Abstract: A low-emission combustor head structure with a V-shaped trailing edge vane solves the problems of a combustor head structure with short service life and uneven outlet air flow leading to poor combustion stability. The low-emission combustor head structure includes a pilot stage and a main stage, where the pilot stage includes a swirler, a venturi, and a centrifugal nozzle. The main stage includes an oblique radial swirler, a swirler vane, a V-shaped trailing edge vane, an annular fuel manifold, and direct injection nozzles. The oblique radial swirler of the main stage ensures swirl intensity while reducing the axial length of the swirler head. The discrete multi-point direct injection nozzles of the main stage enable the initial pressure atomization, and the V-shaped trailing edge structure enhances fuel droplet breakup and mixing. Thus, the fuel is fully premixed in the swirling passage, greatly reducing pollutant emissions, thereby achieving ultra-low emissions.

Abstract: Provided is a self-leveling rotary handling-type multi-autonomous underwater vehicle (AUV) docking and transfer device and its method. The device includes a docking module, a vertical handling module, and a rotary handling module; the docking module includes a rotary platform with a guide frame, and a top surface of the rotary platform is provided with a first clamping device; the vertical handling module is mounted on a side of the docking module; the vertical handling module includes a liftable handling platform, and the handling platform is provided with a locking device and a second clamping device; the rotary handling module is mounted below the docking module; the rotary handling module includes a multi-branch rotating shaft and a horizontal plate mounted on each branch rotating shaft; and the horizontal plate is arranged with an AUV charging and information interaction device and a third clamping device.

Abstract: Provided is a pressure-resistant underwater acoustic coating structure with a mesh structure interlayer, including an outer coating, a mesh structure interlayer, an inner coating, and a metal backing; wherein the outer coating is used for inputting acoustic waves, the mesh structure interlayer and the inner coating are used for consuming acoustic wave energy, and the metal backing is used for enriching a sound absorption mode; and the outer coating, the mesh structure interlayer, the inner coating and the metal backing are attached in sequence.

Abstract: The provided is a coaxially staged burner for a low-emission combustion chamber of a dual-fuel gas turbine utilizing gaseous and liquid fuels. The coaxially staged burner includes a mounting flange, a main fuel sleeve, and a swirler, where the mounting flange is provided with a fuel supply port; the main fuel sleeve is internally provided with coaxially nested four-stage fuel sleeves; the swirler includes a center pilot stage, a first premix stage, a second premix stage, a first-stage hub, and a second-stage hub; when a liquid fuel operates alone, the liquid fuel enters a swirler passage through a pilot-stage liquid fuel nozzle and a second-stage blade liquid fuel hole to achieve premixing and evaporation; and when a gaseous fuel operates alone, the gaseous fuel enters the swirler passage through a first-stage blade fuel hole and a second-stage blade gaseous fuel hole for mixing.

Abstract: The provided is a coaxially staged burner for a low-emission combustion chamber of a dual-fuel gas turbine utilizing gaseous and liquid fuels. The coaxially staged burner includes a mounting flange, a main fuel sleeve, and a swirler, where the mounting flange is provided with a fuel supply port; the main fuel sleeve is internally provided with coaxially nested four-stage fuel sleeves; the swirler includes a center pilot stage, a first premix stage, a second premix stage, a first-stage hub, and a second-stage hub; when a liquid fuel operates alone, the liquid fuel enters a swirler passage through a pilot-stage liquid fuel nozzle and a second-stage blade liquid fuel hole to achieve premixing and evaporation; and when a gaseous fuel operates alone, the gaseous fuel enters the swirler passage through a first-stage blade fuel hole and a second-stage blade gaseous fuel hole for mixing.

Abstract: Provided are a method for calculating a wear amount between an engine valve and a valve seat and a related device. The method includes: establishing an impact wear model according to influence of an impact angle when an exhaust valve is seated; establishing a sliding wear model based on an Archard wear theory; then, calling the impact wear model and the sliding wear model, respectively, to calculate a normal impact wear amount, an impact slip wear amount and a sliding wear amount; and based on this, calculating a total wear amount between the exhaust valve and the valve seat. The above solution of the present disclosure fully takes into account various types of wear between the exhaust valve and the valve seat, for example, specifically dividing impact wear into normal impact wear and tangential impact slip wear, and also calculating sliding wear after the valve is closed.

Abstract: The invention discloses method of improving AUV wireless communications systems, including steps of: collecting the channel frequency response and receiving signal data in the electromagnetic environment where AUV works on the water surface,; constructing a multi-dimensional feature aggregation network model based on self-attention mechanism; training a multi-dimensional feature aggregation network; and preprocessing received AUV signals to obtain improved input data. The network model completed by offline training is loaded, and the input data is input into the network for channel estimation. The invention uses a self-attention mechanism in deep learning to build a multi-dimensional feature aggregation network model. The estimation performance is much higher than the traditional channel estimation method, and the space-time complexity of the network is very low, which can be applied to an AUV wireless communication system through offline training.

Abstract: A three-phase composite, and a preparation method and use thereof are provided. The three-phase composite includes a hollow glass microsphere composite foam and a plurality of carbon fiber tubes filled in the hollow glass microsphere composite foam; where the carbon fiber tubes are arranged in a two-dimensional closest packing manner, two adjacent carbon fiber tubes have a center-to-center spacing of 29.9 mm to 34 mm, and each of the carbon fiber tubes has a wall thickness of 0.45 mm to 1 mm; and two ends of each of the carbon fiber tubes each are sealed by an end cap.

Abstract: Provided is a three-dimensional thermal-hydraulic analysis method and system for a reactor core. The method includes: analyzing a type of a reactor core, dividing an outer-layer mesh and a computational mesh, and establishing a conservative mapping relationship and a set of transport equations; decomposing a coolant viscosity-induced frictional effect, and representing a turbulent mixing-induced exchange of a physical quantity through a source term; establishing a three-dimensional set of governing equations including mass, momentum, and energy conservation equations to describe a flow and heat transfer phenomenon within coolant channels, and forming a fully assembled matrix system based on the set of transport equations; setting a boundary condition and an initial condition for a physical field of the reactor core, and setting an initial field; and iteratively solving the fully assembled matrix system, and obtaining a thermal-hydraulic parameter.

Abstract: The present disclosure provides an antifouling coating and a use method and use thereof. In the antifouling coating of the present disclosure, polyaspartic acid ester is an isocyanate curing agent containing a secondary amine structure. An ester group and aliphatic properties in the polyaspartic acid ester can increase wear resistance of the coating. The polyaspartic acid ester is combined with a polyisocyanate-containing prepolymer in a component A to endow the antifouling coating with desirable toughness and elasticity, such that the antifouling coating has excellent impact and abrasion resistance. In the component A, a polydimethylsiloxane structure is introduced into the hydroxypropyl silicone oil-based isocyanate prepolymer. The polydimethylsiloxane structure can generate microphase separation with a polyurea hard segment and migrate to a surface of the coating, thereby reducing surface energy of the coating to reduce an adhesion between fouling organisms and an interface.

Abstract: The present disclosure relates to the research field of functionalized membrane materials and their preparation methods, in particular to a double-layer functionalized hollow fiber membrane and a preparation method thereof. The present disclosure provides a preparation method for a double-layer functionalized hollow fiber membrane, including preparation of the casting solutions, transverse extrusion casting solution, longitudinal stretching, the first coagulation bath, the second coagulation bath, and the third coagulation bath. The double-layer functionalized hollow fiber membrane prepared by the present disclosure has a double-functionalized layer structure with a dense cortical antibacterial layer and a macroporous structure adsorption layer. The double-layer functionalized hollow fiber membrane not only has the function of separation and purification, but also has the function of bacteriostasis and adsorption.

Abstract: It provides the following solutions: the system includes subsystems such as an integrated management and evaluation subsystem, and constructs a ship six-degree-of-freedom motion model. A thrust calculation model is built for the problem of propeller thrust affected by broken ice during the propulsion process. By treating broken ice as independent moving objects, the motion of broken ice is solved to obtain the relative motion speed between the ship and broken ice. The influence of broken ice on propeller performance is considered by incorporating the relative speed between the ship and broken ice into the propeller modeling process, which acts on the aforementioned model. The annular crack method is used to determine the breaking shape of level ice, and the generated broken ice is close to real-world conditions.

Abstract: A method and apparatus for acquiring aerodynamic noise of a compressor, a medium, and a product are provided. The method includes: performing inverse Fourier transform on a known frequency-domain noise spectrum to obtain known time-domain noise data, then predicting unknown time-domain noise using a time series neural network, obtaining finer time-frequency noise data in combination with the known time-frequency noise data, and finally, performing Fourier transform on the finer time-frequency noise data to obtain new frequency-domain noise data. Limitations of a limited time step and a total simulation time on the acquisition of aerodynamic noise data in traditional numerical calculation of aerodynamic noise can be overcome. Finer aerodynamic noise data can be acquired rapidly and accurately. The frequency resolution of the noise spectrum can be increased, and reducing the consumption of computing resources and saving manpower and material resources can be achieved.

Abstract: Disclosed are a sensor for measuring seating force of an engine intake and exhaust valve and a measuring method. The sensor comprises a mounting boss, a force bearing element, a piezoelectric element, an annular thin-wall shell and an annular diaphragm with a T-shaped section. Meanwhile, the present disclosure also provides a measuring method by using the sensor. The sensor is simple in mechanism and convenient to use, has certain universality, and can realize the measurement of the impact load of the engine intake and exhaust valve.

Abstract: A noise-reducing and nonuniform tip clearance structure of centrifugal compressor is provided, which includes a compressor impeller body and a compressor impeller shroud. The compressor impeller shroud is circumferentially wrapped outside the compressor impeller body, and multiple impeller blade bodies are uniformly arranged in a circumferential direction of the compressor impeller body. A clearance between an impeller tip meridian line of the impeller blade body and an impeller shroud meridian line on the compressor impeller shroud is an impeller tip clearance. The impeller tip clearance gradually decreases in a direction from a leading edge to a trailing edge of the impeller blade body, and a change rate of the impeller tip clearance in the direction from the leading edge to the trailing edge of the impeller blade body also gradually decreases.

Abstract: The present disclosure belongs to the field of underwater target detection, and in particular, to a method for detecting a moving target based on spatial slices of transformed spatio-temporal frequency space.

Abstract: Provided is an intake bypass recirculation structure capable of silencing, including: an intake bypass recirculation structure body and a structure-conducted silencing device. An intake bypass recirculation cavity is provided on the intake bypass recirculation structure body. An inlet of the intake bypass recirculation structure and an outlet of the intake bypass recirculation structure that are provided on the intake bypass recirculation structure body are each connected to the intake bypass recirculation cavity. The structure-conducted silencing device is disposed inside the intake bypass recirculation cavity. In this application, during working, noise generated by a compressor is transmitted into the intake bypass recirculation cavity via an inlet of the intake bypass recirculation structure, and transmitted outside via the outlet of the intake bypass recirculation structure.

Abstract: A polypyrrole-graphene/polyurethane antifouling coating as well as a preparation method and an application thereof are provided. The polypyrrole-graphene/polyurethane antifouling coating includes component A and component B, wherein the component A mainly includes the following raw materials in parts by weight: 500 parts of group-hydrolyzable polyurethane prepolymer, 25-50 parts of bentonite, 25-50 parts of titanium dioxide, 60-120 parts of zinc oxide, 15-30 parts of talcum powder, and 15-30 parts of polypyrrole-graphene nanofiller; and the component B mainly includes the following raw materials in parts by weight: 5-7 parts of leveling agent, 5-7 parts of defoamer, 6-15 parts of chain extender, 10-25 parts of silane coupling agent, and 1-2 parts of catalyst. The two-component polyurethane coating of the present invention has relatively good adhesion, collision resistance and cracking resistance, and the antifouling property and the antifouling durability can be improved.

Abstract: Disclosed is a combustion system design method based on a target heat release rate, which belongs to the technical field of diesel engine combustion chamber design. The method includes: obtaining an ideal heat release rate based on Sabathe-Miller cycle; simulating the ideal heat release rate based on a double-Wiebe function and obtaining the target heat release rate; constructing a mapping relation among the heat release rate, piston geometric parameters and fuel injection parameters, which includes target start of combustion being an function of fuel injection timing and ignition delay, premixed combustion parameters being functions of throat radius, injection pressure and nozzle diameter, and diffusion combustion being a function of piston pit depth; solving target piston geometric parameters and target fuel injection parameters based on the mapping relation; and then designing a combustion system.

Abstract: A method for a three-dimensional temperature and salinity field, including: based on multi-source marine environmental data, analyzing the spatiotemporal distribution characteristics of marine dynamic environmental elements, and studying the characteristics of the temperature-salinity relation; on the basis of analysis of the spatiotemporal characteristics and study of the characteristics of the temperature-salinity relation, establishing a statistical prediction model of marine environmental dynamic elements by a spatiotemporal empirical orthogonal function method; based on the observation data of temperature and salinity obtained by the marine transportation platform, correcting a marine environment forecast field around the marine transportation platform by using a realtime analysis technology of a marine environment field; and adjusting the salinity using a temperature-salinity relation curve after the temperature and salinity are forecasted.