We present the design and performance of a home-built scanning tunneling microscope (STM), which is compact (66 mm tall and 25 mm in diameter), yet equipped with a 3D atomic precision piezoelectric motor in which ...We present the design and performance of a home-built scanning tunneling microscope (STM), which is compact (66 mm tall and 25 mm in diameter), yet equipped with a 3D atomic precision piezoelectric motor in which the Z coarse approach relies on a high simplic-ity friction-type walker (of our own invention) driven by an axially cut piezoelectric tube. The walker is vertically inserted in a piezoelectric scanner tube (PST) with its brim laying at on the PST end as the inertial slider (driven by the PST) for the XZ (sample plane) motion. The STM is designed to be capable of searching rare microscopic targets (defects, dopants, boundaries, nano-devices, etc.) in a macroscopic sample area (square millimeters) under extreme conditions (low temperatures, strong magnetic elds, etc.) in which it ts. It gives good atomic resolution images after scanning a highly oriented pyrolytic graphite sample in air at room temperature.展开更多
预警机全称为空中早期预警(Airborne Early Warningl,简称AEW),是指拥有整套远程警戒雷达系统,用于搜索、监视空中或海上目标,并可指挥和引导己方飞机执行作战任务的飞机。受到地球曲度和复杂地形的限制,地面雷达对低空目标的搜索距离...预警机全称为空中早期预警(Airborne Early Warningl,简称AEW),是指拥有整套远程警戒雷达系统,用于搜索、监视空中或海上目标,并可指挥和引导己方飞机执行作战任务的飞机。受到地球曲度和复杂地形的限制,地面雷达对低空目标的搜索距离非常有限,而且常常受到各种影响。预警机的工作原理,就是将整套雷达系统安装在飞机上,借助飞机的飞行高度,从空中搜索各类空中、海上或者是陆上目标,从而获得较佳的预警与搜索效果,延长反应的时间与弹性。展开更多
文摘We present the design and performance of a home-built scanning tunneling microscope (STM), which is compact (66 mm tall and 25 mm in diameter), yet equipped with a 3D atomic precision piezoelectric motor in which the Z coarse approach relies on a high simplic-ity friction-type walker (of our own invention) driven by an axially cut piezoelectric tube. The walker is vertically inserted in a piezoelectric scanner tube (PST) with its brim laying at on the PST end as the inertial slider (driven by the PST) for the XZ (sample plane) motion. The STM is designed to be capable of searching rare microscopic targets (defects, dopants, boundaries, nano-devices, etc.) in a macroscopic sample area (square millimeters) under extreme conditions (low temperatures, strong magnetic elds, etc.) in which it ts. It gives good atomic resolution images after scanning a highly oriented pyrolytic graphite sample in air at room temperature.
文摘预警机全称为空中早期预警(Airborne Early Warningl,简称AEW),是指拥有整套远程警戒雷达系统,用于搜索、监视空中或海上目标,并可指挥和引导己方飞机执行作战任务的飞机。受到地球曲度和复杂地形的限制,地面雷达对低空目标的搜索距离非常有限,而且常常受到各种影响。预警机的工作原理,就是将整套雷达系统安装在飞机上,借助飞机的飞行高度,从空中搜索各类空中、海上或者是陆上目标,从而获得较佳的预警与搜索效果,延长反应的时间与弹性。