According to the requirements of rain ingestion of airworthiness regulations, the rain ingestion calculation was carried out for the no booster fan part. The movement trajectory of water droplets with different water speeds was studied based on Lagrangian particle tracking, and the separation amount of water droplets ingested to inner duct was obtained. Further more, the requirements for water spray speed from the rain ingestion test rig in the certification for turbofan engine was discussed,which can support the design and verification of rain ingestion airworthiness of turbofan engine. The results show that with the decrease of water speed, the amount of rain impacting on the fan blade and other walls increases, and no water droplets can pass through the fan blade and enter the inner duct. The water entering the engine inner duct at 250 m/s is 15.3 percent of the total amount of water, about 19.1 times of that at 10 m/s. Under the same water velocity, as the distance between the splitter and the fan blade decreases, the increase in water ingested to inner duct increases. At different fan rotational speeds, the change trend of the water ratio ingested to inner duct with initial water velocity is consistent, basically increasing with the increase in water drop velocity, and then remaining or slightly decreasing.

In order to cope with the rapid recovery and growth of air passenger flow and the uncertainty of passenger group structure and consumption behavior, and to give full play to the role of aircraft parking stands resources in improving non-aeronautical revenue, an optimal allocation model for aircraft parking stands based on the maximization of flight route commercial value was established. Firstly, the game theory combinatorial weighting method was used to correct the influence of subjective factors on the evaluation results. Then, the commercial value of aircraft parking stands and flight routes was quantitatively ranked by the VlseKriterijumska optimizacija I kompromisno resenje(VIKOR) algorithm, which could eliminate the mutual influence of multiple indicators. Finally, a trunk airport in northern China was used as an example to verify the feasibility of the method. The results show that three evaluation indicators of commercial value of flight routes are significantly correlated with the per customer transaction at boarding gate and commercial concentration zone, including departure time, dwell time and daily average passenger volume. By reasonably matching flight routes and parking stands based on commercial value, the commercial value of boarding gate and commercial concentration zone can be increased by 9.4% and 6.2% respectively. Therefore, introducing the commercial value of flight routes into the traditional aircraft parking stands allocation model has important practical application value for increasing airports non-aeronautical revenue.

Predicting the emission reduction potential and cost of sustainable aviation fuel (SAF) that aligns with China’s national conditions is essential for advancing the SAF industry and achieving carbon neutrality goals. Based on the principles of international comparability and independent controllability, a lifecycle carbon emission reduction model was developed for two technological pathways: hydroprocessed esters and fatty acids (HEFA) and Fischer-Tropsch (FT). This model forecasted the emission reduction and cost associated with SAF in China’s civil aviation sector from 2025 to 2060.The results indicate that the HEFA pathway, which is suitable for implementation between 2025 and 2030 using waste oils as feedstock, achieves a carbon emissions reduction of 61.3 kgCO_2e/GJ, contributing to an overall reduction of 84.4%. This associated cost ranges from 0 to 1 025.9 CNY/tCO_2e when compared to traditional aviation kerosene. In contrast, the FT pathway-primarily developed between 2030 and 2060 utilizing municipal solid waste as raw material yields the highest carbon emissions reduction at 68.4 kgCO_2e/GJ. Furthermore, routes employing agricultural or municipal solid waste exhibit lower abatement costs than those utilizing forestry waste. Considering China’s specific national conditions, it is determined the FT route utilizing agricultural waste as feedstock is more appropriate for development as the main SAF production technology after 2030 due to its abundant raw materials and comparatively lower abatement costs. Projections suggest that by 2060, reductions in China’s civil aviation SAF could reach approximately 17 177 million tons to 19 819 million tons. From a possible scenario spanning from 2025 to 2060, it is estimated that cumulative carbon abatement costs will amount to between 11 063 to 45 828 billion CNY, this corresponds with a marginal carbon abatement cost ranging from 220 to 697 CNY/tCO_2e.

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.

Transformer calibrators are a kind of equipment used to test the transformer error in the power system. With the development of technology, the transformer calibrator is also constantly innovating, from manual, and automatic to intelligent development, which has become a research hot spot. Two types of calibrators according to the usage method, namely the difference measurement method and the direct comparison method were introduced and the advantages and disadvantages of each method and related products were analyzed. Currently, digital calibrators had became a research hotspot because of their high degree of automation and multiple functions. The digital calibrator could be used for both conventional and non-conventional transformers, with a wide range of applications. Three key technologies that affect the accuracy of the digital calibrator are focused on by the paper. And a new technology based on small-signal on-site calibration were introduced, which had significant advantages over the current commonly used on-site calibration methods, with strong compatibility and high security, making the transformer calibration device smaller and more portable, and suitable for a wide range of occasions. Finally, it was pointed out that the transformer calibrator should continuously develop towards digitalization, intelligence, portability, accuracy improvement, and comprehensive performance improvement.

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.

The influencing factors on the reservoir development of Upper Taiyuan Formation in the eastern Ordos Basin were investigated. Experimental methods such as casting thin sections, high-pressure mercury intrusion, and constant-rate mercury intrusion were employed to examine the pore structure characteristics of Upper Taiyuan Formation, Tai 2 Member. Results show that the average porosity of Tai 2 Member reservoir is 7.84%, with an average permeability of 0.396 mD, primarily characterized by ultra-low porosity and permeability. The pore structure is complex, with strong heterogeneity. Various types of pores were developed in the reservoir, including intragranular dissolution pores, intergranular dissolution pores, intercrystalline pores, and rock fragment dissolution pores. Based on the frequency of pore development, porosity, and permeability in each region, the pore combinations are classified into three types: intragranular dissolution pores, intragranular dissolution pores combined with intercrystalline pores, and intragranular dissolution pores combined with intergranular dissolution pores. The experimental methods of high-pressure mercury intrusion and constant-rate mercury intrusion could effectively characterize the reservoir characteristics of these three types of pore combinations, among which the combination of intragranular dissolution pores and intercrystalline pores represents a favorable reservoir pore type. Based on the laws of sedimentary differentiation and pore differentiation, a set of criteria for evaluating high-quality reservoirs is established on the basis of experimental results. Upper Taiyuan Formation reservoir was classified into Class Ⅰ, Ⅱ, and Ⅲ from good to poor, and predictions were made for favorable areas of high-quality reservoirs.

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.

Under the condition of heavy rainfall, the rock and soil saturation of fully weathered granite slope increases, and the shear strength decreases, which is easy to cause slope instability. In this process, the change of matrix suction is the key factor leading to the change of shear strength. Taking Laoshan fully weathered granite slope in Qingdao as the research object, the soil and water characteristic curve (SWCC) of fully weathered granite based on Van Genuchten model was obtained by means of centrifuge test, undrained direct shear test, X-ray diffraction analysis, conventional silicate chemical total analysis test and scanning electron microscope test. The effect of matrix suction on the shear strength of fully weathered granite was studied systematically. The results show these as follows. The saturation of fully weathered granite soil is negatively correlated with matrix suction, and the soil samples with uneven gradation have stronger drainage capacity. The shear strength index is affected by matrix suction differently. Cohesion is more sensitive to the change of matrix suction than the angle of internal friction. There is a positive correlation between matrix suction and shear strength in fully weathered granite soil. The research results can provide theoretical guidance for slope prevention in fully weathered granite area.

In order to study the disaster susceptibility of debris flow in Yongsheng County, the research area was Yongsheng County of Lijiang City, Yunnan Province, and it was divided into 475 sub-watershed units. Grey correlation analysis method was used to calculate the correlation degree of each factor, and the factor with the lowest correlation degree was eliminated. The independence of factors was tested by collinearity diagnosis. In the end, eight factors including average slope, average annual maximum rainfall, average vegetation coverage, average elevation, average melton ratio, average water system density, average landslide core density and average road density were retained. The information volume of the factors was calculated by the information volume method, and the correlation degree value was taken as the weight value of the superposition of each factor. The grey correlation analysis-information volume model was further constructed to carry out the evaluation research on the vulnerability of debris flow in Yongsheng County. The results show this as follows. The requency ratio of debris flow disaster points in the extremely vulnerable area is as high as 4.06, and the area under the ROC (receiver operating characteristic) curve is 0.818, indicating that the selected eight factors and the grey correlation analysation-information volume method have good forecasting ability for the evaluation of debris flow disaster vulnerability. The results can also be used as reference for the prevention and control of debris flow disaster in Yongsheng County.