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Background Catastrophic issues, such as ecological damages triggered by internal erosion in bare model test within subtropical monsoon climates, are becoming increasingly severe under the combined influence of persistent anthropogenic disturbances and the rapid response of bare model test. However, the mechanisms and critical thresholds governing internal erosion in these settings remain poorly understood, hindering the development of effective long-term prevention and control strategies. Results This study developed natural sample-based synthesis techniques for model test models to establish an optimized ratio parameter system that simulates internal erosion in bare model test under subtropical monsoon conditions. Comprehensive model tests elucidated the patterns of deformation and failure, the dynamics of elemental composition, and the evolution of ecological performance associated with the internal erosion. Furthermore, the study revealed the evolutionary mechanisms and defined the critical state thresholds for internal erosion in these settings. Conclusions The geologically accurate reconstruction of the physico-mechanical properties of bare model test affected by internal erosion within subtropical monsoon climates was achieved. This work provides a theoretical foundation for analyzing the causes of related hazards and for developing targeted prevention and control measures.

Recent trends in abnormal weather patterns leading to sudden and localized heavy rainfall have resulted in an increased frequency of surface landslides. As a result, there is a pressing need for improved prediction and early warning systems. This research focuses on understanding soil behavior under quasi-saturation and elucidating its relationship with pore water pressure and the hydraulic head. In the present study, a mathematical model is formulated to characterize the complex dynamics of quasi-saturation based on established principles. The model demonstrates the correlation between volumetric water content and pore water pressure, considering the influence of the hydraulic gradient. Through two comprehensive model tests, empirical data are generated that highlight the intricate factors influencing quasi-saturation. The findings of this study emphasize the complex interrelationship between volumetric water content, pore water pressure, and the hydraulic head. It is worth noting that under quasi-saturation conditions, the volumetric water content may stabilize over time, indicating an equilibrium between water flow rates driven by the hydraulic gradient and pore water pressure. The present study offers new insights into soil moisture dynamics and lays the foundation for advancements in landslide prediction and mitigation strategies.

Cave collapses emerge during the process of oil reservoir development, seriously affecting oil production. To reveal the collapse and failure mechanism of the carbonate cavern with a buried depth of 5600 m in Tahe Oil Field, using a self-developed ultra-high pressure model test system with the intelligent numerical control function, the model simulation material of carbonate rocks developed to carry out the 3D geo-mechanical model test. The model test and numerical results indicate that: (1) collapse and failure mechanism of the deep-buried caves mainly involve the failure mode of tensile shear. The rupture plane on the side wall is approximately parallel to the direction of maximum principal compressive stress. The V-type tension and split rupture plane then emerges. (2) In the process of forming holes in the model caverns, micro cracks are generated at the foot of the left and right side walls of the caverns, and the roof panels are constantly moving downward. The shorter the distance to the cave wall, the severer the destructiveness of the surrounding rocks will be. (3) The displacement of the top of the model cavern is relatively large and uniform, indicating that the cave roof moves downward as a whole. The area of the cavity suffering damage is 2.3 times as large as the cave span. The research results in this paper lay a solid test basis for revealing the cave collapse and failure mechanism in super depth.

A series of dynamic large-scale model tests and three-dimensional finite element analyses were conducted to investigate the dynamic response of track embankment and XCC pile-raft composite foundation in soft soil for a ballastless high-speed railway under moving train loads. The results indicate that the vibration velocity obtained from the FE numerical simulation agrees well with that from the model test in vibration waveform, amplitude, and frequency characteristics. The peak values corresponding to the passing frequency of train carriage geometry (lc = 25 m), bogie (lab = 7.5 m), and axle distance (lwb = 2.5 m) respectively reflect the characteristic frequencies of the train compartment, adjacent bogie, and wheel load passing through. The peak velocity significantly depends on the distance from the track center in the horizontal direction, of which the attenuation follows the exponential curve distribution. The vibration velocities decrease rapidly within embankment, show a vibration enhancement region from raft to the 1 m depth of foundation soil, then decreases gradually along the subsoil foundation, to a very low level at the bottom of the subsoil, which is much lower than that at the track slab and roadbed. The pile-raft composite foundation can reduce the vibration level effectively and improve the safety of trains running in soft soil areas.

Glycosides have been synthesized using the starting materials magnolol (1) and honokiol (4), isolated from the Japanese white-bark magnolia, and their anti-aging effects on the skin (skin-beautifying effects) have been examined. The advanced glycation end-product (AGE) inhibitory activity test (anti-glycation test) and glycation induction model test, using human-derived dermal fibroblasts, TIG-110 cells, have been conducted to evaluate the anti-aging effects. The synthesized glycoside compounds, 5,5′-di(prop-2-en-1-yl)[1,1′-biphenyl]-2-hydroxy-2′-glucopyranoside (3a), 5,5′-di(prop-2-en-1-yl)[1,1′-biphenyl]-2,2′-diglucopyranoside (3b), 3′,5-di(prop-2-en-1-yl)[1,1′-biphenyl]-4′-hydroxy-2-glucopyranoside (6a) and 3′,5-di(prop-2-en-1-yl)[1,1′-biphenyl]-2,4′-diglucopyranoside (6b), have shown significant anti-glycation activities of less than 0.10 mM in IC50. The glycation induction model test with the fibroblasts, TIG-110 cells, demonstrates that the aforementioned glycosides significantly inhibit the decrease in cell viability. These newly synthesized glycoside compounds are expected to be used as cosmetic ingredients, health foods, and pharmaceutical ingredients, which have inhibitory effects against AGE formation.

Background The HPV vaccination rate of Chinese college students remains low. Therefore, there is an urgent need to provide health education regarding HPV vaccination among college students in China. We used a pre-test/post-test model to implement a health education intervention for the HPV vaccine among undergraduate medical students and subsequently evaluated its effectiveness. Methods A total of 180 undergraduate medical students who were attending classes at the gynaecological department of the Third Affiliated Hospital of Sun Yat-sen University from October 2022 to March 2023 were selected for inclusion in the study. Before class, all students completed a questionnaire and a pre-class quiz to obtain key points in the course. The class regarding HPV and the HPV vaccine was taught by senior teachers. After the course, all students completed a post-class quiz consisting of the same questions as the pre-class quiz. The pre-class and post-class scores were compared to evaluate the effectiveness of this teaching model. Results After the HPV health education intervention in the pre-test/post-test model, the post-class scores were significantly higher than the pre-class scores for different gender, years of study, clinical majors, different willingness of vaccine to receive the vaccine( p  < 0.05). Conclusion A pre-test/post-test model may be an effective approach for HPV health education interventions.

Purpose – Partial least squares (PLS) path modeling is a variance-based structural equation modeling (SEM) technique that is widely applied in business and social sciences. Its ability to model composites and factors makes it a formidable statistical tool for new technology research. Recent reviews, discussions, and developments have led to substantial changes in the understanding and use of PLS. The paper aims to discuss these issues. Design/methodology/approach – This paper aggregates new insights and offers a fresh look at PLS path modeling. It presents new developments, such as consistent PLS, confirmatory composite analysis, and the heterotrait-monotrait ratio of correlations. Findings – PLS path modeling is the method of choice if a SEM contains both factors and composites. Novel tests of exact fit make a confirmatory use of PLS path modeling possible. Originality/value – This paper provides updated guidelines of how to use PLS and how to report and interpret its results.

In the existing statistical literature, the almost default choice for inference on inhomogeneous point processes is the most well-known model class for inhomogeneous point processes: reweighted second-order stationary processes. In particular, the K-function related to this type of inhomogeneity is presented as the inhomogeneous K-function. In the present paper, we put a number of inhomogeneous model classes (including the class of reweighted second-order stationary processes) into the common general framework of hidden second-order stationary processes, allowing for a transfer of statistical inference procedures for second-order stationary processes based on summary statistics to each of these model classes for inhomogeneous point processes. In particular, a general method to test the hypothesis that a given point pattern can be ascribed to a specific inhomogeneous model class is developed. Using the new theoretical framework, we reanalyse three inhomogeneous point patterns that have earlier been analysed in the statistical literature and show that the conclusions concerning an appropriate model class must be revised for some of the point patterns.

Coefficients or hydrodynamic derivatives of autonomous underwater vehicles (AUVs) play a key role in their design and maneuverability. Using a suitable method to estimate these coefficients serves as a time efficient approach to raise the achievable precision in the design and control of AUVs. This paper estimates hydrodynamic derivatives of an AUV using computational fluid dynamics (CFD) for the wings and body. CFD modeling was performed to simulate captive model tests including straight line and planar motion mechanism (PMM). In such runs, the process was implemented separately for the wing and body. Experimental tests for the same AUV in the water tunnel were carried out for CFD validation. Comparing the numerical results to the experimental data, it was shown that the modeling method is able to estimate these coefficients at reasonable accuracy. The proposed modeling method was proved to be efficient in estimating hydrodynamic derivatives and hence can reduce associated computational costs with the process of detail design of AUVs.

The stability of rock slopes under dynamic loading in mining and civil engineering depends upon the slope geometry, mechanical properties of rock mass and discontinuities, and the characteristics of dynamic loads with time. The wedge failure is one of the common forms of slope failures. The authors presented some stability conditions for rock wedges under dynamic loading and they confirmed their validity through the laboratory experimental studies in a previous paper in 2000, which is often quoted by others to validate their softwares, including some commercial software. In this study, the authors investigate the sliding responses of rock wedges under dynamic loads rather than the initiation of wedge sliding. First, some laboratory model tests are described. On the basis of these model tests on rock wedges, the theoretical model proposed previously is extended to compute the sliding responses of rock wedges in time domain. The proposed theoretical model is applied to simulate the sliding responses of rock wedge model tests and its validity is discussed. In the final part, the method proposed is applied to actual wedge failures observed in 1995 Dinar earthquake and 2005 Pakistan–Kashmir earthquake, and the results are discussed.