Abstract: A shear box of shear rheology experiment of a soft rock for simulating the coupling of the rainfall seepage and blasting vibration includes an upper shear box, a lower shear box, a normally-loading indenter, a normally-loading cushion block and a test piece joint. The upper shear box is tightly connected to the lower shear box by a vertical roll. The vertical roll passes through the through holes at both sides of the upper shear box and is engaged with the lower shear box through female thread connection holes. The normally-loading indenter passes through a circular through hole and presses against the normally-loading cushion block. The first end of the test piece joint is installed into a water or gas outlet hole, and the second end of the test piece joint is directly mortised into a rock test piece.

Abstract: A titanium disulfide-sulfur (TiS2—S) composite particle contains a titanium disulfide (TiS2) substrate having solid elemental sulfur (S) disposed directly on a surface of the TiS2. The TiS2 substrate has a layered crystalline hexagonal structure of space group P-3 ml and includes at least 100 distinct layers. The TiS2 and S are present in the composite in a weight ratio (TiS2:S) of 20:80 to 50:50. Cathodes and batteries containing the composite particle, as well as related methods, are also disclosed.

Abstract: A transformer state evaluation method combining a FAHP method, a DEMATEL method, and a CRITIC method is provided and includes: selecting a plurality of groups of state quantities, building a hierarchical indicator system; calculating an influencing degree and an influenced degree by using the DEMATEL method on a subjective level, calculating a weight of each of a plurality of indicators of an indicator layer through the FAHP method and the DEMATEL method, calculating the weights of the indicators of the indicator layer through the CRITIC method on an objective level; calculating an optimal weight according to the indicator subjective weights and the indicator objective weights; and calculating state scores layer by layer, finally determining an actual health condition of each of a plurality of transformers by combining state level classification rules. In the disclosure, the weights are calculated based on the subjective level and the objective level.

Abstract: An apparatus for testing a pressure change rate of a component in an electro-pneumatic braking system of a commercial vehicle includes a pressure change rate test bench, a pneumatic loop configured to implement on-off control of air and detection on a pressure change rate of a tested component in an electro-pneumatic braking system of a commercial vehicle, a signal processing unit configured to acquire a pressure signal and a differential pressure signal and perform analog-digital conversion on the signals to provide signals recognizable by an upper controller and a lower execution component, and a control unit configured to communicate with the pneumatic loop and drive the components in the pneumatic loop to act by setting a control parameter to obtain test data of the tested component in the electro-pneumatic braking system of the commercial vehicle in the pneumatic loop.

Abstract: A spectrally-resolved Raman water lidar, including: a transmitter unit, a receiver unit, and a data acquisition and control unit. The transmitter unit includes a seeder, a solid Neodymium-doped Yttrium Aluminum Garnet (Nd:YAG) laser, a beam expander, and a first reflecting mirror to emit a 354.8-nm laser beam. The receiver unit includes a telescope, an iris, a collimator, a second reflecting mirror, a first bandpass filter, a beam splitter, a narrow-band interference filter, a third lens, a first detector, a second bandpass filter, a coupler and a home-made dual-grating polychromator to enable simultaneous profiling of backscattered Raman spectrum signals from water vapor, water droplets and ice crystals as well as aerosol fluorescence in the atmosphere. The data acquisition and control unit includes a computer to store the acquired data and guarantee an automatic operation of the lidar system through a time-sequence circuit.

Abstract: The invention discloses a method and a system for correction of the junction temperatures of an IGBT module in a photovoltaic inverter.

Abstract: Provided is an apparatus containing, as a cathode catalyst, a metal oxide/carbon catalyst composition. The metal oxide/carbon catalyst composition includes 40 to 95 wt % porous Mn—Co spinel oxide nanoparticles of the formula MnxCo3-xO4. The nanoparticles have an octahedral morphology, an average particle size of 5-100 nm, and average pore sizes of 1-5 nm (where x is the atomic fraction of manganese and 3-x is the atomic fraction of cobalt). The metal oxide nanoparticles are supported on a carbon substrate that contains at least 96 atomic % carbon.

Abstract: A method and a system for predicting remaining useful life of an analog circuit are provided. A simulation model of the analog circuit is built, and an output voltage is selected as a degradation variable. Different degradation cycles are set to extract degradation features of the output voltage. Key features that can reflect a degradation trend of a circuit component are selected. Multi-feature fusion and similarity model are adopted to construct a health indicator curve to characterize a degradation process of a full life cycle of different circuit components. A prediction model is established based on a temporal convolutional network and an attention mechanism, and preferably selected features and a constructed health indicator database are used as an input of a TCN-attention network to predict the remaining useful life of the circuit component.

Abstract: A method and a system for comprehensively evaluating reliability of a multi-chip parallel IGBT module are provided. The method includes: establishing a gate-emitter voltage reliability model of the multi-chip parallel IGBT module, performing a chip fatigue failure test, and selecting a gate-emitter voltage as a failure characteristic quantity; establishing a transconductance reliability model of the multi-chip parallel IGBT module, performing a bonding wire shedding failure test, and selecting a transmission characteristic curve of the module as a failure characteristic quantity; using a Pearson correlation coefficient to characterize a degree of health of the IGBT module, and respectively calculating degrees of health PPMCCC and PPMCCB in different degrees of chip fatigue and bonding wire shedding failure states; and comprehensively evaluating the reliability of the multi-chip parallel IGBT module according to PPMCCC and PPMCCB.

Abstract: Provided are a time domain channel prediction method and a time domain channel prediction system for an OFDM wireless communication system, which relate to the technical field of adaptive transmission in wireless communication. Frequency domain channel information is converted into time domain tap information by inverse Fourier transform. With respect to each time domain tap information, tap information prediction based on an extreme learning machine is realized, and finally predicted tap information is converted into frequency domain channel information by Fourier transform. To improve a generalization ability of a channel predictor, an output weight of the extreme learning machine is punished by a combination of l2 regularization and l1/2 regularization. The disclosure may provide satisfactory prediction performance and may output a sparse output weight, which reduces the requirement for memory storage. The disclosure ensures adaptive transmission and adaptive coding of wireless communication.

Abstract: The disclosure discloses an IGBT module reliability evaluation method and device based on bonding wire degradation, which belong to the field of IGBT reliability evaluation. The realization of the method includes: obtaining a relationship between a IGBT chip conduction voltage drop Uces and an operating current Ic along with a chip junction temperature Tc; for an IGBT module under test, obtaining the conduction voltage drop Uces-c of the IGBT chip through the operating current Ic and the chip junction temperature Tc; obtaining an external conduction voltage drop Uces-m of the IGBT module by using a voltmeter; performing subtraction to obtain a voltage drop at a junction of a IGBT chip and a bonding wire, and combining the operating current to obtain a resistance at the junction; determining that the IGBT module has failed when the resistance at the junction increases to 5% of an equivalent impedance of the IGBT module.

Abstract: A model-based method and system for diagnosing an open-circuit fault of a power transistor of a three-phase converter are provided, which belong to the technical field of fault diagnosis of power electronic equipment and can implement fast and accurate diagnosis of the open-circuit fault of the power transistor of the three-phase converter without adding an additional hardware. The fault diagnosis method of the disclosure only needs current and voltage sampling signals and drive signals that already exist in a control system of the converter and has the advantage of simple implementation. A cycle accumulated value of a difference between a sampling current and an estimated current after the power transistor of the converter has the open-circuit fault is used as a diagnostic variable, which can quickly and accurately complete diagnosis of a faulty power transistor and has relatively strong practicability.

Abstract: A test device for an automatic pressure regulating valve of an electronic braking system includes a test device composed of an air supply, a pneumatic circuit, a valve, a sensor, a signal processing unit, and a control unit. By subjecting an automatic pressure regulating valve to a bench test including a functional test, a static performance test, a dynamic performance test, an air tightness test, a leakage test, and a brake chamber braking force test, the present disclosure avoids the high risk of a field test, improves the test efficiency, and ensures the test consistency. An automatic pressure regulating valve is tested before being loaded on a vehicle, and parameters of the automatic pressure regulating valve are continuously modified through tests to improve the performance, such that the automatic pressure regulating valve can meet the real-time, fast, independent, and accurate regulation requirements of EBS of commercial vehicles.

Abstract: A method for diagnosing an open-circuit fault of a switching transistor of a single-phase half-bridge five-level inverter is provided. It includes the following steps. A semi-physical experiment platform with a DSP controller and an RT-LAB real-time simulator as its core constructed, and an output side voltage is selected as a fault signal variable. Empirical mode decomposition is used to extract a fault feature vector, and then a HHT time-frequency diagram of the fault feature vector is extracted, a voltage signal is converted into spectrum data, and time-frequency diagram fuzzy sets corresponding to different fault types are obtained. Fusion of the time-frequency diagram fuzzy sets of the same fault type is performed to obtain a fusion image that contains more fault features. The fusion images corresponding to all fault types are inputted into the deep convolutional neural network for training and testing, and a fault diagnosis result is obtained.

Abstract: A wind power prediction method and system for optimizing a deep Transformer network by whale optimization algorithm are disclosed. The sequence data of wind power and related influence factors are taken as sample data which is divided into a training set and a test set, where the data is trained and predicted by a Transformer network model established according to values of the initialized hyper-parameters, and an average absolute error of wind power prediction is taken as a fitness value of each whale group. A local optimal position is determined according to the initial fitness value of individual whale group, and the current optimal position is updated by utilizing whale group optimization, and the best prediction effect is obtained by comparing the local optimal solution with the global optimal solution. An optimal hyper-parameter combination is obtained after multiple iterations of the whale optimization algorithm, and the wind power is predicted.

Abstract: The disclosure discloses a single-ended fault positioning method and system for a HVDC power transmission line based on a hybrid deep network. The method comprises the following: collecting rectification side bus output voltage and current signals of a HVDC power transmission system under different fault types, fault distances and transition resistances as an original data set; eliminating electromagnetic coupling of the bipolar direct-current line by using phase-mode transformation, extracting IMF components of fault voltage and current signals under different fault scenes by using variational mode decomposition, and calculating TEO of the IMF components to obtain a fault data set after feature engineering; normalizing the fault data set, and dividing the fault data set into a training set and a test set; and successively inputting the training set and the test set into a hybrid network of a convolutional neural network and a long short-term memory network for training and testing.

Abstract: A method and a system of lithium battery state of charge (SOC) estimation based on second-order difference particle filtering belonging to the technical field of battery management are provided. The method includes the following steps: building a second-order RC battery model of a lithium battery; performing model parameterization by using a least squares algorithm with a forgetting factor; and generating an importance density function through a second-order central difference Kalman filtering (SCDKF) algorithm, improving a particle filtering algorithm to obtain a second-order difference particle filtering (SCDPF) algorithm, and performing SOC estimation on a lithium battery by using the SCDPF. The estimation method provided by the disclosure is accurate and has greater estimation accuracy than an unscented particle filtering algorithm (UPF), an unscented Kalman filtering algorithm (UKF), and an extended Kalman filtering algorithm (EKF). An SOC value of the lithium battery may thus be accurately estimated.

Abstract: A transformer fault diagnosis method and system using induced ordered weighted evidence reasoning is provided. The method includes the following steps. A typical data sample of transformer sweep frequency response analysis is loaded and a diagnostic label is set as an identification framework. Test data of a device to be diagnosed is loaded. Basic probability assignment is calculated and a reliability decision matrix is constructed. An induced ordered weighted averaging operator and its induction vector are calculated according to a sample source of the data. An index weight vector is calculated. All evidence is fused by the induced ordered weighted evidence theory and reliability of comprehensive evaluation is calculated, so as to determine a diagnosis result. The disclosure realizes fault identification, fault type distinction and fault position of power equipment by interpreting detection waveforms.

Abstract: An intermediate relay maloperation preventing device and method based on an improved recursive wavelet algorithm is provided. The device includes a power supply module, a voltage sampling circuit, an analog-to-digital conversion module, a DSP chip, and a relay maloperation signal shielding module. The voltage sampling circuit is connected to the analog-to-digital conversion module. The analog-to-digital conversion module is connected to the DSP chip. The DSP chip is connected to and controls a relay signal control module. The voltage sampling circuit collects a voltage. An improved recursive wavelet is used to extract a voltage feature. As such, identification of a fault signal and a normal signal is achieved, and real-time fault monitoring is accomplished. The detection method may be easily implemented, exhibits good filtering performance and anti-interference capability, delivers high detection accuracy, and may accomplish real-time online monitoring of intermediate relay faults.

Abstract: Provided are a failure diagnosis method and apparatus for open circuit failure of a power tube of a three-phase rectifier based on a current signal, relating to a failure diagnosis technique for power electronic equipment and capable of quickly and accurately diagnosing on an open circuit failure of the power tube of the three-phase rectifier without adding a hardware component. The failure diagnosis method only requires a sampled current existing in the control system of the rectifier and some intermediate computing signals and is therefore simple and requires little computing resource. A distorted current after the open circuit failure occurs in the power tube of the rectifier and a positive/negative half cycle where the current is present when the failure occurs serve as diagnostic variables. By analyzing the sampled current, a quick diagnosis on the power tube having the open circuit failure is provided. Thus, the invention is highly applicable.