A ligand design allows compact nanoparticle materials, such as quantum dots, with excellent colloidal stability over a wide range of pH and under high salt concentrations. 5 mm audio plug with built-in light source, particularly to a light-emitting element arranged in a hollow tube and two conductive portions and several insulating portions arranged on a predetermined position of a surface of the audio plug for acquiring power and supplying the power to the light-emitting element in order to form a laser pen. The same principle is applicable to power-down signals. The watch display may also include an animation mode wherein the lights run through a cycle of turning on and then off, sequentially, one at a time at desired times such as when the power is turned on or just before it is turned off. Thereby, a tilt function maintaining advantages of a tandem drive and being high in rigidity is realized without increasing control axes beyond the number of axes corresponding to tandem axes. The arsine continues to flow through the CVD apparatus to the adsorber where it is adsorbed by the resin contained therein.