Abstract: According to this invention, there is disclosed a compact power circuit breaker having a large breaking capacity and stable breaking performance due to a compact closing resistor unit having high performance. The power circuit breaker includes a main switching mechanism having an arc extinguishing function, an auxiliary switching mechanism parallelly connected to the main switching mechanism and having an arc extinguishing function, and a closing resistor unit connected in series with the auxiliary switching mechanism and incorporated with a resistor containing zinc oxide (ZnO) as a main component and titanium figured out as titanium oxide (TiO.sub.2) in an amount of 0.5 to 25 mol% and nickel figured out as nickel oxide (NiO) in an amount of 0.5 to 30 mol. % as sub-components.

Abstract: A light emitting element for a blue light emitting diode which consists of a semiconductor substrate crystal, a II-VI compound semiconductor layer having an n-type conduction of low resistivity and a II-VI compound semiconductor layer having a p-type conduction of low resistivity, wherein each layer is deposited from a vapor phase on the substrate crystal.

Abstract: A blue light emitting diode which has a multiple layer structure and is grown on a semiconductor crystalline substrate, wherein zinc of a group II element of the periodic table, lithium, sodium, or potassium of group VI elements are used. These elements and their compounds are used as impurities to be introduced into the construction when it is at the condition of vapor growing. A blue light emitting diode has a pair of Ohmic electrodes, an n-type semiconductor layer and a p-type semiconductor layer. These layers are grown from a vapor phase on the substrate and sandwiched between the electrodes.