479 results about "Single pulse" patented technology

The invention discloses a partial discharge mode identification method and device, and relates to the field of power equipment fault diagnosis, and the method comprises the steps: collecting a partial discharge signal of high-voltage electrical equipment; preprocessing the collected data to obtain a single pulse signal; the method comprises the following steps of: generating a time-frequency graph of a single pulse on the basis of a continuous wavelet transform (CWT) method, and carrying out spatial feature extraction on the generated time-frequency graph by using a multi-scale convolutional neural network (MCNN); the features extracted by the MCNN are input into a bidirectional long short-term memory neural network (BiLSTM), and the time sequence characteristics of the partial discharge features are obtained; an attention mechanism is used to focus key segments of a splicing sequence output by the BiLSTM, global features are extracted, and the accuracy of pattern recognition is improved. According to the invention, mode identification can be carried out according to the collected partial discharge signal, the partial discharge type is judged, related personnel are helped to make a targeted maintenance plan, and long-term reliable operation of electrical equipment is guaranteed.

The embodiment of the invention discloses an etching method, an etching device and a solar cell module. The etching method comprises the following steps: controlling a light spot overlapping rate to be smaller than a preset overlapping rate; generating laser with preset performance parameters; shaping the laser into rectangular flat-topped light; and focusing the rectangular flat-topped light into a light spot with a preset size, and etching the perovskite functional layer in the to-be-etched cell according to the light spot overlapping rate. According to the technical scheme provided by the embodiment of the invention, the etching method is set, the perovskite functional layer is etched by adopting point contact, the laser beam adopts rectangular flat-topped light, each pulse independently acts on the film layer, single-pulse etching is performed on the perovskite functional layer in the to-be-etched cell, heat accumulation in an optical pulse overlapping region is avoided, and electrode deposition is more facilitated.

The invention discloses an insulation resistance and capacitance measuring circuit and method based on monopulse double-edge analysis, and relates to the related field of the electrical insulation online monitoring technology, and the circuit comprises a detected object and an insulation detection circuit. The insulation detection circuit comprises a controlled pulse voltage source, a coupling resistance network, a current sensor, a switch control module, a signal modulation circuit and a processor. The measurement method implemented based on the circuit comprises the following steps: injecting a common-mode voltage pulse into a transmission line of the power transmission system by adopting a pulse transmitter; pulse current response is collected in real time, a current oscillogram is drawn, and a three-point sampling method is introduced to record a current value for insulation impedance parameter calculation; according to a load condition, a double-edge verification method is applied based on a pulse current attenuation characteristic, and insulation impedance parameters including a resistive component and a capacitive component are independently calculated by analyzing a pulse current rising edge and a pulse current falling edge. According to the invention, non-intrusive synchronous monitoring of resistive and capacitive components of line-to-ground impedance is realized, and the detection precision is improved.

The invention provides a pulse passing rate improving method based on accumulation signal demodulation, and belongs to the technical field of nuclear electronics digital pulse processing. Comprising the following steps: performing baseline deduction and monopulse screening on a radiation field pulse signal; constructing a nuclear pulse signal model, fitting to obtain model parameters, and constructing a system response matrix; modeling a nuclear detection physical process into a mathematical model; solving a constraint optimization problem by using a non-negative least square method; and demodulating and calculating all the pulse signals including the stacked pulses which are discarded by stacking, so as to obtain delta pulses containing energy information. According to the invention, the accumulation signal which is abandoned by a traditional accumulation abandoning algorithm is demodulated, so that the technical problem of increasing the pulse passing rate is solved, and meanwhile, heavy peaks and high-energy trailing in an energy spectrum are inhibited. Compared with an existing accumulation discarding method, the pulse passing rate effect is remarkably improved on the premise that the energy spectrum accuracy is guaranteed.

Implementations of a method of detecting a plurality of radio pulses may include, using at least one signal processor: pre-processing a wideband intermediate frequency signal to form a channelized segment from a software defined radio; performing coherent single-pulse correlation using a spectrogram of the channelized segment; and performing multi-pulse combining with the spectrogram, and determining whether a pulse train including a plurality of radio pulses from a desired pulsed radio signal may be present in the spectrogram.

The invention provides an automatic frequency locking circuit based on a time-to-voltage converter and a phase-locked loop, and relates to the technical field of phase-locked loops, a first frequency-halving unit and a second frequency-halving unit respectively carry out frequency-halving processing on a reference signal and a frequency division signal of a current comparison period to obtain a first square wave signal and a second square wave signal; the first square wave signal and the second square wave signal are transmitted to the time-to-voltage converter; the time voltage converter comprises a phase generation unit, a first charge pump and a second charge pump, the phase generation unit generates an enable signal according to the first square wave signal and the second square wave signal, and the first charge pump and the second charge pump respond to control of the enable signal and collect single pulse signals from the first square wave signal and the second square wave signal respectively so as to supply power to the input end of the comparator; the comparator compares power supply voltages of the two input ends to achieve frequency comparison of the reference signal and the frequency division signal. And selection in a plurality of phase signals is not needed, and required digital circuit modules are reduced, so that the delay of the reference signal and the frequency division signal in the conversion process is reduced.

Disclosed in the present invention is a near-infrared wavelength scanning pulse fiber laser having a low mode-locking threshold. According to the present invention, a nonlinear amplifying loop mirror and a saturable absorber mirror architecture are used to achieve a low mode-locking threshold and ensure long-term mode-locking stability. After mode-locking self-starting, an automatic control module automatically achieves single-pulse operation by adjusting the intensity of retro-reflected pulses. In the single-pulse operation stage, different frequencies of radio frequency signals and different signal intensities are provided for an acousto-optic tunable filter by means of a radio frequency module to achieve a 1030 nm-1100 nm wavelength scanning and tuning range.

The invention discloses a green laser and a laser welding machine. The green laser comprises a pumping source, a first reflector, a laser crystal, a polarization beam splitter, a second reflector, a frequency doubling crystal, a telescope lens group and a spectroscope; the pumping source provides pulse pumping light; the laser crystal absorbs the pulse pump light to generate fundamental frequency laser in an infrared band, the fundamental frequency laser enters the polarization beam splitter and is split into P polarized light and S polarized light, the P polarized light is transmitted out of the resonant cavity, and the S polarized light is transmitted in the resonant cavity; and the telescope lens group converges the fundamental frequency laser to the frequency doubling crystal to generate frequency doubling laser of a green light wave band, and the frequency doubling laser is transmitted by the spectroscope and then is output. The green laser is used for spot welding of high-reflection materials such as copper and aluminum, the maximum single pulse energy can reach 5 J, the maximum peak power is 2 kW, the pulse width ranges from 0.05 ms to 5 ms, the problem of low absorption of the high-reflection materials to laser in the 1-micron wave band is solved, and the green laser is an edge tool for precise spot welding of the high-reflection materials.

The invention discloses a light path system based on a gas-filled hollow-core optical fiber, and the system comprises a spectrum broadening device which comprises a first gas extraction chamber, a gas inlet chamber and a second gas extraction chamber, the first gas extraction chamber and the second gas extraction chamber are located at the two ends of the gas inlet chamber respectively, and the first gas extraction chamber and the gas inlet chamber are separated through a first sealing part; the second air exhaust chamber and the air inlet chamber are separated through a second sealing piece; the spectrum broadening device is internally provided with a hollow-core optical fiber and is provided with at least one through hole penetrating through the pipe wall of the hollow-core optical fiber, the two ends of the hollow-core optical fiber penetrate through the first sealing piece and the second sealing piece respectively so that the two ends of the hollow-core optical fiber can be communicated with the first air suction chamber and the second air suction chamber respectively, and the through hole is located in the air inlet chamber. The two ends of the hollow-core optical fiber are subjected to air exhaust, so that the ionization rate and the self-focusing effect generated when the laser is output after the spectrum of the inflated hollow-core optical fiber is broadened can be remarkably reduced, the requirement for improving the power input of the laser is met, and a light path system can bear higher laser monopulse energy compression.

The invention relates to a method for detecting a marine corrosion primary process, which comprises the following steps of: constructing three vacuum chambers and connecting the three vacuum chambers by using vacuum pipelines to form a detection system; ultrafast femtosecond laser with the repetition frequency being 1 kHz, the single pulse energy being 6 mJ, the pulse width being 35 fs and the central wavelength being 800 nm is generated through a pulse amplifier; one beam of 2mJ enters a vacuum chamber pipeline to be transmitted as a pulse light beam for detection in the original process of ocean corrosion, the other beam of 4mJ is transmitted outside the vacuum chamber to be used as a pump pulse light beam, and 400 nm pump pulse laser is generated through frequency doubling of a BBO crystal; the pump light beam and the detection light beam are incident on a sample of a sample mechanism in the third vacuum chamber, then the pump light beam is blocked, and only the detection light beam is incident on the sample; xUV light beams reflected from the sample are subjected to spectral dispersion and then enter a CCD detector, and the dynamic response of the sample after being excited by the pump light is monitored by measuring the transmissivity, reflectivity or absorption change of the surface of the sample.

Implementations of disclosed systems and methods are capable of changing the frequency or other waveform characteristics dynamically based on receiving feedback about the effect of an electromagnetic pulse radiation on a target electronic device. Various implementations can be configured to emit electromagnetic pulses at a single radio frequency or a plurality of radio frequencies. For example, the frequency of the carrier electromagnetic radiation in a single pulse can change during the pulse interval. As another example, a single electromagnetic pulse can comprise a frequency comb with two or more frequencies.

The invention provides an adjustable pulse string laser and a design method thereof. The laser comprises a pump light fiber coupling focusing system, an endoscope, a laser crystal, a passive Q-switched crystal, an active Q-switched system and a laser output mirror which are sequentially arranged according to a light path, the adjustable pulse train laser is configured to control the number of pulse trains under the condition of the same dominant frequency or output the same pulse trains under different dominant frequencies through the equivalent length control of the passive Q-switched crystal and the modulation control of the active Q-switched system in a working state. According to the invention, through cooperation of the active Q-switching system and the passive Q-switching crystal, output of a main frequency and a pulse string is obtained in a mode of combination of active Q-switching and passive Q-switching, multi-time processing of the same point in fine processing is facilitated, and single pulse energy is constant, so that a pulse string laser scheme which is lower in cost and more ingenious and uncomplicated in structure is provided; the regulation and control flexibility is good, and the stability and reliability of the laser are higher.

The application discloses a method for simultaneously resisting suppressing interference forward-looking imaging of a missile-borne forward-looking array radar, adopts an array antenna in a cut-off track direction to receive echoes of a forward-looking area, and samples to obtain distance-pulse-array three-dimensional echo data; pulse compression in the distance direction is performed on the three-dimensional echo data, a pulse compression reference function and a migration correction factor are multiplied in the frequency domain, and high resolution in the distance direction is realized; multi-channel receiving data of each distance-pulse unit is selected, and is sequentially arranged to form a corresponding space snapshot of the unit; a covariance matrix of interference and noise is established, and the maximum likelihood estimation value of the target angle and amplitude in the interference environment is approximately solved by using an adaptive single-pulse algorithm on the space snapshot signal of each distance-pulse unit after distance pulse compression; and the angle measurement result is projected to the distance-azimuth domain, and through space coordinate conversion, a two-dimensional forward-looking imaging diagram is obtained. The application realizes high-resolution imaging of a forward-looking target while effectively suppressing main lobe suppressing interference.

The invention belongs to the field of particle accelerator microwaves, and particularly relates to a C-band compact spherical microwave pulse compression device which comprises a shell, a dual-polarization mode coupler and a circular waveguide, a spherical energy storage cavity is formed in the shell, and the circular waveguide and the spherical energy storage cavity are communicated through a coupling hole; the dual-polarization mode coupler comprises a rectangular waveguide, a butterfly-shaped matching section and a cylindrical matching section. According to the klystron radio frequency pulse compression circuit, the radio frequency pulse with the pulse width of 2.5 microseconds of the klystron can be compressed to 300ns, the average power gain in a single pulse is more than 4 times, the peak power gain is 6.3 times, and the compression efficiency is about 54%. According to the dual-polarization mode coupler, the functions of power distribution, mode conversion and polarization mode generation are synchronously realized, a TE10 mode in a rectangular waveguide is converted into two polarization TE11 modes which are equal in amplitude and orthogonal in phase, and then the two orthogonal TE114 modes are excited in a spherical energy storage cavity.

A by-product deposit removal device is provided that can enhance the effect of removing by-product deposits that occur on the electrodes of a storage battery. [Solution] The by-product deposit removal device includes an electrode connection part connected to the electrodes of a storage battery, and a removal signal generation part that generates a by-product deposit removal signal using current extracted from the electrodes of the storage battery via the electrode connection part. The removal signal consists of a periodic pulse current, and when the amplitude value of the rising edge of a single pulse current waveform of the removal signal is H1 and the amplitude value of the undershoot after the falling edge of the pulse current waveform is H2, H2 is 0.2 to 1.0 times H1. Furthermore, when the time width of the rising edge of the pulse current waveform is T1 and the time width of the falling edge accompanied by an undershoot is T2, T2 is 0.02 to 0.2 times T1.

The application provides a leaky-wave antenna array based on a multimode substrate integrated waveguide coupler, relates to the technical fields of wireless communication and radar, and comprises a dielectric substrate, a multimode substrate integrated waveguide coupler and two leaky-wave antenna units. The multimode substrate integrated waveguide coupler is integrated on the dielectric substrate and is configured to excite modes and modes of the substrate integrated waveguide respectively in the same frequency range, generate even-mode signals with equal amplitude and in-phase and odd-mode signals with equal amplitude and opposite phase. The two leaky-wave antenna units are symmetrically arranged on the two sides of the upper surface metal layer of the dielectric substrate and are connected with two output ports of the multimode substrate integrated waveguide coupler respectively. The two leaky-wave antenna units are configured to radiate a wave beam and a difference wave beam in response to the even-mode signals and the odd-mode signals. The application solves the problem of low measurement accuracy of a traditional single-pulse antenna, has the technical effects of simplifying the design of a feed network, improving radiation performance and thus improving measurement accuracy.

The invention provides a multifunctional integrated waveform design method based on a multi-sub-pulse structure, and belongs to the field of radar detection communication anti-interference integration. Specifically, an information transmission modulation method based on joint modulation of partial phase modulation in sub-pulses and waveform position arrangement modulation between sub-pulses is proposed, and the communication rate is remarkably improved; intermittent sampling forwarding interference is effectively suppressed by using the orthogonal characteristic of waveforms between sub-pulses. A signal processing method based on monopulse multifunctional integrated echoes is provided, and Doppler tolerance is enhanced; according to the invention, the integration of detection, communication and anti-interference functions is realized, the detection and communication requirements of a high-speed moving target are met, and the engineering application value is high.

This invention provides a split Hopkinson bar device for achieving single-pulse loading, comprising an incident bar, a transmission bar, an incident wave-catching unit, and a stress wave generating unit. The incident wave-catching unit includes an incident wave-catching sleeve and an absorbing bar. One end of the absorbing bar is spaced apart from the incident bar flange, and the other end is connected to the absorbing bar flange. The incident wave-catching sleeve is fitted around the absorbing bar, with its two ends respectively fitting against the absorbing bar flange and the incident bar flange. The compressive stress wave generated by the stress wave generating unit is reflected by the incident bar flange to form a tensile stress wave. After loading the sample, a portion of the stress wave is reflected back as a compressive wave and absorbed by the incident wave-catching unit. This solves the problem of multiple reflections and interference in traditional Hopkinson bars, achieving pure single-pulse tensile loading. The device is compact, has high energy utilization, and is suitable for testing the dynamic mechanical properties of materials.

The invention belongs to the technical field of laser precision machining and control, and particularly relates to a femtosecond laser single-point trigger control system and method based on subnanosecond synchronization, and the method comprises the following steps: S1, building a system synchronization clock locked with a femtosecond laser pulse signal phase; the specific mode of establishing the system synchronous clock is that phase locking is carried out on pulse synchronous signals or frequency division signals output by an internal high-frequency clock source and a femtosecond laser source through a digital phase-locked loop technology, and the low-jitter system synchronous clock which is strictly synchronous with a laser pulse sequence is generated. According to the invention, a system clock locked with a laser pulse phase can be generated through a digital phase-locked loop, and the influence of inherent frequency drift of a laser and circuit delay temperature drift is effectively overcome by combining real-time delay calculation based on a prediction algorithm and a high-resolution DDS delay line technology; the synchronization precision between the triggering moment of the single pulse and the external instruction is stabilized at the subnanosecond level, and the requirement of leading-edge application for the extreme time sequence precision is met.

According to the corrosion cleaning method and corrosion cleaning system for the surface of the electrical equipment, continuous / pulse laser composite cleaning is conducted on the surface of the electrical equipment through semiconductor continuous laser and pulse laser, and different cleaning strategies are designed according to different corrosion layers of different materials; a set of high-efficiency, high-quality, low-damage and low-energy-consumption laser cleaning strategy is formed, multi-scene laser rust removal of electric power equipment is achieved, the maintenance efficiency and safety of electric power facilities are improved, on one hand, the problems that single-pulse laser energy attenuation is large, energy density is not enough, and long-distance electrified cleaning cannot be achieved can be solved, and on the other hand, the maintenance cost is reduced. On the other hand, the defect that the surface quality of a workpiece is poor due to pure continuous laser cleaning can be overcome, efficient and high-precision remote cleaning is achieved, in addition, semiconductor continuous laser is adopted, the needed equipment is small in size and mass, the light-weight design of the laser cleaning equipment is achieved, and the laser cleaning equipment is low in price and can be better accepted by users.

The invention discloses a silicon carbide color center laser processing and multi-mode real-time in-situ detection optical device, and belongs to the field of quantum optics and quantum precision measurement. The system comprises a laser processing system, a confocal laser transmission and spectrum detection module, a single photon source detection module, a fluorescence imaging module and a data acquisition processing and control system. Monopulse laser emitted by a laser processing system is used for processing a preprocessed silicon carbide wafer, after silicon carbide is irradiated by femtosecond laser, a light source is switched to excite a defect position, and whether a color center is generated or not and whether the prepared color center is a single photon source or not are detected through a confocal laser transmission and spectrum detection module and a single photon source detection module; and the fluorescence imaging module monitors the forming process of the color center in real time and transmits an acquisition result to the upper computer for processing and analysis. The forming condition of the color center can be monitored in real time and in situ, the yield of the color center and the machining efficiency are improved, and meanwhile it is guaranteed that the finally machined color center is more likely to become a high-quality single photon source.

The invention provides an excimer laser monopulse energy real-time detection system and a calibration method thereof. The excimer laser monopulse energy real-time detection system comprises a real-time energy detection module, an FPGA energy control module, a laser air pressure detection and adjustment module, a power supply voltage pulse width adjustment module and an excimer laser. Comprising the following steps: S1, collecting a monopulse energy value in real time; s2, performing transmission filtering processing on the energy value, and performing optimal estimation on laser monopulse energy data; s3, comparing the energy value with a target energy value, and calculating an energy error; s4, calculating a control signal; s5, adjusting the discharge voltage, the pulse width and the gas pressure to enable the output energy to approach the target value; and S6, repeating the steps. Therefore, the problem that the single pulse energy of the excimer laser cannot be calibrated in real time and at high precision can be solved, the single pulse energy of the excimer laser is always kept within the set precision range under various complex working conditions, and the quality and the stability of laser in skin treatment are improved.

The invention discloses an ultrahigh space-time resolution detection imaging method and system, and relates to the technical field of optics, and the method comprises the following steps: carrying out the photon space-time dynamic modulation of multi-wavelength short-short pulse laser, and enabling the number of photons in a single-pulse local irradiation field to be in a single-photon / few-photon state; the patterned photons subjected to photon space-time dynamic modulation are distributed and miniaturized to a sample containing fluorescent molecules for double / multi-photon excitation under few-photon irradiation, and double / multi-photon fluorescence is collected; through a high temporal-spatial resolution detection means, spectral information, life information and spatial position information of dual / multiphoton fluorescence are obtained, fluorescence information in a field of view is reconstructed, and super-resolution imaging and positioning of the whole field of view are completed. According to the invention, large-view-field, high-frame-frequency and super-resolution fluorescence detection imaging can be realized, and opportunities are provided for solving the major scientific problem of optical diffraction limit and realizing super-resolution fluorescence microscopy technology innovation.

A layered pulse generator for a vertical-cavity surface-emitting laser (“VCSEL”) driver is disclosed consisting of three elements: a low-speed pulse generator, a high-speed pulse generator, and a pulse generator selector, all of which are on-chip with the VCSEL driver. By providing these elements on-chip, overall system power and complexity are reduced while allowing for significantly higher pulse train frequencies compared with known systems. The high-speed pulse generator is capable of generating pulses faster and with higher resolution than that of the low-speed pulse generator. The high-speed pulse generator uses multiple clock outputs, phase shifted, and synthesized into a single pulse waveform capable of wide-ranging frequencies, duty cycles and pulse counts.

The invention discloses a broadband oscilloscope input overvoltage protection circuit which is characterized in that an input signal V1 after voltage division attenuation is sent to a shift circuit, so that the input signal V1 is shifted to be within two comparison voltages, when the voltage of an input signal V2 is within the two comparison voltages VH and VL, a low level is output to a D trigger circuit, and when the voltage of the input signal V2 is outside the two comparison voltages VH and VL, a high level is output to the D trigger circuit. When input signal overvoltage occurs, the D flip-flop circuit outputs a high level to the enable end of the switch control circuit, so that output switch switching control signals of the switch control circuit are all low levels, and the switch circuit disconnects the input signal from a post-stage circuit. The shift circuit is adopted to shift the input signal V1 after voltage division attenuation, then comparison is carried out, and the input signal V1 exceeding the range of two comparison voltages VH and VL is overvoltage, so that waveform amplitude does not need to be converted into a waveform amplitude effective value signal, integral time delay does not exist, and the response speed is high; the problem that a single-pulse overvoltage signal cannot be detected due to the fact that a voltage measurement result is small is solved, and the problem that a broadband oscilloscope is prone to being damaged due to the fact that large voltage is input into a low-resistance channel is further solved.

The invention relates to an atmospheric pressure glow discharge atomic emission spectrum analysis device and a detection method. The device comprises an ultrasonic atomization-membrane desolvation sampling system, a high-voltage power supply, an excitation source and a spectrum detection system. The high-voltage system outputs pulse voltage and a synchronous TTL level signal; and the TTL level signal is connected to a detection system. The excitation source is atmospheric pressure glow discharge micro-plasma, and the stable glow discharge micro-plasma can be maintained under atmospheric pressure. The monopulse modulation analysis device provided by the invention effectively solves the problem of insufficient heavy metal excitation efficiency caused by the fact that the discharge current is limited to 20-35mA in the existing atmospheric pressure glow discharge technology. The ultrasonic atomization-membrane desolventizing sampling device can directly sample a liquid sample which is not suitable for volatilization, complex pretreatment is not needed, and the desolventizing membrane is used for removing water from aerosol, so that sensitive and rapid atomic analysis is realized. The device is suitable for efficient detection of trace metal elements, and has the advantages of being simple in structure, low in cost, suitable for real-time online analysis and the like.

The invention provides composite laser shock peening equipment and a turbine blade laser shock peening method. The composite laser shock peening equipment comprises a first laser, a second laser, a third laser and a fourth laser, wherein the first laser outputs large-energy laser shock with single pulse energy larger than 1J to a first target area; the second laser outputs small-energy laser shock with single pulse energy at dozens of to hundreds of mJ levels to a second target area; the movement system is used for clamping and moving the to-be-machined part to the first target area or the second target area; the water restraint loading system is used for applying a water restraint layer; and the control system is used for adjusting working parameters of the modules. The invention further provides a turbine blade composite laser shock peening method implemented through the equipment, and the problem that double requirements of improvement of deep residual compressive stress and improvement of high surface residual compressive stress cannot be considered in a single process mode is solved through a large-energy and small-energy composite laser shock peening process.

The invention provides an RB-SiC polished surface pressure stress strengthening device and an implementation method thereof, and the method comprises the following steps: a femtosecond laser generates an ultrashort pulse laser beam, and the ultrashort pulse laser beam passes through an optical shutter, a beam expander, a laser power attenuator, a reflector, a scanning galvanometer and an F-theta mirror and is finally focused on the surface of an RB-SiC sample. The RB-SiC sample is fixed on an XY displacement platform, the XY displacement platform and a Z axis are adjusted, and laser is focused on the to-be-irradiated surface of the RB-SiC sample; introducing high-pressure and high-speed nitrogen to protect the surface of the sample; a laser scanning path, a scanning speed and scanning times are designed, laser pulse frequency and average power of light emitted by a femtosecond laser and an attenuation coefficient of a laser power attenuator are set, so that laser single pulse energy density is slightly lower than an ablation threshold value of the sample under laser and scanning parameter setting, and finally, laser irradiation on the surface of the RB-SiC sample is started. Pressure stress strengthening can be achieved on the RB-SiC polished surface after sub-ablation threshold femtosecond laser irradiation, and the fatigue strength of a workpiece made of the RB-SiC material can be improved.

The invention provides a sample positioning method suitable for an X-ray free electron laser monopulse experiment, and relates to the field of X-ray free electron laser experiments. The method comprises the following steps: step 1), acquiring an initial sample image of a sample to be detected; step 2), processing the initial sample image to obtain a target sample image; 3) identifying the contour of the target sample in the target sample image, and obtaining the pixel coordinates of the target sample; 4) performing visual proportion calibration on the target sample image to obtain a visual proportion coefficient; 5, based on the visual proportionality coefficient and the pixel coordinates of the target sample, the positioning coordinates of the target sample on the experimental platform are calculated in combination with datum point information.According to the method, accurate coordinate mapping and positioning can be achieved, the experimental performance is improved, and automation of the experimental process is promoted.

The application belongs to underwater acoustic detection technology, and particularly relates to a sonar single-pulse three-dimensional imaging method based on an array element, a storage medium and an electronic device. The method comprises the following steps: constructing a transmitting-receiving array element system, a first array element transmits and receives signals, and the remaining array elements only receive signals, a rectangular coordinate system is established with the first array element as the origin, and the remaining array elements are located on the coordinate axes; a single echo signal is obtained after a transmitted signal is reflected by a single detection target and received by a pth array element, and frequency domain sampling signals of the single echo signal are obtained through orthogonal mixing, pulse compression and Fourier transform processing; the frequency domain sampling signals of the pth array element are the sum of frequency sampling signals of echo signals at M distance gates; the distance of the detection target to the array element is calculated according to the frequency domain sampling signals, the included angle of the detection target with x, y and z is obtained according to a geometric relationship, and a three-dimensional imaging result of the detection target is determined. The application can realize three-dimensional imaging with a single pulse, reduces manufacturing cost, and has low requirements on the moving precision of the sensor.