Abstract: A driver and method for operating a driver circuit for a light-emitting diode (LED) device. In some embodiments, the driver circuit includes a rectifier operatively coupled to a ballast, a current regulator operatively coupled to the rectifier and to the LED device, and a detecting module operatively coupled to the LED device and to the current regulator. During a startup stage, the rectifier of the driver circuit rectifies direct current received from the ballast and provides the rectified current to the current regulator. The detecting module then detects a current through the LED device provided by the current regulator during the startup stage, wherein a value of the current through the LED device is a detecting indictor.

Abstract: A driver for a light-emitting diode (LED) device comprises: a rectifier, a current regulator and a detecting module. The rectifier is coupled to a ballast and configured to convert an alternating current from the ballast into a direct current. The current regulator is coupled between the rectifier and the LED device, and configured to receive the direct current from the rectifier and output a driving current to the LED device. The detecting module is configured to detect a signal indicating an output characteristic of the ballast, during a startup stage of the LED device. The current regulator is configured to convert the direct current from the rectifier into the driving current with a value equal to or less than a preset current threshold when the signal meets a preset condition, and the preset current threshold is less than a maximum current the LED device is able to carry without damage.

Abstract: A device for monitoring and identifying a mountain torrent and debris flow and a method for early warning of disasters relate to the technical field of debris flow protection. The device includes a computation device, sensors, an amplifier and an analog-to-digital converter. The sensors convert an acquired impact force signal into a digital signal by the amplifier and the analog-to-digital converter, and transmits the digital signal to the computation device. The computation device utilizes the digital signal to compute an energy coefficient of a liquid impact signal and a solid-liquid impact energy ratio, and a debris flow mode is monitored and identified in combination with a threshold range of the energy coefficient and a threshold range of the solid-liquid impact energy ratio. The device identifies the nature of the mountain torrent and debris flow through time-frequency analysis of an impact force signal generated by the debris flow to sensors.

Abstract: A method for a whole-process numerical simulation and hazard forecast of a mountain disaster is provided. The method includes: S1, a high space-time rainfall forecast of a mountain area; S2, a hydrodynamic process and numerical simulation: establishing a hydrodynamic process model and solving the hydrodynamic process model; S3, a motion model and numerical simulation of a mountain torrent and debris flow disaster; and S4, a risk analysis and hazard forecast of a small watershed disaster. The present invention predicts disaster hazard and dynamically and quantitatively evaluates risk loss according to a whole-process scenario simulation of the disaster driven by a climate forecast result, improves current disaster level forecasts to hazard forecasts, and serves for accurate disaster preventions and accurate rescues.

Abstract: A device for monitoring and identifying a mountain torrent and debris flow and a method for early warning of disasters relate to the technical field of debris flow protection. The device includes a computation device, sensors, an amplifier and an analog-to-digital converter. The sensors convert an acquired impact force signal into a digital signal by the amplifier and the analog-to-digital converter, and transmits the digital signal to the computation device. The computation device utilizes the digital signal to compute an energy coefficient of a liquid impact signal and a solid-liquid impact energy ratio, and a debris flow mode is monitored and identified in combination with a threshold range of the energy coefficient and a threshold range of the solid-liquid impact energy ratio. The device identifies the nature of the mountain torrent and debris flow through time-frequency analysis of an impact force signal generated by the debris flow to sensors.

Abstract: A driver for a light-emitting diode (LED) device comprises: a rectifier, a current regulator and a detecting module. The rectifier is coupled to a ballast and configured to convert an alternating current from the ballast into a direct current. The current regulator is coupled between the rectifier and the LED device, and configured to receive the direct current from the rectifier and output a driving current to the LED device. The detecting module is configured to detect a signal indicating an output characteristic of the ballast, during a startup stage of the LED device. The current regulator is configured to convert the direct current from the rectifier into the driving current with a value equal to or less than a preset current threshold when the signal meets a preset condition, and the preset current threshold is less than a maximum current the LED device is able to carry without damage.

Abstract: An improved disposable electrochemical test sensor designed to facilitate reducing volume of fluid samples. It has a short fluid chamber having two electrodes that functions as three electrodes (one working electrode, one reference electrode and one blank electrode). The chamber provides a reservoir from which a sample fluid can be quickly drawn into the chamber through capillary action. The novel potential reverse and curve-fitting technology of the test sensor provided by the present invention can effectively eliminate most common interferents existing in the fluid samples.

Abstract: The present invention discloses an LED lighting assembly configured to retrofit a fluorescent tube, comprising at least one LED, and a driving circuit configured to drive the at least one LED. The driving circuit comprises a switch control module and a rectifying circuit. The driving circuit is connected to the at least one LED and configured to receive and process an AC voltage signal from one side or both sides of the LED lighting assembly, and control the driving of the at least one LED based on the processed voltage signal. The rectifying circuit is connected to the at least one LED and configured to convert an AC power inputted to the rectifying circuit into a DC power supplied to the at least one LED. The present invention also discloses an LED driving circuit configured to retrofit a fluorescent tube.

Abstract: An acoustic resonator includes a first electrode disposed over a substrate; a piezoelectric layer disposed over the first electrode; a second electrode disposed over the piezoelectric layer; and a ring disposed in either the first electrode, or in the second electrode. The ring defines at least a portion of a perimeter along an active region of the acoustic resonator.

Abstract: An improved disposable electrochemical test sensor designed to facilitate reducing volume of fluid samples. It has a short fluid chamber having two electrodes that functions as three electrodes (one working electrode, one reference electrode and one blank electrode). The chamber provides a reservoir from which a sample fluid can be quickly drawn into the chamber through capillary action. The novel potential reverse and curve-fitting technology of the test sensor provided by the present invention can effectively eliminate most common interferents existing in the fluid samples.

Abstract: An acoustic resonator device includes a composite first electrode disposed over a substrate; a piezoelectric layer disposed on the composite first electrode, the piezoelectric layer including a piezoelectric material doped with scandium for improving piezoelectric properties; and a second electrode disposed on the piezoelectric layer. The composite first electrode includes a base electrode layer disposed over the substrate; a temperature compensation layer disposed on the base electrode layer; a seed interlayer disposed on the temperature compensation layer, the seed interlayer having a thickness between about 5? and about 150?; and a conductive interposer layer disposed on at least the seed interlayer, at least a portion of the conductive interposer layer contacting the base electrode layer. The piezoelectric layer has a negative temperature coefficient and the temperature compensation layer has a positive temperature coefficient at least partially offsetting the negative temperature coefficient.

Abstract: The present invention discloses an LED lighting assembly configured to retrofit a fluorescent tube, comprising at least one LED, and a driving circuit configured to drive the at least one LED. The driving circuit comprises a switch control module and a rectifying circuit. The driving circuit is connected to the at least one LED and configured to receive and process an AC voltage signal from one side or both sides of the LED lighting assembly, and control the driving of the at least one LED based on the processed voltage signal. The rectifying circuit is connected to the at least one LED and configured to convert an AC power inputted to the rectifying circuit into a DC power supplied to the at least one LED. The present invention also discloses an LED driving circuit configured to retrofit a fluorescent tube.

Abstract: A BAW resonator includes a nonlinear substrate defining a cavity, and an acoustic stack over the cavity, including a bottom electrode, a piezoelectric layer, and a top electrode, where an active region of the acoustic stack includes overlapping portions of the cavity, the bottom electrode, the piezoelectric layer and the top electrode. The BAW resonator further includes a connecting strip extending from a portion of the top electrode for providing electrical excitation of the acoustic stack, where an E-field generated in the BAW resonator begins at the top electrode and terminates at the bottom electrode in response to the electrical excitation. The cavity includes an inner portion in the active region and an extended portion extending from an outer perimeter of the active region underneath the connecting strip. A length of the extended portion are sufficient to substantially prevent portions of the E-field from passing through the substrate.

Abstract: A high voltage direct current power transmission series valve group control device, is used for regulating a series circuit having two or more valve groups provided with controllable power semiconductors respectively. Each valve group is provided with a current regulation unit and a voltage regulation unit. The current regulation unit controls a direct current current flowing through a valve group corresponding thereto, and the voltage regulation unit controls a voltage across two ends of a valve group corresponding thereto. One valve group is selected from the series valve group as a master control valve group, while the others are taken as slave control valve groups. The master control valve group selects a trigger angle output by the current regulation unit to control same, and the slave control valve group selects a trigger angle obtained after the trigger angle transmitted from the master control valve group and an output value of the voltage regulation unit pass through a subtractor to control same.

Abstract: A BAW resonator includes a nonlinear substrate defining a cavity, and an acoustic stack over the cavity, including a bottom electrode, a piezoelectric layer, and a top electrode, where an active region of the acoustic stack includes overlapping portions of the cavity, the bottom electrode, the piezoelectric layer and the top electrode. The BAW resonator further includes a connecting strip extending from a portion of the top electrode for providing electrical excitation of the acoustic stack, where an E-field generated in the BAW resonator begins at the top electrode and terminates at the bottom electrode in response to the electrical excitation. The cavity includes an inner portion in the active region and an extended portion extending from an outer perimeter of the active region underneath the connecting strip. A length of the extended portion are sufficient to substantially prevent portions of the E-field from passing through the substrate.

Abstract: An acoustic resonator includes a first electrode disposed over a substrate; a piezoelectric layer disposed over the first electrode; and a second electrode disposed over the piezoelectric layer; a passivation layer disposed over the second electrode; and a ring disposed between the substrate and the passivation layer

Abstract: An acoustic resonator includes a first electrode disposed over a substrate; a piezoelectric layer disposed over the first electrode; and a second electrode disposed over the piezoelectric layer; a passivation layer disposed over the second electrode; and a ring disposed between the substrate and the passivation layer.

Abstract: A high voltage direct current power transmission series valve group control device, is used for regulating a series circuit having two or more valve groups provided with controllable power semiconductors respectively. Each valve group is provided with a current regulation unit and a voltage regulation unit. The current regulation unit controls a direct current current flowing through a valve group corresponding thereto, and the voltage regulation unit controls a voltage across two ends of a valve group corresponding thereto. One valve group is selected from the series valve group as a master control valve group, while the others are taken as slave control valve groups. The master control valve group selects a trigger angle output by the current regulation unit to control same, and the slave control valve group selects a trigger angle obtained after the trigger angle transmitted from the master control valve group and an output value of the voltage regulation unit pass through a subtractor to control same.

Abstract: A bulk acoustic wave (BAW) resonator comprises: a seed layer disposed over a substrate; a first electrode disposed over the seed layer; and a second electrode disposed over a piezoelectric layer. The seed layer has a thickness in the range of approximately 30 ? to approximately 150 ?.