It is by now well known that one of the outstandingly unsolved questions in gravitational theory is the microscopic origin of black-hole thermodynamic entropy.
另外众所周知，在引力理论中一个还没有解决的重要问题是黑洞热力学特性的微观起源。
2
Some small grain free regions (GFR) near the hole in the transmission electron microscopic specimen of this material prepared by ion milling was observed.