1. 28 DDT tube, photoelectric cell, strain gauge and witness board are used to study the transition characteristics of the deflagration to detonation of NEPE propellant slurry in the mixing process.

2. Polish inventor Jan Szczepanik patented a color television system in 1897, using a selenium photoelectric cell at the transmitter and an electromagnet controlling an oscillating mirror and a moving prism at the receiver.