TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Property: The diameter of lead sulfide quantum dots is 1-20 nm.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Composition: The mass ratio of lead sulfide quantum dots and coupling agent is 100:1-10. The coupling agent is chosen from silane coupling agent, titanate coupling agent and aluminum coupling agent. The solvent is chosen from ethanol, acetone, hexane, cyclohexane, toluene and tetrahydrofuran. The content of solvent is 5-20 times the content of lead sulfide quantum dots. The peroxide crosslinking agent is chosen from paraffin-based peroxide, cyclohexanone peroxide, dicumyl peroxide, methyl ethyl ketone peroxide, benzoyl peroxide, 2,2-azobis(2-methylpropane)hydrochloride, peroxydicarbonate, diisopropyl diacyl peroxide, tert-butyl peroxide, isooctyl peroxide and/or tert-butyl peroxybenzoate. The antioxidant is chosen from N,N'-bis(3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyl)hydrazine, dilauryl thiodipropionate, pentaerythritol diphosphite-bis(2,4-di-tert-butyl-phenyl)phosphite, bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate, 2,2'-methylene-bis(4-methyl-6-tert-butyl-phenol), 2,6-di-t-butyl-4-methylphenol, tris(2,4-di-t-butylphenyl)phosphite, tetra( beta -(3,5-di-t-butyl-4-hydroxyphenyl)propionate) and 4,4'-( beta , beta '-dihydroxy-dipropyl-methoxyphenyl)-2,2-propane. The plasticizer is white wax, stearic acid and/or citrate.    TECHNOLOGY FOCUS - POLYMERS - Preferred Composition: The ultraviolet light stabilizer is chosen from 2,4-dihydroxy-benzophenone, hydroxy-4-methoxy-benzophenone, 2-hydroxy-4-n-octyloxy benzophenone, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-amylphenyl) benzotriazole, 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole, polymer of 2-phenylbenzimidazole-5-sulfonic acid, (4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol) and succinic acid, bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate, monoethyl ester of bis(3,5-di-tert-butyl-4-hydroxybenzyl phosphoric acid)nickel and poly(6-(1,1,3,3-tetramethylbutyl)) compound. The ethylene-vinyl acetate copolymer has vinyl acetate content of 24-40%.