中文摘要：

文章重新讨论了Reissner-Nordstrm黑洞带电粒子辐射谱.发现与黑洞带同种电荷的粒子辐射率大于异种带电粒子或不带电粒子的辐射率.其结果是Reissner-Nordstrm黑洞的荷质比将变得越来越小.此外,还计算了Reissner-Nordstrm黑洞荷质比的最大值,发现这一最大值远小于极端黑洞的荷质比.因此,通过量子隧穿将非极端黑洞变为极端黑洞的相变是不可能发生的.

英文摘要：

In this paper,we re-discuss the emission spectrum of charged particles from the Reissner-Nordstrm black holes.We find that the emission rate of a particle with charge of the same sign as that of the black hole is greater than those of opposite charge or uncharged particle with the same mass.As a result,the charge to mass ratio of the Reissner-Nordstrm black hole will become smaller and smaller.Moreover,we also calculate the maximum of the charge to mass ratio of a Reissner-Nordstrm black hole,and we find that the maximal charge to mass ratio is much less than that of an extreme charged black hole.The phase transitions of the black holes via tunneling from a non-extreme Reissner-Nordstrm black hole to an extreme charged black hole are not possible.