41results about How to "Reduce detection noise" patented technology

The invention discloses an integrated gating active quenching/restoring circuit. The integrated gating active quenching/restoring circuit comprises a quick detection circuit, a pulse generation circuit, a pixel control circuit, a quenching circuit and a restoring circuit, wherein the quick detection circuit is used for processing a detected anode current signal of an SPAD (Single Photon Avalanche Diode) into a pulse signal, the pulse signal can be output through the pulse generation circuit, the pixel control circuit is controlled by an output signal and a gating signal of the pulse generation circuit, the restoring circuit and the quenching circuit are respectively controlled by outputs of the pixel generation circuit, outputs of the restoring circuit and the quenching circuit can be fed back to an anode of the SPAD, and the restoring and the quenching of the SPAD can be controlled. According to the integrated gating active quenching/restoring circuit disclosed by the invention, by adopting a gating control method, the dark counting rate of the SPAD can be effectively reduced, the quenching time can be controlled by the pulse generation circuit, and the integrated gating active quenching/restoring circuit has the advantages of compact area and low power consumption.

The invention discloses a vehicle-borne radar in-loop real-time simulation test system and a method thereof. The system comprises a tested radar located on a turntable, a driving operation unit, a display, a real-time controller and an upper computer, wherein the driving operation unit comprises a driving operation mechanism and a driving operation signal sensor; the upper computer comprises a virtual test field and a target test and analysis unit; a driving vehicle model and a target vehicle model are included in the virtual test field; the driving vehicle model is used for virtually loading the tested radar; the real-time controller comprises a spectrum measurement unit, a target simulation unit, a motion controller and a data acquisition card; and the spectrum measurement unit comprises a millimeter wave signal transceiver, a millimeter wave frequency reducer, a millimeter wave signal analyzer, a time delay controller, a millimeter wave signal generator and a millimeter wave frequency rising device. Through radar hardware-in-the-loop real-time simulation, driving operation, target simulation, turntable rotation control and millimeter wave delay control, simulation test on the radar in various road conditions is realized.

A nano-resonator device comprising at least one fixed element and at least one mobile element with respect to the fixed element, first electromagnetic means, integrated or fixed on the fixed element, and second electromagnetic means, integrated or fixed on the mobile element, to generate an oscillating movement of the mobile element.

A magnetic sensor includes a channel layer, a magnetization free layer placed on a first section of the channel layer, and a magnetization-fixed layer placed on a second section of the channel layer. The areal resistance of the interface between the channel layer and the magnetization free layer is lower than the areal resistance of the interface between the channel layer and the magnetization-fixed layer.

The invention discloses a method for improving phased array ultrasonic detection capability of an R region of a complex-shaped component, and belongs to the field of high-end equipment manufacturing and detection. The method comprises the following steps: establishing a phased array ultrasonic detection model of an R region of a component with a complex shape; designing a phased array ultrasonic surface adaptation method (SAUL), and combining the SAUL with a receiving focusing detection scheme; reading the sound time from each aperture array element to the corresponding focus by using a finiteelement model, and calculating a phased array ultrasonic detection receiving focusing rule of the R region of the complex-shaped component; transmitting ultrasonic waves by utilizing SAUL, receivingthe scanning signal A in parallel by each array element, and carrying out receiving focusing processing to obtain an imaging result of phased array ultrasonic surface self-adaption method combined with receiving focusing. According to the method, on the basis of SAUL, receiving focusing is combined to improve the transverse resolution of phased array ultrasonic detection of the R area of the component in the complex shape, so the detection noise is reduced, the artifacts are avoided, and a support is provided for high-quality detection of defects of the R area of the component in the complex shape.

The application discloses a method of millimeter wave attenuation measurement and a system thereof. The method comprises: dividing a millimeter wave signal into a radio frequency test signal and a radio frequency reference signal; carrying out frequency conversion on the two radio frequency signals to form audio signals; and respectively carrying out voltage dividing on an audio test signal beforeand after insertion of the measured attenuator, using an audio reference signal for coherent receiving on the audio test signal to obtain two signal intensity values, enabling second signal intensityto be equal to first signal intensity, recording a first voltage dividing ratio and a second voltage dividing ratio, and calculating an attenuation value of the measured attenuator. The system of theinvention includes a radio frequency signal generator, a first directional coupler, an inductive voltage divider, a test unit, a reference unit, a lock-in amplifier and the measured attenuator. According to the method and the system, a two-channel signal measurement manner is employed, a measurement circuit is enabled to be stabler, the problem that external reference frequency and audio signal frequency of lock-in amplifiers of single-channel systems are not synchronized is solved, and the reference signal provided to the lock-in amplifier is very accurate.

The invention discloses a differential capacitance detection circuit based on sampling holder demodulation. The circuit comprises a capacitance reading front-end circuit, a demodulation and low-pass filter circuit, an A/D conversion circuit and a digital signal processor 4 used for controlling the carrier frequency and analog switch driving signals. According to the demodulation and low-pass filtering circuit, a sampling holder is adopted as a phase-sensitive demodulation scheme, so that an effective value of a demodulation output signal is close to the amplitude of an envelope, the high-frequency carrier waves are effectively suppressed while demodulation is performed, and the capacitance detection noise is reduced. Under the same capacitance detection gain, the power supply voltage of the device is reduced, so that the static power consumption of a chip is reduced; a buffer amplifier demodulation circuit of the sampling holder is combined with a post-stage low-pass filter, so that anoperational amplifier is saved, the structure is simple, and the product design of the miniaturization of the sensor is facilitated.

The invention relates to an overall type steel-based platform static load test load piling method for civil engineering. The overall type steel-based platform static load test load piling method for civil engineering is characterized in that the method is performed according to the following steps that, a steel-based platform is selected, a jack is installed at the center of test points, a main beam is installed on the steel-based platform, a jack cylinder body and the main beam are effectively connected, and the steel-based platform and the main beam are effectively connected; a reference beam is installed, and loads are piled; after the weight of the piled loads reaches a regulated weight and a test instrument meets the test requirement according to check, test loading can be performed;after a test ends, parts of the loads are unloaded; and the steel-based platform, the main beam and part of the loads are transferred to a next test point, the above steps are repeated till detectionof the test points of the whole program ends. By means of the load piling method, the large tonnage load piling potential safety hazards can be eliminated, the detection time and the detection cost are saved, a large tonnage static load experiment can be safely and conveniently implemented, integrity is good, self moving can be achieved, speed is high, cost is low, and energy conservation and environmental protection are achieved.

Systems and methods for multiplexing two or more channels of a quantum key distribution (QKD) system are disclosed. A method includes putting the optical public channel signal (SP1) in return-to-zero (RZ) format in a transmitter (T) in one QKD station (Alice) and amplifying this signal (thereby forming SP1*) just prior to this signal being detected with a detector (30) in a receiver (R) at the other QKD station (Bob). The method further includes precisely gating the detector via a gating element (40) and a coincident signal (PN1′) with pulses that coincide with the expected arrival times of the pulses in the detected (electrical) public channel signal (SP2). This allows for the public channel signal to have much less power, making it more amenable for multiplexing with the other QKD signals.

The invention discloses a novel electrochemical glucose sensor based on a ferrocene polymer and a preparation method of an electrode thereof. A core element of the glucose sensor is prepared by blending and dispensing a ferrocene polymer electronic mediator, glucose oxidase and polyethylene glycol glycidyl ether according to a certain proportion. Compared with the prior art, sensitivity, reliability and stability of the sensor can be improved, the longer glucose response time can be obtained, and the sensor is suitable for the fields of continuous blood glucose detection, disposable blood glucose test strip detection and the like.

This instant disclosure provides a heart rate detecting module which includes an image sensor and a processor. The image sensor generates a plurality of image frames according to a light from a subject. The processor outputs a heart rate value based on a light intensity variance of the plurality of image frames. This instant disclosure further provides a heart rate detecting method which includes the following steps. A plurality of image frames are generated according to a light from a subject by an image sensor, and a heart rate value is outputted based on a light intensity variance of the plurality of image frames by a processor.

The invention discloses a novel method for preparing an electronic mediator capable of being used for an electrochemical biosensor. The electronic mediator is prepared by carrying out polymerization reaction on polyethylene imine (PEI) and one of ferrocene carboxaldehyde, ferrocene dicarboxaldehyde or homologues of ferrocene dicarboxaldehyde. Compared with the prior art, the sensitivity of the sensor can be improved, the detection noise of the sensor can be reduced, and longer response time can be obtained.

The present invention concerns methods of detecting, identifying and/or quantifying nucleic acids using a terminal transferase based assay. Terminal transferase adds nucleotides to the 3′ end of single-stranded DNA or the 3′ overhang of restricted double-stranded DNA, resulting in production of one molecule of pyrophosphate for each nucleotide incorporated. In various embodiments, a bioluminescence regenerative cycle (BRC) may be used to measure the amount of pyrophosphate produced by terminal transferase activity. In BRC, steady state levels of bioluminescence result from processes that produce pyrophosphate. Pyrophosphate reacts with APS in the presence of ATP sulfurylase to produce ATP. The ATP reacts with luciferin in a luciferase-catalyzed reaction, producing light and regenerating pyrophosphate. The pyrophosphate is recycled to produce ATP and the regenerative cycle continues. During the course of the cycle a steady state is achieved wherein concentrations of ATP and pyrophosphate and the rate of light production remain relatively constant. In preferred embodiments, photon emission is integrated over a time interval to determine the number of target molecules present in the initial sample. In certain embodiments, the targets to be detected may comprise reporter oligonucleotides attached to biomolecules, such as proteins, peptides, antibodies, ligands, etc. In other embodiments, one or more of the enzymes used may be thermostable enzymes.

A magnetic field component in a Z direction is guided by a magnetic field guide layer and applied to a magnetic sensor in an X direction that is the same as a sensitivity axis direction thereof, and a detection output is obtained. A bridge circuit is formed with a plurality of magnetic sensors and configured such that an output is not provided for a magnetic field component in the X direction. However, when an external magnetic field in the X direction is drawn to the magnetic field guide layer, variation of sensitivity for the X direction may occur. Thus, soft magnetic characteristics of a first portion of the magnetic field guide layer are deteriorated to decrease the magnetic permeability of the first portion.