The Long-term Monitoring Results of Insight-HXMT in the First Four-year Galactic Plane Scanning Survey FAST观测的两个快速射电暴源FRB121102、SGR1935+2154研究 LAMOST DR7中发现的极冷矮星 模拟中盘星系形成 Modelling Magnetic Helicity With Solar Cycles And Its Inspiration For Future Solar Magnetic Field Observations