6results 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 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 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.

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.