371 results about "Wave structure" patented technology

The invention discloses a seismic surface wave suppression method based on EWT-Curvelet, and belongs to the technical field of seismic exploration data processing. The method comprises the following steps: firstly, performing empirical wavelet transform (EWT) on post-stack seismic data channel by channel, extracting a frequency localized modal component through adaptive spectrum segmentation, and constructing a surface wave noise model; then converting the model to a curvelet domain, performing physical constraint filtering at a specific scale and in a nearly horizontal direction, and combining pixel connectivity analysis to suppress a continuous noise region; and finally, reconstructing and optimizing noise through inverse transformation and removing the noise from the original data. The method has the advantages that the modal aliasing problem is solved through channel-by-channel adaptive spectrum segmentation, a surface wave energy dense region is accurately locked by curvelet domain scale-direction combined filtering, isolated effective signals are protected in combination with connectivity analysis, high-precision suppression of surface waves is efficiently achieved in a non-iterative mode, meanwhile, the structural integrity of reflected waves is kept, and high-precision suppression of the surface waves is achieved. The seismic section signal-to-noise ratio and the geological interpretation precision are remarkably improved, and the method is suitable for land seismic exploration data processing.

A phased antenna array in a package is provided. The phased array antenna in a package comprises an antenna array with an integrated passive beamformer network, and at least one actuation mechanism. The passive beamformer network comprises at least one phase shifter, and each of the at least one phase shifter comprises a transmission line having a slow-wave structure and a ceramic. Each of the at least one actuation mechanism comprises a magnet and an electromagnet coil, where the magnet is coupled to the ceramic. The at least one actuation mechanism configured to increase or decrease a gap between the transmission line and the ceramic.

The invention provides an anti-wave structure and an anti-wave method suitable for offshore new energy engineering, and belongs to the technical field of offshore new energy engineering, the anti-wave structure comprises a mounting cylinder fixed on the bottom end face of an offshore equipment platform, and an energy consumption assembly is arranged on the mounting cylinder; the energy consumption assembly comprises an outer side fixing ring and a friction metal ring, the outer side fixing ring is fixed to the outer wall of the mounting cylinder, the friction metal ring is arranged on the mounting cylinder in a sleeving mode and located below the outer side fixing ring, and the top of the friction metal ring is rotationally connected with the outer side fixing ring through a fixing ring sleeve; an annular friction strip is arranged at the position, close to the bottom of the friction metal ring, of the friction metal ring, and the surface of the annular friction strip is attached to the rough face in the friction metal ring. A wave receiving disc is arranged at the bottom end of the friction metal ring. According to the structure, through the deformation-friction synergistic effect, the wave impact effect of the offshore equipment platform under the complex sea condition is effectively weakened, and the wave resistance of the offshore equipment platform is improved.

The invention discloses a three-dimensional wave liquid level visual intelligent reconstruction evaluation system, and belongs to the field of ocean engineering monitoring. The system comprises an image acquisition module, an image stereoscopic vision processing module, an attention-enhanced reconstruction neural network module, a camera attitude evaluation module, a visualization and output module and a hydrodynamic parameter analysis module. An image is collected through a fixed baseline binocular camera system, after preprocessing, a neural network fused with a multi-scale attention mechanism is utilized to reconstruct a three-dimensional wave structure, coordinate system conversion is achieved in combination with self-supervised attitude evaluation, and finally hydrodynamic parameters such as significant wave height and a three-dimensional velocity field are extracted and visualized. The system does not need explicit calibration and large-scale data, has high automation, real-time performance and strong environmental adaptability, can be deployed on various platforms, and significantly improves the precision and engineering applicability of non-contact wave observation.

The invention belongs to the technical field of ocean engineering, and particularly relates to a potential flow-viscous flow real-time coupling hydrodynamic analysis method and system for a floating body with a heaving plate. The method comprises the following steps of: 1, establishing a free surface potential flow model based on a three-dimensional potential flow theory, simulating wave-structure interaction, ignoring a viscous effect, converting a frequency domain result of a hydrodynamic load into a time domain load through a frequency-to-hour method, and taking the time domain load as an input for solving a motion state; 2, establishing an unbounded viscous flow CFD model, viscous force not covered by a potential flow model and an updated unbounded turbulent flow field around the heaving plate, and calculating the viscous force of the heaving plate; 3, establishing an unbounded potential flow model, and separating a force component repeated with the potential flow from a viscous flow result; 4, integrating the potential flow force and the viscous force to solve a floating body motion equation, iteratively updating the motion state and feeding back the motion state to the two solvers. The method is used for solving the problems that the efficiency is correspondingly reduced if the precision is improved and the precision cannot meet the requirement if the efficiency is improved in the prior art.

The invention belongs to the technical field of antennas, and discloses a dual circularly polarized leaky-wave antenna based on a substrate integrated waveguide, which comprises a feed structure and a radiation structure, the feed structures are symmetrically arranged at the two ends of the radiation structure, and the feed structures and the radiation structure are substrate integrated waveguides; the feed structure is used for converting received external electromagnetic energy into guided electromagnetic waves and has the characteristic of widening impedance; wherein a gradient coplanar waveguide transmission line is designed in the feed structure; the radiation structure is used for converting the guided electromagnetic waves transmitted by the feed structure into circularly polarized electromagnetic waves in a free space; wherein a grid window leaky wave structure is designed in the radiation structure; by combining the leaky-wave antenna and the substrate integrated waveguide technology, the gradient coplanar waveguide transmission line is designed on the feed structure, and the grid window leaky-wave structure is designed on the radiation structure, so that the millimeter wave working frequency band requirement is met, and the antenna has the characteristics of wide axial ratio bandwidth, low side lobe, large scanning range, low profile and low cost.

The invention discloses a multi-beam VICTS antenna and a communication terminal, and the multi-beam VICTS antenna is of a multi-layer structure, and comprises a continuous cross section node slot radiation layer, a slow wave structure wave guide layer and a microstrip Rotmann lens feed network layer which are sequentially arranged from top to bottom. An air gap between the continuous section nodal gap radiation layer and the slow wave structure wave guide layer forms a quasi-plane parallel plate waveguide. An electromagnetic wave signal emitted by a satellite antenna enters a quasi-planar waveguide formed by the continuous cross section and the slow wave structure wave guide layer through a gap in the continuous cross section joint gap radiation layer, and electromagnetic waves are transmitted in the quasi-planar waveguide and are sent to the microstrip Rotmann lens feed network through the connection waveguide. And the beam is output from the beam port of the microstrip Rotmann lens. The multi-beam VICTS antenna provided by the invention can utilize multi-beam scanning in the same time period, has larger space coverage capability, and is beneficial to quick satellite finding when a communication-in-moving system is started and quick satellite recapturing after a satellite signal is lost.

A wheel disc for vehicle wheels manufactured by flow forming, in particular for passenger cars, which has a stretched disc transition surface subsequently provided with ventilation holes and a radial outer disc edge. All ventilation holes are located in the transition surface and are attached by punching or cutting. In order to improve the competitiveness of vehicle wheels made of steel or other materials suitable in particular for cold forming compared to cast vehicle wheels made of aluminium, the transition surface is provided with several changes in material thickness generated during flow forming by displacement of the tool and, viewed in the radial direction, effecting a wave structure on the surface facing the tool during flow forming. The surface provided with the wave structure can in particular form the non-visible inner side of a vehicle wheel, but can also form the visible side. In addition, the opposite surface can also be provided with a wave structure.

The invention discloses a reinforced photoelectric composite cable of a coal mining machine, which belongs to the technical field of cables, and comprises a composite cable core structure, an armored protective layer and a sheath system, and the armored protective layer comprises a first steel belt, a second steel belt and a metal net braid layer, a third steel belt which is continuously bent to be of a wave structure is arranged in a cavity formed by the first steel belt and the second steel belt, the wave troughs of the third steel belt make contact with the inner wall of the first steel belt, and the wave crests of the third steel belt make contact with the inner wall of the second steel belt. The cable can be subjected to multi-dimensional mechanical property collaborative optimization under complex working conditions, the purpose of graded unloading is achieved through deformation of the steel plate, the situation that a traditional structure generally depends on rigid resistance of an armor layer is not needed, the flexibility is considered while the mechanical property is guaranteed, and the cable adapts to frequent bending scenes; and the long-term stable operation of the cable in a severe mine environment is further ensured.

The invention provides a method, device and equipment for exciting a single-mode guided wave in grounding flat steel, and belongs to the technical field of engineering structure detection, and the method comprises the steps: building a two-dimensional section model of the detected grounding flat steel through finite element analysis software, defining boundary conditions for the width and thickness in the two-dimensional section model, and carrying out the mode analysis and solving of the grounding flat steel. Performing statistics to obtain frequency-wave number data; based on frequency-wave number data, a phase velocity frequency dispersion curve and a group velocity frequency dispersion curve are drawn, after a corresponding mode is selected, excitation of specific single-mode guided waves is achieved in combination with a wave structure diagram and the application size and direction of a modulation load, and due to the fact that a two-dimensional section model including a width condition is obtained through finite element analysis, the excitation accuracy of the guided waves is improved. The phase velocity frequency dispersion curve and the group velocity frequency dispersion curve are recalculated, the corresponding wave structure diagram is combined, and the appropriate modal guided wave under the specific frequency is reselected for single excitation, so that the appropriate modal can be more accurately selected, and the defect detection accuracy is improved.

The invention discloses a high-power super-radiation light-emitting diode based on three-section integration and a preparation method, belongs to the technical field of structures and processing of optoelectronic devices, and solves the technical problem of directional amplification of optical power output by a super-radiation light-emitting diode based on a three-section integration structure. The diode is of a three-section integrated structure, and the three-section integrated structure is of a cascade structure formed by sequentially connecting a DBR grating area, a J-shaped ridge waveguide super-radiation light-emitting diode area and a semiconductor optical amplifier area. The three-section integrated structure is provided with multiple layers of structures from bottom to top, and the multiple layers of structures are a lower electrode, a lower substrate, a lower limiting layer, an MQW multi-quantum well active layer, an upper limiting layer, an upper substrate and an upper electrode in sequence. And the DBR grating region comprises a waveguide layer and a transverse tapered waveguide structure of a cladding. The J-shaped ridge waveguide super-radiation light-emitting diode area is composed of a bent waveguide part and a straight waveguide part. The semiconductor optical amplifier area is of a conical traveling wave structure. The optical power amplifier is suitable for the fields of optical coherence tomography and optical fiber gyroscopes, and optical power amplification is achieved.

The invention discloses an elastic Bragg breakwater structure response prediction method, and belongs to the technical field of ocean engineering structure dynamic response prediction, and the method comprises the steps: obtaining the front and rear wave surface elevation and motion response data of a breakwater; a double-flow attention mechanism based on physical prior guidance is constructed, and wave-structure interaction is decoupled into two parallel attention flows of structural dynamic evolution and wave-structure coupling feedback; a self-attention mechanism is combined with a time decay physical prior coding structure motion feature, and a bidirectional cross attention mechanism based on a resonance characteristic is combined with a wave-structure phase relation physical prior coding coupling feature; the double-flow features are adaptively integrated through a global context fusion module, and a multi-step prediction sequence is output through linear layer decoding; and a time-frequency domain joint loss function optimization model is adopted, so that the prediction precision is improved. According to the method, physical prior is explicitly embedded into an attention mechanism and is improved by more than 16% compared with an optimal baseline model, and the generalization ability is enhanced by more than 13% under the working condition that waves do not appear.

The utility model relates to the technical field of vacuum electronics, in particular to a trapezoidal staggered gate slow-wave structure of a circular electron beam channel, which comprises a metal shell, trapezoidal upper metal gates and trapezoidal lower metal gates which are symmetrically arranged in a staggered manner are arranged in the metal shell, and the upper metal gates and the lower metal gates are respectively provided with arc-shaped concave holes; along the electron transmission direction, the concave holes respectively penetrate through the upper metal gate and the lower metal gate, and the upper and lower concave holes are enclosed to form a circular electron beam channel. Through the slow-wave structure, the bandwidth of the slow-wave structure can be increased, so that the longitudinal electric field in the slow-wave structure is enhanced.

The utility model discloses a kind of based on three-layer separation's multiphase separator, including tank, its one side is equipped with air inlet, the top of the tank is equipped with exhaust port, and the bottom of the tank is equipped with drain and oil outlet respectively;Inlet baffle, the inlet baffle is set in the tank and is close to the one end of the air inlet;Rectifier, it is installed in the tank top;Overflow partition, it is vertically installed in the tank, and with the tank top clearance is kept, forms a overflow port;Anti-wave structure, it includes multiple anti-wave board, driving part and flow control part, multiple the anti-wave board equidistant installation in the tank, and the driving part is set in the tank outside, and its output end extends to the tank inside.The utility model plays the beneficial effect of: solve the technical problem that the hole diameter of hole on anti-wave board in three-phase separator in prior art cannot be adaptively adjusted, resulting in finally affecting the technical problem of equipment oil outlet effect.

The invention provides a permeable breakwater and a design method thereof, and relates to the technical field of permeable breakwater. Aiming at the lack of a design method for high-precision environment coupling and high-accuracy structure stress prediction during design of a permeable breakwater in the prior art, the method comprises the following steps: establishing a wave-structure-foundation coupling model based on structure stress data, environment soil characteristics and a transmission coefficient of waves; s5, selecting a wave-structure-foundation coupling model, simulating different structure parameter combinations based on the wave-structure-foundation coupling model, and when the simulation results do not meet the target requirements, circularly executing the steps S2 to S5 until the simulation results meeting the target requirements are screened out, and determining a corresponding final structure parameter combination. The cooperative working mechanism of the reduction foundation and the pile foundation is realized, the dynamic interaction of the wave load and the structural response is simulated, and the environmental coupling precision and the structural stress prediction accuracy are improved.

A filter material for manufacturing a segment of a smoking article is described. The filter material includes a hydro-entangled nonwoven, which includes fibers. The fibers are selected from the group consisting of pulp fibers, fibers of regenerated cellulose and mixtures thereof. These fibers are contained in the nonwoven in an amount of 50% to 100% of the mass of the hydro-entangled nonwoven. The nonwoven is in the form of a web, has a longitudinal direction in the running direction of the web, a cross direction orthogonal thereto and lying in the plane of the web and a thickness direction orthogonal to longitudinal direction and the cross direction. The nonwoven is shaped to have a wave structure in the plane formed by the cross direction and the thickness direction with a wave height from 50 μm to 1000 μm and a wave length from 150 μm to 5000 μm.

The utility model discloses an anti-slip dilatation balloon, which relates to the technical field of medical balloons, and comprises a sheath tube, a balloon and a soft head, the balloon is fixed between the sheath tube and the soft head, the two ends of the balloon are respectively and fixedly connected with the sheath tube and the soft head, fiber lines are arranged on the surface of the balloon, the fiber lines are divided into transverse limit lines and longitudinal limit lines, and the transverse limit lines and the longitudinal limit lines are connected with the soft head. The balloon is provided with the fragrance line which enables the balloon to deform, so that the balloon has good anti-falling and anti-skidding effects when the balloon is used for expanding a channel, the balloon is prevented from sliding off and moving, the expansion effect is prevented from being affected, gas on the two sides of the balloon can circulate, and the balloon is prevented from falling off and sliding off when the balloon is used for expanding the channel. The air pressure difference between the two sides of the expansion channel is eliminated, pain of a patient is reduced, the balloon can serve as a mark of the insertion depth and slippage, and medical staff can judge conveniently.

The invention discloses a slow wave structure loaded with a wave-absorbing metamaterial and a traveling wave tube. The technical field of microwave electronics; comprising a closed metal cavity structure for transmitting electromagnetic waves and a wave-absorbing metamaterial structure loaded on the wall surface of the closed metal cavity structure, the working frequency band of the wave-absorbing metamaterial structure is the non-working mode frequency band of the slow wave structure; according to the scheme, structural improvement is carried out on the basis of a traditional slow wave structure, and non-working mode signals are filtered out by loading the wave-absorbing metamaterial of the non-working mode frequency band in the slow wave structure; the loading of the wave-absorbing metamaterial has no influence on the working mode of the slow wave structure, but absorbs the non-working mode to achieve the filtering effect, thereby achieving the effect of inhibiting mode competition.

This invention discloses a microwave-millimeter-wave structured multiplexed antenna for vehicle communication, comprising a microwave half-mode Vivaldi antenna, a millimeter-wave vertically polarized oblique-fire phased array, and a millimeter-wave horizontally polarized oblique-fire phased array. The structured multiplexed antenna constructed by this invention embeds the vertically polarized and horizontally polarized millimeter-wave oblique-fire phased arrays into the inherent structure of the ultra-wideband microwave half-mode Vivaldi antenna, forming a seamlessly integrated high-frequency-ratio multi-band antenna. The vertically polarized and horizontally polarized millimeter-wave oblique-fire phased arrays have the characteristics of wide bandwidth, simple structure, and low profile, while the microwave Vivaldi antenna has the characteristics of ultra-wideband bandwidth and miniaturization. The vertically polarized millimeter-wave antenna and the horizontally polarized millimeter-wave antenna respectively utilize multi-mode resonance superposition and equiphase surface adjustment techniques to achieve a stable 45° oblique-fire beam across a wide operating frequency band without adding additional structures.

A slow-wave structure, a traveling wave tube, an electronic device, and a communication system are provided. The slow-wave structure includes a folded waveguide structure, where the waveguide structure has a cycle in a longitudinal direction and an amplitude in a transverse direction perpendicular to the longitudinal direction, and at least one of an amplitude of a first part of the waveguide structure and a cycle of the first part gradually changes in the longitudinal direction. Therefore, reflection of the slow-wave structure can be reduced, backward wave oscillation can be effectively suppressed, and a wider operating bandwidth can be obtained.

This application provides a collector, a traveling wave tube (TWT), and an electronic device, relating to the field of TWT technology. The TWT includes a slow-wave structure and a collector; the end of the slow-wave structure includes a transition channel corresponding to the electron beam; the collector includes multiple stages of sequentially stepped-down electrodes; the end of the first stage electrode in the multiple stages of sequentially stepped-down electrodes is located within the transition channel; or, the end of the first stage electrode is inclined towards the cavity of the collector at a first tilt angle along the axis of the electron beam, the first tilt angle being determined according to the velocity of the electron beam. The technical solution provided by the embodiments of this application enables the collector to simultaneously achieve both low peak backflow rate and high efficiency of deep backflow collectors.

The utility model discloses a water conservancy wave wall structure which comprises a dam foundation and a dam wall, the dam wall is installed on the dam foundation, a wave structure is installed on the dam wall, and the wave structure comprises an arc-shaped baffle and a telescopic structure. The arc-shaped baffle is installed on the dam wall through the telescopic structures, the number of the telescopic structures is not less than three, and the telescopic structures are distributed between the arc-shaped baffle and the dam wall at equal intervals. The telescopic structure comprises a circular groove, a cylinder, a groove, a cross rod and a spring; the circular groove is formed in the dam wall, the cylinder is installed in the circular groove, the groove is formed in the cylinder, and the transverse rod is installed on the arc-shaped baffle. The dam wall with the dam foundation is placed into the water conservancy dam, the two sides of the dam wall are sealed, when water conservancy waves impact, the arc-shaped baffles are impacted, the waves are folded reversely, meanwhile, the arc-shaped baffles drive the transverse rods to move in the grooves in the cylinders, the arc-shaped baffles have buffering performance through the springs, and the dam wall is prevented from being impacted and damaged.

The present invention relates to a special anti-deformation material and box structure for pallets, and belongs to the technical field of transport box structures. The box structure includes a base, a cover plate, two first side plates, two second side plates and a plurality of pull rods. The bottoms of the two first side plates are clamped on the base, the bottoms of the two second side plates are clamped on the base, and the two first side plates and the two second side plates are clamped together to form a circular structure through the side ends. A plurality of the pull rods are clamped in an array between the tops of the two first side plates. The two first side plates are provided with a latch assembly, and the bottom of the cover plate is clamped on the tops of the two first side plates and the two second side plates. By ensuring the firmness of the box structure while adopting a wave structure for lightweight design, and the various components are all detachable, which is convenient for transportation and installation, the box structure as a whole has good load-bearing capacity, is stable and has good buffering performance.

The utility model provides a comfortable back -carrying type hair dryer with damping structure, include: hair dryer body, hair dryer body one side is equipped with backplate support, backplate support one side fixed mounting has damping component, and damping component includes U shaped elastic sheet, and U shaped elastic sheet fixed mounting is in backplate support one side, and U shaped elastic sheet one side surface is equipped with two empty grooves, and two empty grooves are all respectively pasted with silica gel block in, and silica gel block one side is respectively pasted with soft cotton board. When the user carries the hair dryer body through the shoulder strap, the body pressure is passed to the silica gel block through the soft cotton board, and the high elasticity deformation of silica gel absorbs high frequency fine vibration, and the wave plate is located between two soft cotton boards, and the wave structure of the wave plate produces deformation when being pressed, and the dispersion pressure increases the buffer stroke, improves the comfort degree when the user is carrying.

The invention discloses an integrated solar module system suitable for multi-scene installation, relates to the technical field of solar modules, and aims to solve the technical problem that for complex installation base planes such as arched roofs and wave structures, the traditional installation mode is difficult to adjust the angle in a self-adaptive manner. Comprising a solar panel and installation mechanisms arranged on the two sides of the solar panel, and each installation mechanism comprises insertion installation assemblies symmetrically arranged on the two sides of the solar panel. Through a gathering or unfolding mechanism of the clamping plates and a wedge-shaped guide structure, the adjacent solar panels can be simply in butt joint like splicing and inserting building blocks, and the problem that traditional installation is tedious and time-consuming is solved; the series connection locking module can effectively prevent loosening, and the external force performance such as wind resistance of the whole structure is enhanced; and the multi-direction hinging module endows the solar panel with the capabilities of axial rotation and inclination angle adjustment, so that the solar panel can adapt to mounting base planes with different curvatures, such as arched roofs and wave structures, and the application potential of the solar panel in diversified building scenes is greatly expanded.

A folding cascade design is adopted, a single-section amplification process of a traditional slow wave structure is decomposed into a plurality of continuously cascaded amplification stages, namely slow wave sub-structures, each stage is provided with an independent electron beam for driving, an output signal of a front stage is directly fed into a rear stage to serve as input, and the output signal of the rear stage is directly fed into the slow wave sub-structures. In this way, step-by-step transmission and amplification of signals are achieved, high-efficiency sectional signal amplification is achieved, and the working bandwidth and output power of an original structure are not damaged while the interaction length of the slow wave structure is effectively shortened. In order to optimize the layout and reduce the structural size, the signal propagation directions of two adjacent stages are arranged in opposite directions, so that the output end of the front stage is directly aligned with the input end of the rear stage in space, and a compact folding topological structure is formed. Efficient signal transmission between stages is realized through the coupler and the waveguide, and the whole slow wave structure only reserves one input port and one output port, so that the integration level is remarkably improved, the manufacturing complexity is not increased, and meanwhile, the performance of an output signal is not deteriorated. And the electron beams are emitted along the signal transmission direction of each stage, so that the electron beams of two adjacent stages are arranged in a staggered manner in space.

The invention discloses a miniaturized periodic permanent magnet focusing metamaterial backward wave oscillator, which comprises a metamaterial slow wave structure, a coupling cavity, a periodic permanent magnet focusing system and a coaxial output interface, the metamaterial slow-wave structure comprises a waveguide shell, a periodic resonance structure and a first vacuum gap; the coupling cavity comprises a coupling cavity shell, a coupling cavity inner conductor and a second vacuum gap; the coupling cavity inner conductor is connected with the periodic resonance structure and the coaxial output interface; the periodic permanent magnet focusing system comprises a first permanent magnet focusing structure and a second permanent magnet focusing structure which are asymmetrically arranged up and down, and the metamaterial slow wave structure is arranged between the first permanent magnet focusing structure and the second permanent magnet focusing structure. According to the backward wave oscillator, the metamaterial slow wave structure and the periodic permanent magnet focusing system are arranged, and the coupled cavity is multiplexed as the collector, so that the size of the backward wave oscillator is reduced. And an asymmetric focusing magnetic field is generated through the asymmetrically arranged periodic permanent magnet focusing system, so that electron beams can perform energy exchange better.

The invention discloses a three-notch high-rectangularity dielectric filter which comprises a ceramic dielectric body, an input interface arranged at the first end of the ceramic dielectric body and an output interface arranged at the second end of the ceramic dielectric body. A first resonance hole, a second resonance hole, a first trapped wave structure, a second trapped wave structure and a third trapped wave structure are sequentially arranged on the ceramic dielectric body from a first end to a second end, and the first resonance hole and the second resonance hole are blind holes; the first resonance hole is connected with the input interface to form an input resonator, and the third notch structure is connected with the output interface; and metal shielding layers are formed on the surfaces of the ceramic dielectric body, the resonance holes and the notch structures through metallization processing. According to the invention, through the structural design of the first trapped wave structure, the second trapped wave structure and the third trapped wave structure, the three-trapped wave function can be well realized.

The invention discloses a guided wave damage detection and positioning method and system for an underwater water filling pipeline based on an SAFE-PML model. The method comprises the following steps: establishing a guided wave SAFE wave equation of a water filling pipeline waveguide system in a limited fluid domain; the guided wave SAFE wave equation of the water filling pipeline in the limited fluid domain is expanded to the water filling pipeline waveguide system in the infinite fluid domain through a PML coordinate stretching function, and a complete guided wave SAFE wave equation of the underwater water filling pipeline waveguide system is obtained; the guided wave mode speed and the wave structure existing in the complete underwater water filling pipeline are extracted; the independent guided wave mode is excited for the wave structure of the guided wave mode, and damage detection and positioning are carried out on the pipeline through the time characteristics of the reflected wave of the guided wave time domain signal. The damage detection of the underwater water filling pipeline is realized by analyzing the propagation characteristics of the underwater water filling pipeline.

The invention discloses an oil and gas pipeline dredging flexible shaft cleaning device, which relates to the technical field of pipeline dredging, and comprises a spray head main body, a connector, an end cover and a guide piece, and the guide piece is connected to the spray head main body and is glidingly embedded with a guide groove on a rotating part of the connector. The connector is rotationally sleeved with the spray head body, so that the connector enables water flow to enter the water flow channel through the water outlet through the water outlet channel, the water flow is sprayed out from the multiple nozzles obliquely arranged in the circumferential direction, and the spray head body rotates on the connector; by means of a guide groove which is formed in the rotating part of the connector and is of an annular wave structure and a guide piece which is connected to the spray head body and embedded into the guide groove, the spray head body can do reciprocating motion in the axial direction of the connector in the rotating process, so that scales and deposits located on the inner wall of the oil and gas pipeline are rotationally impacted; the dredging efficiency of the oil-gas pipeline is effectively improved.