With the development of global trade, buoyancy-lifting hybrid airship is an important choice for global long-distance and large-load transportation, it has gradually become a research hotspot at home and abroad. In order to improve the transportation efficiency of buoyancy-lifting hybrid airship, its layout and parameter sensitivity were studied. Discussions were conducted on the hull layout and tail wing layout, and several types of hull and tail wing layouts with high lift to drag ratios were proposed. At the same time, a sensitivity analysis was conducted on the impact of design parameters on aerodynamic characteristics. The results indicate that the width of the hull has the most significant impact on the lift coefficient, drag coefficient, and maximum lift to drag ratio of airships. Its relative sensitivity coefficient is nearly ten times that of the longitudinal position and inclination angle of the tail wing. The inclination angle of the tail wing has the strongest impact on the torque coefficient of the airship, and its relative sensitivity coefficient is more than twice the width of the hull.

A novel multi-objective optimization design method for permanent magnet roller based on improved particle swarm optimization algorithm and RMxprt co-simulation was developed to address the issue of low optimization efficiency when relying solely on expert experience. Firstly, an improved particle swarm optimization algorithm was proposed to enhance the convergence speed of the optimization process. Secondly, based on the analysis of the relationship between the structural and performance parameters of the permanent magnet roller, the variable parameters, constraint parameters, and optimization parameters for the improved particle swarm optimization algorithm were determined. Lastly, a MATLAB program for the improved particle swarm optimization algorithm was developed to achieve closed-loop iteration and comparative optimization of the input and output parameters in RMxprt, thereby improving the efficiency and effectiveness of the optimization design for the permanent magnet roller.

In order to solve the problems of excessively long droplet break time and excessively large droplet length to diameter ratio in the production of high-temperature and high-viscosity temporary plugging agent, the minimum velocity of droplet forming of temporary plugging agent was obtained by theoretical calculation, and the formula for calculating the optimal disturbance period was derived. The numerical simulation method was used to analyze the droplet forming process of temporary plugging agent, and the changes of the flow field of the droplet forming under the action of no disturbance and external square wave disturbance were explored. The simulation results show that without disturbance, the jet is difficult to break into droplets within 300 mm, the jet temperature is basically unchanged within 0.5 s, and the jet velocity increases to 2.13 times of the initial velocity. When square wave disturbance is added to the outside, too short disturbance period is not conducive to uniform droplet forming, and too long disturbance period will lead to excessive elongation of liquid column before fracture. When the disturbance period is about 0.11 s, the droplet forming efficiency is the highest, the fracture frequency is stable at 0.11 s, and the final droplet length-diameter ratio is stable at about 2. The research results provide a basis for the selection of process parameters for droplet forming of high viscosity temporary plugging agent.

Landslide geological hazard susceptibility assessment is an important means of hazard prevention and reduction. The selection and optimization of susceptibility assessment model is very important. Sinan County was selected as the study area, and 16 assessment factors such as elevation, slope, curvature, lithology, land use, and average annual precipitation were selected. Frequency ratio (FR) model was coupled with support vector machine (SVM) model and random forest (RF) model. Grid search method was introduced to obtain the optimal parameter combination of SVM model, RF model and their coupling model for model training. Finally, SVM, RF, FR-SVM and FR-RF models were constructed to predict landslide susceptibility in the whole study area, and receiver operating characteristics (ROC) curve was performed verification. The results show that compared with the single machine learning model, the coupled machine learning model has more landslide hazard samples fall in the high zone and the very high zone, and has higher accuracy. In the single model, more landslide hazard samples in the RF model fall in the high zone and the extremely high zone. In the coupled model, more landslide hazard samples in the FR-RF model fall in the high zone and the very high zone, and no hazard samples points in the FR model and the FR-RF model fall in the very low zone, indicating that no matter the single model or the coupled model, The performance of RF model is better than that of SVM model. The AUC values of ROC prediction curves of the four models are 0.831 6, 0.843 9, 0.864 4 and 0.910 4, indicating that the coupling model combined with FR model and RF model has a higher accuracy, and this model is more suitable for the assessment of landslide susceptibility in Sinan County. The assessment results can provide some reference for hazard prevention and reduction of local landslide geological hazards.

Aiming at the problem of white noise amplification of differential microphone array, a design method of parametric differential beamformer was proposed. Through theoretical derivation, it is proved that the delay summing beamformers can maximize the white noise gain and the superdirected beamformers can maximize the directional gain. The orthogonal eigenvector was obtained by using the unitary diagonalization method to deal with the pseudo-correlation matrix between the steering vector and the white noise gain, and the parameters of the beamformer machine were designed based on it. Through simulation experiments, the performance of parametric differential beamformers under different parameter settings was analyzed. Experimental results show that the proposed method can flexibly balance and adjust the white noise gain and directional gain by adjusting the parameters.

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.

The clustering of discontinuity orientation is crucial for revealing the distribution and characteristics of various types of discontinuities. Conventional clustering methods based on discontinuity pole density maps often rely on geological experience and lack objectivity. Therefore, the mean shift clustering algorithm was introduced to study the clustering of discontinuity orientation. Initially, discontinuity orientations with different degrees of dispersion were manually generated. Subsequently, these orientation data were converted into coordinates in 3-D space, and the sinusoidal value γ of the unit normal vector was employed as the similarity measure. The mean shift algorithm was then used to perform clustering analysis on the measured data set. Compared with the conventional pole density map method and the K-means clustering algorithm, the validity test index and clustering error recognition rate were close to those of the K-means clustering algorithm. Finally, taking the Chongqing Sangong rock slope as an example, the rationality and effectiveness of the new method were verified by field data. The results show that the performance of the proposed method surpasses that of the conventional discontinuity pole density map and K-means clustering algorithm. The clustering results are objective and reasonable, and the clustering effect for near-horizontal discontinuities is also satisfactory.

The Guocheng-Yazi area in the northeastern margin of the Jiaolai Basin is located in the southern section of the Muping-Rushan gold metallogenic belt. It is an important gold metallogenic area in the Jiaodong region. In recent years, medium-sized and large-scale gold deposits such as Pengjiakuang, Tudui-Shawang, Xijingkou, Liaoshang, Xilaokou, and Qianchuiliu have been successively explored. The cumulative amount of gold resources explored exceeds 180 t. Based on the field work of geological mapping, ore-bearing structure investigation, controlled source audio-frequency magnetotelluric sounding (CSAMT) and drilling engineering, the distribution of ore bodies, geophysical characteristics, ore-controlling structure and metallogenic regularity were analyzd. The western extension position of the Pengjiakuang detachment fault was preliminarily clarified. Extending westward from the Xijingkou to the Liaoshang to the Guocheng fault, which is the ore-controlling structure of Pengjiakuang, Xijingkou, Xilaokou, Qianchuiliu, Liaoshang and other gold deposits. The Queshan metamorphic core complex and its detachment faults are the main ore-controlling structures and favorable ore-forming spaces for gold mineralization in this area, and are important prospecting targets in future exploration and prospecting work. The mineralization depth of the gold deposit concentration area in this area is mainly 5.01~7.93 km, and the gold deposit has just been eroded as a whole. The deep and peripheral areas have good prospecting potential.

To explore the effects of cardiac magnetic resonance imaging(CMRI) on the assessment of left ventricular function and myocardial changes in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS). Thirty-one patients with OSAHS who were admitted to Handan Central Hospital from November 2019 to June 2021 were selected as the observation group, and 30 healthy volunteers who received CMRI monitoring during the same period were selected as the control group.Two sets of parameters related to left ventricular function were compared, including left ventricular ejection fraction (LVEF), left ventricular end diastolic/end systolic volume (LVEDV/LVESV), left ventricular myocardial activity imaging indexes[T1pre value(measurement of T1 relaxation time before enhancement) before mean injection of contrast agent in left ventricular myocardium, 15 min T1post value(T1 value of myocardial tissue measured by T1 mapping technique after using contrast agent in CMRI) and T2 value(transverse relaxation time of myocardial tissue)]after injection,and histological parameter characteristics of different myocardial layers[mean extracellular matrix volume fraction (ECV) of left ventricular myocardium].The left ventricular function parameters (LVEF, LVED) in the observation group are significantly lower than those in the control group, while LVESV and T2 values are significantly higher than those in the control group (P<0.05). There is no significant difference in T1pre, T1post, ECV in basal segment, middle segment and apical segment between the observation group and the control group (P>0.05).CMRI has a significant clinical effect in patients with OSAHS and can effectively assess the left ventricular function, structure and early myocardial lesions.

Fan nozzle is an important part of high pressure water descaling system, and its internal structure parameters directly affect the performance of jet. The nozzle flow field was analyzed by using fluid simulation software FLUENT, and the nozzle exit diameter, cone section contraction angle and exit contraction angle were selected as reference factors. The jet impact force was used as evaluation index, and the nozzle structure parameters were optimized by response surface method. The results show that the velocity distribution of the internal flow field is affected by the single factor of the diameter of the outlet section and the conical contraction angle, but the flow rate of the nozzle is little affected. The pressure drop of nozzle is affected by the change of the diameter of outlet section and the contraction angle of nozzle outlet, and the influence of the contraction angle of nozzle conical section on the pressure drop is negligible. When the diameter of the outlet section is 3.15 mm, the taper shrinking angle is 26.17°, and the outlet shrinking angle is 40.93°, it is found that the nozzle striking force is increased from the original 94.91 N to the optimized 143 N by establishing the outflow field and applying the gas-liquid two-phase flow model simulation calculation. The research results provide theoretical guidance for optimizing nozzle structure to enhance jet impact force.