摘要:
A method of fabricating an optical waveguide (18) comprises providing a sample of lithium niobate (10) that has one or more periodically poled gratings made by electric field poling, applying a patterned surface layer of metallic zinc (16) to a z-face of the sample so that the layer (16) has a pattern corresponding to an intended pattern of waveguides (18) to be written into the lithium niobate, and heating the sample to diffuse the metallic zinc (16) into the lithium niobate so as to form an optical waveguiding structure (18) within the sample.
摘要:
A mechanically alloyed hydrogen storage material having 75-95 atomic percent Mg, 5-15 atomic percent Ni, 0.5-6 atomic percent Mo, and at least one additional element selected from the group consisting of Al, C, Ca, Ce, Co, Cr, Cu, Dy, Fe, La, Mn, Nd, Si, Ti, V, and Zr, preferably between 1-15 atomic %. The mechanically alloyed hydrogen storage preferably contains from 3-15 atomic % C and at least one other element selected from the group consisting of Al, Ca, Ce, Cu, Dy, Fe, La, Mn, and Nd. The hydrogen storage materials are created by mechanical alloying in a milling apparatus under an inert atmosphere, such as argon, or a mixed atmosphere, such as argon and hydrogen. The speed and length of the milling are varied.
摘要:
A method of fabricating an optical waveguide (18) comprises providing a sample of lithium niobate (10) that has one or more periodically poled gratings made by electric field poling, applying a patterned surface layer of metallic zinc (16) to a z-face of the sample so that the layer (16) has a pattern corresponding to an intended pattern of waveguides (18) to be written int lithium niobate, and heating the sample to diffuse the metallic zinc (16) into the lithium niobate so as to form an optical waveguiding structure (18) within the sample.
摘要:
A method for combining a first metal with a second metal where the melting point of the second metal is higher than the melting point of the first metal. The first and second metals are melted in separate crucibles. The second molten metal is introduced onto or into the first molten metal. Also described is a two-zone furnace for carrying out the method.
摘要:
A method of inducing a periodic variation of nonlinearity value in a sample of ferroelectric material comprises arranging a pair of electrodes on opposite faces of the sample, one electrode defining a desired pattern of nonlinearity variation, applying a pre-bias voltage across the sample for a predetermined time using the electrodes, the pre-bias voltage being less than the coercive field of the ferroelectric material; and after the predetermined time, applying a current-controlled poling voltage across the sample using the electrodes, to produce domain inversion in the sample according to the desired pattern of nonlinearity variation. The pre-bias voltage may be 75% of the coercive field or more, and applied for a pre-determined time between 1 and 100 seconds.
摘要:
A heat exchange apparatus and lighting apparatus for uniform heat dissipation are provided. According to one embodiment of the invention, one or more dissipation plates are provided, each of the one or more dissipation plates having a plurality of upstanding fins disposed from the dissipation plate at a predetermined angle, and each of the one or more dissipation plates defines a plurality of slots configured to permit airflow longitudinally through the housing. A housing is provided to receive the one or more dissipation plates, the housing defining at least one opening to permit an inlet of air into the housing. The configuration of the dissipation plates and the housing permit air to move within the housing in a plurality of directions, permitting heat to be dissipated when the housing is positioned in different orientations. Improved heat dissipation thereby results in greater consistency in the performance of the lighting apparatus.
摘要:
Mechanically alloyed hydrogen storage materials having a major atomic percentage of magnesium and a minor atomic percentage of at least two elements selected from the group consisting of nickel, molybdenum, iron and titanium. Preferably the mechanical alloy comprises a multi-phase material, including at least one amorphous phase. Also, the at least two elements are preferably either nickel (from about 5 to 15 at. %) and molybdenum (from about 0.5 to 5 at. %) or iron (from about 5 to 15 at. %) and titanium (from about 5 to 15 at. %). The hydrogen storage materials are created by mechanical alloying in a milling apparatus under an inert atmosphere, such as argon, or a mixed atmosphere, such as argon and hydrogen. The speed and length of the milling are varied.
摘要:
A method of inducing a periodic variation of nonlinearity value in a sample of ferroelectric material comprises arranging a pair of electrodes on opposite faces of the sample, one electrode defining a desired pattern of nonlinearity variation, applying a pre-bias voltage across the sample for a predetermined time using the electrodes, the pre-bias voltage being less than the coercive field of the ferroelectric material; and after the predetermined time, applying a current-controlled poling voltage across the sample using the electrodes, to produce domain inversion in the sample according to the desired pattern of nonlinearity variation. The pre-bias voltage may be 75% of the coercive field or more, and applied for a pre-determined time between 1 and 100 seconds.
摘要:
Mechanically alloyed hydrogen storage materials having a major atomic percentage of magnesium and a minor atomic percentage of at least two elements selected from the group consisting of nickel, molybdenum, iron and titanium. Preferably the mechanical alloy comprises a multi-phase material, including at least one amorphous phase. Also, the at least two elements are preferably either nickel (from about 5 to 15 at. %) and molybdenum (from about 0.5 to 5 at. %) or iron (from about 5 to 15 at. %) and titanium (from about 5 to 15 at. %). The hydrogen storage materials are created by mechanical alloying in a milling apparatus under an inert atmosphere, such as argon, or a mixed atmosphere, such as argon and hydrogen. The speed and length of the milling are varied.