Abstract: The present disclosure relates to a stray light suppression device for bathymetric LiDAR onboard unmanned shipborne, belonging to the technical field of LiDAR water depth detection, particularly to a stray light suppression device for bathymetric LiDAR onboard unmanned shipborne. The device comprises an optical system component, a first objective lens barrel, a second objective lens barrel, a spectroscope barrel, a first eyepiece barrel a, a first eyepiece barrel b, a second eyepiece barrel a, a second eyepiece barrel b, a PMT detector a, a PMT detector b and a spectroscope supporting structure. Stray light suppression of an optical system with minimal field-of-view is realized, and stray light propagated by first-order, second-order and third-order scattered light paths is suppressed, so that a water depth detection capability of the bathymetric LiDAR onboard unmanned shipborne is improved and a dynamic detection range is expanded.

Abstract: The present disclosure relates to a stray light suppression device for bathymetric LiDAR onboard unmanned shipborne, belonging to the technical field of LiDAR water depth detection, particularly to a stray light suppression device for bathymetric LiDAR onboard unmanned shipborne. The device comprises an optical system component, a first objective lens barrel, a second objective lens barrel, a spectroscope barrel, a first eyepiece barrel a, a first eyepiece barrel b, a second eyepiece barrel a, a second eyepiece barrel b, a PMT detector a, a PMT detector b and a spectroscope supporting structure. Stray light suppression of an optical system with minimal field-of-view is realized, and stray light propagated by first-order, second-order and third-order scattered light paths is suppressed, so that a water depth detection capability of the bathymetric LiDAR onboard unmanned shipborne is improved and a dynamic detection range is expanded.

Abstract: The present disclosure relates to a PointEFF method for urban object classification with LiDAR point cloud data, and belongs to the field of LiDAR point cloud classification. The method comprises: point cloud data segmentation; End-to-end feature extraction layer construction; External feature fusion layer construction; and precision evaluation.

Abstract: The present invention discloses a POS high-accuracy positioning method under occlusion, comprising: integrating single-point positioning data and differential correction data for solution to acquire high-accuracy position information; implementing a buffer through an RAM of an FPGA to cache the collected position information and a sampling time; when a satellite signal loss is detected by a system, fetching five pieces of position information from the RAM at a time before the signal is lost and five pieces of position information at a time after the signal is reappeared, and filtering the information to obtain filtered data; constructing an equation by using the filtered data, and estimating a signal lost position. By triggering an occlusion algorithm through the FPGA, the present invention improves an ability of a POS system to work in areas with weak satellite signals and meanwhile reduces an operation time, thereby meeting practical needs.

Abstract: The present disclosure relates to a lightweight and small bathymetry LiDAR multi-channel high sampling rate high-precision real-time synchronous acquisition and storage system, which adopts an ADC+FPGA+ZYNQ architecture to implement four-channel high-rate real-time synchronous parallel sampling, has synchronization error less than 300 ps, sampling rate s as high as 2 GSPS, and sampling precision as high as 14 bits, and comprises an FPGA system acquisition carrier board unit for implementing laser radar echo data acquisition and storage, PMT controlling, data maximum value feedback, peripheral interface design and storage control; a storage daughter board unit for implementing storage of echo data and export of 100 Mbps Ethernet, and an upper computer data conversion software for implementing conversion of original echo data files into decimal or hexadecimal csv files.

Abstract: The present disclosure relates to a PointEFF method for urban object classification with LiDAR point cloud data, and belongs to the field of LiDAR point cloud classification. The method comprises: point cloud data segmentation; End-to-end feature extraction layer construction; External feature fusion layer construction; and precision evaluation.

Abstract: Disclosed is a method for preparing high-strength coral aggregate concrete under low pressure conditions, including the following steps: weighing cement, mineral admixture, coral aggregate, mixing water, water reducer, and defoamer; mixing the cement and the mineral admixture well to obtain a cementing material; putting the coral aggregate, sea water, water reducer, defoamer, and 55-85% of the cementing material into a closed mixing system to stir for 10-15 min under low pressure conditions, and pouring the remaining cementing material into the mixing system to stir for additional 10-15 min to prepare the high-strength coral aggregate concrete. The high-strength coral aggregate concrete obtained has advantages of high mechanical properties, high compactness, excellent impermeability and durability, drawing on local resources in construction engineering on remote islands and reefs, and maximum resource utilization.

Abstract: A device and method for geo-electric extraction under water layer coverage are provided. The device includes auxiliary tubes, outer casings, main tubes, mud extractors, encapsulated extraction electrodes and a fixing ferrule assembly, where the auxiliary tubes each have one end open and the other end closed; the outer casings each have one end open and the other end detachably connected to a top cover; an inner diameter of each of the outer casings is larger than an outer diameter of each of the auxiliary tubes; an outer diameter of each of the main tubes is smaller than the inner diameter of each of the outer casings; the mud extractors each include an inner rod, an outer rod and a bottom plate; the outer rod is sleeved outside the inner rod; the inner rod has one end provided with a dredging wheel and the other end provided with a handle.

Abstract: Disclosed are a ten-membered fergusonite structure high-entropy oxide ceramic and a preparation method thereof, where the high-entropy oxide ceramic has a monoclinic structure, with a chemical formula of RENbO4, and the RE is any ten rare-earth cations selected from a group consisting of La3+, Ce3+, Pr3+, Nd3+, Sm3+, Eu3+, Gd3+, Dy3+, Ho3+, Er3+, Tm3+, Yb3+, Lu3+ and Y3+. The ten rare-earth cations have a molar ratio of 1:1:1:1:1:1:1:1:1:1 and equal share of RE position. According to the application, by adopting solid state reaction, the fergusonite structure high-entropy oxide ceramic with single-phase structure, uniform element distribution and stable phase is obtained. The high-entropy oxide ceramic prepared by the application is simple in process, uniform in chemical composition and microstructure, and convenient to realize on-demand regulation on properties through a combination of different elements.

Abstract: An aquatic weed planting plate for an aquarium is provided. The aquatic weed planting plate for aquarium includes a plate body and at least four feet. A plurality of planting holes is formed in the plate body at intervals. A plurality of dirt collecting holes is formed around each planting hole. The plate body is provided with fixing devices for fixing aquatic weeds, and each fixing device corresponds to one planting hole. The fixing device includes a fixing sleeve, two clamping members and a luminous ring. The plate body is provided with nets for collecting dirt, each net corresponds to one dirt collecting hole, the lower portion of each net is provided with a connecting tube; a plurality of conveying pipes is also arranged below the plate body, each conveying pipe is communicated with the plurality of connecting tubes, each connecting tube is communicated with the corresponding conveying pipe.

Abstract: Disclosed is a method for preparing high-strength coral aggregate concrete under low pressure conditions, including the following steps: weighing cement, mineral admixture, coral aggregate, mixing water, water reducer, and defoamer; mixing the cement and the mineral admixture well to obtain a cementing material; putting the coral aggregate, sea water, water reducer, defoamer, and 55-85% of the cementing material into a closed mixing system to stir for 10-15 min under low pressure conditions, and pouring the remaining cementing material into the mixing system to stir for additional 10-15 min to prepare the high-strength coral aggregate concrete. The high-strength coral aggregate concrete obtained has advantages of high mechanical properties, high compactness, excellent impermeability and durability, drawing on local resources in construction engineering on remote islands and reefs, and maximum resource utilization.