35results about How to "Reduce background noise distractions" patented technology

The invention relates to a reference signal constraint-based mechanical characteristic acoustic signal frequency-domain semi-blind extraction method, and belongs to the technical field of operation maintenance of mechanical equipment. The method comprises the following steps: constructing a multi-scale morphology filter for a failure signal characteristic on the basis of a dynamic particle swarm algorithm with higher global optimization capability, and maximally weakening background noise interference; constructing a reference signal in combination with structural parameters of a mechanical part, and further performing complex component blind separation band by band by virtue of a unit reference signal constraint semi-blind extraction method; solving order uncertainty problems to obtain a separated and restored source signal to finally realize the extraction and separation of the mechanical failure characteristic signal by virtue of the improved KL distance between complex components. Different from vibration monitoring requiring the mounting of a sensor on the surface of mechanical equipment, acoustic monitoring only requires the placement of 1 to 2 microphones around the equipment, and then the failure characteristic signal can be extracted from a picked up mechanical acoustic signal for further failure source positioning.

The invention relates to a synthesis method and an application of 3-heteroaryl substituted-2H-indazole derivatives for specifically labeling mitochondria. The 3-heteroaryl substituted-2H-indazole derivatives can be used for specifically labeling mitochondria to realize fluorescence imaging. A fluorescence emission spectrum of the derivatives can reach to an infrared / near infrared area, the maximum Stokes displacement can reach 178nm, and the derivatives have the advantages of very small molecular weight, small size, easy penetration of cell membranes and entrance to cells, good light stability and small cytotoxicity. The preparation method is characterized in that the 3-heteroaryl substituted-2H-indazole derivatives are obtained through a C-H / C-H direct oxidative cross-coupling reaction of 2H-indazole derivatives and electron-rich heterocycles under the catalysis of a transition metal. Compared with traditional C-X / C-M coupling and other methods, the method provided by the invention has the advantages of avoiding of tedious pre-activation processes of a substrate, improvement of the function group tolerance, simple reaction conditions, synthesis step simplification, total yield increase and cost reduction. Compared with preset expensive commercial mitochondrial labeling reagents, the 3-heteroaryl substituted-2H-indazole derivatives have high market competitiveness.

The invention relates to a multi-channel evanescent wave all-optical fiber biosensor. The biosensor is characterized in that it comprises a flow sample injection system, an optical system and a control circuit and signal processing system; laser emitted by a semiconductor laser unit is collimated and then divided into a plurality of light beams, each light beam is emitted by a corresponding all-optical fiber system to a corresponding sample pool, each optical fiber probe produces fluorescence after excitation, the generated fluorescence signals are collected and filtered by all-optical fiber systems and are then emitted to a photoelectric detector group, the photoelectric detector group converts the collected fluorescence signals of all the optical fiber probes' surfaces into current signals, multi-channel current signals are processed by a micro-signal simulation preamplifier and a multi-channel lock-in amplifier and then sent to a computer, thus realizing simultaneous quantitative analysis of a sample's multiple indexes; and the computer is also connected to a cooperative control module through a parallel processing module, the parallel processing module is also connected to the semiconductor laser unit through a pulse signal generator, and the cooperative control module is in parallel connection with a peristaltic pump and a ten-position valve.

The invention relates to the technical field of diesel engine starting, in particular to an objective evaluation method for pulse noise of a diesel engine. The method comprises the following specificsteps: 1, respectively filtering a certain sound signal by adopting 24 groups of critical frequency band filters within the range of 20-16000Hz to obtain 24 groups of sound pressure signals, calculating the time-varying characteristic loudness of each group of signals under the condition that frequency domain and time domain masking effects are considered, and finally obtaining 24 groups of characteristic loudness time sequences, called uncompressed signals for short, of the sound signal within 24 critical frequency bands; 2, dividing the pulse sound calculation and identification process intotwo parallel signal processing processes, namely a log2 compressed signal pulse relative amplitude pickup process and a non-compressed signal pulse absolute amplitude pickup process; and 3, calculating a pulse index. An objective evaluation method is provided for the pulse noise of the diesel engine, and the method not only can calculate the total impulse index of the engine noise, but also can analyze the contribution degree of the pulse indexes of critical frequency bands of the pulse noise.

The invention discloses a Camshift algorithm for tracking a centroid correction model on the basis of Grabcut and an LBP (Local Binary Pattern). A target object is separated from an environment through the constant value enhancement tracking of a video stream and Grabcut foreground segmentation to cause the Camshift to obtain a pure histogram. Meanwhile, a Kalman filter assists the Camshift to predict a target movement locus. During a tracking period, carrying out LBP transform on an image in a target frame to obtain a template and current LBP histogram data, a judgment coefficient and a frame body change situation are obtained through comparison, and an S-Grabcut algorithm is executed if the target object is blocked by an object with a similar color, a centroid is removed, and normal tracking is continuously carried out. Compared with a traditional Camshift algorithm, the algorithm disclosed by the invention reduces the interference of background noise to a large extent, and the problem of quick movement and blocking is solved since the Kalman filter is added. Meanwhile, interference brought by the blocking of the object with the similar color can be favorably solved by the centroid correction model. Experiment results indicate that the algorithm has good robustness, meets the requirements of instantaneity and accuracy in tracking and causes the target to be more stably tracked under a complex environment.

The invention discloses a centrifugal separation detection method. The method comprises the steps of: a liquid phase is driven by a centrifugal device to flow through a solid phase membrane, wherein the liquid phase comprises a to-be-tested sample containing a to-be-tested substance and a detection phase, the detection phase is a substance containing a detection indicator capable of directly or indirectly specifically binding to the to-be-tested substance; when the liquid phase flows through the solid phase membrane, the liquid phase is combined with to-be-tested substance specific conjugate coating the solid phase membrane to form a detection indicator-to-be-tested substance-to-be-tested substance specific conjugate complex, the detection indicator-to-be-tested substance-to-be-tested substance specific conjugate complex is captured and immobilized on the solid phase membrane, and a detector detects the amount of the detection indicator indirectly fixed to the solid phase membrane to detect the amount of the to-be-tested substance. The centrifugal separation detection method has the characteristics of high sensitivity and short detection time.

The invention discloses an intelligent flame detection method and device, a detector and a storage medium. The method comprises the steps: obtaining an infrared dynamic signal and an ultraviolet dynamic signal in a certain period of sampling time, and carrying out the quantification of the infrared dynamic signal and the ultraviolet dynamic signal, and obtaining an infrared dynamic signal quantification value and an ultraviolet dynamic signal quantification value; calculating dynamic signal average intensity and dynamic signal discreteness in the mt time window according to the infrared dynamic signal quantification value and the ultraviolet dynamic signal quantification value, and counting discreteness count; obtaining a dynamic signal characteristic value according to the dynamic signalaverage intensity and the dynamic signal discreteness in the mt time window; and if the discreteness count is greater than or equal to the effective count threshold and the difference between the dynamic signal characteristic value and the background noise signal characteristic value is greater than or equal to the identification signal characteristic value threshold, identifying the flame and outputting a flame alarm signal. Background noise interference can be eliminated in a self-adaptive manner, false alarm is prevented, and the reliability of flame detection alarm is improved.