摘要:
The invention claimed herein provides a process to oxidize N-(5-alkoxy-2-methyl-4-nitrophenyl)acetamides to N-acyl-2-amino-4-alkoxy-5-nitrobenzoic acids using potassium permanganate in the presence of magnesium sulfate in aqueous sulfolane or aqueous pyridine.
摘要:
The invention claimed herein provides a process to oxidize N-(5-alkoxy-2-methyl-4-nitrophenyl)acetamides to N-acyl-2-amino-4-alkoxy-5-nitrobenzoic acids using potassium permanganate in the presence of magnesium sulfate in aqueous sulfolane or aqueous pyridine.
摘要:
Electronic devices involving contact structures, and related components, systems and methods associated therewith are described. Contact structures (also referred to as electrical contact structures or electrodes) are features on a device that are electrically connected to a power source. The power source can provide current to the device via the contact structures. The contact structures can be designed to improve current distribution in electronic devices. For example, the contact resistance of the contacts may be modified to improve current distribution (e.g., by controlling the shape and/or structure and/or composition of the contacts). The contact structures may include an intervening layer (e.g., a non-ohmic layer) positioned between a surface of the device and a conductive portion extending from a conductive pad. The intervening layer and/or conductive portions may be designed to have certain shapes (e.g., non-linear shapes) that promote current flow from the conductive pad towards the ends of the contacts to increase current spreading. The intervening layer can also reduce light generation underneath the light absorbing contacts to allow a greater percentage of the generated light to emerge from the surface of the device. Advantageously, devices including contact structures of the invention can increase uniformity of light emission and/or otherwise improve performance. As such, these contact structures are particularly suitable for use in a variety of light-emitting devices, including LEDs.
摘要:
A method of fabricating a semiconductor device includes the steps of forming (or providing) a series of layers formed on a substrate, the layers including a first plurality of layers including an n-type ohmic contact layer, a p-type modulation doped quantum well structure, an n-type modulation doped quantum well structure, and a fourth plurality of layers including a p-type ohmic contact layer. Etch stop layers are used during etching operations when forming contacts to the n-type ohmic contact layer and contacts to the n-type modulation doped quantum well. Preferably, each such etch stop layer is made sufficiently thin to permit current tunneling therethrough during operation of optoelectronic/electronic devices realized from this structure (including heterojunction thyristor devices, n-channel HFET devices, p-channel HFET devices, p-type quantum-well-base bipolar transistor devices, and n-type quantum-well-base bipolar transistor devices). The etch stop layer(s) preferably comprise AlAs that functions as an etch stop during etching by a chlorine-based gas mixture that includes fluorine. The series of layers preferably comprise group III-V materials.
摘要:
A pneumatically actuated drain stopper system and apparatus which includes a source of compressed gas, a pressure regulator, a piston drain, a push-button or toggle switch interposed between the piston drain and the pressure regulator, and pneumatic lines connecting the piston drain to the switch and the switch to the gas source, and bringing all elements into fluid communication with one another.
摘要:
A unitary removable barrier for installation in a cylindrical water line to selectively block the water line to passage of water therethrough. The unitary removable barrier is composed of a single piece rubber body having at least one cylindrical section sized to receive upstream and downstream pipes of the water line. A unitary rubber planar disc molded with the cylindrical section is of a circular circumference and which completely blocks the water line but which is selectively removable from the cylindrical section thus removing the barrier to the passage of the water through the line.
摘要:
A unitary removable barrier for installation in a cylindrical water line to selectively block the water line to passage of water therethrough. The unitary removable barrier is composed of a single piece rubber body having at least one cylindrical section sized to receive upstream and downstream pipes of the water line. A unitary rubber planar disc molded with the cylindrical section is of a circular circumference and which completely blocks the water line but which is selectively removable from the cylindrical section thus removing the barrier to the passage of the waste through the line.