ZHENGZHOU UNIVERSITY

The invention discloses a kind of micrometer-scale porous sodium ferrous sulfate/carbon composite cathode materials and sodium-ion or sodium batteries with it. The materials are prepared by a co-precipitation and solid-phase calcination method, and/or involve the metal-doped elements. The materials feature a porous structure with a three-dimensional conductive network, and have a size distribution (2-30 μm) of particles, consisting of a close stack of primary particles of 80-200 nm tightly covered by an amorphous carbon. Micrometer-scale cathode materials deliver a high vibration density, which helps to improve the volumetric energy density of batteries. As a cathode for sodium-ion or sodium batteries, the materials have the advantages of abundant raw materials, low cost, high operating voltage, good rate performance and cycling stability, and simple preparation process. The assembled sodium-ion or sodium batteries show a broad market application prospect with the advantage of high energy density.

A vibratory grouting rod with drilling and vibrating functions includes: a drill bit, a vibration part, a flexible shock absorption device, a slotted connection part, a connection tail part, and a rigid-flexible conversion device; wherein the vibration part, the flexible shock absorption device, the slotted connection part and the connection tail part are sequentially jointed to form a grouting rod body, and the grouting rod body has a holding cavity; the drill bit is provided at a front end of the vibration part; and the rigid-flexible conversion device is movably sleeved on the flexible shock absorption device, which is configured to move up and down in a bar-shaped slot of the slotted connection part. The rigid-flexible conversion device can be pushed down to a rigid mode for drilling, and pulled up to a flexible mode for grouting with vibration concentrated around the vibration part.

A simulation method of shield tunnel segment floating includes steps of dividing a flow field into grids, obtaining numbers and center coordinates of control bodies, and setting flow field boundary conditions; initializing flow field parameters and calculation parameters; updating the area velocity of the control bodies in the current time step; discretizing the flow field control equation, and solving iteratively the flow field velocity and pressure; updating the velocity and position coordinates of the boundary discrete points; obtaining the velocity of the boundary discrete points, calculating the force generated by the boundary discrete points and discretizing the force to the whole flow field; and finally transmitting the velocity of the boundary discrete points, the force applied to each unit of the flow field, the force applied to the boundary discrete points and the updated slurry viscosity in the current time step to the next time step.

A friction resistance testing device for a side wall of a pipe jacking machine includes: a shell, a pressure gauge unit, a pulley ( 3 ) and a sensing block ( 4 ); wherein the pressure gauge unit, the pulley ( 3 ) and the sensing block ( 4 ) are provided in the shell ( 1 ); the pressure gauge unit is fixed to the shell ( 1 ); the pulley ( 3 ) is provided between the sensing block ( 4 ) and the pressure gauge unit; the sensing block ( 4 ) presses the pressure gauge unit in a horizontal direction to measure a side wall friction resistance; and the sensing block ( 4 ) presses the pressure gauge unit in a vertical direction to measure a soil pressure. The present invention further provides a method for adopting the friction resistance testing device for the side wall of the pipe jacking machine.

A method for lifting a subway shield tunnel by polymer grouting includes steps of: detecting settlement of the shield tunnel, and determining a settlement location, a settlement range and a settlement amount; drilling a row of isolation barrier holes on both sides of a settlement repair area, and injecting quick-setting slurry so that two isolation barriers are formed; drilling grouting channel holes from ground, and then drilling horizontal grouting holes below the settlement; connecting grouting pipes to geotextile bags, and feeding the geotextile bags into each of the grouting holes in turn; using a polymer grouting system to inject polymer slurry into the geotextile bags, wherein the polymer slurry then expands to lift up a soil layer above and jack up a tunnel structure; and after lifting, filling and sealing the grouting channel holes. The method is efficient and convenient without the need for maintenance.

This invention disclosed a full-space intelligent detection method and system for underground drainage networks, as well as storage media, including the following steps: image acquisition, intelligent image denoising, internal pipe defect segmentation, concealed defect detection around the pipe, 3D reconstruction with volume quantification, and pipeline life prediction. This invention introduced a bionic four-wheel-drive, all-terrain detection robot that can effectively navigate through mud and flowing water-challenges that hinder traditional detection devices. By leveraging deep learning algorithms as well as various techniques of computing vision, 3D reconstruction, and point cloud processing, the system thoroughly analyzed collected data to determine defect types and precise locations. Utilizing this analysis, precise location of different defect type and quantitative measurement of their dimensions can be realized. Based on the data analysis results, a deep-learning driven model was developed for predicting pipeline longevity to support maintenance staff with timely information on pipe defects and operational lifespan.

In a method for mineral comminution energy determination and intelligent liberation degree identification based on morphological characteristics of particles, magnetite ore is comminuted with a drop weight impact testing machine and then subjected to particle size classification. Liberation degrees of the comminuted particles of some particle size classes with small relative particle sizes when different comminution energy is applied are detected and recorded using a mineral liberation analyzer. Profiles of liberation degrees of different minerals are established according to the detected data. The profiles are analyzed to determine appropriate comminution energy E, and then the comminuted particles of the particle size classes with the comminution energy are scanned by an electron microscope to obtain electron microscope images. Proportions of intergranular fractures of the particle size classes are counted. Comminution energy E1 corresponding to the particle size classes is calculated based on a function.

This invention unveils an optical microphone utilizing diamond cantilevers and its associated acoustic sensing system. The core component is a diamond cantilever, featuring a diamond diaphragm with a centrally located U-shaped groove. The manufacturing process involves several key steps: initially preparing the diamond diaphragm using silicon in a chemical vapor deposition setup, where methane and hydrogen are reacted under specific temperature and pressure conditions to form a diamond polycrystalline film on the silicon. This film is then separated from the substrate to create the diaphragm. Subsequently, a U-shaped groove is crafted on the diaphragm by applying a dry etching template and etching, resulting in the formation of the diamond cantilever, with a thickness ranging from 10 to 100 μm. This method establishes a novel approach to creating sensitive and durable optical microphones.

Provided is a beam-column joint of a prefabricated self-centering RC (Reinforced Concrete) frame based on an SMA (Shape Memory Alloy) material, including an RC precast column, an RC precast beam, and self-centering energy dissipation dampers arranged, and a friction energy dissipation damper. The self-centering energy dissipation damper includes an SMA kernel, an upper restraint cover plate, a lower restraint cover plate, a column-end connection reinforcing plate and a beam-end connection reinforcing plate, and a set energy dissipation gap is reserved between the SMA kernel and the upper restraint cover plate. The friction energy dissipation damper includes an in-column embedded connecting plate and a beam-end embedded connecting plate. The in-column embedded connecting plate and the beam-end embedded connecting plate each are provided with a primary connecting hole and secondary connecting holes, and each of the secondary connecting holes on the beam-end embedded connecting plate is an arc-shaped elongated hole.

Provided is a method for preparing an electrothermal heating sheet from carbon fiber braided fabric scraps, including: cutting clumps of disordered carbon fiber braided fabric scraps into chopped carbon fibers; washing the chopped carbon fibers by separately using acetone and deionized water, and drying; preparing a corresponding dispersion; adding the chopped carbon fibers to the dispersion, and fully dispersing; performing vacuum filtration by using a double-layer metal screen, and drying to obtain a chopped carbon fiber felt; cutting the chopped carbon fiber felt, sticking electrodes to two ends of the chopped carbon fiber felt, and covering thermoplastic polyurethane (TPU) sheets on front and back surfaces of the chopped carbon fiber felt to form a heating sheet product having electrothermal performance and electromagnetic shielding performance.