23 results about "Long pulse" patented technology

The application discloses an active direct wave suppression method, device, computer and storage medium, which filters a received signal by using a time domain blocking matrix, suppresses an interference frequency component, and forms a new sampling sequence; and performs a discrete Fourier transform on the new sampling sequence generated after filtering to obtain a power spectrum signal after interference suppression. According to the active direct wave suppression method, device, computer and storage medium, the uniformity of a single-frequency signal in time domain sampling is utilized, alignment on a time domain waveform is realized through phase compensation, and a difference cancellation process is performed on a reference signal and an original signal, so that the frequency component is cancelled, and static reverberation is suppressed. The method is convenient to calculate, has good single-frequency direct wave interference and reverberation suppression capability, and can be used for active target detection in a single-frequency long pulse signal transmission mode, and the effective distance is improved.

The invention discloses a long pulse debugging method for a large-area thermionic cathode ion source, and belongs to the technical field of thermionic cathode ion sources, and the method comprises the steps: carrying out the air inlet vacuum debugging after the ion source is assembled; the insulation and voltage endurance capability is improved through cold high-voltage exercise; turning off high voltage, lighting a lamp filament, applying arc voltage, and cleaning the cavity through arc chamber plasma discharge; the extraction voltage is gradually applied to perform beam extraction exercise, and beam transmission is optimized through diversion coefficient scanning; and finally, the diversion coefficient is reduced, the pulse width is prolonged, and long-pulse discharge debugging is realized. According to the method, a systematic debugging process from vacuum verification, insulation and voltage resistance, cavity cleaning to beam extraction and long pulse discharge is established, the stability and reliability of the ion source can be effectively improved, the breakdown risk is reduced, and a technical basis is provided for long-term stable operation of a large-area hot cathode ion source in the future.

This invention discloses a device and method for real-time thermal focal length measurement of a long-pulse LDA side-pump module. The device includes a detector source, a beam expander system, an LDA side-pump module, a knife edge, an energy meter, and a signal generator. The detector source serves as the detection light source for thermal focal length measurement; the beam expander system serves as a beam expander for the detector source size; the LDA side-pump module serves as a heat source generator to achieve high peak power pump injection under long-pulse pumping; the knife edge is placed on both sides of the beam waist position after the detector source passes through the LDA side-pump module to cut the transverse and longitudinal beams, achieving beam size characterization; the energy meter is placed in the rear region of the measurement device to acquire the energy measurement of the detector source; and the signal generator serves as a timing control part to achieve timing synchronization between the detector source and the LDA side-pump module. This invention uses timing synchronization combined with Gaussian beam transmission transformation to obtain the thermal focal length value of the long-pulse LDA side-pump, which has the advantages of simple structure, ease of operation, and high measurement accuracy.

The invention relates to the technical field of electron emission, and discloses a large-current pulse micro-channel plate electron emission source and an X-ray generation device. According to the electron emission source, an electron emission function layer at the head end of an MCP assembly is excited by adopting a rapidly regulated and controlled UV LED light source, and ultrafast time sequence modulation of electron beams is realized through an avalanche multiplication process of the electron beams in the MCP. By adopting a specific high-lead, low-alkali or alkali-free glass component or ceramic substrate composite functional film layer structure, the MCP assembly has long service life stability of low resistance, high current output and high power density operation. Independent bias voltage and gating voltage synchronous with electronic pulse are applied to the MCP assembly through the driving control unit, accurate thermal management is carried out in combination with a pulse-charging circulation mode, and the problems of charge compensation and thermal limitation under large current output are effectively solved. The electron emission source breaks through the bottleneck, supports peak current density exceeding 100 mA / cm under submicrosecond pulse, and realizes hundred microampere level steady-state current output under millisecond level long pulse.

1. The name of the design product: laser instrument (long pulse handle best-selling two NJBF-OTR-HP-02). 2. The use of the design product: for cosmetic laser instrument. 3. The design points of the design product: in shape. 4. The picture or photo that best indicates the design points: perspective drawing.

The invention discloses a double-frequency phased array composite pulse histotripsy system and a double-frequency phased array composite pulse histotripsy method. Comprising a double-frequency phased array transducer, a driving control module, a focus control module and a real-time monitoring module, wherein the double-frequency phased array transducer is a double-frequency hundreds of array element phased array transducer or a double-frequency split array transducer; the double frequency multiplication phased array transducer comprises a fundamental frequency array element group and a frequency multiplication array element group, the driving control module is used for outputting driving signals with corresponding frequencies to two groups of array elements, the focus control module is used for regulating and controlling the positions and the number of focuses, and the real-time monitoring module is used for tracking the effect; the double-frequency phased array composite pulse histotripsy system adopts a four-stage composite pulse time sequence to cooperatively control the working states of a fundamental frequency array element group and a frequency multiplication array element group, and is realized in combination with a multi-focus control strategy; according to the method, the defect of fogging zone front cavitation shielding possibly caused by double-frequency millisecond long-pulse tissue damage and the defect that instant B-ultrasonic monitoring is affected by slow bubble dissipation after treatment are overcome.

The application provides a gyrotron fast voltage regulating method based on long pulse power forbidden zone prediction, belongs to the field of nuclear fusion plasma heating, and comprises the following steps: setting a target power, determining the adjustment range of the anode voltage of the gyrotron based on the target power; starting the gyrotron until the power of the gyrotron reaches a safe advance point, the safe advance point is located before the starting boundary of the power forbidden zone, and the anode voltage of the gyrotron is adjusted to the target voltage at one time according to the adjustment range; under the target voltage, the power of the gyrotron rapidly climbs to the target power after crossing the power forbidden zone and enters long pulse steady-state operation; and the system is also provided; the power forbidden zone and the safe advance point of long pulse operation are identified through statistical analysis, the anode voltage is adjusted at one time predictively when the starting process reaches the safe advance point, the power forbidden zone is quickly regulated after the voltage of the gyrotron is raised, and the gyrotron directly reaches the target power stable region, so that the long pulse starting success rate is significantly improved, the failure risk is reduced, and the starting time is shortened.

This invention provides a fiber optic sensing system and method based on digital dechirping. A coupler splits a narrow-linewidth laser into two paths, which are transmitted to a sweep frequency modulation module and an optical mixer, respectively. The sweep frequency modulation module modulates the narrow-linewidth laser into sweep frequency long pulses, which are then transmitted to the sensing fiber. The sensing fiber returns scattered light to the optical mixer. The optical mixer coherently mixes the narrow-linewidth laser and the scattered light to generate four mixed-frequency beams. A data acquisition and processing module acquires the first and second coherent signals obtained after detecting the mixed-frequency beams by first and second balanced detectors to obtain complex scattered signals. The complex scattered signals are dechirped to obtain dechirped scattered signals. The dechirped scattered signals are converted into frequency-domain scattered signals and demodulated to obtain the perturbation magnitude at various locations on the sensing fiber. This invention has the advantages of high spatial resolution, low sampling frequency, and demodulation unaffected by fading, while also enabling long-distance sensing.

The invention relates to the technical field of radar signal processing, and provides a pulse compression blind area recovery method based on long and short pulse fusion, which comprises the following steps: transmitting a long pulse and a short pulse in a time division multiplexing mode, and obtaining echo signals of the long pulse and the short pulse; performing digital conversion on the echo signals of the long pulse and the short pulse to obtain long pulse baseband signal data and short pulse baseband signal data; substituting the long pulse baseband signal data and the short pulse baseband signal data into a dual-channel parallel signal processing module to obtain a processed long pulse signal and a processed short pulse signal; and selectively replacing data of the processed long pulse signal based on the processed short pulse signal to obtain long and short pulse fusion data. Through system-level waveform design, information fusion and a fusion strategy of long and short pulse signals, the whole-course consistent high-precision distance measurement capability from near to far is ensured, and the capability of distinguishing and detecting a multi-target scene and a strong and weak target coexistence scene in a blind area is greatly improved.

The invention provides a gyrotron rapid voltage regulation method based on long pulse power forbidden zone prejudgment, and belongs to the field of nuclear fusion plasma heating, and the method comprises the steps: setting target power, and determining the adjustment amplitude of the gyrotron anode voltage based on the target power; starting the gyrotron until the power of the gyrotron reaches a safety advance point which is located before the starting boundary of the power forbidden zone, and adjusting the anode voltage of the gyrotron to the target voltage at one time according to the adjustment amplitude; under the target voltage, the power of the gyrotron rapidly passes through a power forbidden zone and then climbs to the target power, and enters long-pulse steady-state operation; the invention further provides a system. A power forbidden zone and a safety advance point of long pulse operation are identified through statistical analysis, and the anode voltage is pre-judged and adjusted at one time when the safety advance point is reached in the starting process, so that the gyrotron quickly adjusts the voltage of the power forbidden zone after boosting, and directly reaches a target power stable zone; therefore, the long-pulse starting success rate is obviously improved, the fault risk is reduced, and the starting time is shortened.

This invention relates to a short-pulse loop induced voltage superimposed device and its assembly method; it solves the problems of long pulse loops and large inductance in existing induced voltage superimposed devices; it includes an induced voltage superimposed device body, which comprises a secondary magnetically insulated transmission line, a first-stage induction cavity, a secondary supporting vacuum cavity, and a ring-shaped short-circuit connecting piece; the secondary magnetically insulated transmission line includes a pulse superimposed section and a cantilever supporting section inner cylinder connected together, the first-stage induction cavity being sleeved outside the pulse superimposed section; the secondary supporting vacuum cavity being sleeved outside the cantilever supporting section inner cylinder, with one side connected to the cantilever supporting section inner cylinder and the other side connected to the first-stage induction cavity; the short-circuit connecting piece is made of conductive material; the short-circuit connecting piece is sleeved outside the pulse superimposed section, located within the gap, and its inner and outer sides are respectively attached to the outer wall of the pulse superimposed section and the inner wall of the first-stage induction cavity; this invention also proposes an assembly method for the above device.

The embodiment of the invention provides a modulation method and device for a three-level inverter and the three-level inverter, and the method comprises the steps: obtaining a target voltage vector which needs to be outputted by the three-level inverter in a modulation period; acquiring a narrow pulse suppression threshold value; judging whether the effective level pulse width corresponding to the target voltage vector is smaller than a narrow pulse suppression threshold value or not; when the pulse width of the effective level is smaller than a narrow pulse suppression threshold value, at least one switch assembly in a modulation period is conducted, and the originally dispersed short-pulse-width effective level is integrated into a continuous long-pulse-width effective level; wherein the duration of the long pulse width effective level is greater than the narrow pulse suppression threshold. According to the scheme, output voltage distortion caused by pulse suppression and dead zone effect superposition is eliminated, and the output waveform quality is remarkably improved.

The application discloses a nonlinear loop mirror passive mode-locked laser based on pulse chopping technology, which comprises a feedback loop module, a fiber-coupled beam splitter 5 and a Sagnac loop module, wherein the Sagnac loop module comprises an electro-optic modulator 6, a passive optical fiber 7 and a phase biasing device 13; the electro-optic modulator 7 is asymmetrically arranged in the loop and is used for chopping continuous light input from the feedback loop into pulse light and providing a linear phase shift of π; and the phase biasing device generates a linear phase difference to compensate for the deficiency of the accumulated nonlinear phase difference in the fiber loop. The application uses the pulse chopping technology of the electro-optic phase modulator based on the Sagnac loop to chop the continuous light or long pulse light input into the Sagnac loop into picosecond-level pulses, completes the mode-locking process, solves the self-starting problem of the NOLM passive mode-locked laser, can realize the output of ultrashort pulse width laser, reduces the complexity of the system and prolongs the service life of the device.

The invention discloses a power transmission fitting crimping area ultrasonic sensor control method and system based on dual-mode focusing, a storage medium and equipment, and relates to the technical field of power compression fitting ultrasonic detection, and the method comprises the steps: S1, system initialization: configuring pulse width parameters of two times of scanning; s2, executing first wave scanning: controlling the central core array element group to emit a first long pulse, and controlling the peripheral edge array element group to emit a first short pulse at the same time to form a central depth focusing sound field; s3, executing second wave scanning: controlling the center core array element group to emit a second short pulse, and controlling the peripheral edge array element group to emit a second long pulse at the same time to form an edge high-resolution focusing sound field; s4, data acquisition: synchronously acquiring and storing full-matrix echo data of two waves; and S5, fusion processing: carrying out fusion processing on the full-matrix data of the two waves, reconstructing a three-dimensional acoustic image in the crimping fitting, and carrying out automatic defect identification and positioning.

The present application belongs to the technical field of music devices, and relates to a seamless loading method and apparatus for an ultra-long pulse response, and a device and a medium. The method comprises: acquiring an input signal and an ultra-long pulse response file to be loaded; performing segmentation on the ultra-long pulse response file, so as to obtain a plurality of file segments; when a signal for switching a pulse response is received, performing a convolution operation on the input signal and a first file segment, so as to obtain a first signal segment, and outputting the first signal segment in real time; and sequentially traversing the file segments according to the sequence of the file segments, and outputting corresponding file segments in real time. Therefore, upon the completion of loading of a file segment, a subsequent signal segment has been output, thereby realizing seamless loading. By means of the present application, real-time convolution can be realized, and seamless loading of an ultra-long pulse response can also be realized.

The invention discloses a laser combined machining method and system for a micropore with a high depth-diameter ratio, and belongs to the technical field of laser precision machining. In a dry protective gas environment, a first laser parameter with high power and long pulse width is adopted to conduct primary punching on the workpiece, and a through prefabricated hole is formed; then forming a flowing water film covering an inlet of the prefabricated hole on the surface of the workpiece, and filling the prefabricated hole with water; and finally, the water environment is maintained, a low-power and short-pulse-width second laser parameter is switched, and secondary laser machining is conducted on the prefabricated hole filled with water. During machining, a laser beam enters a water column in the hole through water film coupling, and energy uniformly acts on the whole hole wall in the hole depth direction by utilizing the optical waveguide effect of laser on the interface of the water column and the hole wall, so that the taper is reduced, the hole wall is trimmed, and a high-quality target hole is formed. The contradiction that traditional laser drilling efficiency and quality are difficult to consider at the same time is effectively solved, and the advantages of high hole pattern quality, high process adaptability and the like are achieved.

The invention discloses an electromagnetic ultrasonic thickness measuring method based on low-voltage excitation, which belongs to the technical field of nondestructive testing, and comprises the following steps: selecting a sub-pulse signal; generating a random sequence and an output sequence based on a Golay code; dynamically selecting a first sub-pulse which does not contain zero level or a second sub-pulse which contains zero level according to values of adjacent bits in the random sequence, and synthesizing a pulse signal; multiplying the pulse signal by a random signal to obtain an output signal, and exciting an electromagnetic ultrasonic transducer after power amplification; and a receiving end multiplies the collected original signal by the inverse code of the pulse signal to obtain an actual receiving signal, and finally performs related processing on the actual receiving signal and the long pulse string signal to obtain a thickness measurement result. The receiving interval is dynamically inserted into the excitation signal, so that echo aliasing in detection of the thin-wall test piece is effectively avoided, and meanwhile, the requirement on excitation voltage is remarkably reduced on the premise of ensuring the signal-to-noise ratio.

The invention relates to a probe for detecting ionizing radiation (1), the probe comprising - a detector material; - a photodetector (3), optically coupled to a coupling face (4r) of the detector material and configured to generate a detection signal, the detection signal comprising pulses resulting from photons generated in the detector material under the effect of interactions of the ionizing radiation in the detector material; - a processing unit (10), configured to: - determine a duration of the pulses of the detection signal; - discriminate the pulses according to their duration, so as to identify short pulses (imp s ), the duration of which is shorter than a time threshold, and long pulses (imp t ), the duration of which is longer than the time threshold; - the probe being characterized in that the detector material is formed of an inorganic transparent matrix (4m) and particles of an inorganic scintillator material (4p).

This invention discloses an ultrasonic level measurement system, including an ultrasonic transducer, a transducer driving circuit, an echo receiving and processing circuit, and an MCU controller. The MCU controller's PWM port alternately generates two different pulse counts of PWM pulses at fixed time intervals, triggering the transducer driving circuit to drive the ultrasonic transducer to alternately emit two types of ultrasonic waves and receive the reflected echo signals of these two ultrasonic waves. The two types of ultrasonic waves include a long pulse train and a short pulse train. This ultrasonic level measurement system, by alternately generating two different pulse counts of PWM pulses, achieves simultaneous measurement of both long and short pulse trains. The combined detection of long and short pulse trains allows for a larger detection range and a wider application range. It combines the advantages of both long and short pulse trains, resolving the inherent contradiction between the small range of short pulse trains and the blind zone of short pulse trains' close-range detection.

The invention provides a water-guided laser double-beam processing system and method for a ceramic coating high-temperature component, and relates to the technical field of water-guided laser processing systems.The water-guided laser double-beam processing system for the ceramic coating high-temperature component comprises a laser generating system, a light path system and a water-guided laser coupling system; the laser generating system comprises a short-pulse-width laser and a long-pulse-width laser, the short-pulse-width laser is used for emitting short-pulse-width first laser, and the long-pulse-width laser is used for emitting long-pulse-width second laser; the light path system is located between the laser generation system and the water-guided laser coupling system and comprises a first reflector and a lens driving device connected with the first reflector, and the lens driving device is used for driving the first reflector to move between the first position and the second position. According to the water-jet guided laser double-beam processing system, high-quality and high-efficiency processing of a high-temperature component with a ceramic coating can be realized.

The application discloses a kind of electromagnetic ultrasonic thickness measurement methods based on low-voltage excitation, belong to nondestructive testing technical field, comprising: selecting sub-pulse signal;Generation random sequence and output sequence based on Golay code;According to the value of adjacent bit in random sequence, dynamically select the first sub-pulse without zero level or the second sub-pulse containing zero level, synthesize pulse signal;Pulse signal is multiplied with random signal to obtain output signal, after power amplification, electromagnetic ultrasonic transducer is excited;The actual receiving signal is obtained by multiplying the original signal collected by receiving end with the inverse code of pulse signal, finally, long pulse string signal is related to process to obtain thickness measurement result.The application inserts receiving interval dynamically in excitation signal, effectively avoids echo aliasing in thin-wall test piece detection, while significantly reduces the demand for excitation voltage under the premise of ensuring signal-to-noise ratio.

The invention relates to the technical field of laser processing, particularly provides a wall-aligning protection material for long pulse-ultrafast laser combined hole making, and further provides a preparation method of the wall-aligning protection material and a hole making method. The wall-facing protection material for long pulse-ultrafast laser combined drilling provided by the invention comprises the following preparation raw materials: a bi-component polymer matrix and inorganic particles, the bi-component polymer matrix comprises a component A and a component B; wherein the component A is fluorinated epoxy resin, the component B is a fluorine-containing amine curing agent, and the mass ratio of the component A to the component B is 10: (1-3); the mass ratio of the bi-component polymer matrix to the inorganic particles is (2-1): 1. The wall-to-wall protection material provided by the invention is formed by compounding the bi-component polymer matrix and the inorganic particles, can form a heterogeneous layered structure after being cured, and can effectively block the heat effect of long pulse laser and the high peak power of ultrafast laser.

The invention discloses a dissimilar metal cable joint welding and surface strengthening integrated processing method and device, after clamping and positioning of a dissimilar metal cable are completed at the same station, laser welding is carried out in a continuous or long pulse mode, protective gas is conveyed, and after it is confirmed that a molten pool is solidified through infrared temperature measurement and the temperature is reduced to a preset threshold value, the dissimilar metal cable is subjected to surface strengthening. Firstly, an acoustic impedance matching support is built, then a constraint water film is built, impact strengthening of a welding seam and a heat affected zone is completed through short-pulse high-peak mode laser, then the support and the water film are removed, air knife flow drying is conducted, and cable preheating and cooling can be completed according to needs; a device for realizing the method comprises a rack, a coaxial three-layer nozzle, a fluid switching valve, an optical fiber laser, a clamp with a temperature control flow channel, an acoustic impedance matching support unit and an infrared temperature measurement sensor, the optical fiber laser can switch a laser working mode, and the coaxial three-layer nozzle realizes collaborative conveying of laser, shielding gas, a water film and compressed gas. The supporting unit can be lifted as required to provide acoustic impedance matching support.