A method for preparing large size beta-type ammonium tetramolybdate monocrystal particle includes industrial ammonium molybdate, ammonia, de-ionized water are used to prepare ammonium molybdate solution with concentration of 0.20.6 g/ml; pH is adjusted to 57, temperature is adjusted to the first temperature of 7090 C. to obtain the first ammonium molybdate solution; beta-type ammonium tetramolybdate crystal seed is put into crystallization container, and the first ammonium molybdate solution is poured in the crystallization container, to form crystallization system; the crystallization system stands still at room temperature, naturally cooling, the beta-type ammonium tetramolybdate crystal seed grows into large size beta-type ammonium tetramolybdate monocrystal particle. A beta-type ammonium tetramolybdate crystal seed is obtained by constant-temperature crystallization at 7090 C. The obtained beta-type ammonium tetramolybdate crystal seed is put stewing in the first ammonium molybdate solution and is naturally cooling to produce large size beta-type ammonium tetramolybdate monocrystal particle forms.

A crystal-orientation controlled complex comprising a connected assembly having a thin film shape, in which a plurality of crystal pieces are connected with each other, the crystal pieces having a flake shape and having a main surface and an end surface, wherein the main surface has a crystal orientation relative to a specific crystal plane, and the thin film shaped connected assembly has a polarization singularity.

According to the present invention, a crystal of reduced glutathione having a reduced content of impurities, particularly L-cysteinyl-L-glycine and a method for producing the same are provided. The present invention relates to a crystal of reduced glutathione, wherein, in a high-performance liquid chromatography (HPLC) analysis, the peak area of L-cysteinyl-L-glycine is 0.02 or less with respect to the peak area of reduced glutathione which is taken as 100.

According to the present invention, a crystal of reduced glutathione having a reduced content of impurities, particularly L-cysteinyl-L-glycine and a method for producing the same are provided. The present invention relates to a crystal of reduced glutathione, wherein, in a high-performance liquid chromatography (HPLC) analysis, the peak area of L-cysteinyl-L-glycine is 0.02 or less with respect to the peak area of reduced glutathione which is taken as 100.

The present invention provides a crystal of reduced glutathione having excellent powder properties and a method for producing the same. The present invention relates to a crystal of reduced glutathione, wherein the average crystal thickness is 10 m or more.

The present invention provides a crystal of reduced glutathione having excellent powder properties and a method for producing the same. The present invention relates to a crystal of reduced glutathione, wherein the average crystal thickness is 10 m or more.

Method for limiting growth of KDP-type crystals with a long seed where an upper and a lower ends of the long seed crystal are respectively limited by an upper baffle plate and a lower tray to restrain growth of a pyramidal surface and allow only four prismatic surfaces in [100] and [010] directions to grow. Finally grown crystal contains no pyramid-prism interface that severely restricts quality of optical element, and all cut optical elements have high optical quality. As four prismatic surfaces are subjected to highly similar growing environment and grow simultaneously, all optical elements cut therefrom have high optical uniformity. Due to uniqueness of a cutting angle of a KDP crystal frequency-tripled element, high cutting efficiency is achieved in the element, and an area of a maximum frequency-tripled element that may be cut is known in advance according to a horizontal size of the grown crystal.

Method for limiting growth of KDP-type crystals with a long seed where an upper and a lower ends of the long seed crystal are respectively limited by an upper baffle plate and a lower tray to restrain growth of a pyramidal surface and allow only four prismatic surfaces in [100] and [010] directions to grow. Finally grown crystal contains no pyramid-prism interface that severely restricts quality of optical element, and all cut optical elements have high optical quality. As four prismatic surfaces are subjected to highly similar growing environment and grow simultaneously, all optical elements cut therefrom have high optical uniformity. Due to uniqueness of a cutting angle of a KDP crystal frequency-tripled element, high cutting efficiency is achieved in the element, and an area of a maximum frequency-tripled element that may be cut is known in advance according to a horizontal size of the grown crystal.

A method for producing a nickel-containing hydroxide is provided that includes a nucleation step of generating nuclei of nickel-containing hydroxide particles by neutralization crystallization in an aqueous solution accommodated in an agitation tank. In the nucleation step, a volume fraction of a highly supersaturated region in the aqueous solution where the molar concentration of the nickel-containing hydroxide dissolved in the aqueous solution is greater than or equal to 5.0 mol/m.sup.3 is less than 0.100% of the aqueous solution.

The present invention provides a crystal of reduced glutathione having excellent powder properties and a method for producing the same. The present invention relates to a crystal of reduced glutathione, wherein the average crystal thickness is 10 m or more.