一、运动光源的位置测不准。在光速不变原理中,观测者所得到的并不是光源的真实位置,只是个虚像位置,当光由 A 点,传播到观测点 C1时,需时间 t.在t同时,光源也由 A 点运动到 V 点。这样 AV 一段是光源的行程。下余的 VC1段才是光的行程...一、运动光源的位置测不准。在光速不变原理中,观测者所得到的并不是光源的真实位置,只是个虚像位置,当光由 A 点,传播到观测点 C1时,需时间 t.在t同时,光源也由 A 点运动到 V 点。这样 AV 一段是光源的行程。下余的 VC1段才是光的行程.图示如下:展开更多
The fabrication and characterization of a laser ionization source for ion mobility spectrometer （IMS） is described with the calculated parameter of the drift tube. Ions are created in air at ambient pressure using l...The fabrication and characterization of a laser ionization source for ion mobility spectrometer （IMS） is described with the calculated parameter of the drift tube. Ions are created in air at ambient pressure using laser ionization （ A = 248 nm） with air as the drift gas. Mobility spectra for positive ions at different electric fields are obtained with the length of drift tube of 25 and 50 mm, respectively. The distribution of the electric field in the drift tube （50 mm） has also been investigated by SIMION simulation with the ion shutter closed and open respectively.展开更多
文摘The fabrication and characterization of a laser ionization source for ion mobility spectrometer （IMS） is described with the calculated parameter of the drift tube. Ions are created in air at ambient pressure using laser ionization （ A = 248 nm） with air as the drift gas. Mobility spectra for positive ions at different electric fields are obtained with the length of drift tube of 25 and 50 mm, respectively. The distribution of the electric field in the drift tube （50 mm） has also been investigated by SIMION simulation with the ion shutter closed and open respectively.
