Abstract: An organic light-emitting device containing both a compound represented by the following general formula (1) and a compound represented by the following general formula (2) has a high light emission efficiency. The rings a to c each are a benzene ring that can be optionally condensed, R1 and R2 each represent a substituted or unsubstituted aryl group, etc., four of R31 to R35 each are a substituted or unsubstituted carbazol-9-yl group, but all of these four are not the same, and the remaining one is a hydrogen atom, a cyano group, etc.

Abstract: There is provided a fully automatic distribution center system capable of preventing mistakes made in distribution caused by human error. The system includes facilities which, after articles to be distributed are brought into the distribution center are conveyed to a storage area, permit the following series of operations to be performed automatically: Sorting of the articles until they are conveyed to a shipping area, storing in various packing styles of the cargoes, arranging of the cargoes, packing, palletizing, and the like. These facilities free workers from the task of handling the articles to be distributed during the usual operation of the center.