A Symmetric-Actuating Linear Piezoceramic Ultrasonic Motor Capable of Producing a Scissoring Effect

Conventionally,to produce a linear motion,one motor’s stator is employed to drive one runner moving forward or backward.So far,there is almost no report of one electromechanical motor or piezoelectric ultrasonic motor that can directly generate two symmetrical linear motions,while this function is desired for precise scissoring and grasping in the minimally invasive surgery field.Herein,we report a brandnew symmetric-actuating linear piezoceramic ultrasonic motor capable of generating symmetrical linear motions of two outputs directly without additional mechanical transmission mechanisms.The key component of the motor is an(2×3)arrayed piezoceramic bar stator operating in the coupled resonant mode of the first longitudinal(L_(1))and third bending(B_(3))modes,leading to symmetric elliptical vibration trajectories at its two ends.A pair of microsurgical scissors is used as the end-effector,demonstrating a very promising future for high-precision microsurgical operations.

探析积极老龄化背景下老年人的网络参与

随着我国社会人口老龄化进程的加快,积极应对人口老龄化已经成为国家的重要战略之一。积极老龄化理论框架中的“三大支柱”之一是“参与”,它鼓励老年人积极参与各种社会活动,保持活力,从而推动积极老龄化的实现。在信息技术迅猛发展的现代社会,老年人接触和使用网络已成为必然。因此,文章聚焦于老年人网络参与现状,通过分析发现老年人在网络参与中存在的数字鸿沟,网络安全和隐私保护,内容适应性的问题。基于这些问题,文章深入探讨其原因,并提出构建友好型网络环境,组织技术培训与教育,加大政策和财政支持,加强社会和文化推广,旨在促进老年人更好地参与网络活动。为积极应对人口老龄化的国家战略提供理论支持和实践经验。