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Invention relates to lighting engineering. The lighting device includes illumination devices (40) which at voltage supply emit primary radiation and solid particles (64, 66) which surround the illumination devices (40) at least by sections and interact with the primary radiation. Concentration of particles (64, 66) changes at least in one direction from the illumination devices (40) from the first concentration section up to the second one. |
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Alkali-earth metal silicate based luminophores and method of improving long-term stability thereof Disclosed is a luminophore with improved long-term stability, which absorbs radiation in a first wavelength range and emits radiation in a second wavelength range different from the first range, formed in form of grains and contains as a matrix an activator-doped alkali-earth metal silicate of general chemical formula EAxSiyOz, where EA is formed by one or more alkali-earth metals and the condition x, y, z>0 applies, characterised by that the surface of the grains is chemically modified such that at least parts of the surface are formed by a chemical compound of general formula EAuZ2. Z is formed by anions which are capable of chemically bonding with cations of EA and have one or more of the following chemical formulae: SO4 2-, PO4 3-, CO3 2-, C2O4 2-, SiO3 2-, SiH6 2-, where u denotes the ion charge of anions of Z. Also disclosed is a method of improving long-term stability of alkali-earth metal silicate based luminophores. |
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Composition for marking of metal products produced by powder metallurgy method includes not more than 50% of wt % of luminophor and 50 wt % and more of binding-lubricating agent being fatty acid derivatives or powders of synthetic wax and/or paraffin. Marking of metal products by this composition consists in mixing of alloy metal powder with marking composition, which consists of at least one inorganic agent with property to provide luminescence at irradiation and binding-lubricating agent with subsequent pressing of obtained mixture and its sintering at temperature not exceeding 900°C. |
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Aqueous solution of quantum dots based on cadmium selenide coated with mercapto acids is stabilised by adding sodium sulphite until achieving its concentration of 0.02-0.2 mol/l in the solution. |
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Polymer nanoparticles containing medium for photon up-conversion Polymer nanoparticles contain a medium for photon up-conversion and a stabilising agent. Said medium contains a polymer matrix having two organic components distributed therein. The first component is capable of absorbing light at a first wavelength in the range w≤λ1≤x and acts as a sensitiser in said medium. The second component is capable of emitting light at a second wavelength in the range y≤λ2≤z, where λ2≤λ1, and acts as an emitting component in said medium. The stabilising agent is selected from hydrophilic or amphiphilic polymers. |
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Polymer luminescent composition for obtaining white light excited by blue light-emtting diode Polymer luminescent composition for obtaining white light excited by a blue light-emitting diode contains the following components, pts. wt: transparent polymer 100; photoluminescent phosphor based on garnet Y3Al5O12:Ce or Gd3Al5O12:Ce, or based on a mixture of said compounds 1.5-5.0; polyethylene wax in form of powder with particle size of 18-30 mcm 0.1-0.7; stabiliser 0.2-1.0. The transparent polymer used can be polycarbonate, polystyrene or a copolymer of styrene with acrylonitrile and butadiene. The stabiliser can be a compound from a group of sterically hindered phosphites. |
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Method for synthesis of semiconductor quantum dots Invention relates to synthesis of nucleus- and nucleus-shell type semiconductor quantum dots through colloidal synthesis, which can be used in making different luminescent materials, as well as a base for making subminiature light-emitting diodes, white light sources, single-electron transistors, non-linear optical devices, photodetector and photovoltaic devices. The method for synthesis of semiconductor quantum dots based on chalcogenides of group II or group IV metals involves synthesis of nuclei of nanocrystals from a precursor containing chalcogen, and a precursor containing group II or IV metals, using an organic solvent and a surface modifier in form of (aminoalkyl)trialkoxysilanes. The nuclei are synthesised at constant temperature within the limits of 150 - 250°C for 15 s to 1 hour and the reaction mixture containing the nucleus of nanocrystals is further treated with UV light for 1-10 minutes and ultrasound for 5-15 minutes. |
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Method of obtaining luminescent nanoparticles of cadmium sulphide, stabilised with polymer matrices Method is described for obtaining luminescent nanoparticles of cadmium sulphide, stabilised with polymer matrices, involving growing nanoparticles of cadmium sulphide directly in polymer matrices. A polymer compound, chosen from a series which includes polystyrene-block-polyethylene oxide, polystyrene-block-polyethylene oxide, polystyrene-block-4-vinylpyridine or polyphenylene, is dissolved, anionic surfactant is added to the obtained mixture with subsequent addition of a compound which contains cadmium cations, and then a compound which contains sulphur anions, and after growing cadmium sulphide nanoparticles excess anionic surfactant is removed. |
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Method for applying protective film on surfaces of phosphor particles Proposed method that can be used for encapsulating phosphor particles to enhance their lighting and servicing parameters by producing continuous silicon dioxide film on their surfaces includes treatment of phosphor particles with 0.5 and 4 mass percent sols of polysilicic acid synthesized by hydrolyses of tetraethoxysilane in 0.6 - 0.8 mass percent aqueous solution of ammonia. |
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Method of preparing moisture-resistant particles of electroluminescent phosphor Nitride coating precursor, in particular aluminum-, gallium-, or tin-containing metalloorganic nitride, is charged into reaction vessel 10a filled with electroluminescent phosphor, e.g. ZuS-Cu, and surrounded by heating means 30a using nitrogen as inert gas carrier. Precursor is passed through pipeline 32 open all over its length. Co-reagent, e.g. anhydrous ammonia is fed into lower part of vessel 12a through porous glass disk 12a. When vessel 10a is heated to 150-225°C, nitride coating precipitates on phosphor particles being in fluidized state. Phosphor bearing nonoxide coating is characterized by high brightness after 100 h use at high humidity. |
Another patent 2513031.