亚洲色无码a片一区二区潘甜甜,免费A级毛片,美女张开腿让男人桶爽,中国凸偷窥XXXX自由视频

At present, the high-precision transformers of the State Grid all use nanocrystalline magnetic cores. This is because the permeability of nanocrystalline alloys is close to that of Permalloy, which is an order of magnitude higher than that of silicon steel, and the accuracy can reach 0.1%. Under the conditions of the same size and similar performance as the permalloy core, the nanocrystalline iron core is lighter in weight and has a wider linear range than the permalloy core, but the manufacturing cost is only 50% of the permalloy price. It is the most ideal soft magnetic material for precision transformers.