A ferrous modified selenium sol for inhibiting accumulation of cadmium and arsenic in rice and the preparation method and application thereof are disclosed. The method includes: dissolving an iron-containing compound and a selenium-containing compound into water; adding a reductant to the solution, and stirring until no more precipitation is generated, then adding carbonate, continuing to stir until no more precipitation is generated, and then filtering, taking the precipitation, and washing to obtain the precipitation of the selenium element and ferrous carbonate; adding an emulsifier to a citric acid buffer solution to obtain an emulsified citric acid buffer solution; adding the precipitation of the selenium element and ferrous carbonate to the emulsified citric acid buffer solution to obtain a sol system; and evaporating to concentrate the sol system, and adjusting the pH to 4.5-8.5 to obtain a ferrous modified selenium sol for inhibiting the accumulation of cadmium and arsenic in rice.

A ferrous modified selenium sol for inhibiting accumulation of cadmium and arsenic in rice and the preparation method and application thereof are disclosed. The method includes: dissolving an iron-containing compound and a selenium-containing compound into water; adding a reductant to the solution, and stirring until no more precipitation is generated, then adding carbonate, continuing to stir until no more precipitation is generated, and then filtering, taking the precipitation, and washing to obtain the precipitation of the selenium element and ferrous carbonate; adding an emulsifier to a citric acid buffer solution to obtain an emulsified citric acid buffer solution; adding the precipitation of the selenium element and ferrous carbonate to the emulsified citric acid buffer solution to obtain a sol system; and evaporating to concentrate the sol system, and adjusting the pH to 4.5-8.5 to obtain a ferrous modified selenium sol for inhibiting the accumulation of cadmium and arsenic in rice.

A process for production of polyferric sulphate (PFS) solution comprises: a) digesting iron oxide in aqueous sulphuric acid, to form an initial reaction solution including ferrous sulphate; b) subsequently oxidising obtained ferrous ions (Fe.sup.2+) with nitric acid to convert ferrous ions to ferric ions(Fe.sup.3+); and c) oxidising evolving nitrogen oxides to nitric acid to recover nitric acid; d) wherein the molar ratio of iron to sulphuric acid is such that the obtained PFS product will be sulphate deficient.

Provided is a cleaning device for cleaning a magnet powder including: a flask provided to contain the magnet powder and a cleaning material used to clean the magnet powder; and a vacuum manifold provided to maintain the magnet powder and the cleaning material contained in the flask in an inert state during cleaning.

Provided is a method for cleaning a magnet powder including a loading operation for loading a magnet powder, a cleaning solution, and zeolite into a flask; a gas injecting operation for injecting an inert gas into the flask; and a vacuum drying operation for drying the magnet powder and the zeolite in a vacuum.

Provided is a method for manufacturing a magnet powder including: preparing a primary mixture by mixing neodymium (III) nitrate, boric acid, and iron (III) nitrate nonahydrate; preparing an oxide by heat-treating the primary mixture; removing a residual organic material of the oxide by heat-treating the oxide; preparing a hydrogen-reduced oxide by reacting the oxide, from which the residual organic material is removed, with hydrogen by heat treatment; preparing a secondary mixture by mixing the hydrogen-reduced oxide with calcium; obtaining a product by subjecting the secondary mixture to reduction-diffusion reaction by heat treatment; and obtaining Nd.sub.2Fe.sub.14B powder by pulverizing the product.

An object of the present invention is to provide a metal-organic framework manufacturing method of manufacturing a metal-organic framework having excellent gas adsorbability and durability.

A metal-organic framework manufacturing method according to an embodiment of the present invention includes: a step of mixing a metal salt containing a metal atom and a polydentate ligand in the presence of a solvent to manufacture a metal-organic framework,

the polydentate ligand contains a compound represented by Formula (1),

a content of the compound represented by Formula (1) in the polydentate ligand is 50 mol % or greater with respect to a total molar amount of the polydentate ligand,

the solvent contains an organic solvent having a boiling point of 100 C. or higher, and

a water content in the solvent is 0 to 90 mass % with respect to a total mass of the solvent.

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The present invention relates to processes employing water produced from wells that, after suitable purification steps, is processed to recover resources that can be used to treat other waste streams, such as flue gases and ashes from combustion of fossil fuels.

The present invention relates to processes employing water produced from wells that, after suitable purification steps, is processed to recover resources that can be used to treat other waste streams, such as flue gases and ashes from combustion of fossil fuels.

The present invention relates to a catalyst for converting CO.sub.2 to synthetic fuel such as CO using metal oxides and a conversion method using the same. The CO.sub.2 conversion catalyst according to the present invention can treat a large amount of CO.sub.2 per unit mole and is oxidized. In the reduction cycle, the catalyst has relatively high structural stability and excellent long-term stability as a catalyst, and it has excellent activity as a CO.sub.2 decomposition catalyst that can be used in a continuous flow reactor, such as for CO.sub.2 decomposition at a relatively low temperature.

Radiofrequency and other electronic devices can be formed from textured hexaferrite materials, such as Z-phase barium cobalt ferrite Ba.sub.3Co.sub.2Fe.sub.24O.sub.41 (Co.sub.2Z) having enhanced resonant frequency. The textured hexaferrite material can be formed by sintering fine grain hexaferrite powder at a lower temperature than conventional firing temperatures to inhibit reduction of iron. The textured hexaferrite material can be used in radiofrequency devices such as circulators or telecommunications systems.

By using a potassium ion secondary battery positive electrode active material comprising a potassium compound represented by general formula (1): K.sub.nMO.sub.m, wherein M is copper or iron, n is 0.5 to 3.5, and m is 1.5 to 2.5, provided is a potassium ion secondary battery positive electrode active material having higher theoretical discharge capacity and higher effective capacity than a potassium secondary battery using Prussian blue as a positive electrode active material.