The conservation management of biodiversity hotspots is of vital significance for biological conservation. For wetlands, which are a special type of ecosystems that are based on water as their main medium, a decline in external hydrological connectivity often leads to wetland degradation inside biodiversity hotspots. In this context, the relationship between hydrological connectivity changes inside and outside hotspots is worth exploring. Based on the wetland biodiversity hotspots identified using systematic conservation planning, this study selected eight representative biodiversity hotspots with concentrated area. Integral index of connectivity, probability of connectivity (representing structural connectivity), and morphological spatial pattern analysis (representing functional connectivity) were used to analyze the hydrological connectivity changes inside various hotspots for 1995–2015. By taking the catchment area involved as the minimum basin perimeter, this study calculated the external hydrological connectivity changes of various hotspots during this period and analyzed the relationship between hydrological connectivity changes inside and outside of hotspots. The internal and external hydrological connectivity of wetland biodiversity hotspots were found to be significantly correlated. Moreover, the internal hydrological connectivity of hotspots not only declined with declining external structural connectivity, but also changed with the proportion of core wetlands, the proportion of edge wetlands, and the proportion of branch corridors. In addition, hotspots located at intersections of high-grade rivers were more significantly affected by climate change than by human activities and their hydrological connectivity increased with increasing rainfall. The internal hydrological connectivity of hotspots near low-grade rivers presented a declining trend, mainly because of human activities. This study clarified the relationship between internal and external hydrological connectivity of wetland biodiversity hotspots. Targeted internal and external control strategies are proposed, with the aim to offer references for the conservation of wetland biodiversity.

Table tennis racquet blades (TTRBs) are specialized wood materials known for their excellent mechanical properties. As one of the widely used physical vapor deposition technologies, magnetron sputtering has become the most effective method for preparing various thin film materials. In this study, the surface of the TTRB is coated with a Ti film with different thicknesses by magnetron sputtering to improve the performance of the TTRB. The surface roughness, crystal structure, viscoelasticity of the TTRB were analyzed by means of non-contact surface profilometry, X-ray diffraction (XRD), and dynamic mechanical analysis (DMA). In order to effectively test TTRB properties, three types of testing devices were designed, including free-fall rebound, laser vibration measurement, and the dynamic rebound test. The results reveal that the deposition of a Ti film on the surface of the TTRB improves the rigidity and rebound efficiency of the TTRB. Under optimized conditions, the initial amplitude, vertical rebound distance, and rebound rate can reach 2.1 μm, 23.7 cm, 13.7%, respectively, when the deposition thickness is 5 μm. It is anticipated that the modification and the corresponding detection methods developed in this study can foster innovative product development, standardize the TTRB industry, and contribute to the advancement of table tennis.

With growing emphasis on sustainable construction, fiber-reinforced polymer (FRP) bars are increasingly being used as alternatives to steel rebars due to their high strength-to-weight ratio, corrosion resistance, and environmental benefits. This study has investigated the bond behavior between FRP bars and concrete of different strength grades under dynamic loading conditions. To analyze the microscopic properties of FRP bar surfaces, the study employs a variety of techniques, including scanning electron microscopy (SEM), atomic force microscopy (AFM), and non-contact surface profilometry. In addition, X-ray photoelectron spectroscopy (XPS), water contact angle (WCA) measurements, and energy dispersive spectrometry (EDS) are used to further investigate surface characteristics. The results reveal a direct correlation between the resin surface roughness of FRP bars and their wettability characteristics, which in turn influence the cement hydration process. Pull-out tests under different loading rates and concrete strength grades have been conducted to evaluate the bond–slip behavior and failure modes. The results indicate that bond strength increases with increasing concrete strength. Dynamic pull-out tests further reveal that higher loading rates generate heterogeneous stress fields, which limit the deformation of FRP bars and consequently diminish the contribution of mechanical interlock to interfacial bonding.