Abstract:
A method of forming a field emission device and the resulting device including emitters formed of fiber segments. Tips are formed on the fiber segments that have a radius substantially small by exposing the tips to a reactive liquid for a duration of time The tips are coated with a low work function conducting material to form emitters.
Abstract:
A system and process for melamine production by gas-phase quenching method and its process are provided. The said system includes a urea scrubber, after which a fluidized bed reactor, a hot-air cooler, a hot-air filter, a crystallizer and a melamine collector are installed in series successively, where the said melamine collector is connected to the said urea scrubber and the said fluidized bed reactor is connected to a carrier gas pre-heater which is connected to a carrier gas compressor; the said system further includes a gas-liquid separator which is connected to the said urea scrubber which is connected to a crystallizer; wherein a cool air blower is provided between the said gas-liquid separator and the crystallizer. The production system of the invention has the advantages of high productivity, stable operation, low energy consumption, low investment and high economic value of tail gas.
Abstract:
A transparent yttrium aluminum garnet precursor composition is provided that includes a plurality of calcined particles of yttrium aluminum oxide having a mean particle domain size of between 10 and 200 nanometers and a predominant hexagonal crystal structure. High levels of YAG transparency are obtained for large YAG articles through control of the aluminum:yttrium atomic ratio to 1:06±0.001 and limiting impurity loadings to less than 100 ppm. The composition is calcined at a temperature between 700° Celsius and 900° Celsius to remove organic additives to yield a predominant metastable hexagonal phase yttrium aluminum oxide nanoparticulate having an atomic ratio of aluminum: yttrium of 1:0.6±0.001. With dispersion in an organic binder and a translucent YAG article is formed having a transmittance at a wavelength of 1064 nanometers of greater than 75%. The translucent YAG article is characterized by an average domain size of less than 1 micron and having a density of at least 99% and inclusions present at less than 2 surface area percent. The ability of a batch of yttrium aluminum oxide nanoparticles to serve as a transparent YAG precursor includes collecting an X-ray fluorescence spectrum from a plurality of aluminum oxide nanoparticles having a predominant crystal structure other than garnet to yield an A1:Y raw integrated peak intensity ratio. The nanoparticles are sintered to yield a predominant garnet phase and a secondary phase and optionally isostatic pressing during sintering. By using only precursor nanoparticles with a standard deviation of ±0.003 in the peak ratio exceptionally high transparency YAG is reproducibly produced.
Abstract:
A composition is provided that includes a plurality of calcined particles of terbium aluminum oxide having a mean particle domain size of between 30 and 600 nanometers. A translucent article having a surface includes polycrystalline terbium aluminum garnet having a mean grain size from 1 to 10 microns and light scattering inclusions of aluminum-rich oxide and/or terbium-rich oxide that are present at less than 2 surface area percent of the surface. A process for forming such an article involves sintering the above provided composition at a temperature between 1500° C. and 1700° C. to yield a sintered article. The article has improved translucency and even transparency as sintering is performed under vacuum at a temperature between 1610° C. and 1680° C. Hot isostatic pressing alone or in combination with article polishing also improves article translucency.
Abstract:
A device and method for forming a device including electron emitters. The method includes exposing a first face of a sheet of bundled fiber segments to a reactive liquid to allow first ends of the fiber segments to react with the reactive liquid to remove material therefrom. A coating material is deposited on the first face which has the material removed. The method also includes exposing a second face of the sheet of bundled fiber segments to a reactive liquid to allow second ends of the fiber segments to react with the reactive liquid to remove material therefrom to expose the coating material.
Abstract:
Systems and methods for providing a light controlling structure, generally referred to as a microlens or microlens array. For example, in accordance with an embodiment of the present invention, a light controlling structure may be employed to provide a display screen.
Abstract:
A method provided for manufacturing a lensed tip optical fiber. The method includes providing an optically transparent cylindrical fiber; and etching a first end of the optically transparent cylindrical fiber to form a tip. The tip is heated which forms a lens surface at the heated tip.