To explore the formation mechanism of safety working style among flight cadets, a hypothetical model was constructed based on the theory of planned behavior, incorporating organizational safety culture as an extended variable. Six questionnaires, including behavioral attitude, subjective norms, perceived behavioral control, behavioral intention, safety working style and organizational safety culture, were compiled and distributed to 160 flight cadets. The feasibility of the theoretical model was analyzed through direct path effects, indirect path effects, and moderation effect analysis. The results indicate that the behavioral intention of flight cadets has a significant positive impact on their safety working style. Behavioral attitude, subjective norms, and perceived behavioral control influence safety working style primarily through behavioral intention. Additionally, subjective norms and perceived behavioral control can indirectly enhance behavioral intention through behavioral attitude, ultimately leading to a positive impact on safety working style. Furthermore, organizational safety culture plays a positive moderating role in the impact of behavioral intentions on flight cadets’ safety working style. These findings give new perspectives that it is significant to enhance flight cadets’ strong sense of safety responsibility, impose strict adherence to regulations and foster the integration of safety culture within civil aviation institutions which could effectively elevate their safety working style and ultimately ensure flight safety.

When utilizing double skin composite shear walls as the primary components for resisting lateral forces in buildings, it is crucial to ensure proper horizontal connection of the walls. Currently, traditional bolt connections and welding are the main methods used for horizontal connection of these walls. However, these methods present significant challenges during construction and do not fully exploit the structural advantages of the wall. Based on the structural characteristics of this type of wall, a new type of horizontal joint connection node was designed for the upper and lower layers of the wall. This new design featured a socket-type square semi-grouted sleeve connection. The influence of steel bar diameter, sleeve length, grouting material strength, and sleeve form on the tensile performance of this new connection node was explored using finite element simulation. The results indicate that this new node effectively connects the horizontal joints of double skin composite shear walls with several advantages including convenient construction and reliable performance. Furthermore, it is observed that failure mainly occurs on connecting steel bars which achieves an “equivalent cast-in-place” goal for prefabricated double skin composite shear walls.

Aiming at the problem of low tension control accuracy existing in the warp yarn tension control of carbon fiber corner link loom, a warp yarn tension control method considering the effect of beating-up was proposed. Firstly, the elongation of the warp yarn during beating-up was analyzed, and then a new tension control model of the warp feeding system was established by combining Hooke’s law with the existing tension model. Secondly, a command filter backstepping sliding mode controller was proposed, which estimated the first-order differentiation of the virtual control law through the filter to avoid the problem of “differential expansion”, and adopted the radial basis function(RBF) neural network to adaptively estimate the unmodeled part of the system, and at the same time, the sliding mode control was introduced to enhance the robustness of the system. Finally, MATLAB/SIMULINK software was used to carry out simulation experiments on the tension system. The results show that the filtered backstepping sliding mode control considering the effect of beating-up in tension control compared with the traditional backstepping sliding mode control in the case of similar response time, the stabilization time is shortened by nearly 16.3%, the amount of overshooting is reduced by 24.6%. Compared with the fuzzy proportional integral derivative(PID) control, the stabilization time is shortened by 51.7%, the amount of overshooting is reduced by 49.2%.

In order to investigate the durability of fiber gypsum-based cementation material, a composite material was prepared by incorporating polypropylene and ramie fibers into high-strength gypsum, fly ash, and slag in a ratio of 44∶34∶22.Sodium methylsilicate was utilized for waterproofing the fiber gypsum-based cementitious material, and the effects of freeze-thaw cycles on its softening property, water absorption, and mass loss were studied after 5, 15, 25, 45, and 90 days under the combined action of H₂SO₄ or NaOH corrosion and freeze-thaw. Freeze-thaw strain testing, flexural and compressive strength testing, as well as industrial computed tomography(CT) scanning were conducted. The results indicate that fibers can mitigate both elastic and plastic deformation of the gypsum-based cementitious material during freeze-thaw cycles. Furthermore, under the combined effect of acid-base corrosion and freeze-thaw cycles, NaOH causes greater damage than H₂SO₄ does. After undergoing 90 days of freeze-thaw cycling with sodium methylsilicate treatment applied to it,the flexural and compressive softening coefficients increase by 0.28 and 0.13 respectively compared to specimens without waterproofing; meanwhile water absorption rates decrease by 1.56% while mass loss rates decreased by 9.52%. As freezing-and thawing times increase,pore development in specimens is still dominated by small holes,and crack diameters are mainly between 0.1~2 mm.

In order to improve the control performance of a doubly-fed wind turbine grid-side converter under unbalanced and harmonic grid voltages, a direct power control algorithm with an improved super-helix fast terminal sliding mode was proposed. First, the mathematical model of the grid-side converter under unbalanced and harmonic grid voltages with power as the state variable was analyzed in a two-phase stationary coordinate system. Then, the power inner-loop design was carried out with a nonlinear expansion state observer for the negative sequence in the mathematical model as well as the disturbances due to each harmonic component. Secondly, to ensure that the system can reach the steady state in a shorter time, the non-singular fast terminal sliding mode surface was constructed and the sliding mode control law for the power inner loop was designed by combining with the improved super-helical sliding mode convergence law. Similarly the terminal sliding mode control rate was also designed for the voltage outer loop. The stability of the non-singular fast terminal sliding mode surface, the improved super-helix control algorithm and the nonlinear expanding state observer was also proved by using the Lyapunov function. Finally, the method was verified to have faster convergence and stronger robustness by comparing it with three different control schemes to perform simulations.

Macro-encapsulated phase change material (PCM) capsules are the core components that form the heat storage tank of the packed bed. In order to enhance the heat storage rate of the packed bed tank, it is necessary to optimize the heat storage and discharge rate of individual PCM capsules. Four different encapsulated shapes of PCM capsules were established while ensuring the uniform volume of individual PCM capsules. The capsules were placed in a flow field with an obstruction rate of 0.5, and the melting and solidification processes of PCM under different encapsulation shapes were analyzed with full consideration of gravity direction and heat transfer fluid flow direction in practical applications. The results show that the natural convection of liquid PCM inside the capsule can accelerate the melting and solidification process of PCM and increase the rate of charging and discharging; compared with the spherical encapsulation capsule, the heat transfer area per unit volume of cylindrical encapsulation capsule is increased by 14.47% and the melting time of PCM is shortened by 42.50%. Therefore, the cylindrical encapsulated capsule has the best thermal performance, and the cylindrical capsule can be applied to the packed-bed storage tank in future research to optimize its thermal storage performance.

The rod of a fire drive production well in Xinjiang oilfield is seriously corroded, and there are many corrosion pits on the surface. In order to find out the cause of rod corrosion failure, the metallographic structure and physical and chemical properties of the failed rod were tested and analyzed, and the corrosion characteristics were analyzed by scanning electron microscope, energy spectrometer and X-ray diffraction analysis, and the failure causes were found out combined with the service conditions of the rod. The results show that the chemical composition, metalloid structure and inclusions of the D-class rod meet the standard requirements of the rod. The rod has only been in service for 1 year and 8 months and its diameter has decreased from 19 mm to 16 mm, the average corrosion rate is 1.796 mm /a, and the maximum surface corrosion pit depth is 2.1 mm. The surface of the rod is mainly attached with FeCO₃, FeS and CaCO₃. It is judged that the rod is corroded by CO₂/H₂S and underscale corrosion caused by high salinity produced water. At the same time, a large amount of Cl^- in the produced liquid promotes the development of pitting pits. It is recommended to inject corrosion and scale inhibitor into production wells with temperature lower than 50 ℃, pH value between 6 and 8, and formation water belonging to high calcium and high chlorine to protect the D-class rod and extend the service life of the rod.

The Yakela region is located in the northern part of the Tarim Basin. The review of old wells in 2021 shows that the new proven geological reserves of oil in the Paleogene Kumugeliemu Formation in the YK6H block of Yakela are 86.7×10⁴ t, and the structural amplitude of the oil and gas reservoirs that have been discovered so far is low, and it is difficult to identify similar low-amplitude structural traps, and the matching relationship between the accumulation conditions is not clear. In order to find new favorable zones for oil and gas development and strengthen the development of remaining oil reservoirs, based on the high-precision 3D seismic data of the Yakela area and guided by the theory of high-precision sequence stratigraphy, the high-precision stratigraphic division and comparative analysis of the Yakela area were carried out. Through ant body extraction, automatic layer tracking, and variable velocity mapping technology, 105 micro-faults were identified, the identification accuracy of low-amplitude structures was improved, and the distribution of low-amplitude structural traps with a minimum closure height of 2 meters was implemented. Based on the reservoir control factors such as structural location, trap characteristics, sedimentary reservoirs and oil and gas migration channels, the newly implemented low-amplitude structural traps were analyzed and evaluated, and favorable targets were selected, and then the favorable reservoir zones were comprehensively analyzed. The “three-element reservoir control” favorable target optimization method suitable for low-amplitude structural traps was summarizes, which is suitable for low-amplitude structural traps, and provides a reference for the evaluation of favorable targets in areas with similar geological conditions.

The boundaries of underground geological bodies are effectively highlighted through gravity inversion based on a typical focusing stabilizer, but this process is significantly affected by the focusing factor. The focusing characteristics are possessed by the exponential focusing stabilizer. To a certain extent, the issue of selecting the focusing factor can be circumvented by it, and it has the potential to have improved the effectiveness of three-dimensional gravity inversion.Furthermore, the multiplicity of solutions in inversion can be improved by the constraint imposed by the penalty function, which confine the inverted physical property values within a certain range. Based on this, in order to explore the improvement effects on three-dimensional gravity inversion by the exponential focusing stabilizer and penalty function constraint, the exponential focusing stabilizer and penalty function were incorporated into the three-dimensional gravity regularization inversion objective function. Comparisons were made of the effects resulting from three-dimensional gravity inversion, both with and without the involvement of the exponential focusing stabilizer, as well as with and without the application of the penalty function constraint. Model experiments have demonstrated that: the physical properties and spatial distribution of anomalous bodies can be accurately restored by the exponential focusing stabilizer, but there exist instances where false anomalies arise and physical property values surpass the true values. Situations like these can be improved by the exponential focusing inversion that is based on penalty function constraints. Furthermore, the accuracy of the solution can be enhanced by the zonal processing of penalty function constraints. The above situation indicates that the inversion method based on the exponential-type focusing stabilizer and constrained by penalty functions has certain potential to be generalized.

Traditional retinal vessel segmentation methods often face challenges such as missegmentation caused by optic disc confusion, lack of continuity in segmentation results, and imprecise segmentation in detailed regions. To address these issues, a retinal vessel segmentation algorithm was proposed based on UNet. The algorithm replaced traditional square convolutions with a fusion of horizontal and vertical one-dimensional convolutions and two-dimensional square convolutions, enhancing the representation capability of the eye region. A multi-scale branch approach was adopted to increase feature space diversity, thereby improving the network’s feature learning and expression capabilities. Additionally, to further enhance segmentation performance, multi-layer dilated convolutions was introduced into the deep structure of the autoencoder, replacing traditional simple pooling operations. This approach enlarged the convolution kernel size and expanded the receptive field, achieving a fusion of multi-scale shallow and deep feature information. The proposed algorithm was evaluated on the public DRIVE and CHASE_DB1 datasets. Experimental results demonstrates that the algorithm achieves precision (0.956 8 and 0.959 8) and F₁ scores (0.832 6 and 0.830 4), respectively. Compared with traditional UNet and recent UNet-based retinal vessel segmentation methods, the proposed algorithm shows advantages in accuracy, sensitivity, specificity, and F₁ metrics, these validation results fully demonstrate the proposed model’s strong capability in precise segmentation tasks.