Abstract: A self-adaptive compensation method for feed axis thermal error, which belongs to the field of error compensation in NC machine tools. First, based on laser interferometer and temperature sensor, the feed axis thermal error test is carried out; following, the thermal error prediction model, based on the feed axis thermal error mechanism, is established and the thermal characteristic parameters in the model are identified, based on the thermal error test data; next, the parameter identification test is carried out, under the preload state of the nut; next, the adaptive prediction model is established, based on the thermal error prediction model, while the parameters in the measurement model are identified; finally, adaptive compensation of thermal errors is performed, based on the adaptive error prediction model, according to the generated feed axis heat.

Abstract: Disclosed is a method for designing a reentry trajectory based on flight path angle planning, including the following steps: S1. extracting an actual operating parameter of an aircraft, setting a maximum dynamic pressure qmax a maximum stagnation point heat flux {dot over (Q)}max, and a maximum overload nmax according to a mission requirement, and solving for a velocity-height boundary of a reentry trajectory; S2. solving for a reentry trajectory in an initial descent stage according to differential equations of reentry motion, and setting up a flight-path-angle lower limit ?min(V) according to the reentry trajectory in the initial descent stage, the velocity-height boundary, and a target point in a velocity-height phase plane; and S3. planning, based on the flight-path-angle lower limit ?min(V), a flight path angle satisfying terminal constraints, and calculating a corresponding bank angle to obtain a reentry trajectory.

Abstract: A method for predicting a structural failure by a strength-criterion-driven peridynamic model is provided. By building a peridynamic model driven by the strength-criterion of structural materials and then applying geometric and material parameters and working conditions of a structure, a life period from a deformation to a complete break of the structure is predicted. The method is of a high reliability, a wide application range, and a high calculation efficiency. The method simulates an initiation and a propagation of multiple cracks on complex structures under complex load conditions until the structure is destroyed.

Abstract: The present invention discloses a method, device and computer readable storage medium (CRSM) for generating a volume foliation. The method comprises: constructing a pants decomposition graph on a smooth closed surface S of genus g>1, wherein the surface S has g handles, and the pants are a genus-zero triangular mesh surface with g boundaries; constructing an initial mapping f0:(T,g)?(Gr, h) from a tetrahedral mesh T to a graph Gr by a process of extending a topological disk Dk into a solid cylinder Ck; evolving the initial mapping into a generalized harmonic map by the nth iterative mapping; and obtaining a volume foliation of the tetrahedral mesh T from preimages of all nodes of a metric graph (Gr, h) and points on edges of the metric graph (Gr, h) under the generalized harmonic map f.

Abstract: An underwater towing test device including a driving mechanism, an observation platform disposed under the driving mechanism, a towing member, and a towed body. The driving mechanism includes an operation platform, an extended platform connected to the operation platform, a crane, a first railing, a lifebuoy, a control center, a power distribution room, and a plurality of bus ports. The operation platform includes two rail grooves disposed in parallel and a moon pool provided with two pool slots on both ends thereof. The crane includes a chassis provided with a plurality of first guide rollers. The first railing is positioned along the edge of the operation platform and the extended platform, with the lifebuoy hanging thereon. The control center, the power distribution room, the plurality of bus ports, and the moon pool are fixedly disposed on the operation platform.

Abstract: A thermal insulation property measuring device, including a tank, a thermal insulator, a cuboidal frame, a support bracket, and a data collector. The tank includes an upper body, a first lower body, and a second lower body. The thermal insulator includes a first thermal insulation layer, a second thermal insulation layer, a first membrane, a second membrane, and a third membrane. The support bracket includes a trapezoidal support and a transition support. The tank is disposed on the support bracket. The support bracket is disposed in the cuboidal frame. The upper body, the first lower body, and the second lower body are spherical and communicate with each other. A filling tube, a pressure relief tube and a piezometer tube are disposed on the upper body. The first membrane is disposed on the tank. The first thermal insulation layer is coated on the first membrane.

Abstract: An inertial mass amplification type tuned mass damper is disclosed. The inertial mass amplification type tuned mass damper comprises a hollow box, an H-shaped mass block, gears a, gears b, a rectangular frame, a steel ring, viscous dampers, a steel sheet, springs, rotating shafts and balls. In the present invention, an inertial damping force is amplified by adjusting the radius ratio of the gears a and the gears b; and damping parameters can be conveniently changed by adjusting the mass of the mass block, the spring stiffness and the like. The present invention has the advantages that the design mass is small, which can avoid the adverse effects of excessive additional gravity on the structure and improve the performance of the structure. The present invention has reasonable design and small occupied space, can save more use area for buildings and can greatly improve the utilization efficiency of the buildings.

Abstract: The present invention belongs to the technical field of underwater communication, and provides a novel highly robust underwater optical communication system which comprises a sending module and a receiving module. The novel highly robust underwater optical communication system realizes highly robust underwater optical communication under strong interference of sunlight and artificial light sources. The system uses a new physical method irrelevant to frequency, and can be used with existing MIMO and CDMA to obtain better communication effects. The circularly polarized light is used for signal transmission, thereby avoiding the problem of channel misalignment caused by the rotation of a platform underwater. At the same time, good polarization maintaining of a marine environment makes the signal characteristics difficult to lose.

Abstract: The present invention provides a method for manufacturing a curved thin-walled intermetallic compound component by winding a mandrel with metal foil strips, which comprises the following steps: designing a prefabricated blank; preparing a support mandrel; determining thicknesses and layer numbers of foil strips; determining widths of the foil strips; establishing a laying process; pretreating surfaces of the foil strips; laying A foil and B foil; carrying out bulge forming on the prefabricated blank; carrying out diffusion reaction and densification treatment on a bulged component; and carrying out subsequent treatment of a thin-walled component. The present invention can solve the problems that impurities generated in the separation process of a support mould and a laminated foil prefabricated blank influence the final performance of a part, and a single homogeneous intermetallic compound component in thickness direction has poor plasticity and toughness at room temperature.

Abstract: The present disclosure discloses an ultrasonic cutting holder for a honeycomb core, including a holder, a swing mechanism, a transducer, a first-stage amplitude transformer, a second-stage amplitude transformer, an ultrasonic cutting tool, and an ultrasonic power transmission mechanism. The present disclosure provides an ultrasonic cutting holder for a honeycomb core with large amplitude output capacity and considering the interchangeability requirements among different vibration systems, which solves the problem of the applicability of ultrasonic cutting holder on the universal machine tool and improves the automation level of ultrasonic cutting.

Abstract: A practical method for short-term operations of large-scale hydropower plants divides all hydropower plants into three categories using operation characteristics such as system hierarchy, space attributes, task requirements, and schedule particularity. A strategy for adjusting spillage based on peak-shaving response and a strategy for equal load reduction in off-peak hours check and adjust power generation of hydropower plants with specified dispatching modes. For medium- and small-sized cascaded hydropower plants, the load distribution among plants is optimized with an objective of minimizing total power release subject to control condition of total generation profile. For large-size cascaded hydropower plants, an optimization model for peak-shaving operations and a method for balancing power plants with equal load rate are combined to respond to system peak demands and guarantee power balance in all periods.

Abstract: Disclosed are a universal alpha-olefin polymerization industrial catalyst, and an application thereof, specifically an industrial production catalyst which consists of (A) a solid catalyst component, (B) a cocatalyst organoaluminium compound and (C) an external electron donor compound, and is used for various alpha-olefin polymerization or copolymerization processes. The solid catalyst component (A) is prepared from a dibutyl phthalate or diisobutyl phthalate and 9,9-bis(methoxymethyl)fluorene composite internal electron donor. A hydrocarbyl alkoxy silicon, an organic acid ester or a hydrocarbyl alkoxy silicon and organic acid ester composite acts as the external electron donor component (C). The solid catalyst component (A), the cocatalyst organoaluminium compound (B) and the external electron donor compound (C) are used together in industrial devices for various alpha-olefin polymerization or copolymerization processes to produce new grades of poly-alpha-olefins.

Abstract: The present invention provides a CT triaxial test apparatus for hydrate-bearing sediment, and belongs to the technical field of fundamental physical property measurement of geotechnical engineering. In the apparatus, aiming at the defects of the invention “a visual test apparatus for mechanical characteristics of natural gas hydrate-bearing sediment”, the CT triaxial test apparatus for hydrate-bearing sediment is redesigned and optimized, on the premise of obtaining static and dynamic mechanical characteristics and creep characteristics of a hydrate reservoir, the stability of the triaxial apparatus during rotation due to scanning, the temperature control accuracy of a hydrate-bearing sample, and the X-ray penetration performance of the pressure chamber of the triaxial apparatus are improved, an optimal CT imaging effect is obtained, and powerful hardware support is provided to ascertain the reservoir deformation mechanism during hydrate decomposition.

Abstract: Square section liquid metal batteries (LMBs) with a grid device to suppress instabilities of fluids. The LMBs include a shell, negative current collector, negative material, metallic nets/plates, grid device, electrolyte, positive material, rectangular holes on partitions of grid device, and positive current collector. The positive material, electrolyte, and negative material are filled in the shell and automatically stratified from bottom to top according to the density from large to small. The negative current collector is linked with negative material, and the positive current collector is linked with positive material. The grid device is composed of partitions which cross each other and pass through the negative material, the electrolyte vertically in sequence, and extend inside the positive material. There are rectangular holes opened on the grid device, and the vertical height of each rectangular hole is larger than the biggest displacement of electrolyte during charging and discharging processes.

Abstract: The present invention belongs to the technical field of multiple bolt transverse load loosing testers, and relates to a closed loop control method for transverse load amplitude of multiple bolt loosing tester. The closed loop control method is used to conduct stepless amplitude modulation and accurate control for transverse loads of a multiple bolt loosing tester, thereby realizing stepless amplitude modulation and accurate control for the transverse loads. The closed loop control method is realized based on the multiple bolt loosing tester. The multiple bolt loosing tester consists of four parts: a transverse load amplitude control part, a transverse load transmission part, a torque load transmission part and an axial load transmission part. The present invention can provide stepless amplitude modulation continuous transverse loads for a flange bolt set and guarantee the accuracy of the transverse loads through a closed loop control system.

Abstract: The present invention provides a method of dense 3D scene reconstruction based on monocular camera and belongs to the technical field of image processing and computer vision, which builds the reconstruction strategy with fusion of traditional geometry-based depth computation and convolutional neural network (CNN) based depth prediction, and formulates depth reconstruction model solved by efficient algorithm to obtain high-quality dense depth map. The system is easy to construct because of its low requirement for hardware resources and achieves dense reconstruction only depending on ubiquitous monocular cameras.

Abstract: An integrated method for manufacturing a high-temperature resistant thin-walled component by preforming by laying a metal foil strip. The integrated manufacturing method includes: designing a preform, preparing a support die, determining a thickness of a foil strip, determining a width of the foil strip, developing a laying process, laying an A foil strip and a B foil strip, obtaining an AB laminated preform, bulging the preform, performing a reactive synthesis and a densification process of a bulged component, and performing a subsequent treatment of the thin-walled component. Various embodiments obtain an integral thin-walled preform with a complex structure, a uniform wall thickness and a shape close to the final part by continuously laying a metal foil strip with an appropriate width.

Abstract: The present invention discloses a method for fault diagnosis of the sensors and actuators of an aero-engine based on LFT, and belongs to the field of fault diagnosis of aero-engines. The method comprises: establishing an aero-engine state space model using a combination of a small perturbation method and a linear fitting method; establishing an affine parameter-dependent linear-parameter-varying (LPV) model of the aero-engine based on the model; converting the LPV model of the aero-engine having perturbation signals and sensor and actuator fault signals into a linear fractional transformation (LFT) structure to obtain an synthesis framework of an LPV fault estimator; solving a set of linear matrix inequalities (LMIs) to obtain the solution conditions of the fault estimator; and designing the fault estimator in combination with the LFT structure to realize fault diagnosis of the sensors and actuators of an aero-engine.

Abstract: The present invention discloses an interface ultrasonic reflectivity-pressure relation curve establishment method and a loading testbed. The loading testbed comprises a force displayer, a control terminal, an oscilloscope, an immersion ultrasonic transducer, a large cylinder, a small cylinder, an upper panel, a movable plate, a force sensor, a lower panel, an ultrasonic transceiver and a small cylinder connecting plate. Compared with the existing schemes, the interface ultrasonic reflectivity-pressure relation curve establishment method and the loading testbed provided by the present invention can construct a more accurate ultrasonic reflectivity-pressure relation curve, and are high in detection precision.

Abstract: The present invention discloses a ventilator with dual flow passages. There is a mode switcher on the partition board. The ventilator has a variety of operating modes, such as, the natural or mechanical driving mode according to outdoor wind speed, and single-effect or multi-effect filtration according to the outdoor air pollution conditions. The single-effect filtration uses only the primary-efficiency filter, while the three-effect filtration uses the primary-, medium-, and high-efficiency filters. The mode switcher on the partition board can open or close the by-pass baffle to bypass or go through the medium- and high-efficiency filters for switching between the single-effect and multi-effect filtration. In case some indoor pollution sources need to be removed quickly, the recirculated indoor air filtration can be run. In such situation, the primary-efficiency filter in the mechanically-driven flow passage is bypassed, while the fan drives indoor air passing the medium- and high-efficiency filters.