The present invention relates to the field of luminescent crystals (LCs), and more specifically to Quantum Dots (QDs) of formula M.sup.1.sub.aM.sup.2.sub.bX.sub.c, wherein the substituents are as defined in the specification. The invention provides methods of manufacturing such luminescent crystals, particularly by dispersing suitable starting materials in the presence of a liquid and by the aid of milling balls; to compositions comprising luminescent crystals and to electronic devices, decorative coatings; and to intermediates comprising luminescent crystals.

An oxychloride infrared nonlinear optical crystal and the preparation method and use thereof, the optical crystal has a general chemical formula of Pb.sub.2+xOCl.sub.2+2x, therein 0<x<0.139 or 0.141<x<0.159 or 0.161<x0.6. The crystal is non-centrosymmetric, belongs to orthonormal system with space group of Fmm2, cell parameter is a=35.4963(14)0.05 , b=5.8320(2)0.05 , c=16.0912(6)0.05 . The crystal is prepared by high temperature melt method or flux method. The crystal has a strong second harmonic generation efficiency of 4 times that of KDP (KH.sub.2PO.sub.4) tested by Kurtz method, it is phase machable, transparent in the range of 0.34-7 m. The laser damage threshold is 10 times that of the current commercial infrared nonlinear optical crystal AgGaS.sub.2. No crystalline water exists in lead oxychloride, and it is stable in the air and has good thermal stability.

An oxychloride infrared nonlinear optical crystal and the preparation method and use thereof, the optical crystal has a general chemical formula of Pb.sub.2+xOCl.sub.2+2x, therein 0<x<0.139 or 0.141<x<0.159 or 0.161<x0.6. The crystal is non-centrosymmetric, belongs to orthonormal system with space group of Fmm2, cell parameter is a=35.4963(14)0.05 , b=5.8320(2)0.05 , c=16.0912(6)0.05 . The crystal is prepared by high temperature melt method or flux method. The crystal has a strong second harmonic generation efficiency of 4 times that of KDP (KH.sub.2PO.sub.4) tested by Kurtz method, it is phase machable, transparent in the range of 0.34-7 m. The laser damage threshold is 10 times that of the current commercial infrared nonlinear optical crystal AgGaS.sub.2. No crystalline water exists in lead oxychloride, and it is stable in the air and has good thermal stability.

A perovskite nanocrystal having improved colloidal stability and a preparation method thereof are proposed. The perovskite nanocrystal includes a CsPbX.sub.3 (X is halogen) perovskite nanocrystal and a hydrazinium (NH.sub.2NH.sub.3.sup.+) ligand bonded to a surface of the CsPbX.sub.3 perovskite nanocrystal.

The invention relates to sulfonated aminomethylated chelate resins, to a method for producing same, to the use thereof for obtaining and purifying metals, in particular rare earth metals, from aqueous solutions and organic liquids, and for producing highly pure silicon.

An H.sub.2S sensor comprising at least one acoustic wave transducer and a film comprising a polymer matrix comprises carboxylate functional groups and lead or zinc cations. Processes for the manufacture of the sensor are also provided.

An isotope production system, emanation generator, and process are disclosed for production of high-purity radioisotopes. In one implementation example, high-purity Pb-212 and/or Bi-212 isotopes are produced suitable for therapeutic applications. In one embodiment the process includes transporting gaseous radon-220 from a radium-224 bearing generator which provides gas-phase separation of the Rn-220 from the Ra-224 in the generator. Subsequent decay of the captured Rn-220 accumulates high-purity Pb-212 and/or Bi-212 isotopes suitable for direct therapeutic applications. Other high-purity product isotopes may also be prepared.

An isotope production system, emanation generator, and process are disclosed for production of high-purity radioisotopes. In one implementation example, high-purity Pb-212 and/or Bi-212 isotopes are produced suitable for therapeutic applications. In one embodiment the process includes transporting gaseous radon-220 from a radium-224 bearing generator which provides gas-phase separation of the Rn-220 from the Ra-224 in the generator. Subsequent decay of the captured Rn-220 accumulates high-purity Pb-212 and/or Bi-212 isotopes suitable for direct therapeutic applications. Other high-purity product isotopes may also be prepared.

A method of forming a lanthanide or transition metal doped metal halide perovskite material whereby the method includes combining a monovalent metal cation-halide compound, a divalent metal cation-halide compound, and a lanthanide or transition metal halide compound in a solvent; evaporating the solvent to form a powder; and annealing the powder to form the lanthanide or transition metal doped metal halide perovskite material. The resultant materials or devices may be applied to various industrial applications or implemented as a scintillator and applied to various industrial applications.

A method for forming CsPbBr.sub.3 perovskite nanocrystals into a two-dimensional (2D) nanosheet includes providing CsPbBr.sub.3 perovskite nanocrystals; mixing the CsPbBr.sub.3 perovskite nanocrystals into a mixture of a first solvent and a second solvent, to form a solution of the CsPbBr.sub.3 perovskite nanocrystals, the first solvent, and the second solvent; and forming an optoelectronic device by patterning the CsPbBr.sub.3 perovskite nanocrystals into a nanosheet, between first and second electrodes. The first solvent is selected to evaporate before the second solvent.