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 signal processing system and method for a radiation detector based on a metal oxide semiconductor (MOS) transistor are disclosed. The signal processing system includes a power supply generation module, an analog signal processing module, and a digital signal acquiring-processing module. The power supply generation module provides a novel power supply method, and converts a positive high voltage power supply into a negative high voltage power supply to supply power to a last dynode of a photomultiplier tube (PMT). The analog signal processing module converts a negative current pulse signal into a voltage difference signal. The digital signal acquiring-processing module acquires a signal of the analog signal processing module, and converts the signal into a digital signal for identification.

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.

Abstract: A liquid ammonia phase-change cooling type hybrid power thermal management system. The system comprises an injector, a liquid ammonia hydrogen supply system, a liquid ammonia common rail pipe, a fuel oil common rail pipe and an oil tank, wherein the liquid ammonia hydrogen supply system comprises a liquid ammonia storage tank, an ammonia pumping system, a flow dividing system and an ammonia inlet and outlet system, the fuel oil common rail pipe is respectively connected with the oil tank and a one-way oil inlet of the injector, the liquid ammonia common rail pipe is respectively connected with the ammonia inlet and outlet system and a one-way ammonia inlet of the injector, an ammonia inlet pipe and an ammonia return pipe are arranged in the ammonia inlet and outlet system, the ammonia pumping system comprises a liquid ammonia storage flow divider, a low-pressure pump and a high-pressure pump.

Abstract: The present disclosure provides a semi-physical simulation test bench and test method for a multi-machine parallel operation device of gas turbines. The gas turbines are all connected with gearbox shafts through SSS clutches, torque meters and couplers, and then a hydraulic dynamometer, an electric turbine dynamometer and a generator are independently or jointly driven through couplers and torque meters so as to charge a storage battery. Multi-shaft gearboxes comprise parallel operation gearboxes, and are connected with a bridging gearbox through couplers, electromagnetic clutches, supports, torque meters and couplers. The gas turbines can drive an electric dynamometer and the electric turbine dynamometer independently or cooperatively, so that the system has good operation characteristics under different working conditions. Meanwhile, the storage battery is additionally arranged, the flexibility of the test bench is improved, and the energy utilization rate is increased.

Abstract: The present disclosure provides a lubrication analysis method for a stern bearing based on magnetic-hydraulic composite support coupling, including: performing structural deformation analysis on a stern bearing on the basis of a magnetic support analysis result and a lubrication support analysis result to obtain a structural deformation amount, correcting a water film thickness, repeating lubrication and interface characteristics analysis to obtain water film pressures before and after correcting, comparing the water film pressures to determine whether convergence occurs, solving for a load carrying capacity of the stern bearing on the basis of the analysis result if the convergence occurs, determining whether the load carrying capacity is balanced with an input load, and calculating a bearing wear depth of the stern bearing on the basis of a contact force of a micro-convex body if the load carrying capacity is balanced with the input load.

Abstract: The disclosure belongs to the technical field of integrated navigation under non-ideal conditions, and in particular relates to a robust filtering method for integrated navigation based on a statistical similarity measure (SSM). In view of the situation that there are normal beam measurement information of the DVL and beam measurement information with a large error simultaneously in a SINS/DVL tightly integrated system, and aiming at the problem that the existing robust filters of an integrated navigation system process the measurement information in a rough manner and are likely to lead to loss of normal measurement information, the disclosure proposes a novel robust filtering method based on decomposition of multi-dimensional measurement equations and the SSM.

Abstract: A method and a system for evaluating and simulating a nuclear power plant based on a model are provided, which includes a plant top-level demand module, a function realization module, a logical architecture construction module, an evaluation and simulation configuration module, a function evaluation module, an overall performance evaluation module, a data information communication module and a model base module.

Abstract: Disclosed is a double-layer oil film lubrication analysis method and system based on a floating bushing. The method includes: determining a roller motion track and a floating bushing motion track according to a roller displacement and a floating bushing displacement; determining, when the motion tracks are closed end to end, minimum values of inner-layer and outer-layer oil film thickness of the floating bushing according to an oil film thickness at each moment; and determining that an abnormality exists in double-layer oil film lubrication when either of the minimum values of the inner-layer and outer-layer oil film thickness of the floating bushing is less than a preset oil film thickness threshold value. According to the present disclosure, more accurate abnormality analysis of double-layer oil film lubrication can be realized.

Abstract: A reduced-scale model experimental device of coupling responses in deep-water J-lay operation is used for studying a coupling response characteristic of a pipeline and a pipe-laying ship in the deep-water J-lay operation under a wave load, a pipe-laying ship model is connected to a center of an adjustable horizontal mooring mechanism, a deep-water pipeline model mainly comprises a polypropylene pipe and stainless steel powder filled in an interior of the polypropylene pipe, two ends of the deep-water pipeline model are respectively connected with the pipe-laying ship model and a seabed simulation mechanism through a pipeline departure angle control mechanism and an anchor end connection mechanism, the device fully ensures a mechanical similarity between the pipeline model and a real pipeline.

Abstract: A strapdown inertial navigation heave measurement method using multiple low-pass filter units includes: firstly, collecting data of a gyroscope and an accelerometer by a system, obtaining attitude information of a carrier by using initial alignment, and then, obtaining a relationship matrix between a body coordinate system and a geographic coordinate system by using the attitude information; obtaining a relationship matrix between the geographic coordinate system and a reference coordinate system according to a geographic position, and obtaining a rough vertical acceleration by using a direction cosine matrix, output information of the accelerometer and gravity information; then, filtering out low-frequency signals by using a first filter unit and integration to obtain a relatively accurate velocity signal; and furthermore, enabling the vertical acceleration to be subjected to a second filter unit and integration to obtain an accurate heave displacement.

Abstract: Disclosed is a self-adaptive horizontal attitude measurement method based on motion state monitoring. Based on a newly established state space model, a horizontal attitude angle is taken as a state variable, an angular velocity increment ??b for compensating a random constant zero offset is taken as a control input of a system equation, and a specific force fb for compensating the random constant zero offset is taken as a measurement quantity. Meanwhile, judgment conditions for a maneuvering state of a carrier are improved, and maneuvering information of the carrier is judged by comprehensively utilizing acceleration information and angular velocity information output by a micro electro mechanical system inertial measurement unit (MEMS-IMU), whereby a measurement noise matrix of a filter can be automatically adjusted, thereby effectively reducing the influence of carrier maneuvering on the calculation of a horizontal attitude.

Abstract: A method for calculating coupled lubrication and dynamics characteristic parameters of a flanged bearing includes three modules: a flanged bearing journal-trust thermal elastohydrodynamic coupled lubrication module, a flanged bearing dynamics characteristic parameter calculation module and a flanged bearing relative position feedback module. It considers the joint motion law of the journal part and the thrust part, and also considers the flow, pressure and thermal continuity conditions of the lubricant on the common boundary of the flange bearing, and finally forms the journal-thrust transient coupled lubrication analysis method of the flange bearing. On the basis, considerations are further given to the stiffness and the damping characteristics of the flanged bearing under the coupled effect, thereby achieving accurate simulation of the dynamic and the tribology performance of the flanged bearing, and solving the problem of lubrication failure of the flanged bearing.

Abstract: The present disclosure relates to an online monitoring method of a nuclear power plant system based on an isolation forest method and a sliding window method. An isolation forest method used in the present disclosure is an abnormal detection model based on the idea of binary tree division, and has no requirements on the dimension and linear characteristics of monitoring data. In view of the characteristics of strong nonlinearity and high dimension of operation data of the nuclear power plant system, in the process of state monitoring, system abnormalities can be detected more quickly and accurately. In the present disclosure, a sliding window method is used to improve an isolation forest model, so that the improved isolation forest model has the functions of model online updating and real-time state monitoring, and the usability of an isolation forest state monitoring method is enhanced.

Abstract: A tensegrity offshore wind power generation support structure is provided, relating to the technical field of offshore wind power. The support structure includes inclined columns, prestressed cables, a rigid support, a floating foundation and anchoring systems. A stable self-balancing space supporting structure is formed by the inclined columns and the cables; the inclined columns inclines outwards, upper parts of the inclined columns are connected with the prestressed cables; the bottom ends of the inclined columns are connected with the floating foundation; the middle parts of the inclined columns are connected with the rigid support; and the floating foundation is fixed with a seabed through the anchoring systems. According to the support structure, a tower in the traditional design is not needed, and all the cables are ensured to be in a tension state through the support of the inclined columns.

Abstract: The present disclosure provides an efficient vibration reduction and isolation base supported by a chained panel fluid bladder, including a chained panel, the vibration reduction fluid bladder, vertical limiting devices and a bottom plate. The chained panel is a discontinuous structure formed by connecting chained substructure panels in series by panel hinge devices. The vibration reduction fluid bladder and the vertical limiting devices are fixedly installed between the chained panel and the bottom plate. The chained panel is constructed based on the impedance mismatch principle and provided with a mechanical device. Mechanical vibration energy is dissipated twice by the chained panel and the vibration reduction fluid bladder, thereby greatly reducing influences of mechanical device operation on a hull structure.

Abstract: A device for measuring a wall surface cooling characteristic of a gas turbine combustor and a modeling method thereof are provided. The device includes a hot flow inlet section, a cold flow inlet section, and a gas discharge section, where the cold flow inlet section is communicated with an experimental section; the cooling structure model is a flat plate structure; a tail end of the experimental section is provided with a thermocouple threading seat; the gas discharge section is provided with a laser injection window; and the experimental section is provided with an infrared thermal imaging measurement window and a visual observation window. The modeling method includes: modeling the wall surface of the gas turbine combustor into the flat plate structure; determining a pressure, a temperature, and a velocity on a hot flow side of the device; and determining a material and a thickness of the cooling structure model.