恒星演化和超生爆发理论中某些重要问题的核物理问题

首先，在第1节中我们依次介绍了各种不同质量的恒星演化进程中各个主要热核燃烧的点火条件，致密物质中自由电子系统的简并性对星体热核燃烧的主导作用以及爆炸性核燃烧条件。其次，在第2节中我们讨论了导致恒星核心不稳定坍缩的物理因素和条件。此后，在本第3节中我们评述了Ia型超新星爆发理论尚在急论中的核物理和固体物理的问题。在第4节中我们评述了Ⅱ型（以及Ib型）超新星爆发理论中的严重困难，并且介绍了我们（南京大学研究小组）就超新星中微子延缓爆发机制的关键问题（强大的中微子暴如何产生？）的物理机制提出的具体过程：这中微子暴的强大中微子流量是从刚刚坍缩的高温高密核心通过核物质－－（u,d）夸克系统－－（u,d,s)系统的相变过程在不到1微秒的时间内很快地产生出来的。而且，这个过程导致核心区域的负熵梯度，引起核心区域大规模对流，它将这强大的中微子流量很快地向外输送到中微子球的表面。在第5节中本还介绍了我们就超新星核心高密条件下电荷屏蔽对电子俘获过程的影响所作的探讨研究以及讨论了它对超新星坍缩核心质量（它对超新星瞬时爆发机制成功与否起着关键作用）的可能影响。

SOME IMPORTANT QUESTIONS OF NUCLEAR PHYSICS ON THE THEORYOF BOTH STELLAR EVOLUTION AND SUPERNOVA EXPLOSION

First, we present in § Ⅰ the ignition condition of main nuclear burning during evolution of stars with different mass, the dominant role of electron degeneracy played on the nuclear burning of stars under dense density and the condition of explosive nuclear burning respectively. Next we present the main physical factors which cause the stars to be unstable and to collapse in §Ⅱ. We review some unsolved questions of nuclear physics or solid physics in the theory of type Ia supernova explosion in § Ⅲ. We review in §Ⅳ the serious difficulties in the theory of type Ⅱ (and type Ib) explosion and we also introduce our work of the neutrino delayed explosion mechanism of SNII. We suggested that the strong neutrino flux required in the neutrino delayed explosion mechanism of SNII may be produced by a phase transition of (nuclear matter)-(u,d) quark-(u,d,s) quark during very short time scale (＜1 μsec) in the collapsed core (a new born neutron-proton star). Besides, it may be also transported outwards to the surface of neutrino sphere due to the negative entropy gradient. We discuss in §Ⅴ an electric screening effect on the electron capture process in the dense core of the pre-supernova and its possible effect on mass of the collapsed core of the supernova, which plays a key role of the instantaneous explosion mechanism of supernova.