We have designed a Coupled-tank System virtual simulation platform to address the limitations of restricted site conditions, fluid flow, and lengthy experimental periods. This is to enhance data monitoring and improve experimental efficiency, while inspiring user interest. This platform uses the STM32 microcontroller to simulate the mathematical model of the Coupled-tank System and the incremental PID controller. The WeChat Mini Program is built using wxml, wxss, and javascript. Additionally, we used the WIFI module ESP8266 and the MQTT server to achieve data conversion between the single-chip microcomputer and the WeChat Mini Program. The system can interact with mobile terminals, and users can set the PID parameters on their mobile phones, display real-time level values and monitor the entire experimental process. The system can also display the historical level curve and, on the LCD screen, simulate the dynamic water column changes, making the user experience more vivid and intuitive.

DNA N6-methyladenine (6mA) is an important DNA methylation modification that plays a significant role in many biological regulatory processes. This article use a publicly available mouse dataset to study this modification. Firstly, the mouse gene sequence (A, T, C, G) is encoded using mathematical representation symbols. Then, the encoded information is subjected to feature selection using chi-square testing to select features related to 6mA sites for further study. Seven machine learning algorithms are then used to construct a classification model, and the predictive results are validated using a five-fold cross-validation method. The results showed that selecting the top 20 optimal features as training set sample features using a sliding window encoding method yielded a random forest model that achieved an accuracy of 1 in predicting mouse 6mA sites.

The goal of Shapelet discovery is to find the Shapelet with the best quality, and the quality of Shapelet depends on the discriminability of the subsequence. Aiming at the problem of accurately discovering effective Shapelet, a fast discovery algorithm of Shapelet based on subclass clustering and SAX representation is proposed, which combines subclass clustering with classical symbolic representation SAX method to obtain the optimal Shapelet quickly and accurately. The algorithm uses subclass clustering to reduce the dimension of time series and obtains multiple subsequence prototypes as Shapelet candidate sets. SAX representation is used to symbolize the candidate set, and the candidate set is intuitively represented by string, which is convenient to find the optimal Shapelet.Finally, the Shapelet with the largest information gain in the candidate set was selected as the optimal Shapelet for time series classification. Experimental results show that this algorithm has good classification effect and improves the classification speed.

Intelligent fault diagnosis is important for improving the reliability of smart manufacturing. Fault diagnosis methods based on deep learning have been very successful in industry, but there are some differences in the features extracted by different models. A fusion network model (CLOD) based on deep learning is proposed for problems such as incomplete data feature extraction. Firstly, a time-frequency analysis of the fault signal is carried out by Fourier transform to obtain a time-frequency spectrum sample, then the sample is fed into a convolutional network model (CLOD) trained and learned after the fusion of LSTM model and improved CNN model, and finally the model performance is improved by updating the network parameters to achieve accurate and intelligent diagnosis of bearing faults. Compared with the traditional method, CLOD greatly increases the fitting speed and stability of the model on the basis of guaranteed accuracy.

In order to solve the problems of slow dynamic response and large lag in boiler drum water level control, a control strategy combining Particle Swarm Optimization (PSO) algorithm with PID control is proposed in this paper, and a set of PSO three-impulse PID adaptive controller is designed to realize the control of water level. The results show that PSO-PID algorithm has small overshoot and short adjustment time on drum water level control.

The gantry crane lifting system is decoupled by a new underdrive system decoupling algorithm, and the optimal control is realized through the particle swarm optimization LQR weight matrix. According to experimental simulation, the precise positioning control and stable swing control of the lifting system are realized, so that the system has strong resistance to internal disturbance and has important practical application value.

In the study of mixed gas identification, a gas classification recognition algorithm based on convolutional neural network is proposed to solve the problem that it is difficult to achieve ideal accuracy when electronic nose is used in the monitoring of chemical pollutant types. Firstly, the adaptive feature extraction ability of convolutional neural network is used to effectively reduce the impact of original data on subsequent operations. Secondly, several experiments are conducted to optimize the parameters of the convolutional neural network to improve the performance of the network model. Finally, the proposed convolutional neural network algorithm and BP neural network algorithm are applied to the experimental data of carbon monoxide and ethylene mixture gas in the public dataset of the University of California, respectively. The experimental results show that the gas species detection accuracy of the convolutional neural network algorithm in this dataset reaches 93%,which is higher accuracy and smaller error than the BP neural network algorithm when applied to gas identification, which provides a new method for gas species detection in the electronic nose system.

Based on the law of conservation of energy and the lumped heat capacity, a mathematical model of central heating system is analyzed and established. A simulation program is developed to simulate the dynamic process of the system under temperature disturbance. Two control strategies, the conventional PID control and the improved climate compensation control, are used to simulate the heating system respectively. The results show that the improved strategy based on the climate compensation can effectively solve the problem that the conventional PID control strategy is prone to heat supply and demand imbalance under the interference of temperature fluctuations. It has certain reference value for the research and design of heating system.

In order to explore the characteristics of safety helmet testing at home and abroad, CiteSpace was used as an analysis tool to visually analyze the data related to safety helmet testing from 2010 to 2021 in CNKI database and WOS database. From the number of published documents, national distribution, institutions, keyword co-occurrence, keyword clustering, time line distribution six aspects were analyzed. Through the analysis, the field of safety helmet testing at home and abroad has received more and more attention from related scholars and institutions in the past decade. Compared with other countries in the world, China attaches more importance to the field of safety helmet testing, but the centrality is low, the international cooperation is not deep enough, and needs to be improved.

For extended Kalman filter (EKF) , the ability to track mutation status is poor. Zhou et al. proposed a strong tracking filter (STF) to obtain the fading factor adaptively and calculate the optimal value of the fading factor by forcing the residual sequence to be orthogonal. Therefore, the strong tracking filter improves the robustness of the filter and the estimation precision, and is widely used in various fields. Taking the azimuth-only missile guidance system as an example, it is verified by the MATLAB simulation platform, STF has better tracking effect than EKF.

This article summarized the structural analysis method and in-situ analysis method of the lithium ion secondary battery by using diffracted by neutron. Due to the interaction between neutron and nucleus, it can analyze the overall structure of the sample and can analyze a small amount of micro-phase at the same time. In addition, the neutron has a high penetration power and can be analyzed in situ in place in a non-destructive state. In addition, neutron ray photos can also be used to observe whether there is liquid or gas in the system. Therefore, the use of neutron diffraction to analyze the deterioration reaction, secondary phase of lithium ion secondary battery, and the problems that occur during the actual battery operation are very suitable methods.

In recent years, the layer-by-layer stacking principle of 3D printing technology makes it more flexible, which has attracted more and more attention and become a new research hotspot.Starting from the forming quality, this paper discussed the optimal process parameters of the fused deposition modeling 3D printing technology, with emphasis on the process principle and process flow of the equipment, the effects of printing temperature, printing speed, printing layer height, filling angle and filling density on the forming quality were summarized, the optimal conditions of 3D printing process parameters was obtained. The oxygen bottle model design is taken as an example to show that the application requirements of different parts can be improved by 3D printing parameters.

Liquid-liquid extraction is an effective method for separation, enrichment and detection of combustion promoters at the fire scene. In the liquid-liquid extraction process, the interfacial tension is an important factor affecting the extraction ability. The higher the interfacial tension, the lower the extraction ability. To provide a theoretical reference for the analysis of combustion promoters by extraction method, the effect of interfacial tension on the extraction ability of zinc was studied in this paper. The commonly used amine extractants (primary amine N1923) as well as the phosphonic acid extractants, di (2,4,4-trimethylpentyl)-phosphinic acid (Cyanex272), dialkyl-dithiophosphonic acid (Cyanex302), and dialkyl-dithiophosphonic acid (Cyanex301) were selected in this study. The interfacial tension of zinc ions (ZnCl2) extracted from hydrochloric acid (HCl) was measured, and the interfacial properties of different liquid-liquid systems were studied. The experimental results were analyzed and discussed.

In order to improve the hardness and wear resistance, the study carried out laser cladding to prepare the Ni alloy coating on Cr12MoV. The results showed that the microstructure of the coating was the abnormal growth dendrite. The phases of the coating were consist of γ-(Fe,Ni)、Cr7C3、BNi2  and Ni-Cr-Fe. Because of the fine grain strengthening, solid solution strengthening and second phase strengthening, the microhardness of the coating was improved  175% as compared with that of the substrate. The coefficient of friction of the coating was 0.2, which was obviously lower than that of the substrate(0.5). As compared with the substrate, the wear volume of the coating decreased 1orders of magnitude.

As the main energy source of electric vehicle, lithium battery has an important influence on the safety performance of the whole vehicle, and the safety valve is the pressure relief device of the battery, when the internal pressure of the battery increases to a certain extent out of control, in order to prevent the explosion accident of the battery due to the increase of the pressure, the safety valve will automatically explode to release the pressure, and in order to reduce the experimental cost, in this paper, a finite element modeling method using strength index as the condition of safety valve opening is presented. According to the strength distribution, the open pressure of safety valve can be judged to meet the design requirements, and the weak position of strength can be found out, the notch depth of the relief valve groove is adjusted to help the structural designer predict the rationality of the model design at the initial stage of design.

In order to adapt to complex environment and unstructured terrain, a dynamic chassis of tracked vehicle with dual power flow differential steering and balanced rocker arm is proposed. The tracked vehicle can meet the design requirements of adjusting ground clearance, adaptive road surface, obstacle crossing, flexible attitude adjustment, stable attitude maintenance and wheel-shoe combination. The overall configuration scheme of tracked vehicle with differential steering mechanism is determined. The driving model is established according to the balance of driving force and driving resistance, and the power model required for climbing is established according to the climbing angle and speed of tracked vehicle. On this basis, the relationship between the maximum power of driving motor and the maximum gradient and the speed of climbing is determined. The power of linear traveling motor, steering traveling motor and swing arm adjusting motor of tracked vehicle are analyzed and calculated. The steering resistance moment of the inner and outer tracks during steering are deduced, and the total steering resistance moment of the vehicle to the center of mass is determined. The research results can provide theoretical basis and research means for the prototype development and test of tracked vehicles.

In the working process of hydraulic retarder, idle power loss will occur under non-braking condition. In order to reduce the air loss, three-dimensional flow field numerical simulation was carried out for the air loss of the spoiler mechanism with and without installation at different speeds. The pressure field and velocity field of flow field are analyzed, and the suppression effect of spoiler mechanism on air loss is analyzed. Taking the structural parameters of the turbulence mechanism as design variables, the parameters of the turbulence mechanism were optimized. The RSM model was built through DOE test design, and the structural parameters of the optimal turbulence column were obtained by the second generation of non-inferior sequencing genetic algorithm. Compared with the loss reduction rate before and after optimization, the average loss reduction rate of the optimized turbulence mechanism can reach 9.5%.

The Trudinger-Moser inequality has important applications in the study of the existence of solutions for partial differential equations with critical exponential growth nonlinear terms. Using Schwartz symmetric rearrangement in radial space and taking cut-off function based on unit decomposition are two main methods to prove Trudinger-Moser inequality.

The problem of insufficient load bearing capacity of crossing over the goaf has become increasingly serious. In order to solve the problem of the Mujia Passenger Dedicated Railway crossing the goaf of the coal mine, this paper designs and implements the on-site grouting scheme for the goaf, and finally evaluates its effect with a variety of grouting reinforcement effect evaluation methods. The research shows that the full filling pressure grouting method can effectively improve the broken and hole problems in the goaf of the Mujia Passenger Dedicated Railway. At the same time, the feasibility and accuracy of the design scheme and on-site implementation are further verified through on-site coring, indoor mechanical property test, wave velocity measurement, regional hole location grouting effect detection and CT detection technology. Finally, the grouting effect is evaluated in combination with relevant professional specifications. The conclusions can be used as an effective supplement to the survey, design, implementation and detection of such projects.