, and SrLaTaO.sub.12 into the Ba.sub.3CoTa.sub.2O.sub.9 to form a solid solution having a high Q value of greater than 12000 at about 10 GHz.

Disclosed are embodiments of making a high Q ceramic material. The method includes providing Ba.sub.3NiTa.sub.2O.sub.9 and incorporating one of Ba.sub.2MgWO.sub.6, Ba.sub.8LiTa.sub.5WO.sub.24, Ba.sub.8LiTa.sub.5WO.sub.24, Ba.sub.2MgWO.sub.6, Ba.sub.3LaTa.sub.3O.sub.12, Ba.sub.8LiTa.sub.5WO.sub.24, BaLaLiWO.sub.6, Ba.sub.4Ta.sub.2WO.sub.12, Ba.sub.2La.sub.2MgW.sub.2O.sub.12, BaLaLiWO.sub.6, Sr.sub.3LaTa.sub.3O.sub.12, and SrLaTaO.sub.12 into the Ba.sub.3NiTa.sub.2O.sub.9 to form a solid solution having a high Q value of greater than 12000 at about 10 GHz.

Disclosed are embodiments of a barium magnesium tantalate including additional components to increase the Q value of the material. In some embodiments, complex tungsten oxides and/or hexagonal perovskite crystal structures can be added into the barium magnesium tantalate to provide for advantageous properties. In some embodiments, no tin is used in the formation of the material.

Methods of synthesizing transition metal dichalcogenide nanoparticles include forming a metal-amine complex, combining the metal-amine complex with a chalcogen source in at least one solvent to form a solution, heating the solution to a first temperature for a first period of time, and heating the solution to a second temperature that is higher than the first temperature for a second period of time.

A positive electrode active material includes a lithium-rich lithium manganese-based oxide, wherein the lithium-rich lithium manganese-based oxide is represented by the following chemical formula (1),
Li.sub.1+aNi.sub.xCo.sub.yMn.sub.zM.sub.vO.sub.2-bA.sub.b  (1) wherein, 0<a≤0.2, 0<x≤0.4, 0<y≤0.4, 0.5≤z≤0.9, 0≤v≤0.2, a+x+y+z+v=1, and 0≤b≤0.5; M is one or more elements selected from the group consisting of Al, Zr, Zn, Ti, Mg, Ga, In, Ru, Nb, and Sn; and A is one or more elements selected from the group consisting of P, N, F, S and Cl; wherein (i) lithium tungsten (W) compound, or the (i) lithium tungsten (W) compound and (ii) tungsten (W) compound
are contained on the lithium-rich lithium manganese-based oxide; in an amount of 0.1% to 7% by weight based on the total weight of the positive electrode active material, wherein the (i) lithium tungsten (W) compound includes a composite of the (ii) tungsten (W) compound and a lithium.