A battery cell having an anode or cathode comprising an acidified metal oxide (“AMO”) material, preferably in monodisperse nanoparticulate form 20 nm or less in size, having a pH<7 when suspended in a 5 wt % aqueous solution and a Hammett function H.sub.0>−12, at least on its surface.

A sintered ferrite magnet represented by the general formula of Ca.sub.1-xLa.sub.xFe.sub.2n-y-zCo.sub.yZn.sub.z expressing the atomic ratios of metal elements of Ca, La, Fe, Co and Zn, wherein x, y, z, and n [2n is a molar ratio represented by 2n=(Fe+Co+Zn)/(Ca+La)] meet 0.4<x<0.75, 0.15≤y<0.4, 0.11≤z<0.4, 0.26≤(y+z)<0.65, and 3≤n≤6.

A sintered ferrite magnet represented by the general formula of Ca.sub.1-xLa.sub.xFe.sub.2n-y-zCo.sub.yZn.sub.z expressing the atomic ratios of metal elements of Ca, La, Fe, Co and Zn, wherein x, y, z, and n [2n is a molar ratio represented by 2n=(Fe+Co+Zn)/(Ca+La)] meet 0.4<x<0.75, 0.15≤y<0.4, 0.11≤z<0.4, 0.26≤(y+z)<0.65, and 3≤n≤6.

A hexagonal strontium ferrite powder, in which an average particle size is 10.0 to 25.0 nm, a content of one or more kinds of atom selected from the group consisting of a gallium atom, a scandium atom, an indium atom, and an antimony atom is 1.0 to 15.0 atom % with respect to 100.0 atom % of an iron atom, and a coercivity Hc is greater than 2,000 Oe and smaller than 4.000 Oe. A magnetic recording medium including: a non-magnetic support; and a magnetic layer including a ferromagnetic powder and a binding agent on the non-magnetic support, in which the ferromagnetic powder is the hexagonal strontium ferrite powder. A magnetic recording and reproducing apparatus including this magnetic recording medium.

A combined remediation method of petroleum-contaminated soil includes: impurity removal pretreatment, photocatalytic pre-oxidation, stepwise thermal desorption of petroleum from soil, and high-temperature oxidation; with iron-titanium composite metal oxide (ITCMO) as a catalyst, conducting oxidation pretreatment under light conditions so that some cross-linked structures in macromolecular petroleum contaminants are broken and degraded; and conducting stepwise pyrolysis to achieve a removal rate of more than 98.00%. The new method adopts a combined remediation technology of photocatalytic pre-oxidation-stepwise pyrolysis, which realizes a relatively-high removal rate of petroleum hydrocarbons and the efficient and harmless remediation of high-concentration petroleum-contaminated soil, and remedied soil can be reused.

Magnetic beads comprise a plurality of magnetic nanoparticles, dispersed in a non-magnetic matrix. The magnetic beads have an average particle size of 0.1 μm to 100 μm. The matrix may comprise an inorganic metal oxide or a polymer. The magnetic beads have a specific surface area of at least 40 m.sup.2/g.

A negative electrode active material for a lithium-ion battery has the following formula (I): Li1-xOHFe1+xS (I). x varies from 0.00 to 0.25, preferably from 0.05 to 0.20.

Provided is an active material for a fluoride-ion secondary battery, the active material containing a composite fluoride. The composite fluoride has a layered structure and is represented by a composition formula A.sub.mM.sub.nF.sub.x, where A is an alkali metal, M is a transition metal, 0<m≤2, 1≤n≤2, and 3≤x≤4. The alkali metal may be at least one kind selected from the group consisting of Na, K, Rb, and Cs. The transition metal may be a 3d transition metal.

Electromagnetic-wave-absorbing particles for a GHz band are represented by the following [Empirical Formula 1] and include M-type hexaferrite as a major phase:

Sr.sub.1-xR.sub.xFe.sub.y-2zM.sub.2zO.sub.a,  [Empirical Formula 1] where R is one or more selected from Ba, Ca, and La, M is one or more selected from Zn, Ti, and Zr, 0<x≤0.8, 8≤y≤14, 0<z≤1.5, and a is 19.

The invention relates to a method for isolating an aqueous hydrochloric acid solution of FeCl.sub.3 from an aqueous multi-component system.