background brightness
1.Atmospheric Transparency And Sky Background Brightness at Yunnan Observatory And The Reduction Coefficients of Photometric System to 35cm Telescope
2.Based on cloud-top brightness temperature data and circulation background, and the physical quantities, Diagnosis of severe convection weather caused by MCS in Mei-yii front over the Yellow Sea-Changjiang River during June 21 to 23, 2002 is made.
3.With the EN polarity time increasing, the liquid metal of welding rod end congregates and its diameter increases, which shows the arc effect of EN polarity for welding rod consumable, Arc creeps up and the brightness of arc column region decreases with EN polarity of AC PMIG welding, and the brightness of arc column region increases with background level of EP polarity. This kind of AC arc is propitious to reduce the arc plasma jet force and the arc force on molten pool.
