In order to predict perforation velocity of SCS (steel-concrete-steel) slab against missile impact and obtain influence sequence of structural factors of SCS slab on the perforation velocity, a dimensionless equation of the perforation velocity was established and a prediction model was obtained based on dimensional analysis and artificial neural network. Orthogonal experiment design was used to determine finite element calculation, and the influence degree of 7 factors of SCS slab on perforation velocity was quantitatively evaluated by variance analysis. The deviation between the predicted perforation velocity and the actual value is less than 12%, and the quantitative evaluation results of variance analysis show that the thickness of steel plate has a largest effect, followed by the distance of tie bar and the thickness of concrete, the yield strength of steel plate, the yield strength of tie bar and the diameter of tie bar have a smaller effect, and the concrete compressive strength has a smallest effect. The established model solves the prediction problem of perforation velocity from a new perspective with a good prediction effect, which can effectively evaluate the ability of SCS slab against perforation failure of missile impact, and the order of the factors is beneficial to the optimal design of SCS slab resisting perforation from missile impact.

In order to solve the problem that the tunnel crosses the water-rich fault fracture zone, the construction risk is large, and the problems of surrounding rock instability and water inrush are very likely to occur. Based on the engineering background of the Xiaocaoba tunnel of the Chongqing-Kunming high-speed railway crossing the water-rich fault fracture zone, the fluid-structure interaction numerical model was established by using FLAC^3D to study whether to consider the influence of groundwater action, different grouting forms, grouting ring thickness and the force of the supporting structure under the influence of groundwater. The results show that the stability of the surrounding rock is poor under the consideration of groundwater, and after the tunnel excavation, the groundwater is distributed in a “funnel-shaped” manner around the tunnel after the seepage reaches a steady state, and the stability of the surrounding rock is enhanced after the advanced grouting reinforcement, and the grouting reinforcement form of the whole perimeter is better than that of the grouting around the arch wall. On the basis of selecting the grouting form, the parameters of the grouting ring were continuously optimized, and it was concluded that with the increase of the ratio of grouting ring thickness and permeability coefficient, it can effectively reduce the displacement of surrounding rock, limit the development of plastic zone, and reduce the pore water pressure of the primary branch, and the increase of the thickness of the grouting ring can significantly change the distribution range of the pore water pressure of the primary branch. After the construction of the appropriate grouting scheme on site, the feasibility of the grouting scheme and the rationality of the selection of grouting parameters were verified by comparing the monitoring values around the tunnel with the simulated values, and the stability of the surrounding rock was effectively controlled. The research results can provide reference value for the design and construction of similar tunnel projects in the future.

In order to improve the efficiency of finite element analysis and reduce memory consumption, the storage algorithm of the overall matrix was studied. The constraints were uniformly processed as matrix partitions at the element level. Subsequently, taking the stiffness matrix as an example, the distribution pattern of non-zero elements under the constrained condition was determined. A calculation method and corresponding formulas suitable for the number of non-zero elements in the stiffness matrix of two-dimensional and three-dimensional finite elements were proposed, and the correctness was verified. The correspondence between one-dimensional equal bandwidth storage and the original square matrix address was deduced, and it was applied as an auxiliary array in the process of integrating the overall matrix in CSC format, which has improved the efficiency of the overall matrix assembly and avoided the difficulty of node numbering optimization. Finally, the correctness and practicability of the proposed algorithm were verified by using thefour-span single-line girder bridge in the Changdao section of the Fangshan Line in Beijing. The results show that the overall matrix assembly time is reduced by 30%, the storage space is saved by more than 68%, and the calculation efficiency of linear equations is improved by more than 71% while ensuring the calculation accuracy.

A semantic segmentation-based method for defect segmentation on thin strip cast and rolled steel plates was proposed to accurately and quickly identify surface defects. Firstly, defect images from the production line were annotated using Labeling software to create a defect segmentation dataset. Secondly, a TransUNet network model was established to recognize and segment surface defects, integrating an optimized DANet dual-attention fusion network to enhance model segmentation performance. Finally, comparative experiments between the improved model and other segmentation models were designed. The feasibility and effectiveness of the proposed method are verified through analysis of experimental results and evaluation metrics. The experiments demonstrate that the improved network achieves a segmentation accuracy of 96.85%, an average intersection over union of 96.99%, and a similarity coefficient of 92.98% for foreign object defects on thin strip cast and rolled steel plates, respectively increasing by 1.19%, 0.61%, and 0.63% compared to the TransUNet network. Additionally, the improved network achieves a segmentation accuracy of 92.86% on the publicly available hot-rolled strip steel defect dataset, indicating its versatility and providing technical guidance for intelligent detection of surface defects on steel plates.

Vegetation fires may lead to tripping and shutdown of overhead transmission lines, thus endangering the safe and stable operation of power grids. In order to study the change of flame inclination of vegetation under the influence of ambient wind, a square fir crib with the size of 1 m×1 m×0.6 m was used as the research object, and a 5 m×5 m×5 m outdoor site with ventilation was set up by Pyrosim software, and simulation research was carried out on 10 free burning cases with the wind speed of 1~10 m/s, and the change of the flame pattern with the size of the wind was analysed. The formula for calculating the flame inclination applicable to this wind speed range was fit. The flame inclination calculation formula was based on the flame inclination of this range, and the flame inclination calculation formula was based on the flame inclination of this range. The change of flame shape with the wind speed was analyzed. The formula for calculating the flame inclination angle applicable to the wind speed range was fitted. And the horizontal offset distance of the flame was obtained according to the change of the flame inclination angle. The results show that the larger the wind speed is, the smaller the change of flame inclination and flame horizontal offset distance are. The results of this study can be used as a reference for the prevention of tripping accidents on transmission lines and the cutting distance of vegetation on both sides of transmission line corridors.

In order to solve the problems of SHO (seahorse optimization), such as low accuracy, precocity and insufficient global search ability. MSHO (multi-strategy seahorse optimization) algorithm based on nonlinear inertial weight strategy, improved whale encircling strategy and improved sine and cosine strategy was MSHO designed. Firstly, the nonlinear inertia weight was introduced into the motion behavior of SHO algorithm to overcome the shortcoming that the algorithm is prone to premature convergence. Secondly, the improved strategy of whale encircling prey was introduced into the updated equation of seahorse hunting success to reduce the probability of the algorithm falling into the local optimal solution. Then, the improved sine-cosine strategy was introduced into the reproduction behavior of the algorithm to enhance the quality of the hippocampal progeny solution, and further improve the global optimization ability and stability of the algorithm. Finally, in order to evaluate the performance of the proposed MSHO algorithm, SHO algorithm, chaotic SHO algorithm, subtraction average algorithm, gray Wolf algorithm, Seagull algorithm, whale optimization algorithm, particle swarm algorithm and MSHO algorithm were compared on 23 benchmark test functions. The experimental results show that MSHO algorithm shows higher convergence accuracy on 20 functions and stronger stability on 16 functions compared with other 7 algorithms. In addition, in order to test the application ability of MSHO algorithm in engineering problems, the algorithm is applied to solve the design problems of welded beams, cantilever beams and pressure vessels. The experimental results show that MSHO algorithm has better search accuracy in these three kinds of engineering design problems than other 7 different algorithms.

In order to study the hydrothermal characteristics of the sand soil replacement subgrade, the method of indoor freeze-thaw cycle test was used to investigate the hydrothermal changes at different depths of the sand samples with different gradations, and to compare and analyze the effects of coarse sand and fine sand on the silty clay in the lower layer. The results show that during the freezing process, the soil close to the cold end will have a “water increase phenomenon”, and the silty clay is more prone to water migration than the sandy soil. Both the replacement of fine sand and the replacement of coarse sand can inhibit the cooling of the lower silty clay and reduce the freezing depth, so as to avoid the frost heave and thawing of the subgrade. Compared with coarse sand, the replacement of fine sand has a better effect on inhibiting the downward transmission of negative temperature at the top, and the replacement of fine sand is more conducive to maintaining temperature stability. The freezing depth of the replacement of fine sand is smaller than that of the replacement of coarse sand, which is more conducive to inhibiting the frost heave of the subgrade soil and maintaining the internal water stability. The freezing characteristic curve of soil and the thawing characteristic curve of soil do not coincide, and the freeze-thaw characteristic curve of replacement fine sand is least affected by temperature at the interface of replacement. It is concluded that the replacement of sand can effectively avoid the occurrence of frost heave phenomenon of subgrade, and the effect of replacing fine sand is better than that of coarse sand.

Aiming at the problem of determining the effective design range of parameters during the optimization design of planetary gear transmission system, the dynamic sensitivity of two-stage planetary gear transmission system parameters was studied. Taking the two-stage planetary gear transmission system of vehicle as the research object, the natural vibration model of the system was established by Lagrange, the vibration modal characteristics of the two-stage planetary system were summarized, the expression of the vibration energy of the planetary system was deduced, the distribution state and the law of the vibration energy transfer in the same order were studied, and the mode change mechanism of the natural frequency of the system was further explored. The vibration energy transfer essential of the system natural frequency mode transition triggered by parameter change was analyzed. The parameter sensitivity equation of the natural frequency of the system is derived, the influence law of the modal transition phenomenon on the parameter sensitivity was studied, and the dynamic change law of the natural frequency sensitivity with the change of the parameter value was revealed. The method of dividing the parameter sensitivity interval based on the modal transition phenomenon was proposed, which realizes the effective guidance for the selection of the variable value range in the optimization design stage.

In order to reveal the association patterns between ferroptosis-related diseases and genes and predict potential Disease-Gene associations, ferroptosis-related research literature was analyzed to extract disease and gene entities, and a disease-gene complex network was constructed. The network's basic characteristics were further analyzed, and the Apriori algorithm was applied to extract strong disease-gene association rules. Link prediction technology was used to identify potential disease-gene associations. The results show as follows. ferroptosis plays a critical role in lethal diseases such as hepatocellular carcinoma, adenocarcinoma, breast cancer, and colorectal cancer. The genes such as GPX4 and ROS play key roles in cell survival or death through the regulation of iron homeostasis, oxidative stress, and lipid peroxidation. GPX4 and ROS are significantly associated with various diseases. The link prediction method revealed potential target genes for adenocarcinoma, lung cancer, colorectal cancer, and breast cancer, and preliminary validation of some predicted results was conducted through literature review.It is concluded that the research methodology employed in this study is both feasible and effective. The findings offer valuable references and suggest future directions for research on the prevention and treatment of ferroptosis-related diseases.

In order to meet the automatic safety needs of the assembly of fixed threaded hole bolts for underground coal mine roadway pipelines, a flexible operation control algorithm for bolt tightening based on admittance method was studied for the six-degree-of-freedom robotic arm equipped with six-dimensional force/torque sensor. The main contents include the theoretical research of gravity compensation algorithm based on six-point positioning method and admittance-based bolt tightening compliance control algorithm. A bolt fastening experimental system based on the robotic arm was set up, and the assembly experiment of fixed threaded hole bolts was carried out. The results indicate a decreasing trend in the forces and torques experienced during assembly, demonstrating the effectiveness and safety of the compliant operation control algorithm based on the admittance method.