The effectiveness of monitoring and early-warning systems for ground deformation phenomena, such as sinkholes, depends on their ability to accurately resolve the ongoing ground displacement and detect the subtle deformation preceding catastrophic failures. Sagging sinkholes with a slow subsidence rate and diffuse edges pose a significant challenge for subsidence monitoring due to the low deformation rates and limited lateral strain gradients. In this work, we satisfactorily illustrate the practicality of the Brillouin optical time domain analysis (BOTDA) to measure the spatial-temporal patterns of the vertical displacement in such challenging slow-moving sagging sinkholes. To assess the performance of the approach, we compare the strain recorded by the distributed optical fiber sensor with the vertical displacement measured by high-precision leveling. The results show a good spatial correlation with the ability to identify the maximum subsidence point. There is also a good temporal correlation with the detection of an acceleration phase in the subsidence associated with a flood event.

在对图像位移进行测量时，不同亚像素位移迭代算法的性能不同，将反向组合对角近似算法和反向组合Dog-Leg算法用于数字图像相关法并进行位移测量，同时对反向组合Levenberg-Marquardt算法的参数更新策略进行简化，以反向组合高斯牛顿（IC-GN）法作为对比，通过模拟散斑图像和真实散斑图像的压缩变形实验，对3种算法的性能进行对比，并进行相应的评估。实验结果表明：在模拟散斑实验中，各个算法在收敛速度、收敛频率和计算速度上各有不同；在真实实验下，小变形实验得到与IC-GN法相似的精度，大变形实验得到的收敛半径更大。

针对现有压电振子驱动的共振隔膜泵中存在隔膜往复运动位移及位移放大比小的问题，该文设计出一种可应用于共振隔膜泵的大位移压电叠堆执行器，利用压电叠堆作电-机转换器，提高其响应速度，采用矩形弹簧结构，保证系统稳定性，提高系统的一阶固有频率。建立压电叠堆执行器的数学模型，并分析了系统的位移放大比和各阶固有频率，测试了样机的相关性能。实验结果表明，在输入激励信号幅值60 V、频率510 Hz的正弦信号下，该压电叠堆执行器输出位移为154 μm，位移放大倍数为18.11倍，研制的压电叠堆执行器具有较高的响应速度及较大的输出位移，可用于提升共振隔膜泵的输出性能。