The invention relates to a lithium metaborate crystal and a preparation method and use thereof. The crystal has a chemical formula of LiBO.sub.2, a molecular weight of 49.75, and is a member of the monoclinic crystal system. The crystal has a P2.sub.1/c space group and lattice constants of a=5.85(8) , b=4.35(7) , c=6.46(6) , =115(5), and Z=4. The crystal can be applied in wavelengths of infrared-visible-deep ultraviolet, and is grown by utilizing a melt crystallization method or a flux method. The crystal obtained using the method described in the invention is easily grown and processed, and can be used in the manufacture of a polarizing beam splitting prism such as a Glan prism, a Wollaston prism, a Rochon prism or a beam-splitting polarizer, and other optical components, enabling crucial applications in the fields of optics and communication.

A lead-based alloy containing alloying additions of bismuth, antimony, arsenic, and tin is used for the production of doped leady oxides, lead-acid battery active materials, lead-acid battery electrodes, and lead-acid batteries.

A nonlinear optical crystal of cesium fluorooxoborate, and a method of preparation and use thereof. The crystal has a chemical formula of CsB.sub.4O.sub.6F and a molecular weight of 291.15. It belongs to an orthorhombic crystal system, with a space group of Pna2.sub.1, crystal cell parameters of a=7.9241 , b=11.3996 , c=6.6638 , and ===90, and a unit cell volume of 601.95 .sup.3. A melt method, high temperature solution method, vacuum encapsulation method, hydrothermal method or room temperature solution method is used to grow the crystal of CsB.sub.4O.sub.6F.

A positive electrode active material for a secondary battery contains second particles which are produced by aggregation of primary particles of a lithium transition metal oxide containing Ni and W, and a boron compound present inside and on the surfaces of the secondary particles.

A method of forming a dissolvable part of amorphous borate includes: preparing a mixture comprising one or more boron compounds and one or more alkali compounds, at least one of the one or more boron compounds and the one or more alkali compounds being hydrous; heating the mixture to a melting temperature for a predetermined time to melt the mixture and release water from the mixture to form an anhydrous boron compound that is moldable, wherein the amount of alkali compound being selected to achieve an alkali oxide content of between about 10 to 25%; with the anhydrous boron compound at a molding temperature, molding the anhydrous boron compound in a mold; and cooling the anhydrous boron compound to form a solid.

A method of forming a dissolvable part of amorphous borate includes: preparing a mixture comprising one or more boron compounds and one or more alkali compounds, at least one of the one or more boron compounds and the one or more alkali compounds being hydrous; heating the mixture to a melting temperature for a predetermined time to melt the mixture and release water from the mixture to form an anhydrous boron compound that is moldable, wherein the amount of alkali compound being selected to achieve an alkali oxide content of between about 10 to 25%; with the anhydrous boron compound at a molding temperature, molding the anhydrous boron compound in a mold; and cooling the anhydrous boron compound to form a solid.

The removal of acid gases (e.g., non-carbon dioxide acid gases) using sorbents that include salts in molten form, and related systems and methods, are generally described.

A calcium metaborate birefringent crystal and a preparation method and use thereof, the crystal having a chemical formula of CaB.sub.2O.sub.4 and a molecular weight of 125.70, and belonging to the orthorhombic crystal system and space group Pbcn with unit-cell parameters a=11.60(4), b=4.28(8), c=6.21(6), and Z=4, wherein the calcium metaborate birefringent crystal is a negative biaxial crystal with a transmission range of 165-3400 nm and a birefringence between 0.09-0.36; the crystal is applicable to infrared-visible-ultraviolet-deep ultraviolet bands, and is grown by a melt method, a flux method, a Bridgman method or a heat exchange method; the crystal obtained by the method of the present invention is easy to grow and easy to process; and can be used for making polarizing beam-splitting prisms.

A method of forming a dissolvable part of amorphous borate includes: preparing a mixture comprising one or more boron compounds and one or more alkali compounds, at least one of the one or more boron compounds and the one or more alkali compounds being hydrous; heating the mixture to a melting temperature for a predetermined time to melt the mixture and release water from the mixture to form an anhydrous boron compound that is moldable, wherein the amount of alkali compound being selected to achieve an alkali oxide content of between about 10 to 25%; with the anhydrous boron compound at a molding temperature, molding the anhydrous boron compound in a mold; and cooling the anhydrous boron compound to form a solid.

A method of forming a dissolvable part of amorphous borate includes: preparing a mixture comprising one or more boron compounds and one or more alkali compounds, at least one of the one or more boron compounds and the one or more alkali compounds being hydrous; heating the mixture to a melting temperature for a predetermined time to melt the mixture and release water from the mixture to form an anhydrous boron compound that is moldable, wherein the amount of alkali compound being selected to achieve an alkali oxide content of between about 10 to 25%; with the anhydrous boron compound at a molding temperature, molding the anhydrous boron compound in a mold; and cooling the anhydrous boron compound to form a solid.