The present invention relates to a method for controlling a condition of a plant.

Disclosed are a preparation method for manganese-doped red phosphor, a device and a backlight module including the product. The method includes: 1) mixing A.sub.2BF.sub.6 polycrystalline particles with mill balls; 2) mixing A.sub.2BF.sub.6 powder obtained after ball-milling with a hydrofluoric acid for secondary crystallization; 3) filtering out solid particles in A.sub.2BF.sub.6 and hydrofluoric acid solution after the secondary crystallization; 4) performing ion exchange between A.sub.2BF.sub.6 particles and A.sub.2BF.sub.6; and 5) filtering out solid particles to obtain a filter cake, and performing drying treatment to obtain manganese-doped red phosphor.

The invention relates to a material represented by the following formula (I)
(M′).sub.8(M″M′″).sub.6O.sub.24(X,X′).sub.2:M″″   formula (I).
Further, the invention relates to a luminescent material, and to different medical imaging and diagnostic methods of using the material. Also disclosed is a method of securely identifying an item using the material.

The present invention provides a method for producing a fluoride fluorescent material, comprising: contacting a fluoride particles represented by the following general formula (I):
K.sub.2[M.sub.1−aMn.sup.4+.sub.aF.sub.6]  (I)
wherein M is at least one member selected from the group consisting of elements belonging to Groups 4 and 14 of the Periodic Table, and a satisfies the relationship: 0<a<0.2; with a solution containing alkaline earth metal ions in the presence of a reducing agent to form an alkaline earth metal fluoride and less than tetravalent manganese ions on the surface of the fluoride particles.

The present invention relates to a red phosphor, a preparation method thereof and a light-emitting device prepared therefrom. A particle of the red phosphor consists of a phosphor inner core having a chemical formula of A.sub.x1Ge.sub.z1F.sub.6:y.sub.1Mn.sup.4+ and an outer shell having a chemical formula of B.sub.x2M.sub.z2F.sub.6:y.sub.2Mn.sup.4+, wherein 1.596≤x.sub.1≤2.2, 1.6≤x.sub.2≤2.2, 0.001≤y.sub.1≤0.2, 0≤y.sub.2≤0.2, 0.9≤z.sub.1≤1.1, and 0.9≤z.sub.2≤1.1; A and B are independently selected from alkali metal elements; and M is Si, or Si and Ge. The red phosphor provided by the present invention has high luminous efficiency and stability. Moreover, the phosphor alone or in combination with other luminescent materials can be used for preparing a light-emitting device with high performance.

The present invention provides a method for producing a powder containing zirconia particles and a fluorescent agent that enables easy production of a zirconia sintered body having both high translucency and high strength despite containing a fluorescent agent. The present invention relates to a method for producing a zirconia particle- and fluorescent agent-containing powder, comprising: a mixing step of mixing a zirconia particle-containing slurry and a liquid-state fluorescent agent; and a drying step of drying the slurry containing the zirconia particles and the fluorescent agent. Preferably, the fluorescent agent comprises a metallic element, and the powder comprises the fluorescent agent in an amount of 0.001 to 1 mass % in terms of an oxide of the metallic element relative to a mass of zirconia. Preferably, the zirconia particles have an average primary particle diameter of 30 nm or less. Preferably, the zirconia particles comprises 2.0 to 9.0 mol % yttria.

To provide a semiconductor light emitting device which is capable of accomplishing a broad color reproducibility for an entire image without losing brightness of the entire image. A light source provided on a backlight for a color image display device has a semiconductor light emitting device comprising a solid light emitting device to emit light in a blue or deep blue region or in an ultraviolet region and phosphors, in combination. The phosphors comprise a green emitting phosphor and a red emitting phosphor. The green emitting phosphor and the red emitting phosphor are ones, of which the rate of change of the emission peak intensity at 100 C. to the emission intensity at 25 C., when the wavelength of the excitation light is 400 nm or 455 nm, is at most 40%.

Synthesizing a color stable Mn.sup.4+ doped phosphor by contacting a gaseous fluorine-containing oxidizing agent with a precursor of: A.sub.aB.sub.bC.sub.cD.sub.dX.sub.x:Mn.sup.4+; A.sub.aiB.sub.biC.sub.ciD.sub.dX.sub.xY.sub.d:Mn.sup.4+; A.sup.1.sub.3G.sub.2mnMn.sub.mMg.sub.nLi.sub.3F.sub.12O.sub.p; or AZF.sub.4:Mn.sup.4+. Where A is Li, Na, K, Rb, Cs, or a combination; B is Be, Mg, Ca, Sr, Ba, or a combination; C is Sc, Y, B, Al, Ga, In, Tl, or a combination; D is Ti, Zr, Hf, Rf, Si, Ge, Sn, Pb, or a combination; X is F or a combination of F and one of Br, Cl, and I; Y is O, or a combination of O and one of S and Se; A.sup.1 is Na or K, or a combination; G is Al, B, Sc, Fe, Cr, Ti, In, or a combination; Z is La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sc, Y, In, or a combination.

The present invention relates to a metal fluoride red phosphor and an application of the phosphor as a light emitting element, the metal fluoride red phosphor having a tetragonal crystal structure of a novel composition, and emitting light in the red color wavelength by being excited by ultraviolet rays or a blue excitation source, thereby being usefully applicable to a light emitting element such as a light emitting diode, a laser diode, a surface emitting laser diode, an inorganic electroluminescence element, and an organic electroluminescence element.

A material represented by the following formula (I)
(M).sub.8M.sub.6M.sub.6O.sub.24(X,S).sub.2:Mformula (I).
Also disclosed is an ultraviolet radiation sensing material, an X-radiation sensing material, a device and a method for determining the intensity of ultraviolet radiation.