Abstract: The present disclosure relates to the technical field of fiber-optic gas sensing and laser photoacoustic spectroscopy, and reliability of a gas detection system is improved by actively selecting a working frequency of low noise interference combined with an optical fiber photoacoustic sensing probe capable of isolating high-frequency noise. A gas enters a photoacoustic microcavity through gaps on a sound-sensitive diaphragm after diffusing into a miniature air chamber through a plurality of micropores. Photoacoustic excitation light is incident into the photoacoustic microcavity through a fiber-optic collimator and then excited to generate a photoacoustic pressure wave to cause the sound-sensitive diaphragm to vibrate periodically. An end face of a single-mode optical fiber and the sound-sensitive diaphragm constitutes a fiber-optic Fabry-Perot interferometer. The interferometer measures a deflection of the diaphragm and inverts a concentration of the to-be-measured gas.

Abstract: The present invention provides a method for forming an aluminum alloy thin-walled curved part by ultra-low temperature gradient drawing. This method includes: placing the aluminum alloy sheet on a die, and closing a blank holder to hold the aluminum alloy sheet in a flange zone; filling a cavity of a die with an ultra-low temperature medium to cool a die cavity zone of the aluminum alloy sheet to a set low temperature, and forming an ultra-low temperature gradient in which the temperature of the die cavity zone is lower than the temperature in the flange zone; applying a set blank holder force to the blank holder, and controlling a punch to move downwards to form a deep-cavity thin-walled curved part; and controlling the punch to move upwards, opening the blank holder, and taking out the formed deep-cavity thin-walled curved part.

Abstract: A honeycomb core with S-shaped reinforced structures includes multiple cylindrical unit cells arranged in a honeycomb shape and with a polygonal cross section, the cylindrical unit cells are divided into plain unit cells and S-shaped reinforced unit cells, an inner cavity of the plain unit cell is hollow, and the inner cavity of the S-shaped reinforced unit cell is equipped with an S-shaped reinforced structure, a cross section of the S-shaped reinforced structure is S-shaped and the inner cavity of the S-shaped reinforced unit cell is divided into two halves on average. This structure guides the load-transfer path effectively by controlling the rotation of S-shaped reinforced cells, it changes the position of plastic collapse in the structure, and finally changes the peak load of the core. Under different working conditions, the design of the arrangement of S-shaped reinforced structures can make the core produce different peak loads.

Abstract: An impact forming device and method for local small features on a metal thin-walled curved-surface part. The impact forming device includes impact forming dies, impact loading units and a forming supporting die, wherein the impact forming die is provided with an impact forming part, and the impact forming part is a convex part corresponding to a local small feature; the forming supporting die can support and fix a metal thin-walled curved-surface part without forming local small features, and the forming supporting die is provided with concave parts matched with the impact forming parts; and the impact loading unit includes a guide rail, an explosive ball and a detonating block, under the impact loading of the impact loading units, the impact forming parts can impact the metal thin-walled curved-surface part without forming local small features under the matching action of the concave parts to form the local small features.

Abstract: The disclosure discloses a method and system for adjusting user field of view (FoV) in a three-dimensional virtual reality (VR) scene. The method includes: acquiring two consecutive frames of scene pictures during a period of a user experiencing a VR scene by using a VR device; determining a projected scene flow vector on the basis of the two consecutive frames of scene pictures; generating a virtual scene graph of the two consecutive frames of scene pictures; determining a projected scene flow value of the virtual scene graph on the basis of the projected scene flow vector; determining a peripheral vision pixel of the virtual scene graph; calculating a projected scene flow average value of the peripheral vision pixel on the basis of the projected scene flow value of the virtual scene graph; and dynamically adjust a FoV of the user on the basis of the projected scene flow average value.

Abstract: A vibration isolation/damping satellite mount of a chopped carbon fiber reinforced thermoplastic composite material mainly includes two parts, and the two parts are connected through bolts. Considering the limitation of the molding process, the mount configuration is further optimized, and the mount structure is prepared by using the injection molding process. Furthermore, the vibration isolation/damping satellite mount of the chopped carbon fiber reinforced thermoplastic composite material prepared in the present invention can be used for large loads and complex working conditions, and the connectivity, overall strength stability, vibration isolation performance and service life of the mount all meet the design requirements.

Abstract: The disclosure discloses a method and system for adjusting user field of view (FoV) in a three-dimensional virtual reality (VR) scene. The method includes: acquiring two consecutive frames of scene pictures during a period of a user experiencing a VR scene by using a VR device; determining a projected scene flow vector on the basis of the two consecutive frames of scene pictures; generating a virtual scene graph of the two consecutive frames of scene pictures; determining a projected scene flow value of the virtual scene graph on the basis of the projected scene flow vector; determining a peripheral vision pixel of the virtual scene graph; calculating a projected scene flow average value of the peripheral vision pixel on the basis of the projected scene flow value of the virtual scene graph; and dynamically adjust a FoV of the user on the basis of the projected scene flow average value.

Abstract: A wing model for static aeroelasticity wind tunnel test belongs to the technical field of aeroelasticity tests. In the wing model, the model steel joint and the spar frame are connected with the composite material skin. The piezometer wing ribs are arranged among the spar frame and the plurality of supporting wing ribs. The embedded piezometer tubes are arranged in the piezometer wing ribs, the lightweight filling foam is arranged among the spar frame and the plurality of supporting wing ribs. An outer surface of a frame segment formed by the lightweight filling foam, the plurality of supporting wing ribs, the piezometer wing ribs and the spar frame is covered with the composite material skin. The frame segment is assembled on the model steel joint to form the wing model for the static aeroelasticity wind tunnel test.

Abstract: The present disclosure relates to a power supply system for improving plasma uniformity and a method thereof, wherein the power supply system includes a signal generating device, a first electrode and a second electrode. The signal generator is respectively connected with a plurality of signal processing circuits and is used for generating a plurality of initial signals at different frequencies; the signal processing circuits are used for processing the initial signals at corresponding frequencies; the plurality of signal processing circuits are all connected with the first electrode; and the initial signals are processed by the signal processing circuits and then act on the plasma through the first electrode. The present disclosure may effectively process signals in different power supplies, improve the stability of plasma discharge, reduce the impact of the coupling effect between different power supplies, and realize the independent control of ion flux and ion energy.

Abstract: A zero-Poisson-ratio honeycomb structure and an interlocking assembly manufacturing method thereof are provided. The honeycomb structure is formed by combining a four-pointed star shaped structure and horizontal and vertical honeycomb wall arrays at star corners. The zero-Poisson-ratio honeycomb structure not only has the zero-Poisson-ratio characteristic, but also can achieve respective design of in-plane and out-of-plane mechanical properties. Meanwhile, due to the existence of the horizontal honeycomb walls and the vertical honeycomb walls, the connection of multiple honeycomb walls at angular points in the honeycomb structure is avoided. Moreover, a novel manufacturing mode is provided for the honeycomb structure in addition to prepare the honeycomb structure by utilizing a 3D printing process. The honeycomb structure can be manufactured by combining an interlocking assembly process with resin matrix composites. The performance of the honeycomb structure is further improved at the material level.

Abstract: A separation and purification coupled process with a high helium yield and diversified products is provided. The process is as follows. Firstly, a low-concentration helium-containing gas after being pressurized and pre-treated enters a two-stage and two-section membrane separation unit to produce a helium product with a medium concentration by concentrating stage by stage through the membrane separation unit. A part of the helium with medium concentration enters an adsorption unit for further concentration to produce a helium product above grade A.

Abstract: A pressure measuring device for a scale model for elastic similar structure of a wing in a large transport plane adopts a bracket for pressure measuring steel pipes formed by 3D printing, shapes of an upper surface and an lower surface of the bracket are completely the same as local airfoile profiles of a skin at required pressure measuring positions, and the upper surface and the lower surface of the bracket are bonded to the skin and wing beams; a pressure measuring hose is connected with the pressure measuring steel pipe, and the pressure measuring steel pipe is embedded into the bracket and fixed to it; the upper surface and the lower surface of the bracket are provided with semi-cylindrical convex structures; and the pressure measuring steel pipe extends out of the pressure measuring hole in the surface of the skin for pressure measuring steel pipe in the bracket.

Abstract: An overlapping and progressive forming method for a high-performance multi-element NiAl-based alloy tubular part, including: winding continuously flexible substrates of Ni and Al, and alloying coating continuously or selectively along a width direction or a rolling direction to obtain coated flexible substrates; winding continuously the coated flexible substrates on an outer surface of a core roller according to a sequence of Ni above and Al below to form a Ni/Al laminated structure having a plurality of layers with an outermost layer being a Ni layer, and consolidating with ultrasonic with assistance of a pulse current to combine the continuously wound flexible substrates into a laminated tube blank; and placing the laminated tube blank into a mold, applying a pulse current to both ends of the laminated tube blank for hot fluid high-pressure forming, and synthesizing in-situ to prepare the tubular part with assistance of the pulse current.

Abstract: The present disclosure belongs to the technical field of new energy utilization, and provides an offshore oscillating water column wave energy conversion device with an external permeable structure. The offshore oscillating water column wave energy conversion device with the external permeable structure comprises an oscillating water column system, an anchoring fixing system and a permeable structure. According to the offshore oscillating water column wave energy conversion device with the external permeable structure provided by the present disclosure, the offshore oscillating water column wave energy conversion device and the permeable structure are effectively combined. Using an offshore floating structure, the offshore oscillating water column wave energy conversion device with the external permeable structure can be applied to deep and far sea areas with higher wave energy density, and the output power of the device can be effectively improved.

Abstract: The present invention discloses a device for measuring gas temperature in plasma, including: a vacuum chamber, a fiber optic temperature sensor, a quartz tube, a circulator, a spectrometer, a broadband light source and a computer. One end of the quartz tube is inserted into the vacuum chamber. The fiber optic temperature sensor is located in the plasma in the vacuum chamber and fixed to the quartz tube. The fiber optic temperature sensor is connected to the circulator by means of an optical fiber passing through the quartz tube. The circulator is connected to the broadband light source and the spectrometer through optical fibers, respectively. The spectrometer is electrically connected to the computer which is configured to read and record spectra collected by the spectrometer.

Abstract: Provided is a performance controlling method for a high-strength aluminum alloy shell during an ultra-low temperature forming process. The present disclosure greatly improves the performance of an aluminum alloy sheet by applying an ultra-low temperature. The present disclosure cools the aluminum alloy sheet to an ultra-low temperature by using an ultra-low temperature cooling medium, so as to compensate for insufficient hardening caused by insufficient deformation and avoid cracking caused by increased deformation. The present disclosure cools the sheet blank zonally according to a deformation law of a desired curved part, and controls the ultra-low temperature distribution of the sheet blank during forming so as to promote the formation of a substructure in a small-deformation zone. In this way, the present disclosure improves a subsequent age-hardening effect, and corresponding uniformity of microstructure and performance, and effectively solves the problem of non-uniformity due to uneven deformation.

Abstract: Disclosed are a self-righting unmanned ship suitable for adverse sea conditions and a self-righting working mode thereof, belonging to the field of unmanned ship equipment and techniques. The unmanned ship comprises a main hull, a self-righting deck, an equipment and pipeline mast, a propeller, a radar, an air inlet and exhaust system, and a main engine system. Through the design of a watertight deck, the hull of the unmanned ship has a self-righting function, avoiding the possibility of the unmanned ship itself turning over, without installing additional self-righting equipment. Meanwhile, the internal structure and the self-righting working mode of the unmanned ship make it possible for the hull to automatically turn off the main engine and the air inlet and exhaust system when the heeling angle of the hull exceeds a certain angle, making the whole ship watertight.

Abstract: A radiation resistant high-entropy alloy is provided, having an FCC structure, defined by general formula of FeCoNiVMoTixCry, where 0.05?x?0.2, 0.05?y?0.3, x and y are molar ratios. The radiation resistant high-entropy alloy has excellent irradiation resistance and is subject to radiation hardening saturation at high temperature (600° C.) in a condition of a high dose (1-3×1016 ions/cm2) of helium ion irradiation. A lattice constant of the high-entropy alloy decreases abnormally after irradiation. The high-entropy alloy has a radiation resistance far higher than that of a conventional alloy and has an excellent plasticity and specific strength. In an as-cast condition and at room temperature, a tensile break strength of the high-entropy alloy is higher than 580 MPa, an engineering strain (a tensile elongation) of the high-entropy alloy is greater than 30%.

Abstract: A broadband ultrathin acoustic wave diffusion structure has a plurality of acoustic wave diffusion units. Each acoustic wave diffusion unit has at least one acoustic wave propagation section, and an acoustic wave focused section communicating with the acoustic wave propagation section is arranged according to needs. The acoustic wave focused section is formed by an acoustic wave focused cavity filled with acoustic material. The acoustic wave focused cavity is a variable-section cavity. The acoustic wave propagation section is formed by a simply connected acoustic wave propagation passage with a close end. Different acoustic wave diffusion units have different lengths of the simply connected acoustic wave propagation passages. The maximum length of the simply connected acoustic wave propagation passage may be dozens or even hundreds of times of the thickness of the acoustic wave diffusion structure, which can meet the diffusion requirements for low frequency acoustic waves to the maximum extent.

Abstract: The present invention discloses a magnetic probe device. The magnetic probe device includes a magnetic probe body and a signal processing circuit, and an output end of the magnetic probe body is connected with an input end of the signal processing circuit; the signal processing circuit includes a first capacitor, a second capacitor, a Faraday shield and a step-up transformer, and the Faraday shield is fixedly arranged between a primary winding and a secondary winding of the step-up transformer; a center tap is arranged at the primary winding of the step-up transformer, and the center tap is grounded; and a first end of the primary winding is in series connection with the first capacitor, and a second end of the primary winding is in series connection with the second capacitor. The magnetic probe device provided by the present invention can improve the signal-to-noise ratio of a magnetic probe and the measurement accuracy of the magnetic field in plasma.