摘要:
A matching layer for ultrasound transducers has a gradient in impedance value from one surface to the other surface of the matching layer. The matching layer is composed of a plurality of sublayers made of composite materials and securely attached together and is disposed on the surface of the transducer element. The first sublayer adjacent to the transducer element has an impedance value less than or equal to that of the transducer element. The last sublayer adjacent to the target has an impedance value greater than or equal to that of the target. The impedance values of the sublayers decrease monotonically from the first to the last sublayer.
摘要:
A flexible organic light emitting diode (OLED) fiber light source is provided. The OLED contains a fiber core, a cathode, at least one organic radiation emitting layer and a transparent anode. The fiber light source may be used as a flexible novelty lighting article or coiled inside a large area lighting source.
摘要:
A method of making an electronic device, according to an exemplary embodiment of the invention, comprises the steps of: forming a polycrystalline substrate in a desired shape; converting the polycrystalline substrate into a single crystal substrate using a solid state crystal conversion process; and forming an electronic element on the substrate. Typically, alumina is formed in the shape of a wafer, sintered to form a densified polycrystalline alumina wafer, and heated to a temperature between the melting point of alumina and one-half the melting point of alumina to convert the densified polycrystalline alumina wafer into a sapphire wafer. A light-emitting diode or other electronic device, such as a laser diode, a high frequency microwave device, or an optoelectronic detector, can be formed on the wafer by depositing layers of semiconductor material on the wafer. The solid state crystal conversion process provides several advantages in forming electronic devices. For example, the cost of the single crystal substrate is significantly reduced since crystal growing from a melt is not required. Also, less processing is required after the crystal is formed, since the precursor polycrystalline substrate can be formed to near net shape. In addition, the polycrystalline substrate can be made in many shapes, in contrast to the shapes possible when growing a crystal from a melt.
摘要:
A current limiting device utilizes an electrically conductive composite material and an inhomogeneous distribution of resistance structure. The current limiting device has a conducting filler and at least two electrodes, where at least one of the electrodes comprises a grooved electrode structure. The grooved electrode structure maintains contact between the electrodes and the composite material, even with consumption of the composite material and production of residue during a high current condition.
摘要:
A method for removing defects at high pressure and high temperature (HP/HT) or for relieving strain in a non-diamond crystal commences by providing a crystal, which contains defects, and a pressure medium. The crystal and the pressure medium are disposed in a high pressure cell and placed in a high pressure apparatus, for processing under reaction conditions of sufficiently high pressure and high temperature for a time adequate for one or more of removing defects or relieving strain in the single crystal.
摘要:
A current limiting arrangement comprises at least two electrodes and at least two electrically conductive composite materials. The current limiting arrangement has predetermined operational bounds. The at least two composite materials each comprising a low pyrolysis temperature binder and an electrically conductive filler. The at least two conductive composite materials are in parallel with one another. Each conductive composite material has electrical and physical characteristics that define operational bounds, and at least two conductive composite materials having at least one different characteristic. A total of the electrical and physical characteristics of the at least two conductive composite materials being substantially similar to the operational bounds of the current limiting arrangement.
摘要:
The invention relates to a light source comprising a phosphor composition and a light emitting device such as an LED or a laser diode. The phosphor composition absorbs radiation having a first spectrum and emits radiation having a second spectrum and comprises at least one of: YBO3:Ce3+,Tb3+; BaMgAl10O17:Eu2+,Mn2+; (Sr,Ca,Ba)(Al,Ga)2S4:Eu2+; and Y3Al5O12—Ce3+; and at least one of: Y2O2S:Eu3+,Bi3+; YVO4:Eu3+,Bi3+; SrS:Eu2+; SrY2S4:Eu2+; CaLa2S4:Ce3+; and (Ca,Sr)S:Eu2+. The phosphor composition and the light source together can produce white light with pleasing characteristics, such as a color temperature of 3000-6500° K, a color rendering index of about 83-87, and a device luminous efficacy of about 10-20 lumens per watt.
摘要:
An ignition system for a gas appliance comprises an ignition controller that receives a current from a power source. The ignition controller is also coupled to an ignitor and to a current actuated valve that releases a flow of gas when the current is greater than a first predetermined current value and less than a second predetermined current value. Ignition safety for the gas appliance is provided by establishing a fixed range of current through the ignitor before the gas valve is opened.
摘要:
The invention relates to a light source comprising a phosphor composition 14 and a light emitting device 12 such as an LED or a laser diode 32. The phosphor composition 14 absorbs radiation having a first spectrum and emits radiation having a second spectrum and comprises at least one of: YBO3:Ce3+,Tb3+; BaMgAl10O17:Eu2+,Mn2+; (Sr,Ca,Ba)(Al,Ga)2S4:Eu2+; and Y3Al5O12—Ce3+; and at least one of: Y2O2S:Eu3+,Bi3+; YVO4:Eu3+,Bi3+; SrS:Eu2+; SrY2S4:Eu2+; CaLa2S4:Ce3+; and (Ca,Sr)S:Eu2+. The phosphor composition 14 and the light source 12 together can produce white light with pleasing characteristics, such as a color temperature of 3000-6500° K, a color rendering index of about 83-87, and a device luminous efficacy of about 10-20 lumens per watt.
摘要:
A catalyst system and method for making carbon fibrils is provided which comprises a catalytic amount of an inorganic catalyst comprising nickel and one of the following substances selected from the group consisting of chromium; chromium and iron; chromium and molybdenum; chromium, molybdenum, and iron; aluminum; yttrium and iron; yttrium, iron and aluminum; zinc; copper; yttrium; yttrium and chromium; and yttrium, chromium and zinc. In a further aspect of the invention, a catalyst system and method is provided for making carbon fibrils which comprises a catalytic amount of an inorganic catalyst comprising cobalt and one of the following substances selected from the group consisting of chromium; aluminum; zinc; copper; copper and zinc; copper, zinc, and chromium; copper and iron; copper, iron, and aluminum; copper and nickel; and yttrium, nickel and copper.