The study area is located in the southeastern part of the Badanjilin Basin, in the Benbatu region. Multiple airborne radiometric anomalies have been discovered in the area. To further explore the causes of these anomalies and provide references for subsequent uranium exploration work, these airborne radioactive anomalies were classified, summarized, ground verified, and analyzed for their potential for uranium mineralization. The results show that there are two types of anomalies in the area, one is a densely distributed strong anomaly in the central part, which is mainly an airborne radiometric anomaly for exploring hard sandstone-type uranium ores. The other is a weak anomaly distributed in a strip in the southeast, which is mainly an anomaly for exploring in-situ leachable sandstone-type uranium ores and represents a new type of uranium mineralization discovered in the area. By combining regional geological data, the potential for mineralization of the weak anomalies HFU-03 and HFU-04 was analyzed. The research results provide new clues and ideas for the types of uranium exploration in the area.

In order to comprehensively analyze and evaluate the monitoring capabilities of the integrated multi-satellite retrievals for global precipitation measurement (GPM) final run (IMERG-F) satellite retrieval product for daily and sub-daily scale precipitation, as well as various intensity rainfalls, under complex mountainous conditions in southwest China, ground-based dense rain gauge data was used to investigate these aspects. The results show that within the daily and sub-daily scales, the critical success index (CSI) of IMERG for short-term accumulated precipitation primarily ranges from 0.2 to 0.6, with the correlation coefficient fluctuating between 0.25 and 0.5. The daily scale precipitation detection accuracy is the highest, with better performance in summer months compared to winter. For different intensity rainfall events, IMERG exhibits a high probability of detection (POD) for light rainfall, while the false alarm rate (FAR) is relatively low. However, there is an underestimation phenomenon for moderate to heavy rainfall. The elevation difference significantly impacts the stability of IMERG products, but there is no direct linear relationship with the elevation itself. Compared to areas with significant topographic variations, IMERG-F demonstrates higher reliability in detecting weak rainfall events in areas with less topographic variation. It is concluded that the application of IMERG products in southwest China should consider the limitations imposed by seasonal and topographic characteristics.

In the natural gas pipeline transportation system, the series elbows is particularly susceptible to erosion due to its special structure and the sand-producing characteristics of natural gas. The erosion behavior of the series elbows is affected by multiple factors, among which the length of the connecting pipe between the two elbows is a variable that cannot be ignored. For this reason, the computational fluid dynamics(CFD)-discrete phase model(DPM) numerical simulation method was used to study the erosion behavior of the series elbows at different spacings of sand-containing natural gas. The results show that when two elbows are installed in series, the corrosion morphology and rate of the second elbow are greatly affected by the distance between the two elbows. With the increase of the length of the middle section of the series elbow, the corrosion morphology of the first elbow is V-shaped, but the corrosion morphology of the second elbow gradually changes from a triangle to a V-shape. In addition, due to the influence of gravity on the migration trajectory of sand particles, the area with the most serious erosion and wear of the second elbow is 5° to 8° behind the upstream elbow. By analyzing the multi-angle section flow field of the second elbow, it is found that the airflow generates a more complex secondary flow at the second elbow after passing through the middle section. Therefore, the maximum erosion rate of the second elbow decreases first and then increases with the increase of the length of the middle section of the series elbows. The research results can provide certain theoretical guidance and basis for optimizing the engineering design and erosion prevention of the double elbow system.

Errenshan area of Weiningbeishan is located in the southern margin of Alashan microcontinent, which is one of the important hydrothermal polymetallic mineralization areas in Ningxia. In order to serve the next prospecting in the periphery and deep part of the area, the multidimensional anomaly system in this area was discussed on the basis of borehole rock geochemical survey. The results show that in the known polymetallic ore bodies in this area, there are negative anomaly systems characterized by major element Na₂O, mineralization agent element anomaly system represented by S, mineralization and associated element anomaly system, etc., which confirms the existence of multidimensional anomaly system. Under the guidance of the theory of multi-dimensional anomaly system, the metallogenic conditions and favorable areas of metallogenic potential in the study area are further delineated. The research result is a new attempt to optimize geochemical exploration methods for hydrothermal polymetallic deposits in Weiningbeishan area, and has important practical value for geological prospecting in this area.

Collapse, as a common geological hazard in China, are widely distributed, highly concealed, sudden, and pose significant risks. In southwestern China, where disaster-prone red beds are extensively distributed, high cutting slopes are highly susceptible to landslides and collapses if not promptly managed, especially under the combined effects of back-end catchment and freeze-thaw cycles. Taking the collapse at Shejian Town in Guangyuan as a case study, on-site investigations, image analysis, and formula calculations were conducted to examine the failure mechanisms of red bed high cutting slopes influenced by back-end catchment and freeze-thaw effects, aiming to provide insights for disaster prevention in infrastructure development within red bed regions. The results indicate that the unique topography and climate conditions of the study area contribute to abundant rainfall, creating a water-intensive environment due to the extensive back-end catchment in the collapse area and infiltration from irrigated farmlands. The prolonged saturation of rock masses, combined with repeated freeze-thaw cycles, significantly weakens the rock strength, reducing the tensile strengths of sandstone and mudstone to 166.12 kPa and 72.77 kPa, respectively. Both values are lower than the fracture water pressure of 174.87 kPa in the fractures of the red bed cut slope, ultimately leading to the occurrence of the collapse. Given the variations in failure modes of red bed high cutting slopes with different rock structures under the effects of back-end catchment and freeze-thaw cycles, it is recommended to enhance drainage measures during prevention efforts and to implement targeted treatments based on the identified failure modes.

The novel electro-hydraulic composite intelligent completion system primarily involves downhole flow control technology and multi-parameter detection technology and so on. Based on the principles of mechanical structure design, the structural design of the core component of the electro-hydraulic composite intelligent completion flow control valve was conducted, namely the throttle valve sleeve. Finite element analysis was utilized to numerically simulate and study the mechanical performance and fluid flow characteristics of the throttle valve sleeve. The the flow field characteristics under various openings, water cut rates, displacements, and working conditions were analyzed by this method. The results indicate that the downhole temperature and pressure conditions have little effect on the flow control performance of the throttle valve sleeve. The performance is stable and meets the design requirements under high temperature and high pressure (125 ℃, 50 MPa). With different openings, the pressure difference gradually increases as the flow rate increases. At a constant flow rate, the pressure difference decreases with the increase of the opening. When the flow rate and opening are constant, the pressure difference gets greater when water cut becomes larger. When the flow rate and water content are constant, the greater the control series of the throttle valve sleeve, the smaller the pressure difference. The research results can provide theoretical guidance for the structural design of intelligent completion flow control valve.

In order to address the problems of poor flame stability, low combustion efficiency and high lean-combustion limit in traditional direct-fired porous media burners, five porous media burners with different pore arrangements were constructed for low-concentration methane (LCM) combustion experiments, and the effects of porous media arrangements, equivalence ratios and flow rates on the combustion properties of LCM were investigated. CH₄ conversion, pollutant emissions and flue gas temperatures were also analyzed under lean combustion conditions. The results show that the E-type gradually-varied porous media burner exhibits the optimal LCM combustion adaptability, which can partially compensate for the interface temperature perturbation and improve combustion stability during LCM combustion. At an equivalence ratio of 0.39 and a flow rate of 50 L/min, the stationary combustion time of LCM in the burner exceeds 140 min and the flame position is consistently maintained at 60 mm. The LCM combustion in the E-type porous media achieves a CH₄ conversion of 99.99% with CO and NO_x emissions of 531×10^-6 and 23×10^-6, respectively, generating high-quality flue gas with a mean temperature of more than 588 ℃ that can be employed in industrial production. The research results provide an important reference for improving the utilization efficiency of low-concentration methane in coal mines and reducing methane emissions.

In order to solve the problem of combining plasma equipment with robots to process casting risers, where variations in riser dimensions due to mold accuracy necessitate precise trajectories and poses for proper arc initiation and operation, a method based on a process parameter library was employed for investigation. This method was comprised of process parameter library, analysis module, similarity measurement module, path generation module, and parameter module. Through the construction of two-stage comparison method, target parameters can be quickly filtered from the library. Using path generation algorithms and deep learning algorithms, working paths and process parameters matching the point cloud model were obtained. The results show that this method can accurately generate operational trajectories and poses based on the workpiece, enabling the reduction of manual intervention, lowering of operational complexity, and enhancement of the reliability and safety of the cleaning operations for coupler castings.

A calculation method of effective power based on heat transfer mathematical simulation of intercooling system was proposed for an aviation piston engine, and the heat transfer simulation model of the intercooling system was developed with VB language. The validity of the simulation model was verified by the test data. The results show that the errors between the simulation values and the test values of the intercooler cold side outlet temperature and the hot side outlet temperature are within 1.5%. Using the simulation model, the influence of fan air flow on the effective power of the aviation piston engine was studied, and the air effective power recovery was studied. The results show that with the increase of fan air volume, the amplification of fan power increases, while the amplification of engine power decreases. Under the combined effect of the two, the effective power of the engine first increases and then decreases with the increase of fan air volume. For the aviation piston engine studied, when the fan air volume is 1 400 m³/h, the effective power of the engine reaches the maximum, which is 101.6 kW. When the flight altitude is below 2 000 m, the engine effective power recovery coefficient increases slightly with the increase of flight altitude, and when the flight altitude is above 2 000 m, the engine effective power decreases significantly with the increase of flight altitude. Under the condition of 50 ℃ at sea level, the effective power recovery coefficient of the engine at 7 000 m is only 92.2%.

The accumulated water in the cavity behind the tunnel lining in cold regions may freeze under low-temperature conditions, resulting in local frost heave pressure. Assuming that the cavity behind the tunnel lining was a semi-elliptical space, the interaction between the surrounding rock, ice body, and lining during the frost heave process was simplified as springs in series, and an analytical solution for the local frost heave pressure in the semi-elliptical water-accumulated space was proposed. A three-dimensional numerical model was developed to verify the effectiveness of the analytical solution. Further, the relationships between local water-accumulated frost heave pressure and surrounding rock grade, lining stiffness, water-accumulated depth, and frost heave level were studied, and the influences of frost heave position on the mechanical characteristics of lining structure were analyzed. The results show that the local water-accumulated frost heave pressure of the cold region tunnel is negatively correlated with the surrounding rock grade and positively correlated with the lining stiffness, water-accumulated depth, and frost heave level. The influence degree of various factors on frost heave pressure is as follows: water-accumulated depth > lining stiffness > surrounding rock grade > frost heave level. The impact of water-accumulated frost heave on the lining structure mainly occurs in the contact area between the ice body and the lining, leading to the convergence of the tunnel towards the inner side. The principal stress of the lining is maximum when the water-accumulated space is located at the inverted arch, and the principal stress of the lining is minimum when it is located at the arch foot. Under the action of local frost heave, there is a sudden change in the bending moment and axial force of the lining structure, manifested as the bending moment increase and axial force decrease of the lining under tension on the air side, as well as the bending moment decrease and axial force decrease of the lining under tension on the surrounding rock side. The stiffness differences in different zones of the lining lead to different impacts of frost heave pressure on structure safety. The influence degree of frost heave position on structure safety is as follows: vault > inverted arch > arch shoulder > arch foot > wall foot.