摘要:
A system for growing a crystal is provided that includes a crucible, a furnace, and a heat transfer device. The crucible has a first volume to receive therein a material for growing a crystal. The furnace has an ampoule configured to receive the crucible within the ampoule. The furnace is configured to produce a lateral thermal profile combined with a vertical thermal gradient. The heat transfer device is disposed under the crucible and configured to produce a leading edge of growth of the crystal at a bottom of the crucible. The heat transfer device includes at least one elongate member disposed beneath the crucible and extending along a length of the crucible.
摘要:
The present invention relates to a cesium borosilicate compound, a nonlinear optical crystal of cesium borosilicate, and a preparation method therefor and a use thereof. The cesium borosilicate compound has a chemical formula of Cs2B4SiO9 and a molecular weight of 481.15, and is prepared using a solid phase method. The nonlinear optical crystal of the cesium borosilicate compound has a chemical formula of Cs2B4SiO9 and a molecular weight of 481.15, does not have a center of symmetry, belongs to the tetragonal system with space group I4 and unit-cell parameters a=6.731(3) Å, c=9.871(9) Å and V=447.2(5) Å3, and has a wide transmittance range. The shortest ultraviolet cutoff edge is smaller than 190 nm, the frequency doubling effect of the crystal is 4.6 KDP, and the crystal is grown by a high-temperature solution spontaneous crystallization method and a flux method. The crystal has advantages of high growth rate, being transparent and inclusion free, low cost having a wide transmittance range, high hardness, good mechanical property, being crack resistant and not prone to deliquescence, being easy to process and store, and the like. The crystal is widely applied to manufacturing of nonlinear optical devices such as frequency doubling generators, frequency up-converters, frequency down-converters or optical parametric oscillators.
摘要:
An afterglow property of cesium iodide:thallium (CsI:Tl), in which CsI is a host material and doped with thallium, is improved. It is possible to improve the afterglow property of a scintillator by doping a crystal material including CsI (cesium iodide), as a host material, and thallium (Tl), as a luminescent center, with bismuth (Bi).
摘要:
The present invention relates to an apparatus and method for purifying materials using a fractional solidification. Devices and methods shown provide control over a temperature gradient and cooling rate during fractional solidification, which results in a material of higher purity. The apparatus and methods of the present invention can be used to make silicon material for use in solar applications such as solar cells.
摘要:
A casting pattern for a lost-pattern casting, the pattern being in a shape of a turbine engine blade with a root and a body on either side of a platform that is substantially perpendicular to a main axis of the blade, and a method of producing a shell mold from the pattern, and a casting method using the shell mold. The blade body presents a pressure side, a suction side, a leading edge, and a trailing edge. The pattern also includes an expansion strip adjacent to the trailing edge, and a refractory core embedded in the pattern but presenting, both on the pressure side and on the suction side, a respective flush varnished surface between the trailing edge and the expansion strip. A web extends between the platform and the expansion strip and presents a free edge between them.
摘要:
A directional solidification furnace includes one or more movable cooling plates disposed beneath a crucible. In a first position, the cooling plates are free from contact with a crucible support positioned adjacent the crucible. In a second position, the cooling plates are in contact with the crucible support. A control system is used to control the amount of force exerted by the cooling plates against the crucible.
摘要:
The present disclosure is directed to a group of newly discovered intrinsic scintillation compounds. As intrinsic scintillators, these compounds do not require an external activator as a dopant. The new scintillators may include members of two elpasolite families with the general exemplary formulas of A2BMX(6-y)X′y and A3MX(6-y)X′y, (0
摘要:
A casting method and cast article are provided. The casting method includes providing a casting furnace, the casting furnace including a withdrawal region in a lower end, positioning a mold within the casting furnace, positioning a molten material in the mold, partially withdrawing the mold a withdrawal distance through the withdrawal region in the casting furnace, the withdrawal distance providing a partially withdrawn portion, then reinserting at least a portion of the partially withdrawn portion into the casting furnace through the withdrawal region, and then completely withdrawing the mold from the casting furnace. The reinserting partially re-melts a solidified portion within the partially withdrawn portion to fill pores formed therein with the molten material. The cast article includes a microstructure and a porosity corresponding to being formed by a process comprising partially withdrawing, reinserting, and completely withdrawing of a mold from a casting furnace to form the cast article.
摘要:
A crucible for formation of a crystalline material by solidification by growth on seed, including a bottom, at least one side wall orthogonal to the bottom of the crucible, and at least two marks extending on the inner surface of the at least one side wall in an orthogonal direction to the bottom of the crucible, for materialising the position of at least one seed designed to be positioned at the bottom of the crucible, the seed including at least first and second surfaces orthogonal to the bottom of the crucible. The respective positions of at least two of the marks on at least one of the side walls define, in the crystalline material, a first cutting plane tangent to the first surface of the seed and a second cutting plane tangent to the second surface of the seed.