In order to investigate the vortex characteristics and wave propulsion generated by the undulating pectoral fins of the flatworm, a simplified model of the flatworm's pectoral fin was re-established using the linear interpolation method in MATLAB. The relationship between thrust and kinetic energy, during the flatworm's swimming was derived, and the undulating posture of the flatworm was simulated using Fluent software. The results show that compared to similar MPF propulsion fish species such as rays and cownose rays, the flatworm, due to its narrow and elongated body structure, exhibits better stability, adaptability, and flexibility in water. When the Reynolds number is set to 1.05×10⁵, the pectoral fins of the flatworm demonstrates more stable thrust, effectively reducing flow separation and turbulence effects. At a frequency of 0.6 Hz and a wavelength of 2.5 m, the pectoral fins displays optimal undulating parameters, enhancing fluid mixing and energy transfer efficiency, thereby improving the flatworm's propulsion performance. It is concluded that, during the mid-phase of an undulation cycle, the pressure distribution on the pectoral fins changes significantly, with the lift efficiency being highest at the peak of the undulation.

On December 18, 2023, a M_S6.2 earthquake occurred in Jishishan County, Gansu Province, marking the largest earthquake recorded in the area since seismic observations began. To investigate the practical application of interferometry synthetic aperture radar(InSAR) technology in monitoring surface deformation in Jishishan County and its surrounding areas before and after the earthquake, 13 C-band Sentinel-1A SAR images covering the earthquake event and study area were utilized. D-InSAR and SBAS-InSAR techniques were employed to process the data, obtaining surface deformation information along the radar line of sight before and after the earthquake, and a comparative analysis of the deformation rates before and after the event was conducted. The results show that the monitoring results of the two techniques show a bulge phenomenon centered in Liugou Township (the epicenter), which gradually expands outward in an elliptical shape, and then evolves into irregular subsidence. The maximum line-in-line shape variables before and after the earthquake are 41 mm and 16 mm, respectively. The overall deformation of the whole region after the earthquake is relatively stable, which is consistent with the relevant data. The D-InSAR and SBAS-InSAR technologies can be used to monitor the long-term surface deformation process and abnormal conditions before and after earthquakes, and provide effective support for quickly obtaining the distribution range of coseismic geological disasters and guiding post-earthquake emergency rescue and post-disaster recovery and reconstruction.

Seasonal deltas are deltaic sedimentary systems controlled by seasonal rivers in continental basins. Modern seasonal deltas are mainly developed in arid and semi-arid climate with gentle topography. However, the study on the sedimentary model of seasonal deltas in ancient sedimentary records is still insufficient. Suweiyi Formation in Tabei area, Tarim Basin was selected as the research object. Based on 63 logging data and 215.52 m core data in the study area, logging facies templates of different sedimentary microfacies and lithofacies type combination templates were established, and the vertical evolution law of sedimentary facies plane characteristics was analyzed and summarized, and the overall sedimentary model of the study area was established. The results show that the Suweiyi Formation in Tabei area developed 4 categories and 17 subtypes of rock facies. During the depositional period of the lower Suweiyi Member, seasonal shallow water braided river deltas were developed in the study area. A seasonal shallow meandering river delta with multiple flood events and retrograde accumulation developed in the north of the study area during the sedimentary period of the upper Suweiyi Member. Finally, the profile and single well sedimentary model of seasonal shallow water delta affected by factors such as accommodable space, frequent change of sedimentary base level and sudden events were established. The results provide a reference for further understanding of the seasonal shallow water delta depositional model under the background of arid climate, and also provide geological basis for lithologic trap exploration.

The high-altitude & dense-vegetation landslide is difficult to investigate and lack of data, its appearance and subsurface information also difficult to get. Therefore it is difficult to identify and threat the road greatly. A case study of the Xiaojiapo landslide was presented. Detailed on-site geological surveys were performed, and drone-based oblique and orthophoto imaging techniques were employed to get the landslide's characteristics. Historical deformation of the landslide was analyzed using satellite image, airborne LiDAR was used to collect point cloud and digital imagery data of the landslide surface. A digital elevation model and centimeter-level three-dimensional model of the landslide surface were created following vegetation removal to assess the surface characteristics. The combined investigations reveal that the Xiaojiapo landslide is situated at an elevation of 3 030 m with a vegetation coverage reaching up to 90%. It is a typical landslide with high-altitude and dense vegetation. The key internal factors contributing to the landslide including the unique alpine valley topography, the slope structure with advantageous free faces, and easily erodible geological layers. Precipitation induces internal water infiltration, which reduces the strength of the rock and soil mass. Additionally, freeze-thaw cycles further diminish slope strength, while earthquakes and road constructions disturb the internal structure, weakening it further. These combined internal and external factors drive the landslide deformation. This study offers technical insights for the landslide identifying, early-warning, and mitigation of road landslides in high-altitude regions with dense vegetation.

The terrain in western Sichuan is complex and varied, and the geological structure is active, which makes the construction and maintenance of the traffic trunk line face the challenge of frequent geological disasters. Ensemble learning algorithm can optimize the shortcomings of the algorithm in geological hazard susceptibility assessment and improve the accuracy of the model, which has significant advantages in geological hazard susceptibility assessment. Taking the riverside high-speed as an example, 12 feature variables such as slope and relief were selected to construct the geological hazard susceptibility evaluation system. The forecasting performance of the modeling of the integrated algorithm and a single algorithm was compared and analyzed. The main control factors of the geological disasters along the riverside high-speed were discussed and the practicability of the model was verified. The results show that the proportion of high and extremely high geological hazard prone areas along the Yangtze River high speed is 18.21% and 9.85%, respectively, which are concentrated in the Leibo section and Jinyang section. The area under curve (AUC) of the receiver operating characteristics (ROC) curve and the precision-recall (P-R) curve in the integrated model. The AUC of ROC curve (0.84~0.86), the AUC of P-R curve (0.81~0.85) and the F₁ score (0.78~0.79) of the three single machine learning models are significantly higher, and the prediction performance is better than that of a single machine learning algorithm. The development of high-speed geological hazards along the Yangtze River is controlled by topographic and geomorphic factors. The new damage points are located in the highly prone areas of the model, which verifies the accuracy and reliability of the Stacking model.

Recently, the vessel-shaped aquacultural farm has received much attention from the academia and industry because of its importance in promotion and sustainability of marine fishery. Polluted surroundings unsuitable for fish growth are always introduced by traditional multiple point mooring system. Therefore, single point mooring system is more suitable for the aquacultural farm. In recent years, mooring scheme optimization and performance assessment was frequently investigated in most existing literature, while studies on design of the single point mooring system are rare. Based on the requirement of reducing hull reconstruction, an external turret single point mooring system was proposed, which is composed of the turret device, the mooring anchor, the truss structure and the bearings. And their working principle were also clearly illustrated. Then, three dimensional potential theory was applied to obtain the hydrodynamic coefficients of the ship by use of the software AQWA. Finally, in order to verify the positioning ability of the mooring system under both operational and survival conditions, the direction of wind, wave and current was combined according to the rules, and time-domain coupling analysis of the farm-mooring system was carried out. From the numerical results, it can be seen that yaw, relatively large sway and roll motions will be induced due to different direction of the wind, current and wave. The mooring line tension is adequate and safe under all conditions, indicating that this proposed single point mooring system exhibits good positioning performance.

Soil seed banks serve as the foundation for plant restoration and succession, playing a crucial role in sustaining biodiversity and ecological balance. The effect of short-term enclosure and grazing ban on soil seed bank was studied in the marsh meadow of Napahai Lake in northwest Yunnan Plateau. Through field sampling and seed germination identification, the effects of grazing and short-term confinement (3 years) on species composition, diversity and functional group structure of topsoil seed bank were compared. The findings show that short-term grazing exclusion significantly alters the diversity of the soil seed bank, reducing the Shannon-Wiener and Pielou indices (P<0.05) and increasing the density of sedge seeds (P<0.05). Weeds dominate in both enclosed and grazed conditions, with grasses and sedges following, and legumes being minimal. The percentage of weed species decreases, while that of sedge species increases under grazing exclusion, with no significant change observed in grasses and legumes. Weed importance values are significantly negatively correlated with grass and sedge importance values (P<0.05), and grass density is significantly positively correlated with sedge density (P<0.05). These results indicate that while short-term grazing exclusion reduces the diversity of the soil seed bank in swamp meadows, it also enhances the replenishment and recovery of sedge seeds, offering new insights for the restoration management of wetland ecosystems.

The laminectomy robot is an auxiliary surgical robot developed for laminectomy in recent years. In order to explore the differences in reducing orthopedic surgeons' mental workload between laminectomy robot techniques and traditional laminectomy methods, a multimodal evaluation incorporating an electrocardiogram, eye tracking, and the NASA-TLX scale was utilized to assess the mental workload of orthopedic surgeons undergoing both surgical procedures. Through simulated surgical trials, 12 orthopedic surgeons performed laminectomies employing both the robot-assisted and the conventional techniques, collecting multimodal data for both variance and correlation analyses. The findings indicate significant differences in subjective mental workload between the laminectomy robot and traditional techniques (P<0.05). However, in terms of electrocardiogram indicators such as average heart rate, the low frequency/high frequency ratio (LF/HF), and the standard deviation of NN intervals (SDNN), no significant differences are noted. Significant differences are observed in eye movement indicators, including pupil diameter (P<0.05), fixation rate (P<0.05), and saccade rate (P<0.01). Further correlation analysis underscored a notably significant relationship between pupil diameter and levels of subjective mental workload in both surgery techniques. In conclusion, compared to traditional laminectomy methods, the use of laminectomy robots can alleviate the mental workload on orthopedic surgeons, with both pupil diameter and subjective mental workload levels providing effective reflections of the orthopedic surgeons’mental workload.

In order to explore the relationship between the ratio of non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol (NHHR) and the risk of rapid decline in kidney function, data from the China health and retirement longitudinal study (CHARLS) conducted in 2011 and 2015 was utilized. It includes 4 055 participants aged 40 and above with a baseline estimated glomerular filtration rate (eGFR) of at least 60 mL/(min·1.73m²), calculated using serum creatinine and cystatin C levels. Rapid kidney function decline is defined as a decrease in eGFR of 3 mL/(min·1.73m²·a). A multivariable logistic regression model was used to investigate the association between NHHR and the risk of rapid kidney function decline. Additionally, restricted cubic spline and threshold effect analyses were used to evaluate the dose-response relationship. The results show that over the 4-year follow-up, 447 participants (11.02%) experienced rapid decline in kidney function. In the fully adjusted multivariable logistic regression model, those in the highest NHHR group (T3) faced a 1.94-fold increased risk of rapid kidney function decline compared to the lowest NHHR group (T1) (OR=1.94,95%CI:1.46~2.61). As a continuous variable, each unit increase in NHHR is associated with a 1.21-fold increase in risk (OR=1.21, 95%CI:1.08~1.36). The restricted cubic spline analysis demonstrates a near logarithmic curve saturation effect between NHHR and rapid kidney function decline (P_nonlinearity<0.05). It is concluded that with NHHR ≤3.52, the risk increases as NHHR rises, while NHHR >3.52 marks a saturation point. In conclusion, among middle-aged and elderly individuals, a higher NHHR is linked to a greater risk of rapid decline in kidney function, displaying a nonlinear relationship.

To address the current situation of low flatness, poor cutting quality and cane bud damage at the cane cutter due to insufficient optimization of the structure and motion parameters and installation coordination of the cutting tool of the cane seed cutter. Finite element cutting simulation tests were conducted using single-factor tests on the distance between the cutting edge and the pivot point of the transport roller, tool drop speed, tool installation offset angle, tool front angle and tool back angle of the cane seed cutter to determine the evaluation indexes affecting the cane seed cutting quality and the trend of the influence of each factor on this index. The significant interaction effect of each factor on the evaluation index was analyzed based on the rotating orthogonal test, and the quadratic polynomial regression model of the orthogonal test results was obtained. Combining the agronomic requirements with the cutting characteristics of the tool, the optimal evaluation index was established, the optimized optimal combination of parameters was obtained, and the cutting section simulation test and bench validation test were conducted. The final selection results are as follows: the distance between the incision and the fulcrum is 177.944 mm, the tool landing speed is 1.569 m/s, the tool installation offset angle is 5.923°, the tool front angle is 10.899°, and the tool back angle is 8.637°. The equivalent stress at the incision site and the sugarcane shoot site are 5.053 mm and 1.592 MPa, respectively. The comprehensive analysis error rate is 4.97%. This study can provide a research basis for the optimization of the structure parameters and installation parameters of sugarcane seed cutting knife and its motion parameters, so as to improve the seed cutting quality of cane.