Abstract:
Hematin, a hydroxyferriprotoporphyrin, is derivatized with one or more non-proteinaceous amphipathic groups. The derivatized hematin can serve as a mimic of horseradish peroxidase in polymerizing aromatic monomers, such as aromatic compounds. These derivatized hematins can also be used as catalysts in polymerizing aromatic monomers, and can exhibit significantly greater catalytic activity than underivatized hematin in acidic solutions. In one embodiment, polymerization is in the presence of a template, along which aromatic monomers align. An assembled hematin includes alternating layers of hematin and a polyelectrolyte, which are deposited on an electrically charged substrate. Assembled hematin can also be used to polymerize aromatic monomers.
Abstract:
A circuit of reducing a pop-up noise in a digital amplifier includes a switch unit and a switch signal generator. The switch unit is coupled in parallel to an output load between an output node of the digital amplifier and a reference node. The switch unit controls a current flowing through the output load by forming a conduction path between the output node and the reference node in response to a switch signal. The switch signal generator generates the switch signal in response to a switch control signal indicating a power-on or a power-off. The pop-up noise is reduced by the conduction path that is formed when the digital amplifier is powered on or off.
Abstract:
Hematin, a hydroxyferriprotoporphyrin, is derivatized with one or more non-proteinaceous amphipathic groups. The derivatized hematin can serve as a mimic of horseradish peroxidase in polymerizing aromatic monomers, such as aromatic compounds. These derivatized hematins can also be used as catalysts in polymerizing aromatic monomers, and can exhibit significantly greater catalytic activity than underivatized hematin in acidic solutions. In one embodiment, polymerization is in the presence of a template, along which aromatic monomers align. An assembled hematin includes alternating layers of hematin and a polyelectrolyte, which are deposited on an electrically charged substrate. Assembled hematin can also be used to polymerize aromatic monomers.
Abstract:
The invention relates to a pulse width modulator, more particularly to a cross-coupled pulse width modulator. A crossing input signal modulator according to the present invention comprises: a positive path block which includes a first integrator for performing the first-order integration of feedback signals in first input and output signals and then transmitting the first-order integrated signals to a second integrator, and a second integrator for performing the second-order integration of a signal from the first integrator and a second input signal and then transmitting the second-order integrated signals; and a negative path block which includes a third integrator for performing the first-order integration of feedback signals in the second input and output signals and integration of a signal from the third integrator and the first input signal and then transmitting the second-order integrated signals. This configuration allows cross-coupling of the inputs from two integrators to generate an accurate differential pulse width modulation (PWM) single, and enables optimization of the IC implementation by adopting a feedback system that features a simplified implementation and minimal application area.
Abstract:
A blue electroluminescent polymer having an indolocarbazole unit in the backbone of a polyarylene polymer and an organo-electroluminescent device using the same.
Abstract:
A biphenyl derivative having an amino group with or without alkoxy substituent in the biphenyl backbone, and an organic electroluminescent device using the same.
Abstract:
An Analog-to-Digital (A/D) converter includes signal paths that are responsive to an analog input signal, to generate a multi-bit digital signal. A respective signal path includes a comparator. A synchronizing circuit is responsive to a clock signal and outputs of the comparators, to generate a respective delayed clock signal that is applied to a respective comparator. A respective signal path also includes a respective decoder that is responsive to a respective comparator and to the clock signal.
Abstract:
Provided are a digital condenser microphone having a preamplifier with variable input impedance and a method of controlling the variable input impedance of the preamplifier. The preamplifier includes a bias terminal for applying a bias voltage to an input signal when the input signal is output from a microphone condenser. An impedance unit includes at least one variable input impedance element which is connected to the bias terminal and to which the bias voltage is applied via the bias terminal. An operational amplifier receives the input signal, converts the input signal into an output signal, and outputs the output signal. A control block determines whether a DC voltage level of the output signal output from the operational amplifier has reached a reference value, and controls a total impedance of the impedance unit based on a result of the determination.
Abstract:
The present invention provides a digital condenser microphone having a preamplifier with variable input impedance and a method of controlling the variable input impedance of the preamplifier. The preamplifier includes a bias terminal (Bias) for applying a bias voltage to an input signal when the input signal is output from a microphone condenser. An impedance unit (Z) includes at least one variable input impedance element which is connected to the bias terminal and to which the bias voltage is applied via the bias terminal. An operational amplifier receives the input signal, converts the input signal into an output signal, and outputs the output signal. A control block (40) determines whether a DC voltage level of the output signal output from the operational amplifier has reached a reference value, and controls a total impedance of the impedance unit based on a result of the determination.
Abstract:
A spirofluorene-based polymer which contains a spirofluorene structure as a basic unit and which is end-capped with functional moieties substituted by fluorine, and an organic electroluminescent device using an organic layer using the spirofluorene-based polymer. The organic electroluminescent device has improved efficiency, reduced driving voltage, and excellent thermal, optical and electrical stability.