Magnetic powder includes: at least one epsilon-phase iron oxide-based compound selected from the group consisting of -Fe.sub.2O.sub.3 and a compound represented by Formula (1); and a surface treatment layer including a silane compound on at least a part of a surface. The magnetic powder has an average particle diameter of 8 nm to 20 nm. The content ratio of carbon atoms of the silane compound included in the surface treatment layer to iron atoms of the at least one epsilon-phase iron oxide-based compound selected from the group consisting of -Fe.sub.2O.sub.3 and the compound represented by Formula (1) is 0.05% to 0.5% in terms of the number of atoms. A manufacturing method thereof and applications thereof are also provided. In Formula (1), A represents at least one metal element other than Fe and a represents a number that satisfies a relationship of 0<a<2.
-A.sub.aFe.sub.2-aO.sub.3(1)

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.

The present disclosure provides an anisotropic lamellar inorganic fiber aerogel material and a preparation method thereof. The method includes: mixing a polymer solution, an inorganic precursor and a chloride to obtain a spinning precursor solution; blow spinning the spinning precursor solution to obtain a composite fiber aerogel; calcinating the composite fiber aerogel to obtain the anisotropic lamellar inorganic fiber aerogel material. Therefore, the method has advantages of simplicity, easy operation, low cost, high efficiency and easy industrialized production. The inorganic fiber aerogel materials prepared by the above method are composed of multi-layer stacked fibers and have an anisotropic lamellar structure, which can be cut into any desired shape, and stacked to any desired thickness. In addition, the inorganic fiber aerogel materials have good flexibility and compressibility, excellent fire resistance, good high and low temperature resistance and superior thermal insulation, which greatly expands their application field.

The present disclosure provides an anisotropic lamellar inorganic fiber aerogel material and a preparation method thereof. The method includes: mixing a polymer solution, an inorganic precursor and a chloride to obtain a spinning precursor solution; blow spinning the spinning precursor solution to obtain a composite fiber aerogel; calcinating the composite fiber aerogel to obtain the anisotropic lamellar inorganic fiber aerogel material. Therefore, the method has advantages of simplicity, easy operation, low cost, high efficiency and easy industrialized production. The inorganic fiber aerogel materials prepared by the above method are composed of multi-layer stacked fibers and have an anisotropic lamellar structure, which can be cut into any desired shape, and stacked to any desired thickness. In addition, the inorganic fiber aerogel materials have good flexibility and compressibility, excellent fire resistance, good high and low temperature resistance and superior thermal insulation, which greatly expands their application field.

Generating ferrate ex situ by activating persulfate with BOF steel slag fines and/or ferric iron. A persulfate solution flows therethrough or thereover the BOF steel slag within, for example, a filter, fluidized bed or continuously stirred tank reactor. The ex situ generation will produce a leachate that contains multiple reactive oxidant species (ROS) such as hydrogen peroxide (H.sub.2O.sub.2), superoxide (O2.), sulfate radicals, hydroxyl radicals (OH.) and uniquely ferrate species including Fe IV, V and VI. These ROS will destroy organic compounds, sterilize, and can oxidize inorganics and a wide range of targeted contaminants in distressed water (e.g., drinking water, process water, wastewater, industrial process streams/waters, municipal process streams/waters, landfill leachate, sewage/septic systems, bilge waters, drilling fluids, mine effluents). The use of BOF steel slag avoids the need for additional pH buffers and ferrate stabilizers and is an industrial byproduct comprised of recycled materials instead of a specialized reagent.

The piezoelectric composition is represented by the following Chemical Formula (1):
x[Bi.sub.mFeO.sub.3]-y[Ba.sub.mTiO.sub.3]-z[Sr.sub.mTiO.sub.3](1)
wherein 0.5x0.8, 0.02y0.4, 0.02z0.2, x+y+z=1, and 0.96m1.04.

A powder for dust cores includes an aggregate of soft magnetic particles, each of which includes a soft magnetic metal particle, and a ferrite film that covers a surface of the soft magnetic metal particle and includes ferrite crystal grains having a spinel structure. A diffraction peak derived from the ferrite crystal grains exists in a powder X-ray diffraction pattern. By a method for producing a powder for dust cores, a raw material powder that includes an aggregate of soft magnetic metal particles is prepared. Furthermore, many ferrite fine particles are formed on a surface of each of the soft magnetic metal particles of the raw material powder. Additionally, the ferrite fine particles are coarsely crystallized through heat treatment to form a ferrite film, which includes ferrite crystal grains having a spinel structure, on the surface of the each of the soft magnetic metal particles.

A highly active trimetallic mixed transition metal oxide material has been developed. The material may be sulfided to generate metal sulfides which are used as a catalyst in a conversion process such as hydroprocessing. The hydroprocessing may include hydrodenitrification, hydrodesulfurization, hydrodemetallation, hydrodesilication, hydrodearomatization, hydroisomerization, hydrotreating, hydrofining, and hydrocracking.

Provided is a material that can be used as a potassium secondary battery positive electrode active material (particularly a potassium ion secondary battery positive electrode active material), other than Prussian blue, by using a potassium compound and a potassium ion secondary battery positive electrode active material comprising the potassium compound, the potassium compound being represented by general formula (1):
K.sub.nA.sub.kBO.sub.m,
wherein A is a positive divalent element in groups 7 to 11 of the periodic table; B is positive tetravalent silicon, germanium, titanium or manganese, excluding a case in which A is manganese and B is titanium, and a case in which A is cobalt and B is silicon; n is 1.5 to 2.5; and m is 3.5 to 4.5.

Metal-hydroxide-organic framework compositions, methods of making metal-hydroxide-organic framework compositions and methods of using metal-hydroxide-organic framework compositions are described.