The need for high dynamic range imaging is crucial in many astronomical elds, such as extra-solar planet direct detection, extra-galactic science and circumstellar imaging. Using a high quality coronograph, dynamic ranges of up to 10 5 have been achieved. However the ultimate limitations of coronographs do not come from their optical performances, but from scattering due to imperfections in the...

With the development of gears towards high temperature, pressure, speed and stress, gear measurement, in which only static geometric accuracy is considered, unable to meet current application requirements. While, low precision single function tester constrains measurement dynamic performance. For resolution this problem, based on principle system dynamics several mechanical design techniques, a...