The present invention provides oxide particles having a compositional formula of Pb(Zr.sub.xTi.sub.1-x)O.sub.3, wherein x is 0.46?x?0.6; wherein a size of the particle is from 0.5 to 10 ?m; a porosity of a surface of the particle is 20% or less; and a shape of the particle is any one of a cube, a rectangular parallelepiped, or a truncated octahedron.

The present invention provides oxide particles having a compositional formula of Pb(Zr.sub.xTi.sub.1-x)O.sub.3, wherein x is 0.46?x?0.6; wherein a size of the particle is from 0.5 to 10 ?m; a porosity of a surface of the particle is 20% or less; and a shape of the particle is any one of a cube, a rectangular parallelepiped, or a truncated octahedron.

A method for preparing semiconductor nanocrystals comprises reacting cation precursors and anion precursors in a reaction mixture including one or more acids, one or more phenol compounds, and a solvent to produce semiconductor nanocrystals having a predetermined composition. A method for forming a coating on at least a portion of a population of semiconductor nanocrystals is also disclosed. The method comprises forming a first mixture including a population of semiconductor nanocrystals, one or more amine compounds, and a first solvent; adding cation precursors and anion precursors to the first mixture at a temperature sufficient for growing a semiconductor material on at least a portion of an outer surface of at least a portion of the population of semiconductor nanocrystals; and initiating addition of one or more acids to the first mixture after addition of the cation and anion precursors is initiated. Semiconductor nanocrystals and populations thereof are also disclosed.

A method for preparing semiconductor nanocrystals comprises reacting cation precursors and anion precursors in a reaction mixture including one or more acids, one or more phenol compounds, and a solvent to produce semiconductor nanocrystals having a predetermined composition. A method for forming a coating on at least a portion of a population of semiconductor nanocrystals is also disclosed. The method comprises forming a first mixture including a population of semiconductor nanocrystals, one or more amine compounds, and a first solvent; adding cation precursors and anion precursors to the first mixture at a temperature sufficient for growing a semiconductor material on at least a portion of an outer surface of at least a portion of the population of semiconductor nanocrystals; and initiating addition of one or more acids to the first mixture after addition of the cation and anion precursors is initiated. Semiconductor nanocrystals and populations thereof are also disclosed.

The present invention relates to a nintedanib diethanesulfonate salt A-type crystal represented by formula (II), and also relates to a crystalline composition and pharmaceutical composition comprising the crystal, and preparation method and use thereof. An X-ray powder diffraction spectrum of the nintedanib diethanesulfonate salt A-type crystal of the present invention has a diffraction peak at about 14.64, 18.79, 19.31, 20.11, 21.20, 22.45 and 26.71 when represented via a 2 value. The nintedanib diethanesulfonate salt A-type crystal of the present invention has a stable property, is non-hygroscopic and difficult to degrade, and is particularly suitable for medicine production.

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The present invention relates to a nintedanib diethanesulfonate salt A-type crystal represented by formula (II), and also relates to a crystalline composition and pharmaceutical composition comprising the crystal, and preparation method and use thereof. An X-ray powder diffraction spectrum of the nintedanib diethanesulfonate salt A-type crystal of the present invention has a diffraction peak at about 14.64, 18.79, 19.31, 20.11, 21.20, 22.45 and 26.71 when represented via a 2 value. The nintedanib diethanesulfonate salt A-type crystal of the present invention has a stable property, is non-hygroscopic and difficult to degrade, and is particularly suitable for medicine production.

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A semiconductor wafer forms on a mold containing a dopant. The dopant dopes a melt region adjacent the mold. There, dopant concentration is higher than in the melt bulk. A wafer starts solidifying. Dopant diffuses poorly in solid semiconductor. After a wafer starts solidifying, dopant can not enter the melt. Afterwards, the concentration of dopant in the melt adjacent the wafer surface is less than what was present where the wafer began to form. New wafer regions grow from a melt region whose dopant concentration lessens over time. This establishes a dopant gradient in the wafer, with higher concentration adjacent the mold. The gradient can be tailored. A gradient gives rise to a field that can function as a drift or back surface field. Solar collectors can have open grid conductors and better optical reflectors on the back surface, made possible by the intrinsic back surface field.

Provided is a self-supporting polycrystalline GaN substrate composed of GaN-based single crystal grains having a specific crystal orientation in a direction approximately normal to the substrate. The crystal orientations of individual GaN-based single crystal grains as determined from inverse pole figure mapping by EBSD analysis on the substrate surface are distributed with tilt angles from the specific crystal orientation, the average tilt angle being 1 to 10. There is also provided a light emitting device including the self-supporting substrate and a light emitting functional layer, which has at least one layer composed of semiconductor single crystal grains, the at least one layer having a single crystal structure in the direction approximately normal to the substrate. The present invention makes it possible to provide a self-supporting polycrystalline GaN substrate having a reduced defect density at the substrate surface, and to provide a light emitting device having a high luminous efficiency.

Provided is a self-supporting polycrystalline GaN substrate composed of GaN-based single crystal grains having a specific crystal orientation in a direction approximately normal to the substrate. The crystal orientations of individual GaN-based single crystal grains as determined from inverse pole figure mapping by EBSD analysis on the substrate surface are distributed with tilt angles from the specific crystal orientation, the average tilt angle being 1 to 10. There is also provided a light emitting device including the self-supporting substrate and a light emitting functional layer, which has at least one layer composed of semiconductor single crystal grains, the at least one layer having a single crystal structure in the direction approximately normal to the substrate. The present invention makes it possible to provide a self-supporting polycrystalline GaN substrate having a reduced defect density at the substrate surface, and to provide a light emitting device having a high luminous efficiency.

The present application provides a preparation method for iridium nanocrystal, including the following steps: mixing an iridium salt, an alcohol solvent and a centrifugal waste liquid to form a mixed solution, and adding an alkali solution in an inert atmosphere for a heating reaction. After centrifugation, an iridium nanocrystal is obtained. The centrifugal waste liquid is a waste liquid produced in the pre-synthesis process of iridium nanocrystal. The preparation method can shorten the reaction time, and the obtained iridium nanocrystal has the advantages of high yield and low cost.