Sliding bearings–rotor systems are widely present in rotating machinery structures. The dynamic behavior triggered by friction and rub-impact faults is a key factor restricting the safe and stable operation of a rotor system. Existing studies mainly focus on analyzing dynamic characteristics but rarely explore the degree of friction and rub-impact in the system. This paper takes the sliding bearing–double-disk rotor system with friction and rub-impact as the research model, and defines the concept of the rubbing ratio. It analyzes the influence of relevant structural parameters on the system. The results reveal that the system exhibits rich nonlinear dynamics. Specifically, increasing either the rotor–stator clearance or the lubricant viscosity can drive the system into a broader regime of chaotic motion, while simultaneously reducing the extent of the rub-impact contact region. As the stator stiffness increases from 10⁷ N/m to 9 × 10⁷ N/m, the number of chaotic windows in the bifurcation diagram increases from one to three, while the maximum rubbing force rises by approximately 58% and the rubbing ratio increases from 50% to 56%. The phenomenon of coexisting attractors in the system is also revealed and analyzed. The above research results help to reveal the motion laws of this type of rotor system and have certain guiding significance for parameter matching and optimization design of the system dynamics.

Transparent superhydrophobic coatings for photovoltaic (PV) cover glass must combine high optical transmission with durable liquid repellency and resistance to outdoor soiling. Here, we report a bioinspired bifunctional transparent superhydrophobic coating (BTSC) inspired by moth-eye optical gradients and sponge-spicule anchoring, comprising an inductively coupled plasma (ICP)-etched moth-eye-like nanopillar scaffold and a dip-coated fluorinated SiO₂ nanoparticle layer. The nanopillars create a gradient effective refractive-index interface to suppress reflection, while their interstices spatially confine and physically interlock the nanoparticles, enhancing retention under mechanical stress. BTSC-glass exhibits a water contact angle of 153.9°, a peak transmittance of 95.3%, and an average transmittance of 94.3% over 380–1100 nm, exceeding the average transmittance of pristine glass (93.0%) by 1.3 percentage points, while retaining robust wettability after more than 100 sandpaper abrasion cycles and water-jet and sand-particle impact. It also exhibits thermal and acidic stability together with anti-icing and self-cleaning functionality. As PV cover glass, BTSC-glass yields a 1.61% relative increase in power conversion efficiency (PCE). After 14 days outdoors, its PCE decreased only from 19.60% to 19.50%, compared with 19.29% to 18.14% for pristine glass, corresponding to an approximately 11.5-fold reduction in PCE loss. This interfacial strategy integrates antireflection, superhydrophobicity, durability, and self-cleaning for photovoltaic cover glass.

Saxitoxin (STX) is a highly potent marine biotoxin, and trace contamination in aquatic environments can pose serious risks to human health. Therefore, reliable detection of low-concentration STX is crucial for water safety monitoring. Here, we developed a robust electrochemical aptasensor based on a gold nanoparticle/chitosan (AuNP/CS) conductive network for STX detection in freshwater samples. The chitosan matrix provides a three-dimensional scaffold for aptamer immobilization, while interconnected AuNPs create efficient electron-transfer pathways across the sensing interface. This integrated architecture improves interfacial conductivity and supports stable target-induced aptamer recognition. The aptasensor exhibits a linear response from 1 to 1000 nM and a limit of detection of 0.74 nM, with an apparent dissociation constant K_d = 70.29 ± 29.2 nM, together with high batch-to-batch consistency and long-term stability, retaining 93% of its initial response after 25 days. In spiked freshwater samples, the aptasensor achieved recoveries ranging from 99.10% to 111.33%, demonstrating the practical potential of this platform for monitoring STX contamination in aquatic environments.