The picture taken on July 11, 2004 showing China's first superconductor network at Puji Power...

The picture taken on July 11, 2004 shows China's first superconductor network at Puji Power Station in Kunming, the capital of southwest China's Yunnan province. China's first superconductor cable network became operational on Saturday, making the nation one of the only three countries in the world which have such advanced electricity transmission network. The other two are the United States and Denmark. Superconductor refers to some metals or alloys that will lose resistance in power transmission when they are cooled to certain very low temperature. This amazing nature of metals inspired scientists to invent superconductor materials and try to make them available for commercial use.