Abstract: According to various aspects of the present invention, a positive electrode composition for a lithium-ion secondary battery includes an active material capable of inserting and extracting lithium ions, and a conductor, wherein the active material is a lithium-nickel-cobalt-manganese complex oxide; the conductor is a carbon black and carbon nanotubes; the carbon black has a BET specific surface area of 100 to 400 m2/g, and a DBP absorption of 210 to 380 ml/100 g; and the carbon nanotubes have an average diameter of 7 to 15 nm.

Abstract: A depth-stage dependent and hyperparameter-adaptive lightweight CNN-based model, named Faster R-Stair, which relates to the field of concrete crack detection technology. The structure of the backbone in this model is depth-stage dependent, which includes suitable structures in different depths. The backbone is also hyperparameter-adaptive. The basic components in different depths of the backbone have variations according to the adjustment of some hyperparameters. The proposed model in this embodiment has the advantages of high convergence speed in training, fast detection speed and high accuracy when used in crack detection.

Abstract: A three-stage modularized convolutional neural network (CNN) called Stairnet is disclosed for efficient classification of concrete cracks in images. Unlike traditional CNNs which exhibit similar structural characteristics in each layer, Stairnet is composed of three distinct parts: stair1, stair2, and stair3, each possessing its own unique structural characteristics. Stair1 exclusively consists of convolution layers, while stair2 incorporates a greater number of layers. Stair3, on the other hand, utilizes larger expansion factors and kernel size. Stair1 and stair2 exhibit various variations that result in their modification alongside certain parameters of Stairnet. In contrast to traditional CNNs utilized for the classification of thousands of classes, Stairnet stands out with its smaller model size, faster training speed, and high accuracy in classifying concrete cracks.

Abstract: An implementation for a splay state based on amplitude envelopes in the coupled oscillator system includes introducing a heterogeneous oscillator into the globally coupled identical oscillator network, when the frequency mismatch and repulsive coupling strength of the coupled heterogeneous oscillator system satisfy a certain relationship, the time series of the coupled oscillator will modulate an amplitude envelope, which can realize the generation of splay states between the amplitude envelopes of the identical oscillators except for the heterogeneous oscillator; applying the polar coordinate transformation and perturbation analysis in the condition of small coupling strength, it is easy to obtain the evolution equation of the amplitude envelope from the coupled heterogeneous oscillators. Solving the evolution equation of the amplitude envelope, the average amplitude, amplitude, and other parameters of the amplitude envelope in the splay state can be theoretically determined.

Abstract: Embodiments of the present application provide a prediction method, device and system for rock mass instability stages, and belong to the technical field of rock mass instability prediction. The method includes the steps: acquiring acoustic emission signals of rock mass; extracting feature parameters from the acquired acoustic emission signals; and predicting instability stages of the rock mass in accordance with the feature parameters and a preset back propagation (BP) neural network model, wherein the preset BP neural network model is obtained by training a BP neural network and a genetic algorithm by virtue of the feature parameters of the acoustic emission signals at different rock mass instability stages. According to the technical solution in the present application, the problem in the training process of the BP neural network model that model parameter optimization may be easily trapped in a locally optimal solution is effectively solved.

Abstract: The present disclosure discloses a method for dual-motor control on an electric vehicle based on adaptive dynamic programming. First, total torque required is calculated based on obtained data information of the electric vehicle under various driving conditions, and offline training is conducted on an execution network and an evaluation network. Then total torque is dynamically distributed for two motors of the electric vehicle under various driving conditions to obtain an efficiency MAP database. Afterwards, iteration and online learning are conducted on the execution network and the evaluation network based on data information of the electric vehicle under different driving conditions that is obtained in real time, so as to find an optimal control law for the electric vehicle under a real-time driving condition. In this way, the dual-motor control on the electric vehicle is optimized.

Abstract: The present disclosure provides a method for optimizing a liquid injection process of ionic rare earth ore, including the following steps of: 1) testing the hydraulic properties of an ore body; 2) determining the diffusion degree of the ore body; 3) determining the spatial distribution of the rare earth grade and the impurity grade of the ore body prior to leaching; 4) determining model parameters of competitive exchange of rare earth ions and impurity ions with ammonium ions; 5) obtaining distribution of rare earth ion concentration within the ore body after completion of leaching; 6) obtaining a profile plot of a rare earth leaching rate as a function of the concentration and dosage of an injected leaching agent; and 7) determining a minimum leaching agent dosage to achieve a target leaching rate according to the profile plot, and then determining the ammonium sulfate concentration according to the minimum leaching agent dosage.

Abstract: The present disclosure relates to a method for determining a source sink term of an ionic type rare earth ore leaching process. The method includes the following four steps: (1) determining an ion exchange selection coefficient of a rare earth ore sample; (2) determining the rare earth grade of the rare earth ore sample; (3) building a source sink term model of the ore leaching process; and (4) determining parameters in the source sink term model. The present disclosure can simulate the ionic type rare earth ore leaching process by combining a convection-dispersion equation, and determine the optimal concentration of the ore leaching agent. When an ammonium sulfate solution at an optimal concentration of 12.0 g/L is used to perform a column leaching test, the obtained rare earth leaching rate is up to 96.3 percent.

Abstract: An evaluation method for corrosion damage evolution of underwater concrete structures includes performing the time reversal test on the concrete beam specimen placed in the water, performing the uniaxial compression test on the concrete cube specimens; immersing the concrete beam specimen and the concrete cube specimens in a hydrochloric acid solution, and performing the time reversal test on the concrete beam specimen on the 10th, 20th and 30th days respectively. At the same time, a concrete cube specimen is taken out to perform the uniaxial compression test on the 10th, 20th and 30th days respectively; and using the above calculation results to evaluate the corrosion evolution process thereof without damaging the underwater concrete structure.

Abstract: A boundary adaptive structural fatigue damage detection method driven by time-domain information entropy comprises a sensor sequence composed of several sensors arranged on the structure, which is used to apply excitation to the structure, collect the displacement time-history response curves at different positions on the structure, and establish a database of time-history data. According to the data set in the database, the information entropy of the time-history response at different positions on the acquisition structure is obtained based on the information entropy to measure the disorder degree of the time-domain response signal. According to the location of several sensors, the information entropy values of the time-history response are connected in turn to obtain the time-history information entropy curve of the whole structure. Analyze of time-history information entropy curve, and the information entropy curve will show jump phenomena to determine the location of the crack.

Abstract: A damage identification method for a cantilever beam based on a multifractal spectrum of a multi-scale reconstructed attractor includes: acquiring an original acceleration signal of the cantilever beam by a dynamic measurement system, performing stationary wavelet decomposition on a pretreated acceleration signal to obtain multi-scale sub-signals, selecting the multi-scale sub-signal that can represent main vibration characteristics of the cantilever beam for phase space reconstruction and normalization to obtain a normalized multi-scale reconstructed attractor, constructing the multifractal spectrum of the multi-scale reconstructed attractor, establishing a damage index based on a singularity index of the multifractal spectrum, and identifying and locating damage of the cantilever beam according to a relative numerical value of the damage index.

Abstract: A cable tension calculation method simultaneously considering the sag, inclination angle and bending stiffness includes: querying basic parameters of a stay cable according to design data and construction data; considering influences of the sag, the inclination angle ? and the bending stiffness EI, to calculate dimensionless parameters ?, ? and ?2; testing an acceleration response of the stay cable by an acceleration sensor, to identify a frequency ? of the acceleration response of the stay cable, further calculating a dimensionless frequency {circumflex over (?)} of the stay cable and the dimensionless parameters ?, ? and ?2, and substituting the dimensionless frequency {circumflex over (?)} of the stay cable into a vibration characteristic equation, to establish a function relation between the dimensionless frequency {circumflex over (?)} and a cable tension H* of the stay cable; and solving a root of the vibration characteristic equation, and identifying the cable tension H* of the stay cable according to

Abstract: A structural dynamic parameter identification method aided by a rPCK surrogate model comprises the following steps. Establish a finite element model that roughly reflects the structural system to be analyzed. Establish the dynamic parameter space sample set. The structural system response space sample set driven by the dynamic parameter space sample set is established by using the probabilistic finite element analysis. The robust polynomial Chaos Kriging surrogate model is obtained by mapping the dynamic parameter space sample set to the structural system response space sample set. The measured structural system response is used to drive the rPCK surrogate model, and then Bayesian inference is used to identify the structural dynamic parameters. The mean value of Bayesian posterior estimation is used as the estimated value of structural dynamic parameters. The proposed method creates conditions for establishing a high-fidelity finite element model of the actual engineering structural system.

Abstract: The present invention provides a rare earth hard alloy and a preparation method and application thereof. The rare earth hard alloy includes 6 to 15 wt % of a binding phase and the balance of a hard phase, wherein the binding phase includes 30 to 50 wt % of Ni3Al, 0.1 to 0.5 wt % of a rare earth element and the balance of Ni. According to the rare earth hard alloy provided by the invention, the Ni—Ni3Al-rare earth element (e.g., Ni—Ni3Al—Y)-based binding phase is strengthened by Ni3Al, and an ordered strengthening phase is formed and is diffused and distributed in the binding phase, such that the rare earth hard alloy has a better high-temperature oxidation resistance, a better room-temperature fracture toughness and a better high-temperature bending strength than a conventional hard alloy.

Abstract: A high-strength and high-plasticity TWIP steel and a preparation method thereof are disclosed. In the disclosure, comprehensive properties of TWIP steel are improved by inclusion modification with Ce and Ba addition, fine grain strengthening and twinning nanocrystallization; the grain size is controlled by a low-temperature cold rolling, a transient annealing treatment and a low-temperature tempering treatment. Considering the addition of Ce, stacking fault energy of the TWIP steel is reduced, and the formation of twins, and the division of twins into grains are promoted, which further reduces a mean free path of dislocation motion, thereby improving yield strength, and finally obtaining a high-strength and high-plasticity TWIP steel.

Abstract: The present disclosure provides rare earth die steel. Mg and B elements are added on the basis of adding rare earth element Y, so that the rare earth element purifies a matrix, and grain boundary occupation by Mg and B is fully utilized to regulate grain network chromium carbides. In addition, the B element can fully improve hardenability of austenite and ensure that non-martensite such as bainite does not appear during the cooling process, and therefore rare earth die steel with high impact toughness and high isotropy is obtained.

Abstract: The embodiments of the present invention provide a crushing cavity structure for the technical field of crushing cavities of cone crushing equipment.

Abstract: An ultrasonic thrombus removing system includes a front sheath tube (1) and a rear sheath tube (5) that are independent and that are inserted into a blood vessel (2); a rear end outer portion of the front sheath tube (1) is mounted with a front blocking balloon (105), and a front end outer portion of the rear sheath tube (5) is mounted with a rear blocking balloon (504); a breaking cavity (4) being formed between the two blocking balloons; the front blocking balloon (105) and the rear blocking balloon (504) expand or contract in the blood vessel (2) by means of the squeezing or loosening of an external force so as to block or open front and rear sides of the thrombus (3); an inner portion of the rear sheath tube (5) is provided with a core tube (502) that co-axially penetrates therethrough, a front end of the core tube (502).

Abstract: The present invention discloses a method for effectively decomposing mixed wolframite and scheelite ore in an alkaline system, specifically comprising steps of: grinding mixed wolframite and scheelite ore, putting in an autoclave, adding an appropriate amount of water, and then adding sodium phosphate, sodium hydroxide and calcium fluoride for decomposition, and treating by solid-liquid separation to obtain crude sodium tungstate solution. The present invention has the advantage that the high-efficiency decomposition of the mixed wolframite and scheelite ore can be realized with low consumption of leaching agents. By this method, the mixed wolframite and scheelite ore can be directly treated by an existing tungsten smelting autoclave, with low leaching cost, high decomposition rate and easy industrial application.

Abstract: An automatic harvesting and collecting device for sisal hemp leaves includes an up-and-down moving assembly, a steering device, a braking mechanism, a mechanical vision sensor device, a vehicle traveling and controlling device, a forward-and-backward moving assembly, an omnidirectional automatic positioning and rotating device, a shearing and clamping device, a collecting device and a frame.