The quality of unmanned surface vehicle (USV) local path planning directly affects its safety and autonomy performance. The USV local path planning might easily be trapped into local optima. The swarm intelligence optimization algorithm is a novel and effective method to solve the path-planning problem. Aiming to address this problem, a hybrid bacterial foraging optimization algorithm with a simulated annealing mechanism is proposed. The proposed algorithm preserves a three-layer nested structure, and a simulated annealing mechanism is incorporated into the outermost nested dispersal operator. The proposed algorithm can effectively escape the local optima. Convention on the International Regulations for Preventing Collisions at Sea (COLREGs) rules and dynamic obstacles are considered as the constraints for the proposed algorithm to design different obstacle avoidance strategies for USVs. The coastal port is selected as the working environment of the USV in the visual test platform. The experimental results show the USV can successfully avoid the various obstacles in the coastal port, and efficiently plan collision-free paths.

为进一步探索共存吸引子中复杂的动力学行为，本文构建了一个具有四种类型共存吸引子的四阶混沌系统，该系统具有四个不稳定的平衡点。采用相轨迹图、时域波形图、庞加莱映射、Lyapunov指数谱和分岔图等方法对新系统的动力学行为进行分析。实验结果表明：随着参数的变化，系统表现出稳定点、倍周期分岔、共存分岔模式、混沌危机等丰富的动力学行为。当改变系统参数和忆阻参数时，发现系统具有不同类型的共存吸引子，如：两个周期吸引子共存、两个单涡卷混沌吸引子共存、两个双涡卷混沌吸引子共存、两个点吸引子共存。特别地，该系统还存在共存吸引子的旋转现象。最后设计了一个非线性反馈控制器，可使新系统在短时间内实现混沌同步。采用FPGA硬件平台捕捉到的相图与数值仿真结果保持一致，证明了该系统的可实现性。

To address the issues of poor environmental adaptability and high costs associated with traditional methods of measuring water body boundaries, this paper proposes an innovative path planning approach for water body boundary measurement based on Unmanned Surface Vehicles (USVs)—the Chemotactic Search Traversal (CST) algorithm. This method incorporates the chemotaxis operation mechanism of the Bacterial Foraging Optimization algorithm, integrating it with high-resolution grid maps to enable efficient traversal and accurate measurement of water body boundaries within large-scale grid environments. Simulation experiments demonstrate that the CST algorithm outperforms the Brute Force Algorithm (BFA), Roberts operator, Canny operator, Log operator, Prewitt operator, and Sobel operator in terms of optimal pathfinding, stability, and path smoothness. The feasibility and reliability of this algorithm in real water environments are validated through experiments conducted with actual USVs. These findings suggest that the CST algorithm not only enhances the accuracy and efficiency of water body boundary measurement but also offers a cost-effective and practical solution for measuring water body areas.

Wildlife monitoring and environmental microbiome profiling provide complementary perspectives for assessing habitats of protected aquatic species. This study integrated long-term computer vision monitoring, 16S rRNA amplicon sequencing, and water-quality measurements to examine stream sites differing in the camera-confirmed detection frequency of wild Chinese giant salamanders (Andrias davidianus). Monitoring from July 2024 to January 2026 recorded 47 independent detection events, of which 35 occurred at S1. S1 was therefore designated as the high-frequency detection site, while S2–S6 served as comparison sites. Stream-water bacterial communities were characterized from one composite sample per site, together with measurements of water temperature, pH, dissolved oxygen, conductivity, ammonia nitrogen, and nitrate nitrogen. S1 differed from several comparison sites in bacterial taxonomic composition, alpha-diversity estimates, and site-specific ASVs. Comamonadaceae, Rhodoferax, and Flavobacterium showed relatively high abundances at S1. However, RDA, envfit, Mantel, partial RDA, and variation-partitioning analyses found no significant independent relationship between the measured water-quality variables and bacterial-community variation. The observed spatial patterns likely reflect interactions among water quality, hydrology, substrate, riparian shading, refuge availability, organic-matter inputs, and anthropogenic disturbance. These results establish an exploratory spatial baseline and support the use of stream-water bacterial communities as a complementary component of Chinese giant salamander habitat monitoring.

多双涡卷忆阻 Hopfield 神经网络凭借其复杂的非线性混沌动力学特性，在图像加密、信息安全等领域展现出重要的应用价值。然而，构建多双涡卷的忆阻模型通常采用多项式的方法，其数学形式较为复杂，从而限制了其应用。为解决这一问题，本文提出了一种基于分段函数的忆阻模型，并将其作为可变突触权重引入至 Hopfield 神经网络中，替代固定权重的突触，进而构建了一种新型的双忆阻全连接 Hopfield 神经网络。理论分析表明，该系统能够生成数目可控的多双涡卷混沌吸引子，其中包含复杂的网格多双涡卷混沌吸引子，且涡卷数量可通过忆阻的内部参数灵活调整。此外，研究发现该系统可展现出具有初始偏移增强特性的共存吸引子，其数量也可由忆阻模型的内部参数进行调控。同时，基于 NIST SP 800-22 测试结果，验证了该网络生成的混沌序列具备良好的随机性与不可预测性，满足密码学应用要求，预示了其潜在的应用价值。最后，基于FPGA 完成了该系统的数字电路实现，并验证了其物理存在性与可行性。