A method of manufacturing a gas sensor for detecting xylene is provided. A method of manufacturing a gas sensor includes reacting a mixed material including a first material containing a cobalt (Co) element and a second material containing a chromium (Cr) element to form a CoCr.sub.2O.sub.4 hollow structure having a hollow shape.

The invention concerns pre-alloyed powders useful for the manufacture of metal-bonded diamond tools. A process for the synthesis of such powders is presented, characterized in that at least a major part of the phosphor is introduced by adding an aqueous solution of a phosphorus salt to one or more of the metal-bearing compounds. The powder can have a low cobalt content, or even be cobalt-free, yet remain suitable for the production of diamond-loaded segments having harness and bending characteristics approaching or exceeding that of cobalt.

The invention concerns pre-alloyed powders useful for the manufacture of metal-bonded diamond tools. A process for the synthesis of such powders is presented, characterized in that at least a major part of the phosphor is introduced by adding an aqueous solution of a phosphorus salt to one or more of the metal-bearing compounds. The powder can have a low cobalt content, or even be cobalt-free, yet remain suitable for the production of diamond-loaded segments having harness and bending characteristics approaching or exceeding that of cobalt.

Quantum dots and methods of making quantum dots are provided.

A carbon nanosheet, which is a sheet-form carbon nanomaterial having a larger area as compared with that of a similar conventional product and a side length of about 1 μm, and a method for producing the carbon nanosheet. The carbon nanosheet production method includes a step of mixing a solution of an iron atom-containing compound dispersed in a solvent with an alcohol, to thereby prepare a solution mixture; and a step of irradiating the solution mixture with plasma, to thereby produce a carbon nanosheet. The carbon nanosheet has a side length of 0.5 μm to 2.5 μm.

A method of producing a compacted article according to one embodiment may involve the steps of: Providing a copper/molybdenum disulfide composite powder including a substantially homogeneous dispersion of copper and molybdenum disulfide sub-particles that are fused together to form individual particles of the copper/molybdenum disulfide composite powder; and compressing the copper/molybdenum disulfide composite powder under sufficient pressure to cause the copper/molybdenum disulfide composite powder to behave as a nearly solid mass.

This invention relates to a preparation method of rare earth oxide dispersion strengthened fee grain tungsten materials, the mass percent of the rare earth oxide is of 0.1-2%, and the rest ingredient is W. Weigh soluble rare earth salt and tungstate, dissolve into water to made into 50-100 g/L of rare earth salt solution and 150-300 g/L of tungstate solution, respectively. Firstly, add trace alkali in rare earth salt solution to control pH in 7-8, then add organic dispersant and stir to form evenly suspended R(OH).sub.3 particle colloid (R refers to rare earth element). Secondly pour the tungstate solution into the R(OH).sub.3colloid, add trace acid to control pH in 6-7, then add organic dispersant and stir to form tungstic acid micro particles, which wrap around the colloidal particles, forming coprecipitation coating particle colloid. Thirdly, the coprecipitation coating particle colloidal is spray-dried, forming tungsten and rare earth oxide compound precursor powder. Alter that, ultrafine or nanoscale tungsten powder with particle size of 50˜500 nm is obtained through a process of calcination subsequent with hydrogen thermal reduction. Finally, the tungsten powder is subjected to ordinary compression molding and then conventional high temperature sintering. The trace rare earth oxide dispersion strengthened high performance fine grain tungsten materials prepared by this invention, its density is close to full density (98.5% or higher), its grain size is uniform and very fine (average in 5˜10 microns), and the rare earth oxides particles evenly distribute in tungsten intracrystalline or grain, boundary with particle size of 100˜500 nm.

This invention relates to a preparation method of rare earth oxide dispersion strengthened fee grain tungsten materials, the mass percent of the rare earth oxide is of 0.1-2%, and the rest ingredient is W. Weigh soluble rare earth salt and tungstate, dissolve into water to made into 50-100 g/L of rare earth salt solution and 150-300 g/L of tungstate solution, respectively. Firstly, add trace alkali in rare earth salt solution to control pH in 7-8, then add organic dispersant and stir to form evenly suspended R(OH).sub.3 particle colloid (R refers to rare earth element). Secondly pour the tungstate solution into the R(OH).sub.3colloid, add trace acid to control pH in 6-7, then add organic dispersant and stir to form tungstic acid micro particles, which wrap around the colloidal particles, forming coprecipitation coating particle colloid. Thirdly, the coprecipitation coating particle colloidal is spray-dried, forming tungsten and rare earth oxide compound precursor powder. Alter that, ultrafine or nanoscale tungsten powder with particle size of 50˜500 nm is obtained through a process of calcination subsequent with hydrogen thermal reduction. Finally, the tungsten powder is subjected to ordinary compression molding and then conventional high temperature sintering. The trace rare earth oxide dispersion strengthened high performance fine grain tungsten materials prepared by this invention, its density is close to full density (98.5% or higher), its grain size is uniform and very fine (average in 5˜10 microns), and the rare earth oxides particles evenly distribute in tungsten intracrystalline or grain, boundary with particle size of 100˜500 nm.

The invention relates to vertical or inclined electrodes of an electrolyzer for electrolytically producing aluminum from aluminum oxide. An electrode contains an electrode base and a surface coating based on refractory ceramics. According to a first variant of the invention, the electrode base is made of a composite material containing between 5% and 90% by mass of refractory ceramics, and of at least one metal having a melting temperature exceeding 1000° C., which forms refractory intermetallic compounds upon interaction with aluminum, and/or containing at least one alloy of such a metal. According to a second variant of the invention, the electrode base is made of a metal alloy, for example structural steel or another alloy, and the surface of the electrode base has applied thereto an intermediary layer consisting of a composite material having the composition described above.

A printable lithium composition is provided. The printable lithium composition includes lithium metal powder; a polymer binder, wherein the polymer binder is compatible with the lithium powder; and a rheology modifier, wherein the rheology modifier is compatible with the lithium powder and the polymer binder. The printable lithium composition may further include a solvent compatible with the lithium powder and with the polymer binder.