Reconfiguration of Six Teaching Links in the Intelligent Teaching Model

The research is part of the achievements of the research project of higher education reform in Jiangsu Province.No.2019JSJG257(Sponsoring information) Abstract The six teaching links include teaching, learning, practicing, testing, evaluating, and managing. Over time, the traditional classroom has some problems in implementing six teaching links, such as teacher-centered, unchanging teaching content, and inertia of student learning. With the support of the series of functions of intelligent teaching tools, the six teaching links are integrated into the pre-class, in-class, and post-class. And the six links are reconstructed in the three stages of pre-class preview, in-class teaching, and post-class consolidation, thus students' learning ability can be comprehensively improved. Keywords: Six teaching links; Intelligent teaching; Teaching reconfiguration DOI: 10.7176/JEP/12-29-01 Publication date:October 31st 202

Long lived central engines in Gamma Ray Bursts

The central engine of Gamma Ray Bursts may live much longer than the duration of the prompt emission. Some evidence of it comes from the presence of strong precursors, post-cursors, and X-ray flares in a sizable fraction of bursts. Additional evidence comes from the fact that often the X-ray and the optical afterglow light curves do not track one another, suggesting that they are two different emission components. The typical "steep-flat-steep" behavior of the X-ray light curve can be explained if the same central engine responsible for the main prompt emission continues to be active for a long time, but with a decreasing power. The early X-ray "afterglow" emission is then the extension of the prompt emission, originating at approximately the same location, and is not due to forward shocks. If the bulk Lorentz factor Gamma is decreasing in time, the break ending the shallow phase can be explained, since at early times Gamma is large, and we see only a fraction of the emitting area. Later, when Gamma decreases, we see an increasing fraction of the emitting surface up to the time when Gamma ~ 1/theta_j. This time ends the shallow phase of the X-ray light curve. The origin of the late prompt emission can be the accretion of the fall-back material, with an accretion rate dot M proportional to t^(-5/3). The combination of this late prompt emission with the flux produced by the standard forward shock can explain the great diversity of the optical and the X-ray light curves.Comment: 6 pages, 6 figures, To appear in: 2008 Nanjing GRB Conference, AIP, Eds. Y.F. Huang, Z.G. Dai, B. Zhan

Cosmology-Independent Distance Moduli of 42 Gamma-Ray Bursts between Redshift of 1.44 and 6.60

This report is an update and extension of our paper accepted for publication in ApJ (arXiv:0802.4262). Since objects at the same redshift should have the same luminosity distance and the distance moduli of type Ia supernovae (SNe Ia) obtained directly from observations are completely cosmology independent, we obtain the distance modulus of a gamma-ray burst (GRB) at a given redshift by interpolating or iterating from the Hubble diagram of SNe Ia. Then we calibrate five GRB relations without assuming a particular cosmological model, from different regression methods, and construct the GRB Hubble diagram to constrain cosmological parameters. Based upon these relations we list the cosmology-independent distance moduli of 42 GRBs between redshift of 1.44 and 6.60, with the 1-$\sigma$ uncertainties of 1-3%.Comment: 6 pages, 2 figures, 3 tables. To appear in the proceedings of "2008 Nanjing GRB conference", Nanjing, 23-27 June 200