15results about How to "Short wavelength" patented technology

The invention belongs to the technical field of hydraulic engineering, and provides a sediment particle size distribution measuring system and method.The method comprises the steps that images of sediment particles in a water body are collected, and a first sediment particle image is obtained; processing the first sediment particle image to obtain a sediment grayscale image; a K-means clustering algorithm is adopted to carry out clustering analysis on the sediment gray level image, and an image with a first-level clustering result is obtained; carrying out clustering analysis on sediment particles with particle sizes smaller than a preset threshold value in the image with the first-level clustering result by adopting a DBSCN clustering algorithm to obtain an image with a second-level clustering result; and carrying out edge detection on the sediment particles in the image with the secondary clustering result, and then sequentially carrying out binarization processing, equivalent circle diameter transformation and statistics on the particle size distribution of the sediment particles to obtain a particle size distribution result. The problem that an existing sediment particle size measurement system is low in measurement precision in a complex underwater environment with dense sediment and more fine particles is solved.

The invention discloses a near-infrared light mediated heterogeneous composite photocatalyst as well as a preparation method and application thereof, the heterogeneous composite photocatalyst is an up-conversion luminescent material loaded semiconductor material, and can realize up-conversion luminescent catalysis under the irradiation of 980nm near-infrared light; the up-conversion luminescent material is rare earth ion doped fluoride nanoparticles, fluoride is one or two of yttrium fluoride and sodium yttrium tetrafluoride, the doped rare earth ions comprise rare earth luminescent center ions and light absorption ions, the luminescent center ions comprise one of Er < 3 + >, Tm < 3 + >, Tb < 3 + > and Pr < 3 + >, and the light absorption ions comprise Yb < 3 + >; the semiconductor material is of a heterojunction structure which is tightly formed by Co3O4 quantum dots and g-C3N4 nanosheets. The up-conversion nanoparticles are synthesized by adopting a simple hydrothermal method and are loaded on the g-CN nanosheets modified by the CoO quantum dots, and the obtained composite material can effectively convert near-infrared light into visible green light, so that generation of photocatalytic reaction species is increased, and the up-conversion nanoparticles are recycled and reused for multiple times without inactivation.

This invention discloses a method for enhancing and controlling the radiation of an LPP-EUV light source based on dual-pulse spatiotemporal co-constraint, belonging to the field of semiconductor manufacturing technology. This invention obtains a spatiotemporal reference by real-time monitoring of a liquid metal droplet, uses a pre-pulse laser to induce target material deformation into a fogged target cloud, and combines high-speed imaging and a hydrodynamic model to predict the time and coordinates of the target cloud's energy absorption peak. It dynamically adjusts the delay time and optical axis direction of the main pulse laser to achieve dual-pulse spatiotemporal co-constraint, and constructs a closed-loop control system through a recursive least squares algorithm with a dynamic forgetting factor. This invention effectively improves the extreme ultraviolet light conversion efficiency, controls the power fluctuation of the light source within ±0.5%, and extends the maintenance cycle of optical components by 2 times. It can be widely applied to next-generation high-power extreme ultraviolet lithography light source systems, meeting the application requirements of semiconductor miniaturization processes.

The present invention relates to a method for preparing a large-angle light-emitting light source, a surface light source module and a light-emitting light source, wherein the large-angle light-emitting light source comprises an LED chip, the LED chip is a flip-chip structure, the LED chip comprises a P-GaN layer, a light-emitting layer, an N-GaN layer and a substrate arranged in sequence from bottom to top, and a lower reflection layer is arranged on the bottom surface of the LED chip, a blue light re-excitation layer is arranged on the top surface and the side surface of the LED chip, an upper reflection layer is arranged on the top surface of the blue light re-excitation layer, the four sides of the blue light re-excitation layer are full light-emitting areas, and the top surface of the upper reflection layer is a full reflection or partial reflection area. The advantages of the present invention are: in the present invention, the reflection layer is directly arranged on the top and bottom of the flip-chip LED chip, the light emitted by the LED chip is reflected by the upper reflection layer and the lower reflection layer, so that the light is emitted from the four sides of the LED chip, and large-angle light emission is achieved; in addition, since the large-angle light-emitting light source of the present invention is a separate monomer, rather than making the reflection layer on the substrate as a whole, it can be applied to different substrates.

The present invention relates to a spectral dimming packaging structure containing a violet or near-ultraviolet chip, and also to a manufacturing method of the packaging structure, which is characterized by comprising a first wavelength blue light chip, a second wavelength blue light chip, a violet or near-ultraviolet chip and a packaging layer, a long wavelength phosphor glue layer is arranged on the surface of the first wavelength blue light chip to form a long wavelength package, a short wavelength phosphor glue layer is arranged on the surface of the violet or near-ultraviolet chip to form a short wavelength package, and the packaging layer is used to encapsulate each short wavelength package, the second wavelength blue light chip and the long wavelength package as a whole. The advantages of the present invention are: using multiple chips with different wavelengths for excitation can take into account the excitation wavelengths of different phosphors, and can avoid the short wavelength fluorescence generated by the short wavelength phosphor from exciting the long wavelength phosphor again and being reabsorbed; the optimal excitation wavelength achieves the highest quantum efficiency and improves the light efficiency of the light source at the same time.

The present invention discloses an ultrasonic nondestructive testing method and nondestructive detector based on directional shear waves, which belongs to the field of nondestructive testing of materials, and includes the following steps: S1, determining the material to be tested; S2, exciting directional shear waves based on the material to be tested: S21, applying multiple longitudinal excitations to the material to be tested in half space; S22, fixing the spacing between multiple longitudinal excitations, and optimizing the phase of the longitudinal excitations; S23, using the phase optimization result obtained in step S22 as a fixed value, optimizing the spacing between multiple longitudinal excitations; S24, using the optimization result obtained in step S23 as the excitation result, at which time the shear wave energy accounts for no less than 90%; S3, determining the parameters of the metasurface based on the phase and spacing obtained in step S2. The present invention adopts the above-mentioned ultrasonic nondestructive testing method and nondestructive detector based on directional shear waves, which have the advantages of long propagation distance, strong anti-interference ability, no need for coupling agent, and light equipment.

The invention discloses a cable terminal liquid level monitoring system which at least comprises a processor, an ultrasonic ranging module, a wireless power supply module and an energy storage module. The wireless power supply module is electrically connected with the energy storage module, and the energy storage module is electrically connected with the ultrasonic ranging module; the ultrasonic ranging module comprises an ultrasonic transmitting unit and an ultrasonic receiving unit which are in signal connection with the processor, and when the processor judges that two ultrasonic signals received by the ultrasonic receiving unit are larger than or equal to the pulse width of the ultrasonic transmitting unit, the pulse width of the ultrasonic transmitting unit is reduced. Ultrasonic waves are used for detecting the oil sealing height, the wireless power supply module is used for taking electricity for equipment, the wireless signal transmission technology is used for data transmission, and signal collection and transmission are completed under the condition that any construction environment does not need to be changed.

Ellipsometer, polarimeter, reflectometer and spectrophotometer systems include one or more wavelength modifiers that convert the wavelength provided by the electromagnetic radiation source to a different wavelength for use in investigating a sample, and / or a wavelength that can be detected by its detector.

The invention provides a high-order torsional mode flexible magnetostriction phased array guided wave sensor which comprises a double-layer flexible circuit board, at least one excitation coil is arranged in the double-layer flexible circuit board, and flexible silica gel shells are arranged on the two sides of the double-layer flexible circuit board. An iron-cobalt alloy belt is arranged on the lower side of a flexible silica gel shell arranged on the lower side of the double-layer flexible circuit board in an attached mode, the iron-cobalt alloy belt is pasted on a carbon steel pipeline to be detected through epoxy resin, and the flexible silica gel shell is connected with a signal processing and analyzing device through a switching circuit board. According to the invention, the precision and sensitivity of defect detection are improved by virtue of the shorter wavelength of the frequency dispersion guided wave, meanwhile, the axial and circumferential resolution of defect detection in the pipeline is enhanced by utilizing a phased array detection mode of a multi-sensor array element, and automatic remote monitoring and long-term evaluation of the health condition of the carbon steel pipeline are realized.

The present application mainly relates to an earphone, wherein the movement shell is used to contact the user's skin, the transducer device enables the skin contact area of ​​the movement shell to generate bone conduction sound under the action of the transducer device, the diaphragm divides the accommodating cavity into a front cavity and a rear cavity, the movement shell is provided with a sound outlet hole connected to the rear cavity, and the diaphragm generates air-conducted sound transmitted to the human ear through the sound outlet hole during the relative movement of the transducer device and the movement shell; the movement shell is provided with a tuning hole connected to the rear cavity, which can destroy the high-pressure area of ​​the rear cavity, reduce the wavelength of the standing wave in the rear cavity, and make the peak resonance frequency of the resonance peak in the frequency response curve of the air-conducted sound shift to a high frequency; the movement shell is connected to a sound-conducting component for guiding the air-conducted sound to the human ear, shortening the distance between the sound outlet hole and the human ear, and increasing the intensity of the air-conducted sound; the effective area of ​​the outlet end of the sound-conducting channel is larger than the effective area of ​​the outlet end of the tuning hole, so that the user can hear more of the air-conducted sound output by the sound-conducting channel.

The present invention relates to a light-like gravitational wave detector, which belongs to the technical field of weak signal detection. The light-like gravitational wave detector comprises: an emitting electrode, a graphene substrate, a light-like beam splitter, a collecting electrode, an insulating layer and a substrate electrode. The emitting electrode and the collecting electrode are electrically connected to the graphene substrate respectively. The carriers emitted by the emitting electrode are split by the light-like beam splitter after passing through an electronic light-like momentum selector, and are respectively transmitted to the collecting electrode through three mutually perpendicular detection arms. The gates of the electronic light-like momentum selector and the light-like beam splitter are both arranged vertically above the graphene substrate. Beneficial effects: The wavelength of graphene-like light transport is shorter, and it is more sensitive to gravitational waves, which improves the sensitivity of the gravitational wave detector and can reduce the size of the gravitational wave detector; and the coordinate orientation information of the gravitational wave source can be obtained by using three mutually perpendicular detection arms.

This invention relates to the field of metal environment imaging, and more particularly to an environmental imaging method and apparatus based on millimeter-wave radar. The method includes the following steps: transmitting multi-frequency signals to the metal environment to be detected using a millimeter-wave radar array, and extracting multipath signal sequences; performing interferometric phase analysis based on the multipath signal sequences to obtain the three-dimensional coordinates of the metal and the actual target reflection point; performing iterative forward calculation based on the three-dimensional coordinates of the metal and the actual target reflection point to obtain a first metal environment image; and performing iterative residual convergence on the first metal environment image to output a second metal environment image. This invention achieves high-precision and reliable three-dimensional imaging of complex metal environments.

The invention provides a cholesteric liquid crystal composition, a liquid crystal display device containing the cholesteric liquid crystal composition and application of the cholesteric liquid crystal composition. The cholesteric liquid crystal composition comprises at least one liquid crystal composition A and at least three chiral agents, the liquid crystal composition A comprises at least one compound with a general formula I and at least one compound with a general formula II, and at least one chiral agent is R / S-2011. The cholesteric liquid crystal composition has a proper clearing point and small wavelength variation along with temperature, that is, the cholesteric liquid crystal composition has small wavelength drift, and a liquid crystal display device comprising the cholesteric liquid crystal composition can have a good display effect and a wide temperature use range. # imgabs0 #

The embodiment of the present invention discloses an ultraviolet laser, including a fundamental frequency laser light source, a first frequency doubling structure and a second frequency doubling structure; the fundamental frequency laser light source emits a laser beam of a first wavelength; the first frequency doubling structure is located on the propagation path of the laser beam emitted by the fundamental frequency laser light source, and performs frequency doubling conversion on the laser beam of the first wavelength to generate a laser beam of a second wavelength; the first wavelength is twice the second wavelength; the second frequency doubling structure is located on the propagation path of the laser beam emitted by the first frequency doubling structure, and performs frequency doubling conversion on the laser beam of the second wavelength to generate a laser beam of a third wavelength; the second wavelength is twice the third wavelength; the ultraviolet laser also includes a beam shaping structure, which is located on the optical path between the first frequency doubling structure and the second frequency doubling structure, and is used to change the transmission and distribution of the laser beam of the second wavelength in space. The embodiment of the present invention reduces the generation of secondary light spots on both sides of the main light spot and improves the beam quality.

The invention discloses a C / Ku double-frequency common-caliber phased array scanning antenna, and relates to the technical field of scanning antennae, the C / Ku double-frequency common-caliber phased array scanning antenna comprises a Ku frequency band patch and a C frequency band antenna oscillator, and the Ku frequency band patch and the C frequency band antenna oscillator are distributed on a perforated printed board in a square array according to the caliber surface; all the C-frequency-band antenna oscillators are arranged in the same direction and are perpendicular to the polarization direction of the ku-frequency-band microstrip patch, the Ku-frequency-band patch and the C-frequency-band antenna oscillators both adopt a coaxial feed form, and the Ku-frequency-band patch adopts a coupling slot form to radiate the patch; in the strip line polarization direction of the Ku frequency band microstrip patch, a dummy dummy C oscillator without excitation is arranged between two adjacent C frequency band antenna oscillators in each row and each column of C frequency band antennas. According to the invention, the microstrip patch of the ku frequency band and the oscillator antenna of the C frequency band are reasonably arranged and are in the same spatial range, and a dummy encryption decoupling technology is adopted, so that the dual-frequency antenna array planes with different physical forms are integrated, and the coupling effect is reduced.